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Agronomy, Volume 14, Issue 6 (June 2024) – 253 articles

Cover Story (view full-size image): This study tested wood distillate (WD) as a protective agent against ozone damage in basil plants. Basil treated with WD weekly (0.2% v/v) for four weeks and exposed to chronic ozone (80 ppb for 5 h day−1) showed reduced chlorotic spots, poor chlorophyll loss, and unaltered membrane integrity. WD also boosted antioxidant production, increasing abscisic and salicylic acid content. These findings demonstrate WD’s efficacy in protecting basil from ozone-induced oxidative stress. View this paper
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17 pages, 3031 KiB  
Article
Effect of Soil Texture on Soil Nutrient Status and Rice Nutrient Absorption in Paddy Soils
by Chang Ye, Guangjie Zheng, Yi Tao, Yanan Xu, Guang Chu, Chunmei Xu, Song Chen, Yuanhui Liu, Xiufu Zhang and Danying Wang
Agronomy 2024, 14(6), 1339; https://doi.org/10.3390/agronomy14061339 - 20 Jun 2024
Viewed by 468
Abstract
Soil texture affects rice nutrient uptake and yield formation by influencing soil structure, microbial activity, and soil nutrient supply capacity. Analyzing the relationship between soil texture, nutrient content, and rice agronomic traits is of great significance for precise and efficient fertilizer application. The [...] Read more.
Soil texture affects rice nutrient uptake and yield formation by influencing soil structure, microbial activity, and soil nutrient supply capacity. Analyzing the relationship between soil texture, nutrient content, and rice agronomic traits is of great significance for precise and efficient fertilizer application. The tillage layer (0–20 cm) of 31 paddy fields in China’s main rice-producing areas was collected to perform rice pot experiments, and soil texture characteristics, physicochemical properties, microbial-related indicators, and rice agronomic traits were measured and analyzed. The results showed that these soils could be classified into four types of soil texture: loamy sandy soil, sandy loam soil, silty loam soil, and silty soil. Analysis of variance showed that the available nitrogen (AN), available potassium (AK), and available phosphorus (AP) contents were the highest in silty loam, silty, and sandy loam soils, respectively, and silt loamy soil had the highest CEC. Principal component analysis (PCA) also showed that soil physicochemical properties can be distinguished to a certain extent according to soil texture types. For the relationship of soil texture parameters and soil physicochemical properties, soil organic matter (OM), total nitrogen (TN), AN, ammonium nitrogen (NH4+-N), and microbial carbon (MBC) contents were positively correlated with soil clay content, AK was positively correlated with silt content, and soil phosphorus status was significantly related to pH. Mantel’s test revealed significant correlations between rice N, P, and K nutrient status, dry matter accumulation, and yield, and soil available nutrient content, MBC, pH, and soil texture parameters. Structural equation modeling (SEM) indicated that sand affected soil available nutrients by regulating pH, while clay can positively influence soil available nutrients by affecting soil organic matter mineralization and microbial activity, thus influencing nutrient absorption and yield formation in rice. Overall, in rice production, the silty and silty loam paddy soil with fine texture and higher clay content facilitates the mineralization of soil organic matter and the activity of soil microbes, resulting in more available soil nutrients, which benefits the rice absorption and accumulation of nutrients. Furthermore, a higher content of clay also promotes the distribution of dry matter to the panicle, thereby promoting rice yield formation. Full article
(This article belongs to the Special Issue Fertility Management for Higher Crop Productivity)
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13 pages, 2880 KiB  
Article
Effect of Soil pH on the Uptake of Essential Elements by Tea Plant and Subsequent Impact on Growth and Leaf Quality
by Miao Jia, Yuhua Wang, Qingxu Zhang, Shaoxiong Lin, Qi Zhang, Yiling Chen, Lei Hong, Xiaoli Jia, Jianghua Ye and Haibin Wang
Agronomy 2024, 14(6), 1338; https://doi.org/10.3390/agronomy14061338 - 20 Jun 2024
Viewed by 230
Abstract
Tea plant is an acidophilic plant, and soil pH has an important effect on the absorption and enrichment of elements, tea plant growth and quality. In this study, rhizosphere soils and leaves of tea plants from 30 tea plantations were collected to determine [...] Read more.
Tea plant is an acidophilic plant, and soil pH has an important effect on the absorption and enrichment of elements, tea plant growth and quality. In this study, rhizosphere soils and leaves of tea plants from 30 tea plantations were collected to determine soil pH and multi-element content of soil and leaves of tea plants, to obtain and validate key elements that are enriched by pH affecting tea plants, and to analyze the effects of pH on the growth and quality of tea plants. The results showed that soil pH significantly affected the enrichment of 15 elements by tea plants, and the enrichment coefficients of 11 elements (C, Mg, Si, N, P, Mn, Sr, Cd, S, Ca and Sb) tended to increase significantly with the increase of soil pH, while the opposite was true for the other four elements (Cu, Rb, Ba and Al). TOPSIS analysis showed that soil pH had the greatest effect on tea plant enrichment of seven elements, namely N (100%), Mn (43.32%), C (39.22%), P (27.66%), Sr (15.30%), Mg (13.41%) and Ba (10.47%). Pot experiments with tea seedlings also verified that soil pH significantly affected the enrichment of tea leaves for seven key elements. Moreover, with the increase of soil pH, the growth indexes, photosynthesis indexes and quality indexes of tea seedlings showed a significant upward trend. Interaction analysis showed that the enhanced enrichment of N, Mn, C, P, Sr and Mg by tea plants was beneficial to increase the photosynthetic capacity of tea plants, promote the growth of tea plants and improve the quality of tea leaves. This study provides an important theoretical basis for the cultivation and management of tea plants. Full article
(This article belongs to the Special Issue Advances in Soil Fertility, Plant Nutrition and Nutrient Management)
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17 pages, 8861 KiB  
Article
Moving toward Automaticity: A Robust Synthetic Occlusion Image Method for High-Throughput Mushroom Cap Phenotype Extraction
by Quan Wei, Yinglong Wang, Shenglan Yang, Chaohui Guo, Lisi Wu and Hua Yin
Agronomy 2024, 14(6), 1337; https://doi.org/10.3390/agronomy14061337 - 20 Jun 2024
Viewed by 268
Abstract
Mushroom cap is a key trait in the growth process and its phenotypic parameters are essential for automatic cultivation and smart breeding. However, the edible mushrooms are usually grown densely with mutual occlusion, which is difficult to obtain the phenotypic parameters non-destructively. Although [...] Read more.
Mushroom cap is a key trait in the growth process and its phenotypic parameters are essential for automatic cultivation and smart breeding. However, the edible mushrooms are usually grown densely with mutual occlusion, which is difficult to obtain the phenotypic parameters non-destructively. Although deep learning methods achieve impressive performance with superior generalization capabilities, they require a large amount of ground truth label of the occluded target, which is a challenging task due to the substantial workload. To overcome this obstacle, a novel synthetic cap occlusion image method was proposed for rapidly generating edible mushroom occlusion datasets using raw images, in which the ground truth is obtained from the real world and the occlusion is randomly generated for simulating real scenes. Moreover, variants of amodal instance segmentation models with different backbone were trained and evaluated on our synthetic occlusion image datasets. Finally, an amodal mask-based size estimation method was presented to calculate the width and length of the cap. The experimental results showed that the amodal instance segmentation achieved an AP@[0.5:0.95] of 82%, 93% and 96% on Oudemansiella raphanipes, Agrocybe cylindraceas and Pholiota nameko synthetic cap datasets, respectively, with a size of 1024 × 1024 px, which indicates that our occlusion image synthesis method can effectively simulate the real cap occlusion situation. The size estimation method achieved an R2 of 0.95 and 0.98 between predictive amodal caps and manually labeled caps for the length and width of Agrocybe cylindraceas cap, respectively, which can be applied to obtain the phenotypic parameters of each cap effectively and accurately. These methods not only meet the demand for automatic monitoring of edible mushroom morphology in factories but also provide technical support for intelligent breeding. Full article
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14 pages, 10800 KiB  
Article
Relationships and Changes in Grassland Community Diversity and Biomass in the Pastoral Areas of the Two Rivers under Grazing Disturbance
by Weilong Chen, Mao Ye, Xiaoting Pan, Miaomiao Li, Guoyan Zeng, Xi Zhang, Qingzhi He, Xinchen Gu, Jiaorong Qian, Yexin Lv and Jing Che
Agronomy 2024, 14(6), 1336; https://doi.org/10.3390/agronomy14061336 - 20 Jun 2024
Viewed by 306
Abstract
Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points [...] Read more.
Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points using sampling methods. The effects of grazing on the structural characteristics of plant communities were analysed using the α-diversity index, and the relationship between species diversity and the above-ground biomass of plant communities, as well as their changes, was explored. The results showed that grazing disturbance decreased the number of family species in the grassland plant communities and the similarity between communities; grazing activities significantly decreased the above-ground biomass of the grassland plant communities; the height and cover also showed a decreasing trend (p < 0.01), but the density of the grassland plant communities improved (p < 0.01). The Margalef index, the Shannon–Wiener index, and the Simpson index of the grassland plant communities all showed different degrees of decrease after grazing, while the Alatalo index showed an increase; biomass was positively correlated with the Margalef, Shannon–Wiener, and Alatalo indices and negatively correlated with the Simpson index (p < 0.01). Therefore, in the management and maintenance of grasslands, the impact of grazing on the structural characteristics of plant communities should be taken into account, and reasonable response policies should be implemented according to the actual local situation. This study provides a theoretical basis for grassland maintenance and management and the sustainable development of ecosystems in the pastoral areas of the two river sources of the Altay Mountains. Full article
(This article belongs to the Special Issue Sustainable Forage Production in Crop–Livestock Systems)
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8 pages, 6423 KiB  
Communication
Optimization of Hairy Root Transformation and Application of RUBY as a Reporter in Lotus corniculatus
by Kaidi Lyu, Xingli Zhang, Wenjie Yu, Shanhua Lyu and Yinglun Fan
Agronomy 2024, 14(6), 1335; https://doi.org/10.3390/agronomy14061335 - 20 Jun 2024
Viewed by 322
Abstract
Lotus corniculatus is an important perennial legume forage species and has been widely used to study the relationships between plants and rhizobia or arbuscular mycorrhizal fungi. Composite plants (wild-type shoots with transgenic hairy roots) can be produced via genetic transformation mediated by Agrobacterium [...] Read more.
Lotus corniculatus is an important perennial legume forage species and has been widely used to study the relationships between plants and rhizobia or arbuscular mycorrhizal fungi. Composite plants (wild-type shoots with transgenic hairy roots) can be produced via genetic transformation mediated by Agrobacterium rhizogenes. The A. rhizogenes puncture method and a method of cutting embryonic roots and coating the hypocotyl incision with A. rhizogenes were used to induce hairy roots from seedlings. The identification of transgenic hairy roots from composite plants is also an important task. Here, young branches from adult plants were used as explants to produce composite plants instead of seedlings via the one-step cutting method in the natural environment. The results showed that the explants of young branches had higher transformation frequency than those of seedlings, and the composite plants obtained from the young branches had greater growth and were also more robust than the plants obtained from the seedlings. In this study, a system for the biosynthesis of betalains named RUBY was integrated into an expression vector as a reporter gene. It is very easy to distinguish transgenic roots from nontransgenic roots based on the red color of the hairy roots. Young branches were used as explants for hairy root transformation with higher transformation frequency than the seedlings. RUBY was used as a reporter gene to distinguish transgenic roots from nontransgenic roots based on the red color of the hairy roots. Full article
(This article belongs to the Section Horticultural and Floricultural Crops)
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21 pages, 4061 KiB  
Article
A Lightweight Crop Pest Classification Method Based on Improved MobileNet-V2 Model
by Hongxing Peng, Huiming Xu, Guanjia Shen, Huanai Liu, Xianlu Guan and Minhui Li
Agronomy 2024, 14(6), 1334; https://doi.org/10.3390/agronomy14061334 - 20 Jun 2024
Viewed by 356
Abstract
This paper proposes PestNet, a lightweight method for classifying crop pests, which improves upon MobileNet-V2 to address the high model complexity and low classification accuracy commonly found in pest classification research. Firstly, the training phase employs the AdamW optimizer and mixup data augmentation [...] Read more.
This paper proposes PestNet, a lightweight method for classifying crop pests, which improves upon MobileNet-V2 to address the high model complexity and low classification accuracy commonly found in pest classification research. Firstly, the training phase employs the AdamW optimizer and mixup data augmentation techniques to enhance the model’s convergence and generalization capabilities. Secondly, the Adaptive Spatial Group-Wise Enhanced (ASGE) attention mechanism is introduced and integrated into the inverted residual blocks of the MobileNet-V2 model, boosting the model’s ability to extract both local and global pest information. Additionally, a dual-branch feature fusion module is developed using convolutional kernels of varying sizes to enhance classification performance for pests of different scales under real-world conditions. Lastly, the model’s activation function and overall architecture are optimized to reduce complexity. Experimental results on a proprietary pest dataset show that PestNet achieves classification accuracy and an F1 score of 87.62% and 86.90%, respectively, marking improvements of 4.20 percentage points and 5.86 percentage points over the baseline model. Moreover, PestNet’s parameter count and floating-point operations are reduced by 14.10% and 37.50%, respectively, compared to the baseline model. When compared with ResNet-50, MobileNet V3-Large, and EfficientNet-B1, PestNet offers superior parameter efficiency and floating-point operation requirements, as well as improved pest classification accuracy. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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15 pages, 2427 KiB  
Article
Iron Composition of a Typical Loess-Paleosol Sequence in Northeast China
by Zhong-Xiu Sun, Si-Wei Liu and Ying-Ying Jiang
Agronomy 2024, 14(6), 1333; https://doi.org/10.3390/agronomy14061333 - 20 Jun 2024
Viewed by 227
Abstract
Iron isotope compositions, along with the partial extraction of iron in its various forms, can be utilized to investigate the complex interplay of iron migration and transformation with respect to iron isotope patterns. This study investigated the iron composition of a typical loess-paleosol [...] Read more.
Iron isotope compositions, along with the partial extraction of iron in its various forms, can be utilized to investigate the complex interplay of iron migration and transformation with respect to iron isotope patterns. This study investigated the iron composition of a typical loess-paleosol sequence in Northeast China and aimed to understand the influence of iron migration and transformation of the typical loess-paleosol sequence on iron isotopes and environmental and climatic changes that occurred in the region over time by analyzing the distribution and characteristics of iron compositions in sedimentary layers. Samples were collected from Chaoyang in Northeast China, and the iron isotopic composition was analyzed using the multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS). The findings revealed depth-dependent variations in the content of different iron forms, reflecting paleoclimatic shifts primarily through pedogenic transformation processes. Notably, iron migration within the section was observed to be limited. The variations in the reddening index and magnetic susceptibility of the loess-paleosol were primarily influenced by the presence of free iron (Fed), exhibiting a range of colors from yellow to red-yellow and red. The δ56Fe values for loess and paleosols ranged from 0.097 ± 0.035‰ to 0.167 ± 0.010‰, with an average of 0.133 ± 0.024‰ and a coefficient of variation (CV) of 15.66% at the stratum scale. These values indicated a systematic enrichment of heavy iron isotopes and a significant negative correlation with the slightly fluctuating total iron content. Specifically, our analysis highlighted distinct differences in δ56Fe values between paleosol (0.126 ± 0.024‰) and loess (0.146 ± 0.021‰). The δ56Fe in Fed was negative, averaging −0.101 ± 0.022‰, while the δ56Fe in silicate-bound iron was positive, averaging 0.156 ± 0.032‰. Intense pedogenesis, driven by warm and wet climates, facilitated iron transformations and migrations, resulting in the accumulation of light iron isotopes in the paleosols. These transformations and migrations were predominantly observed in microdomains characterized by iron depletions and concentrations, as reflected in the profile morphologies. However, the limited iron transformations and migrations did not result in significant Fe redistribution within the soil section, as evidenced by the limited variations in δ56Fe with soil depth at the stratum scale. Sampling from the stratum or pedogenic horizon could potentially create the illusion of the minimal fractionation of iron isotopes within the sequence. Therefore, a detailed examination of the iron isotope composition in the micro-domains of the loess-paleosol sequence is crucial to elucidate the fractionation processes and mechanisms of iron isotopes during the formation of these sequences. Full article
(This article belongs to the Special Issue Soil Evolution, Management, and Sustainable Utilization)
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20 pages, 4129 KiB  
Article
Analysis of the Rainfall Pattern and Rainfall Utilization Efficiency during the Growth Period of Paddy Rice
by Mengting Chen, Yingying Shen, Haili Wang, Xiangju Cheng and Yufeng Luo
Agronomy 2024, 14(6), 1332; https://doi.org/10.3390/agronomy14061332 - 20 Jun 2024
Viewed by 341
Abstract
Rainfall is one of the most important water sources for rice production in China. However, its temporal and spatial variability is leading to water shortages. The present study collected a long series of historical rainfall data from research sites during the rice growth [...] Read more.
Rainfall is one of the most important water sources for rice production in China. However, its temporal and spatial variability is leading to water shortages. The present study collected a long series of historical rainfall data from research sites during the rice growth period to analyze the characteristics of rainfall distribution and the correlation with rainfall utilization efficiency, aiming to investigate its impact on rice irrigation practices. It is found that the rainfall distribution varied greatly between the different locations and growth periods. The average rainfall of the whole growth period ranges from 135.5 mm to 694.5 mm. The rainfall curve exhibits a typical unimodal pattern with variations in the intensity, duration, and timing of peak precipitation across different growth periods. During the rice growth period, the cases in southern China are more prone to waterlogging for a high probability of continuous rainfall, and the cases in northern China are more prone to drought. The rainfall utilization efficiency of all cases exhibits a significant inter-year fluctuation range, negatively influenced by the rainfall amount and rainfall inhomogeneity. The efficiency in utilizing precipitation is diminished with greater and more uneven rainfall experienced during the growth period. These findings can provide a decision-making basis for optimizing rice irrigation strategies and enhancing rainfall utilization efficiency in diverse regions across China. Full article
(This article belongs to the Section Water Use and Irrigation)
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16 pages, 3882 KiB  
Article
Highly Accurate and Lightweight Detection Model of Apple Leaf Diseases Based on YOLO
by Zhaokai Sun, Zemin Feng and Ziming Chen
Agronomy 2024, 14(6), 1331; https://doi.org/10.3390/agronomy14061331 - 19 Jun 2024
Viewed by 412
Abstract
To mitigate problems concerning small-sized spots on apple leaves and the difficulties associated with the accurate detection of spot targets exacerbated by the complex backgrounds of orchards, this research used alternaria leaf spots, rust, brown spots, gray spots, and frog eye leaf spots [...] Read more.
To mitigate problems concerning small-sized spots on apple leaves and the difficulties associated with the accurate detection of spot targets exacerbated by the complex backgrounds of orchards, this research used alternaria leaf spots, rust, brown spots, gray spots, and frog eye leaf spots on apple leaves as the research object and proposed the use of a high-accuracy detection model YOLOv5-Res (YOLOv5-Resblock) and lightweight detection model YOLOv5-Res4 (YOLOv5-Resblock-C4). Firstly, a multiscale feature extraction module, ResBlock (residual block), was designed by combining the Inception multi-branch structure and ResNet residual idea. Secondly, a lightweight feature fusion module C4 (CSP Bottleneck with four convolutions) was designed to reduce the number of model parameters while improving the detection ability of small targets. Finally, a parameter-streamlining strategy based on an optimized model architecture was proposed. The experimental results show that the performance of the YOLOv5-Res model and YOLOv5-Res4 model is significantly improved, with the mAP0.5 values increasing by 2.8% and 2.2% compared to the YOLOv5s model and YOLOv5n model, respectively. The sizes of the YOLOv5-Res model and YOLOv5-Res4 model are only 10.8 MB and 2.4 MB, and the model parameter counts are reduced by 22% and 38.3% compared to the YOLOv5s model and YOLOv5n model. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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28 pages, 24618 KiB  
Article
Winter Wheat Aboveground-Biomass Estimation and Its Dynamic Variation during Coal Mining—Assessing by Unmanned Aerial Vehicle-Based Remote Sensing
by Xiaoxuan Lyu, Hebing Zhang, Zhichao Chen, Yiheng Jiao, Weibing Du, Xufei Zhang, Jialiang Luo and Erwei Zhang
Agronomy 2024, 14(6), 1330; https://doi.org/10.3390/agronomy14061330 - 19 Jun 2024
Viewed by 470
Abstract
Underground coal mining in coal-grain overlapped areas leads to land subsidence and deformation above the goaf, damaging cultivated land. Understanding the influencing process of coal mining on cultivated land and crops is important for carrying out timely land reclamation and stabilizing crop yield. [...] Read more.
Underground coal mining in coal-grain overlapped areas leads to land subsidence and deformation above the goaf, damaging cultivated land. Understanding the influencing process of coal mining on cultivated land and crops is important for carrying out timely land reclamation and stabilizing crop yield. Research has been carried out by using crop growth parameters to evaluate the damaging degree of cultivated land when the mining subsidence is stable, but few studies focus on the influence of land damage on crop growth when the subsidence is unstable during coal mining. Therefore, this study tracked the three growth stages of winter wheat by using UAV multispectral imagery to explore the dynamic influence of underground mining on winter wheat aboveground biomass (AGB). Firstly, a winter-wheat-AGB estimation model (R2 = 0.89, RMSE = 2.18 t/ha) was developed by using vegetation indexes (VIs), textures, and terrain data extracted from UAV imagery. Secondly, based on the winter-wheat-AGB estimation model, the winter wheat AGB was successfully estimated and mapped at different growth stages. The AGB of winter wheat in the coal mining-affected area was approximately 5.59 t/ha at the reviving stage, 8.2 t/ha at the jointing stage, and 15.6 t/ha at the flowering stage. Finally, combined with the progress of coal mining, the dynamic changing process of crops during underground mining can be inferred by analyzing the spatiotemporal variation in winter wheat AGB. Results showed that, in the dip direction, winter wheat AGB at the flowering stage was the highest at the compression zone, followed by the inner stretch zone, outer stretch zone, and neutral zone. The distance from the waterlogged area and the existence of cracks were found to be the important moderating variables affecting the crop growth status in the mining subsidence area. In the strike direction, there were significant differences in the wheat AGB-affected area as the mining proceeded. Even areas where AGB had previously significantly increased gradually transitioned to significant decreases with the end of mining. The research explores the dynamic changes in winter wheat AGB and land damage status during coal mining. It provides a rapid and non-destructive land-damage-monitoring method to protect cultivated land in mining areas. Full article
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18 pages, 3074 KiB  
Article
Environmental Impact of Choline Dihydrogenphosphate ([Chol][DHP]) on Seed Germination and Soil Microbial Activity
by Óscar Cruz, Otilia Reyes, Carmen Trasar-Cepeda, Teresa Sixto, Juan José Parajó and Josefa Salgado
Agronomy 2024, 14(6), 1329; https://doi.org/10.3390/agronomy14061329 - 19 Jun 2024
Viewed by 348
Abstract
The applicability of ionic liquids has grown exponentially over the last few decades. This growth is due to the easy modification of these compounds formed by ions, through the proper choice of both moieties, and the possibility of introducing functional groups into their [...] Read more.
The applicability of ionic liquids has grown exponentially over the last few decades. This growth is due to the easy modification of these compounds formed by ions, through the proper choice of both moieties, and the possibility of introducing functional groups into their cations and anions. However, studies of their toxicity and effects on the environment remain scarce. This study analyses firstly the response to adding different concentrations of choline dihydrogen phosphate to the germination of seeds of eight plant species. It also examines the microbial population and the respiration of two soils with contrasting organic matter contents. Seeds were incubated in a Petri dish in a Phytotron with a photoperiod of 16 h under light at 24 °C and 8 h in darkness at 16 °C. The activity of microbial populations of untreated and treated soils was analysed by isothermal microcalorimetry at 25 °C. Basal soil respiration kinetics were measured at optimal moisture (80% of field water retention capacity) and temperature (25 °C) over 10 days. The results indicate that this compound has diverse effects on the different endpoints. Nevertheless, this compound can be classified as non-toxic considering its effects on seeds and on soil, at least in the medium- to long-term. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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20 pages, 8435 KiB  
Article
Efficient Damage Assessment of Rice Bacterial Leaf Blight Disease in Agricultural Insurance Using UAV Data
by Chiharu Hongo, Shun Isono, Gunardi Sigit and Eisaku Tamura
Agronomy 2024, 14(6), 1328; https://doi.org/10.3390/agronomy14061328 - 19 Jun 2024
Viewed by 345
Abstract
In Indonesia, where the agricultural insurance system has been in full operation since 2016, a new damage assessment estimation formula for rice diseases was created through integrating the current damage assessment method and unmanned aerial vehicle (UAV) multispectral remote sensing data to improve [...] Read more.
In Indonesia, where the agricultural insurance system has been in full operation since 2016, a new damage assessment estimation formula for rice diseases was created through integrating the current damage assessment method and unmanned aerial vehicle (UAV) multispectral remote sensing data to improve the efficiency and precision of damage assessment work performed for the payments of insurance claims. The new method can quickly and efficiently output objective assessment results. In this study, UAV images and bacterial leaf blight (BLB) rice damage assessment data were acquired during the rainy and dry seasons of 2021 and 2022 in West Java, Indonesia, where serious BLB damage occurs every year. The six-level BLB score (0, 1, 3, 5, 7, and 9) and damage intensity calculated from the score were used as the BLB damage assessment data. The relationship between normalized UAV data, normalized difference vegetation index (NDVI), and BLB score showed significant correlations at the 1% level. The analysis of damage intensities and UAV data for paddy plots in all cropping seasons showed high correlation coefficients with the normalized red band, normalized near-infrared band, and NDVI, similar to the results of the BLB score analysis. However, for paddy plots with damage intensities of 70% or higher, the biased numbering of the BLB score data may have affected the evaluation results. Therefore, we conducted an analysis using an average of 1090 survey points for each BLB score and confirmed a strong relationship, with correlation coefficients exceeding 0.9 for the normalized red band, normalized near-infrared band, and NDVI. Through comparing the time required by the current assessment method with that required by the assessment method integrating UAV data, it was demonstrated that the evaluation time was reduced by more than 60% on average. We are able to propose a new assessment method for the Indonesian government to achieve complete objective enumeration. Full article
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18 pages, 3342 KiB  
Article
Effects of Warming and No-Tillage on Soil Carbon, Nitrogen, Phosphorus and Potassium Contents and pH of an Alpine Farmland in Tibet
by Zhiming Zhong, Yong Qin, Guangyu Zhang and Gang Fu
Agronomy 2024, 14(6), 1327; https://doi.org/10.3390/agronomy14061327 - 19 Jun 2024
Viewed by 284
Abstract
There are still great uncertainties about effects of climate warming and no-tillage on soil carbon, nitrogen, phosphorus and potassium contents and pH in alpine farmlands. A warming (control; daytime warming, DW; nighttime warming, NW; all-day warming, DW + NW) and no-tillage (no-tillage vs. [...] Read more.
There are still great uncertainties about effects of climate warming and no-tillage on soil carbon, nitrogen, phosphorus and potassium contents and pH in alpine farmlands. A warming (control; daytime warming, DW; nighttime warming, NW; all-day warming, DW + NW) and no-tillage (no-tillage vs. tillage) experiment was conducted in an alpine farmland of the Lhasa, Xizang since 2015. Soil organic carbon, total nitrogen, total phosphorus, total potassium (TK), available nitrogen, available phosphorus, available potassium, dissolved organic carbon (DOC), active organic carbon, particulate organic carbon (POC), light fraction organic carbon, and heavy fraction organic carbon contents and pH at four depths (0–5, 5–15, 15–25, and 25–35 cm) were measured. Warming effects on concerned soil variables differed with warming time, soil depth, and no-tillage. No-tillage effects on concerned soil variables differed with warming-time (daytime, nighttime, and all-day warming) and soil depths. Therefore, daytime warming and nighttime warming have different effects on soil variables, although the effects of nighttime warming on soil variables are not always greater than those of daytime warming. Effects of daytime warming and nighttime warming on soil variables are not simple addition or subtraction effects. There are interactions between diurnal asymmetrical warming and no-tillage on soil variables. Full article
(This article belongs to the Section Agricultural Biosystem and Biological Engineering)
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16 pages, 2514 KiB  
Article
Effect of Melatonin on the Growth of Dendrobium officinale Protocorm-Like Bodies
by Jiaqi Tang, Ruyan Huang, Dan Yuan, Han Sun, Yuping Li, Zekang Pei, Congqiao Wang, Chengyue Li, Dongliang Qiu and Qingqing Chen
Agronomy 2024, 14(6), 1326; https://doi.org/10.3390/agronomy14061326 - 19 Jun 2024
Viewed by 303
Abstract
Dendrobium officinale Kimura & Migo is a perennial herbaceous plant of the genus Dendrobium in the family of Orchidaceae with high medicinal value. Melatonin (MT) is an indole-like tryptamine with functions such as regulating plant growth and development. This experiment investigated the effects [...] Read more.
Dendrobium officinale Kimura & Migo is a perennial herbaceous plant of the genus Dendrobium in the family of Orchidaceae with high medicinal value. Melatonin (MT) is an indole-like tryptamine with functions such as regulating plant growth and development. This experiment investigated the effects of different concentrations of MT on the growth and development of protocorms of D. officinale protocorm-like bodies (PLBs). The results showed that the changes in morphological indicators such as color, cluster size, and surface changes were more significant under 75 µM MT than those of 0 µM (CK), and the appearance of white on the PLB surface was expedited, which was more conducive to the proliferation of PLBs. MT treatment of 100 µM inhibited the differentiation of adventitious buds, and the contents of photosynthetic pigments, polysaccharides, and flavonoids were significantly increased. Moreover, as compared with CK, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in PLBs increased significantly, while the content of malondialdehyde (MDA) decreased gradually with 75 µM or less. In conclusion, a concentration of 75 µM melatonin can enhance the rapid propagation rate of D. officinale in vitro, providing insights into the effects of melatonin on the growth of tissue-cultured D. officinale seedlings. Full article
(This article belongs to the Section Horticultural and Floricultural Crops)
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15 pages, 41936 KiB  
Article
An Improved YOLOv8 Model for Lotus Seedpod Instance Segmentation in the Lotus Pond Environment
by Jie Ma, Yanke Zhao, Wanpeng Fan and Jizhan Liu
Agronomy 2024, 14(6), 1325; https://doi.org/10.3390/agronomy14061325 - 19 Jun 2024
Viewed by 377
Abstract
Lotus seedpod maturity detection and segmentation in pond environments play a significant role in yield prediction and picking pose estimation for lotus seedpods. However, it is a great challenge to accurately detect and segment lotus seedpods due to insignificant phenotypic differences between the [...] Read more.
Lotus seedpod maturity detection and segmentation in pond environments play a significant role in yield prediction and picking pose estimation for lotus seedpods. However, it is a great challenge to accurately detect and segment lotus seedpods due to insignificant phenotypic differences between the adjacent maturity, changing illumination, overlap, and occlusion of lotus seedpods. The existing research pays attention to lotus seedpod detection while ignoring maturity detection and segmentation problems. Therefore, a semantic segmentation dataset of lotus seedpods was created, where a copy-and-paste data augmentation tool was employed to eliminate the class-imbalanced problem and improve model generalization ability. Afterwards, an improved YOLOv8-seg model was proposed to detect and segment the maturity of lotus seedpods. In the model, the convolutional block attention module (CBAM) was embedded in the neck network to extract distinguished features of different maturity stages with negligible computation cost. Wise-Intersection over Union (WIoU) regression loss function was adopted to refine the regression inference bias and improve the bounding box prediction accuracy. The experimental results showed that the proposed YOLOv8-seg model provides an effective method for “ripe” and “overripe” lotus seedpod detection and instance segmentation, where the mean average precision of segmentation mask (mAPmask) reaches 97.4% and 98.6%, respectively. In addition, the improved YOLOv8-seg exhibits high robustness and adaptability to complex illumination in a challenging environment. Comparative experiments were conducted using the proposed YOLOv8-seg and other state-of-the-art instance segmentation methods. The results showed that the improved model is superior to the Mask R-CNN and YOLACT models, with recall, precision, mAPbox and mAPmask being 96.5%, 94.3%, 97.8%, and 98%, respectively. The average running time and weight size of the proposed model are 25.9 ms and 7.4 M, respectively. The proposed model obtained the highest mAP for lotus seedpod maturity detection and segmentation while maintaining an appropriate model size and speed. Furthermore, based on the obtained segmentation model, 3D visualization of the lotus pond scene is performed, and cloud point of lotus seedpods is generated, which provides a theoretical foundation for robot harvesting in the lotus pond. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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22 pages, 4968 KiB  
Article
Water-Saving Irrigation and N Reduction Increased the Rice Harvest Index, Enhanced Yield and Resource Use Efficiency in Northeast China
by Sicheng Du, Zhongxue Zhang, Jian Song, Ming Liu, Peng Chen, Zhijuan Qi, Tiecheng Li, Yu Han and Dan Xu
Agronomy 2024, 14(6), 1324; https://doi.org/10.3390/agronomy14061324 - 19 Jun 2024
Viewed by 468
Abstract
For agricultural production, improving the rice harvest index (HI) through agricultural management practices is a major means to enhance water and N utilization efficiency and yield. Both irrigation regimes and nitrogen (N) rates are important aspects of agricultural management practices. However, it is [...] Read more.
For agricultural production, improving the rice harvest index (HI) through agricultural management practices is a major means to enhance water and N utilization efficiency and yield. Both irrigation regimes and nitrogen (N) rates are important aspects of agricultural management practices. However, it is unclear how the rice HI is affected by water and N. This study aimed to clarify the mechanism underlying the response of the rice HI to water and N, and to explore the most suitable water-saving and N reduction management practices to ensure yield. A two-year (2021~2022) field experiment was conducted on Mollisols in Northeast China. In this experiment, nine treatments were performed, involving three irrigation regimes (flooded irrigation, controlled irrigation, and “thin-shallow-wet-dry” irrigation) and three N rates (110, 99, and 88 kg/ha). The rice agronomic traits and transfer of photoassimilates under different water and N management practices were observed and studied; rice HI, WUE, and the NUE of rice was calculated and analyzed. The highest HI was achieved under controlled irrigation with a 99 kg/ha N rate, at values of 0.622 and 0.621 in 2021 and 2022, respectively. Controlled irrigation (CI) with an appropriate reduction in the N rate increased the proportion of productive tillers, the transfer rate of dry matter and non-structural carbohydrates (NSCs), the sugar–spikelet ratio, the grain–leaf ratio, and the leaf area index (LAI) during the heading–flowering stage. A subsequent analysis indicated that the main reason for the increase in the HI was the increase in the sugar–spikelet ratio during the heading–flowering stage. A high HI increased the rice yield by increasing the thousand-grain weight. The present study suggested that water-saving irrigation regimes and appropriate N reduction not only led to water and fertilizer resource savings but also improved agronomic characteristics during rice growth and enhanced transport capacity. Thus, these practices improved the rice HI and have enormous potential for increasing yield. Therefore, regulating the rice HI through water and N management methods should be considered an important strategy for improving rice yield. Full article
(This article belongs to the Section Water Use and Irrigation)
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14 pages, 4124 KiB  
Article
A Quadruple Mutant of OsPRP1 Controls Pollen Fertility by Regulating the Expression of Anther Development-Related Genes in Oryza sativa L.
by Mudan Qiu, Zhongxiao Hu, Bin Li, Shufeng Song, Yixing Li, Lei Li, Mengmeng Gong, Jianlong Wang and Li Li
Agronomy 2024, 14(6), 1323; https://doi.org/10.3390/agronomy14061323 - 19 Jun 2024
Viewed by 385
Abstract
Plant proline-rich proteins (PRPs) are cell wall proteins that are widely distributed in plants. Previous studies have shown that these proteins play a crucial role in adversity stress processes, but their function in the regulation of pollen fertility in rice remains unknown. In [...] Read more.
Plant proline-rich proteins (PRPs) are cell wall proteins that are widely distributed in plants. Previous studies have shown that these proteins play a crucial role in adversity stress processes, but their function in the regulation of pollen fertility in rice remains unknown. In this study, we identified that OsPRP1 contains a Pollen_Ole-e_I allergenic structural domain, obtained the OsPRP1 quadruple mutant named osprp1.1/1.2/1.3/1.4, and observed significant reductions in pollen fertility, seed-setting rates, and the deformation and collapse of microspores during the late stages of pollen development. RNA-Seq analysis indicated the down-regulation of genes involved in anther development in osprp1.1/1.2/1.3/1.4, suggesting that OsPRP1 plays a role in regulating pollen fertility. In conclusion, a loss of function in OsPRP1.1/1.2/1.3/1.4 leads to decreased pollen fertility and seeding rates, which not only expands the functional spectrum of plant PRP genes but also provides new theoretical insight into the mechanism of fertility regulation in rice. Full article
(This article belongs to the Section Plant-Crop Biology and Biochemistry)
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14 pages, 2104 KiB  
Article
The Infection of Barley at Different Growth Stages by Bipolaris sorokiniana and Its Effect on Plant Yield and Sowing Value
by Barbara Wiewióra and Grzegorz Żurek
Agronomy 2024, 14(6), 1322; https://doi.org/10.3390/agronomy14061322 - 19 Jun 2024
Viewed by 347
Abstract
Bipolaris sorokiniana, a barley pathogen, can infect via seeds, co-growing plants, or soil, causing yield and seed value reductions. This study aimed to assess B. sorokiniana’s impact at various growth stages on seed yield and quality. Results showed no direct impact [...] Read more.
Bipolaris sorokiniana, a barley pathogen, can infect via seeds, co-growing plants, or soil, causing yield and seed value reductions. This study aimed to assess B. sorokiniana’s impact at various growth stages on seed yield and quality. Results showed no direct impact on yield (which ranged from 0.49 kg·m−2 for the naked variety Rastik to 0.77 kg·m−2 for the Widawa variety), but revealed significant seed quality differences. Thousand kernel weight (TKW) and germination capacity (GC) varied notably between examined varieties. The largest kernels were observed for the Bryl variety (27.33 g), which also had the best germination (82.8%). The variety Ryton had the smallest kernels (24.04 g), while the poorest germination (56.7%) was observed for naked kernels of Rastik. A seed health analysis found a relation between inoculation stage and the intensity of spontaneous infection by pathogenic fungi, ranging from 86.4% for the control to more than 95% for the kernels harvested from plants inoculated at the flowering stage. Strong correlation emerged between B. sorokiniana grain infection and germination capacity, highlighting the fungus’s role in seed quality decline. Full article
(This article belongs to the Section Agroecology Innovation: Achieving System Resilience)
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19 pages, 929 KiB  
Article
Examining the Effect of Agrochemicals on Soil Microbiological Activity, Micronutrient Availability, and Uptake by Maize (Zea mays L.) Plants
by Tariku Neme Afata, Seblework Mekonen, Trine Aulstad Sogn, Manoj K. Pandey, Eshetu Janka and Gudina Terefe Tucho
Agronomy 2024, 14(6), 1321; https://doi.org/10.3390/agronomy14061321 - 18 Jun 2024
Viewed by 452
Abstract
Agricultural practices profoundly influence soil microbial populations and physicochemical properties, vital for crop growth and quality. This study aims to explore the impact of diverse agrochemical applications on soil microbial dynamics, physicochemical properties, and maize yield and proximate properties. Topsoil samples, collected at [...] Read more.
Agricultural practices profoundly influence soil microbial populations and physicochemical properties, vital for crop growth and quality. This study aims to explore the impact of diverse agrochemical applications on soil microbial dynamics, physicochemical properties, and maize yield and proximate properties. Topsoil samples, collected at depths of 1 to 15 cm, were transported to Jimma University for maize cultivation. Over 120 days, soil and maize samples were collected at specified intervals for analysis, including soil pH, microbial populations, and nutrient content. Statistical analysis using one-way ANOVA (p < 0.05) was conducted. Soil bacterial and fungal populations were measured on days 5, 10, 20, 40, 80, and 120. The highest total mesophilic bacterial count (TMBC) was in compost-treated pots (G) and the lowest in those receiving macronutrient fertilizers and glyphosates (B). The highest total mesophilic fungal count (TMFC) was in pots with glyphosates and compost (F), and the lowest was in pots treated with macronutrient fertilizers and glyphosates (B). Pots treated with macronutrient fertilizers and glyphosates (B), macronutrient fertilizers (A), and micronutrient fertilizers (C) showed the lowest Fe and Zn levels. Maize in pots treated with macronutrient fertilizer combined with glyphosate (B) exhibited the lowest protein, fats, and carbohydrates. Notably, compost-treated soils showed the highest bacterial and fungal counts, Fe, and Zn concentrations, while micro-mineral fertilizer combined with glyphosate (B) depleted the soil. Agrochemical treatments negatively affected maize yield quality, indicating complex treatment-related changes in soil parameters. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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19 pages, 5666 KiB  
Article
Sunflower Origin Identification Based on Multi-Source Information Fusion Technique of Kernel Extreme Learning Machine
by Limin Suo, Hailong Liu, Jin Ni, Zhaowei Wang and Rui Zhao
Agronomy 2024, 14(6), 1320; https://doi.org/10.3390/agronomy14061320 - 18 Jun 2024
Viewed by 364
Abstract
This study constructs a model for the rapid identification of the origins of edible sunflower (Helianthus) using Kernel Extreme Learning Machine (KELM) with multi-source information fusion technology. Near-infrared spectroscopy (NIRS) and nuclear magnetic resonance spectroscopy (NMRS) were utilized to analyze 180 sunflower samples [...] Read more.
This study constructs a model for the rapid identification of the origins of edible sunflower (Helianthus) using Kernel Extreme Learning Machine (KELM) with multi-source information fusion technology. Near-infrared spectroscopy (NIRS) and nuclear magnetic resonance spectroscopy (NMRS) were utilized to analyze 180 sunflower samples from the Xinjiang, Heilongjiang, and Inner Mongolia regions. Initially, the identification models for the origin of sunflowers using NIR and NMR data were compared between two algorithms: the Extreme Learning Machine (ELM) and KELM, combined with various spectral preprocessing methods. The experiment found that the NIR spectral model preprocessed with standard normal variate (SNV) using the KELM algorithm was the most accurate, achieving accuracies of 98.7% in the training set and 97.2% in the test set. The spin-echo NMR spectral model preprocessed with non-local means (NLMs) using the KELM algorithm was the second best, with accuracies of 98.4% in the training set and 96.4% in the test set. To further improve the accuracy of the identification models, innovative sunflower origin identification models were developed based on data layer fusion and feature layer fusion using NIRS and NMRS. In the data layer fusion model, the KELM algorithm model was optimal, achieving a test set accuracy and F1 score of 98.2% and 98.18%, respectively, an improvement of 1.0% over the best single data source model. In the feature layer fusion model, four types of feature-layer information-fusion identification models were established using two feature extraction algorithms, Competitive Adaptive Reweighted Sampling (CARS) and Variable Importance Projection (VIP), combined with joint feature and simple merging feature strategies. The CARS-KELM algorithm combined with the joint feature method was found to be the best, achieving 100% accuracy in both the training and test sets, an improvement of 2.8% over the best single data source model. Identifying the origin of edible sunflower using NIRS and NMRS is demonstrated as feasible by the results. The best single-spectrum sunflower origin identification model was achieved using the KELM algorithm with SNV preprocessing. The feature layer fusion method combining NIRS and NMRS data is suitable for handling the task of sunflower origin identification. This method significantly improves the recognition accuracy of the model compared to a single model, achieving fast and accurate origin identification of edible sunflowers. The research results provide a new method for rapid identification of sunflower origin. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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12 pages, 5395 KiB  
Article
Submergence Stress Reduces the Ability of Rice to Regulate Recovery after Disaster
by Yanmei Yu, Yan Meng, Peng Chen and Kaihua Cao
Agronomy 2024, 14(6), 1319; https://doi.org/10.3390/agronomy14061319 - 18 Jun 2024
Viewed by 254
Abstract
Flood submergence has devastating effects on agricultural production in China, with rice being particularly vulnerable to its impacts. Previous studies on rice submergence stress have primarily focused on immediate yield reduction and short-term growth. In this study, a submergence stress experiment was carried [...] Read more.
Flood submergence has devastating effects on agricultural production in China, with rice being particularly vulnerable to its impacts. Previous studies on rice submergence stress have primarily focused on immediate yield reduction and short-term growth. In this study, a submergence stress experiment was carried out by using the method of potted rice flooding. The growth recovery characteristics of rice under different submergence stress were analyzed through the continuous observation of rice growth after the disaster. The results showed that submergence stress had a persistent effect on rice growth, which persisted until the recovery period after the disaster. The recovery ability of rice plants decreased with the aggravation of stress, leading to increased damage to the plant. The average yield decreased by 17.07% and 15.56% due to submergence stress during the jointing and booting stage, respectively. The current study pointed out that the growth traits of and, furthermore, the mechanism of physiological changes in rice during the recovery period need to be explored in order to understand the effects of flooding stress on rice. Full article
(This article belongs to the Special Issue Rice Germplasm Innovation and Tolerance to Abiotic Stress)
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12 pages, 3347 KiB  
Article
Prohexadione Calcium and Gibberellin Improve Osmoregulation, Antioxidant Response and Ion Homeostasis to Alleviate NaCl Stress in Rice Seedlings
by Meiling Liu, Naijie Feng, Dianfeng Zheng and Rongjun Zhang
Agronomy 2024, 14(6), 1318; https://doi.org/10.3390/agronomy14061318 - 18 Jun 2024
Viewed by 362
Abstract
Prohexadione calcium (EA) and gibberellin (GA) are two different types of plant growth regulators that have different effects on the regulation of plant development. The objective of this study was to evaluate the impacts of EA and GA on rice plant growth, development [...] Read more.
Prohexadione calcium (EA) and gibberellin (GA) are two different types of plant growth regulators that have different effects on the regulation of plant development. The objective of this study was to evaluate the impacts of EA and GA on rice plant growth, development and morph-physiological traits in two rice varieties: ‘Huang Huazhan’ and ‘Guang Hong 3’. At the three-leaf seedling stage, the plants were treated with 50 mM NaCl 24 h after foliar application of EA (100 mg·L−1) and GA (1 mg·L−1). Data on morphological indexes, osmotic regulators and antioxidant activities were compared with the treatment of EA and GA on the 4th, 7th, 10th and 13th days after NaCl stress. Our data analysis showed that NaCl stress inhibited the leaf area growth of rice seedlings, altered the microstructure and disrupted the antioxidant system, ion uptake and transport balance. The significant increase in malondialdehyde (MDA) content and superoxide anion production rate (O2·¯) indicated that NaCl stress caused a severe oxidative stress response to rice seedlings. Treatment with EA and GA activated the antioxidant system under NaCl stress, significantly elevated superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and suppressed the increase in MDA content and the O2·¯ production rate. Under NaCl stress, EA and GA treatments improved the osmoregulatory balance, significantly increased soluble protein and proline contents and maintained lower Na+/K+ levels. EA and GA treatments significantly increased the K+ and Ca2+ contents, thereby maintaining ionic balance, which was favorable for maintaining the growth of rice seedlings. In this study, moth plant growth regulators maintained the growth and development of rice seedlings under NaCl stress by inducing an increase in osmoregulation and antioxidant levels, reducing the degree of membrane damage and regulating the selective uptake of ions by rice seedlings. Current findings also clarified that foliar application of EA was more effective than GA in three-leaf seedlings by enhancing the morph-physiological and antioxidant parameters under NaCl stress. Full article
(This article belongs to the Section Plant-Crop Biology and Biochemistry)
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16 pages, 4746 KiB  
Article
The Impact of Different Phosphorus Fertilizers Varieties on Yield under Wheat–Maize Rotation Conditions
by Chutao Liang, Xiaoqi Liu, Jialong Lv, Funian Zhao and Qiang Yu
Agronomy 2024, 14(6), 1317; https://doi.org/10.3390/agronomy14061317 - 18 Jun 2024
Viewed by 603
Abstract
The global phosphate (P) rock shortage has become a significant challenge. Furthermore, the misalignment between crops, soil, and P usage exacerbates P rock wastage in agriculture. The distinctions among various types of phosphorus fertilizers influence the phosphorus cycle, which subsequently impacts biomass, the [...] Read more.
The global phosphate (P) rock shortage has become a significant challenge. Furthermore, the misalignment between crops, soil, and P usage exacerbates P rock wastage in agriculture. The distinctions among various types of phosphorus fertilizers influence the phosphorus cycle, which subsequently impacts biomass, the number of grains per ear, the weight of a thousand grains, and, ultimately, the overall yield. In a four-year field experiment conducted from 2017 to 2021, we assessed the impact of various P fertilizer types on crop yield in a continuous wheat–maize rotation system. Prior to planting the crops, P fertilizers were applied as base fertilizers at a rate of 115 kg P2O5 ha−1 during the wheat season and 90 kg P2O5 ha−1 during the maize season. Additionally, nitrogen (N) was applied at rates of 120 kg ha−1 for wheat and 180 kg ha−1 for maize. The P fertilizers used included ammonium dihydrogen phosphate, ammonium polyphosphate, calcium–magnesia phosphate, ammonium phosphate, and calcium superphosphate. Urea was used as the N fertilizer with a split application—60% at planting and 40% at the jointing stage for wheat or the V12 (twelve leaf collar) stage for maize. The results showed that different P fertilizers increased the average yield of wheat and maize by 21.2–38.0% and 9.9–16.3%, respectively. It was found that ammonium polyphosphate, calcium superphosphate, and monoammonium phosphate were more suitable for application in a summer maize–winter wheat rotation system on loess soil. Full article
(This article belongs to the Special Issue Advances in Application Effects and Mechanisms of Fertilizer Products)
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26 pages, 3874 KiB  
Article
Use of Biofertilizers as an Effective Management Strategy to Improve the Photosynthetic Apparatus, Yield, and Tolerance to Drought Stress of Drip-Irrigated Wheat in Semi-Arid Environments
by Chayma Ikan, Fatima-Ezzahra Soussani, Redouane Ouhaddou, Lahoucine Ech-Chatir, Farid Errouh, Abderrahim Boutasknit, Amine Assouguem, Essam A. Ali, Riaz Ullah, Essaid Ait Barka, Rachid Lahlali and Abdelilah Meddich
Agronomy 2024, 14(6), 1316; https://doi.org/10.3390/agronomy14061316 - 18 Jun 2024
Viewed by 617
Abstract
Irrigation scheduling, coupled with the use of biofertilizers, constitutes an effective management strategy to overcome soil drought. This study aimed to assess the individual and combined effects of three selected biofertilizers—(R) Bacillus sp. and Bacillus subtilis, (M) native arbuscular mycorrhizal fungi, and [...] Read more.
Irrigation scheduling, coupled with the use of biofertilizers, constitutes an effective management strategy to overcome soil drought. This study aimed to assess the individual and combined effects of three selected biofertilizers—(R) Bacillus sp. and Bacillus subtilis, (M) native arbuscular mycorrhizal fungi, and (C) compost—on Triticum durum L. The agro-physiological and biochemical traits, along with the soil properties, were evaluated under two different water regimes, 100% crop evapotranspiration (ETc) for the well-watered regime and 30% ETc for the drought-stressed regime under field conditions, using a drip irrigation system. Drought stress (DS) led to significant reductions in the biomass, physiological parameters, and biochemical markers. Furthermore, the application of CM and MR significantly boosted the shoot and root dry weight by 137% and 72%, respectively, under DS compared to the control. Moreover, CM and R resulted in a notable increase of 167% and 130% in the grain and straw yield, respectively, under the same conditions. The normalized difference vegetation index showed improved values in the plants inoculated with MR and CMR, respectively, under DS conditions. Additionally, the soil quality was positively influenced by the application of M and/or R and/or C biofertilizers. These findings provide valuable insights into the intricate soil–plant interactions and the beneficial effects of combined biofertilizers in enhancing wheat’s resilience to drought stress. Full article
(This article belongs to the Section Water Use and Irrigation)
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13 pages, 3237 KiB  
Article
Effect of Three Novel Thiazolidiones on the Development, Reproduction, and Trehalase Activity of Spodoptera frugiperda (Lepidoptera: Noctuidae)
by Liuhe Yu, Fan Zhong, Xinyi Jiang, Biner He, Haoyu Fu, Xiangyu Liu, Qixuan Mao, Ying Zhao, Shigui Wang, Yan Wu, Hongxia Duan and Bin Tang
Agronomy 2024, 14(6), 1315; https://doi.org/10.3390/agronomy14061315 - 18 Jun 2024
Viewed by 345
Abstract
Spodoptera frugiperda was used to investigate its role as a trehalase inhibitor of three new thiothiazolidone compounds—6d, 6e, and 6f. The development and reproduction of S. frugiperda were investigated to evaluate the potential of these compounds as a novel [...] Read more.
Spodoptera frugiperda was used to investigate its role as a trehalase inhibitor of three new thiothiazolidone compounds—6d, 6e, and 6f. The development and reproduction of S. frugiperda were investigated to evaluate the potential of these compounds as a novel pesticide for pest control. Compounds 6d, 6e, and 6f were injected into larvae and female pupae. Molecular changes in trehalose and chitin metabolism genes were monitored. Pupal trehalase activity, the female pupal emergence rate, ovarian development, and SfVg and SfVgR gene expression levels were assessed. The results revealed that all three compounds significantly inhibited trehalase activity in the larvae. The expression of TRE was significantly downregulated, and compounds 6d and 6f significantly downregulated the expression of TRE2. Treated larvae exhibited significantly decreased survival rates and a higher incidence of abnormalities. The egg production and hatching rates were markedly diminished by the inhibitors, and the ovaries displayed blackening and clumping. These compounds exhibit promise as eco-friendly insecticides, but further experiments are required to test their multifaceted capabilities. Full article
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20 pages, 3772 KiB  
Article
Examining Nicotinamide Application Methods in Alleviating Lead-Induced Stress in Spring Barley
by Beata Smolik and Maja Sędzik-Wójcikowska
Agronomy 2024, 14(6), 1314; https://doi.org/10.3390/agronomy14061314 - 18 Jun 2024
Viewed by 304
Abstract
Cereals are a staple food in many regions of the world and are essential for global food security. Lead is one of the most significant environmental stressors, impacting plants throughout their life cycle and causing substantial damage to plant growth and development. It [...] Read more.
Cereals are a staple food in many regions of the world and are essential for global food security. Lead is one of the most significant environmental stressors, impacting plants throughout their life cycle and causing substantial damage to plant growth and development. It disrupts intracellular processes, thereby reducing plant productivity. The aim of this study was to determine the effect of exogenously applied vitamin PP (100 µM) (nicotinamide) on the morphological, physiological, and biochemical parameters of spring barley var. Eunova under lead stress (1 mM Pb(NO3)2) and to determine the most effective method of applying this vitamin in a pot experiment. Vitamin PP was applied exogenously through three different methods: seed soaking, foliar application, and soil irrigation. The application of 1 mM Pb(NO3)2 resulted in decreased root (from 13.9% to 19.9%) and shoot length (from 16.2% to 24.8%) and increased catalase (CAT) activity from 45% to 106%, and peroxidase (POX) activity from 39% to 46% compared to the control. Lead stress led to an increase in proline (Pro) content from 30 to 63% and comparatively in malondialdehyde (MDA) content (rising from 61% to 79.4%), as well as elevated assimilatory pigment content (by 35%) in barley grown in the pot experiment. Exogenous vitamin PP significantly and positively influenced the improvement of the measured morphological, biochemical, and physiological parameters, reducing the toxicity of lead salts. It was shown that the most effective method of vitamin PP application was achieved through foliar spraying and irrigation. Full article
(This article belongs to the Topic Effect of Heavy Metals on Plants, 2nd Volume)
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18 pages, 7977 KiB  
Article
Integration of Unmanned Aerial Vehicle Spectral and Textural Features for Accurate Above-Ground Biomass Estimation in Cotton
by Maoguang Chen, Caixia Yin, Tao Lin, Haijun Liu, Zhenyang Wang, Pingan Jiang, Saif Ali, Qiuxiang Tang and Xiuliang Jin
Agronomy 2024, 14(6), 1313; https://doi.org/10.3390/agronomy14061313 - 18 Jun 2024
Viewed by 385
Abstract
Timely and accurate estimation of Above-Ground-Biomass (AGB) in cotton is essential for precise production monitoring. The study was conducted in Shaya County, Aksu Region, Xinjiang, China. It employed an unmanned aerial vehicle (UAV) as a low-altitude monitoring platform to capture multispectral images of [...] Read more.
Timely and accurate estimation of Above-Ground-Biomass (AGB) in cotton is essential for precise production monitoring. The study was conducted in Shaya County, Aksu Region, Xinjiang, China. It employed an unmanned aerial vehicle (UAV) as a low-altitude monitoring platform to capture multispectral images of the cotton canopy. Subsequently, spectral features and textural features were extracted, and feature selection was conducted using Pearson’s correlation (P), Principal Component Analysis (PCA), Multivariate Stepwise Regression (MSR), and the ReliefF algorithm (RfF), combined with the machine learning algorithm to construct an estimation model of cotton AGB. The results indicate a high consistency between the mean (MEA) and the corresponding spectral bands in textural features with the AGB correlation. Moreover, spectral and textural feature fusion proved to be more stable than models utilizing single spectral features or textural features alone. Both the RfF algorithm and ANN model demonstrated optimization effects on features, and their combination effectively reduced the data redundancy while improving the model performance. The RfF-ANN-AGB model constructed based on the spectral and textural features fusion worked better, and using the features SIPI2, RESR, G_COR, and RE_DIS, exhibited the best performance, achieving a test sets R2 of 0.86, RMSE of 0.23 kg·m−2, MAE of 0.16 kg·m−2, and nRMSE of 0.39. The findings offer a comprehensive modeling strategy for the precise and rapid estimation of cotton AGB. Full article
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20 pages, 5560 KiB  
Article
Silicon Fertilization Improves Sunflower Rhizosphere Microbial Community Structure and Reduces Parasitism by Orobanche cumana Wallr.
by Tengqi Xu, Jihong Ke, Yufan Wang, Yiqiong Zhang, Jiao Xi, Xiaomin Wei, Yongqing Ma and Yanbing Lin
Agronomy 2024, 14(6), 1312; https://doi.org/10.3390/agronomy14061312 - 18 Jun 2024
Viewed by 362
Abstract
Sunflower broomrape (Orobanche cumana Wallr.) has severely restricted the development of the sunflower industry in China, and more efficient and convenient control methods are urgently needed. In this experiment, we investigated the effects of N, P and silica fertilizers on the parasitism [...] Read more.
Sunflower broomrape (Orobanche cumana Wallr.) has severely restricted the development of the sunflower industry in China, and more efficient and convenient control methods are urgently needed. In this experiment, we investigated the effects of N, P and silica fertilizers on the parasitism rate of O. cumana, as well as on the yield of sunflower and native microbial communities in the field. Firstly, pot experiments were conducted to select the most effective fertilization method and to determine the physiological and biochemical indexes of sunflowers. Subsequently, field application studies were carried out to determine the physiological indexes, yield, O. cumana parasitism on sunflower, and the effect on the indigenous microbial community. The results demonstrate that compared with the CNP treatment (Control), the number of parasites under the N1P5 treatment significantly decreased by 66.15%. The exogenous application of silica can significantly reduce the number of O. cumana parasites. The treatments with N1P5 (N/P = 1:5) and available SiO2 content higher than 40 mg/kg (NS2, NS3, SF2 and SF3) significantly increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in sunflower leaves. In the field, fertilization significantly decreased the number of O. cumana parasites. The S treatment improved the native microbial community structure and enriched beneficial microorganisms, including Vicinamibacteria and Pyrinomonadaceae. Additionally, applying the S treatment significantly increased sunflower yield by 23.82% and crude protein content by 20.20%. In summary, the application of silicon fertilizer can effectively improve the host microbial community, reduce O. cumana parasitism and improve the yield and quality of sunflower. Full article
(This article belongs to the Special Issue Soil Microbe and Nematode Communities in Agricultural Systems)
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14 pages, 3424 KiB  
Article
Influence of Vermicompost on the Concentration of Exogenous Indole-3-Acetic Acid and Its Effect on the Development of Tomato Plants (Lycopersicum esculentum L.)
by Miguel Ángel Segura-Castruita, Mariano Ángel Valdivia-Dávila, Pedro Yescas-Coronado, Juan Florencio Gómez-Leyva and Saraí Cueto-Medina
Agronomy 2024, 14(6), 1311; https://doi.org/10.3390/agronomy14061311 - 18 Jun 2024
Viewed by 592
Abstract
Indole-3-acetic acid (IAA) concentration is directly proportional to the amount of vermicompost (VC) added to sand substrates. The objectives of this work were to establish the effect of the amount of VC in sand substrates on the concentration of IAA and to determine [...] Read more.
Indole-3-acetic acid (IAA) concentration is directly proportional to the amount of vermicompost (VC) added to sand substrates. The objectives of this work were to establish the effect of the amount of VC in sand substrates on the concentration of IAA and to determine its influence on tomato plants. Sand substrates with VC percentages (0, 20, 40, and 50%) were placed in pots; in each one, the concentration of IAA was determined at the beginning and the end (after supporting tomato plants), and its bacterial load was determined. In tomato plants, some vegetative and yield components were measured. The results show that by adding 1 kg of VC in a sand-based substrate, the concentration of exogenous IAA increases by 0.0470 and 0.0642 mg g−1 (at the beginning and the end, respectively). This increase was reflected in the development of the plants; for example, their roots demonstrated their maximum development (370.20 cm−3) when the amount of VC in the substrate was 3.95 kg. Therefore, the amount of VC used in the preparation of substrates influences the concentration of IAA in them, which is reflected in the development of tomato plants. Full article
(This article belongs to the Section Farming Sustainability)
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15 pages, 2473 KiB  
Article
Assessing the Effectiveness of Vermi-Liquids as a Sustainable Alternative to Inorganic Nutrient Solutions in Hydroponic Agriculture: A Study on Diplotaxis muralis
by Sami ur Rehman, Alessio Aprile, Federica De Castro, Carmine Negro, Danilo Migoni, Michele Benedetti, Erika Sabella and Francesco Paolo Fanizzi
Agronomy 2024, 14(6), 1310; https://doi.org/10.3390/agronomy14061310 - 18 Jun 2024
Viewed by 481
Abstract
Organic products are gaining popularity due to their positive impact on human health and the environment. While hydroponics is commonly used in vegetable production, it relies on mineral fertilizers derived from limited and non-renewable resources. As a result, farmers are actively seeking sustainable [...] Read more.
Organic products are gaining popularity due to their positive impact on human health and the environment. While hydroponics is commonly used in vegetable production, it relies on mineral fertilizers derived from limited and non-renewable resources. As a result, farmers are actively seeking sustainable farming solutions. This study comprehensively evaluated the effectiveness of vermi-liquids (organic nutrient solutions) as a replacement for conventional inorganic nutrient solutions in promoting growth and nutrient acquisition in Diplotaxis muralis plants in a controlled environment. The results showed that plant biomass and SPAD values of D. muralis grown in Hoagland solution and enhanced vermitea (vermitea having relatively low pH and high EC) were higher compared to standard vermitea (high pH and low EC). The findings also revealed improved nutrient assimilation of phosphorus, potassium, calcium, iron, manganese, copper, and zinc in the enhanced vermitea plants. The heavy metal contents in D. muralis leaves were evaluated, too, and they were found to fall significantly below the safe threshold, rendering them safe for human consumption. However, the standard vermitea, with its high pH and low EC, performed poorly as a hydroponic solution. This research suggests that enhanced vermitea can completely replace chemical nutrient solutions in hydroponic agriculture. This substitution could lead to reduced production costs and improved product quality. Full article
(This article belongs to the Section Plant-Crop Biology and Biochemistry)
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