Agronomy

Maize (Zea mays L.) leaf angle is an important characteristic affecting high-density planting, and it is also a central indicator for maize plant type selection to improve yield. Brassinosteroids (BRs) are a class of phytohormones that could modulate the growth and development of plant leaf angles. However, its functional mechanism remains unclear in maize. In this study, we used maize self-line B73 as material to analyze the transcriptome of leaf cushion after BR treatment at the seedling stage. Using seven concentrations of exogenous BR-treated maize B73 plants, the results show that the leaf angle and the cell length near the leaf pillow increased and then decreased with BR concentration increasing, and the 50 μM level was the best treatment. Analysis of 11,487 differences expressed genes (DEGs) found that genes related to cell volume were up-regulated, and the expression of genes related to the cell division was down-regulated. It is speculated that exogenous BR regulates the size of the maize leaf angle by regulating cell volume and cell division, and so we constructed a molecular mechanism model of maize response to exogenous BR. The molecular mechanism model of exogenous BR through weighted gene co-expression network analysis (WGCNA) DEGs, and two gene modules related to changes in maize leaf angle were identified. The results can provide a theoretical basis for determining the mechanism of exogenous BR-regulated maize. Full article

The development of varieties with strong tolerance is one of the important strategies to diminish the negative impact of chilling stress during heading on the spikelet fertility and yield formation of late-season rice. However, whether such genetic improvement has been made in inbred late rice lines in China is not clear. In the present study, three late-season inbred rice varieties, Xiangwanxian2 (XWX2, released in 1988), Xiangwanxian8 (XWX8, released in 1998) and Xiangwanxian17 (XWX17, released in 2008) were subjected to moderate (20 °C) and extreme (17 °C) chilling stress during heading, and the grain yield components and flowering-related traits of the three varieties in response to different temperature were investigated. The results showed that the newly released inbred late rice variety XWX17, demonstrated better chilling tolerance during heading than the early released varieties with respect to higher grain filling percentage. The improved grain filling percentage in XWX17 might be the results of increased spikelet fertility, which was attributed to the increase in pollen viability, anther dehiscence length and anther volume. In addition, the SPAD value and the chlorophyll a content of the flag leaf can be used as indicators to predict the rice spikelet fertility when suffering from chilling stress during heading. The present study provides evidence that the genetic approach has been made to improve the chilling tolerance of inbred late rice lines during heading; however, further research is needed to explore the physiological and molecular mechanism underlying the relationship between leaf characteristics and function with rice spikelet fertility. Full article

Renovating pastures to increase forage species diversity is a burgeoning practice among producers. Over a century of grassland and small-plot research suggests that increasing plant diversity can lead to improved pasture productivity, resilience, and soil health. However, it remains hard to decipher how these benefits translate to grazed production systems given the limited experimentation in realistic grazing systems. There is a disconnect between ecological and agronomic research regarding what qualifies as a “diverse” grassland or pasture. This review aims to examine the current state of research regarding plant diversity and its potential benefits for soil health in pasture systems, and outlines how we can improve our understanding and implementation of this practice in production systems. Full article

The expansion of the super-high-intensive cultivation of olive groves requires irrigation techniques that are compatible with the increasing scarcity of water due to climate change and olive oil demand. For this, the effect of two regulated deficit irrigation treatments (RDI) and a sustained deficit irrigation (SDI) treatment was studied. The treatments consisted of: (i) control treatment, which supplied 100% of the water lost by evapotranspiration (ET₀); (ii) the “optimal RDI” treatment, which only reduced irrigation water (~37–54% reduction) during the pit hardening stage; (iii) the “confederation RDI” which limited water restriction to the donation of the Guadalquivir hydrographic confederation (~72% reduction); and, (iv) the “confederation SDI”, similar water restriction (~72%) but dying the whole tree cycle. In general, the reduction in the irrigation water caused no negative effects on the studied parameters. However, the total phenolic content (TPC) was increased when the deficit irrigation was applied. Fatty acid profile showed changes with respect to the control, increasing oleic acid and the total content of monounsaturated fatty acids (MUFA). For the volatile compound profile, reducing water intake caused changes in mayor volatile compound (trans-2-hexenal), related with green flavors. The application of deficit irrigation treatments increased the value obtained in the fruity parameter with respect to the control. On the other hand, irrigation deficit treatments did not generate changes in the olive oil yield. Full article

To explore the changes of leaf functional traits of Zanthoxylum planispinum ‘dintanensis’ with growth and development and its relationship with soil properties, which can clarify the response of the plantation to soil properties and suitable strategy. The research results can provide a scientific basis for plantations management. We explored the response of leaf functional traits to soil by using redundancy analysis in 5–7-, 10–12-, 20–22-, and 28–32-year Z. planispinum ‘dintanensis’ plantations. The results showed that: (1) The coefficients of variation of leaf traits ranged from 0.41% to 39.51%, with mostly medium and low variation, with the lowest variability in leaf water content (0.51–0.85%); The 5–7, 10–12, 20–22-year-old plantations were laid at the “slow investment-return” end of the economic spectrum while 28–32-year plantations were close to “fast investment-return” end. (2) The Z. planispinum ‘dintanensis’ tended to suit the environment via making trade-off and coordination of leaf functional traits. Leaf dry matter content decreased with an increase in leaf carbon/leaf nitrogen ratio, which is the trade-off between nitrogen usage efficiency and nutrient fixation capacity in Z. planispinum ‘dintanensis’. (3) Redundancy analysis suggested that soil carbon/nitrogen ratio, soil total calcium, soil water content, soil available phosphorus, soil carbon/calcium ratio were highly correlated with leaf functional traits, while soil elemental stoichiometry had a greater reflection on leaf functional traits than their own content. Full article

The goal of this research was to analyze the load and safety of the transplanting device of the 4-bar link type semi-automatic vegetable transplanter under different workload conditions. To measure the strain at the transplanting device, a load measurement system was developed using 15 strain gauges. Field tests were conducted at 4 levels of engine speeds (750, 1000, 1250, and 1500 rpm) and 10 levels of the planting distance (0.29–0.47 m). The static safety factor was defined as the ratio between the strength of the material and the maximum stress in the transplanting device. The calculated stress data were converted from the time domain to the frequency domain using the rain-flow counting methods and Goodman’s Equation. The sum of fatigue damage was acquired based on the Palmgren–Miner’s rule. It was observed that the stresses increased with increasing engine speed and planting distance. The results show the higher engine speed and the longer planting distance will decrease the static safety factor and fatigue life. The static safety factor value was more than 1.0 for all locations and all working conditions. The minimum fatigue life was 49,153.3 h at link A (S_14), under the working condition of engine speed 750 rpm and planting distance of 0.35 m. Full article

Salvia tomentosa is a perennial sage of the maquis vegetation, strongly aromatic, with medicinal and ornamental value. Aiming to facilitate the promotion of the species in the floriculture sector, its micropropagation was studied in terms of the effect of explant origin and medium plant growth regulators on in vitro cultures establishment, shoot proliferation and rooting. Shoot tip or single node explants excised from either in vitro grown seedlings or greenhouse plants grown from cuttings of mature plants were cultured on MS medium supplemented with 6-benzyladenine (BA) at concentrations 0.0–3.2 mg L⁻¹ in combination with 0.0, 0.01 and 0.1 mg L⁻¹ 1-naphthaleneacetic acid (NAA). Infections were the biggest problem for establishing cultures from greenhouse plants, while explants from in vitro seedlings showed hyperhydricity, especially the nodal ones. In the multiplication stage, high BA concentrations reduced explant response to produce shoots as well as the length of shoots produced, and although they increased shoot number per responding explant, a large number of shoots were hyperhydrated especially in explants of seedling origin. In general, the highest multiplication indexes, relevant to normal shoots, were given by the hormone-free medium or one with low BA concentration, and by shoot tip explants originated from greenhouse adult plants. The highest rooting rates (70–78%) were achieved either at full or half strength hormone-free or with 0.1 mg L⁻¹ indole-3-butyric acid (IBA) medium. Increasing IBA resulted in an increase in root number, but a decrease in rooting rate and root length. Ex vitro acclimatization was highly successful (92–96%) in peat-perlite (1:1 v/v) substrate. The micropropagation protocol developed will contribute to the promotion of S. tomentosa in the floriculture and pharmaceutical industry and will be a tool for breeding programs targeting high value products. Full article

In a wheat/maize rotation system, nitrogen (N) accounts for a large proportion of basal fertilizer, but soil N loss and the resulting environmental risk simultaneously exist worldwide. This study applied different urease/nitrification inhibitors together with basal fertilizers and investigated their effects on soil N level and grain yield. Six N stabilizing combinations consisted of two urease inhibitors (HQ and NBPT) and three nitrification inhibitors (DCD, DMPP, and Nitrapyrin). The treatments supplied with urease/nitrification inhibitors reduced, to some degree, the conversion rate of ${\mathsf{N}\mathsf{H}}_4^{+}$ into ${\mathsf{N}\mathsf{O}}_3^{-}$, and kept ${\mathsf{N}\mathsf{H}}_4^{+}$ content higher in surface soils for a longer time. Compared to CK, A1 treatment supplied with 1.5% HQ + 4% DCD well-maintained the levels of soil alkali-hydrolyzable N and ${\mathsf{N}\mathsf{H}}_4^{+}$. For example, alkali-hydrolyzable N and ${\mathsf{N}\mathsf{H}}_4^{+}$ contents at 0–20 cm soil layer under A1 were increased by 8.59–41.6% and 8.15–14.5% more than CK, respectively. Based on the entire growth period of wheat and maize rotation, urease/nitrification inhibitors improved soil available N in surface soils but did not prevent ${\mathsf{N}\mathsf{H}}_4^{+}$ and ${\mathsf{N}\mathsf{O}}_3^{-}$ leaching, especially in the intensive rainfall season. The combinations of HQ and DCD or Nitrapyrin significantly enhanced crop yield. Specifically, crop yields under A1 and A3 (1.5% HQ + 0.25% Nitrapyrin) were 16.3% and 14.3% higher than CK, respectively. The N stabilizing combinations also promoted N intake and transport at every growth stage. The maximum N accumulation was increased by 27% under A1, when compared to CK. The treatments supplied with urease/nitrification inhibitors also achieved higher apparent N recovery efficiency, N agronomic efficiency, and N partial factor productivity. Consequently, the combinations of urease/nitrification inhibitors could improve N availability at 0–40 cm soil layer, which in turn improved N use efficiency of wheat and maize. The results suggested that the two urease/nitrification inhibitor combinations, 1.5% HQ + 4% DCD (A1) and 1.5% HQ + 0.25% Nitrapyrin (A3), were optimal N stabilizing agents and worthy of further study. Full article

The use of agricultural practices such as fertilization and intercropping can improve the production of forage cacti. The objective of this study was to evaluate the agronomic characteristics of forage cactus intercropped with leguminous trees and fertilized with different sources of manure in the tropical semiarid region of Brazil. The research was carried out at the Agricultural and Livestock Research Enterprise of Pernambuco State during the period from March 2011 to September 2013. The following cultivation systems were used: (i) Gliricidia sepium (Jacq.) Kunth + forage cactus cv. IPA-Sertania [Opuntia cochenillifera (L.) Mill]; (ii) Leucaena leucocephala (Lam.) de Wit + forage cactus; and (iii) forage cactus in monoculture. All of these systems were fertilized with different sources of manure (cattle, goat, sheep, and broiler litter). The goat and sheep manure (16.6 and 16.5 Mg DM ha⁻¹ year⁻¹) provided the least production of cactus in the different cropping systems. Cattle manure provided greater production of forage and wood from legumes (1.4 and 4.3 Mg DM ha⁻¹ year⁻¹) and cactus (20.9 Mg DM ha⁻¹ year⁻¹). Gliricidia produced more forage and wood than Leucaena. Total production of the forage cactus-Gliricidia system produced 4.7 and 3.8 Mg DM ha⁻¹ of biomass and wood in two years, respectively. The production and morphological characteristics of the cactus increased at further distance from the trees (3 m), and the opposite effect was observed for the concentrations of N, p, and K. Thus, cropping systems using forage cactus and tree legumes fertilized with manure represent an option for tropical semiarid regions. Full article

The production of middle-season rice is an important part of agriculture in the Yangtze River basin of China. In recent years, the chalky grain rate of middle-season rice has decreased with the release of new cultivars. However, limited information is available on the factors responsible for this change in the chalky grain rate. This study evaluated the trends in the chalky grain rate and grain size traits of the new cultivars and the relationships between the chalky grain rate and grain size traits for middle-season hybrid rice in a province located in the middle reaches of the Yangtze River basin during 2006–2021. The results indicate that the recently reduced chalky grain rate of middle-season hybrid rice in the new cultivars is closely associated with a decrease in rice width, suggesting that it is feasible to reduce the chalky grain rate of middle-season hybrid rice by slimming the grain through breeding. Full article

The consumer market has a strong tendency to consume specialty coffees, making it essential to understand the influence of environmental conditions, such as solar radiation and altitude, on coffee quality. This study aimed to analyze the physical and sensory quality of Arabica coffee as a function of different altitudes and incident solar radiation on the coffee tree. The study was carried out in the city of Manhuaçu-MG, Brazil. Three altitudes (950, 1050 and 1150 m above mean sea level) and two sides of coffee exposure to solar radiation (east face: morning sun and west face: afternoon sun) were studied in two post-harvest processing (natural and peeled cherry). Sensory attributes, granulometry and occurrence of coffee defects were evaluated, in order to verify if there was variation in the physical and sensorial characteristics of the coffee. It was found that at an altitude of 1150mamsl, on the exposed face of the plant that received the afternoon sun, there was the formation of better-quality coffee, when compared to the face that received the morning sun. On the other hand, at lower altitudes, coffees from the face of the plant exposed to the morning sun showed a greater association with physical and sensory quality parameters. Full article

The production of onions bulbs (Allium cepa L.) requires a high amount of nitrogen. According to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos Aires, Argentina, between 8000 and 10,000 hectares per year⁻¹ are cultivated in the districts of Villarino and Patagones. This work aimed to analyze the relationship of biophysical variables: leaf area index (LAI), canopy chlorophyll content (CCC), and canopy cover factor (fCOVER), with the nitrogen fertilization of an intermediate cycle onion crop and its effects on yield. A field trial study with different doses of granulated urea and granulated urea was carried out, where biophysical characteristics were evaluated in the field and in Sentinel-2 satellite observations. Field data correlated well with satellite data, with an R² of 0.91, 0.96, and 0.85 for LAI, fCOVER, and CCC, respectively. The application of nitrogen in all its doses produced significantly higher yields than the control. The LAI and CCC variables had a positive correlation with yield in the months of November and December. A significant difference was observed between U250 (62 Mg ha⁻¹) and the other treatments. The U500 dose led to a yield increase of 27% compared to U250, while the difference between U750 and U500 was 6%. Full article

One of the most common annual overwintering weeds in various crops worldwide is silky bent grass (Aspera spica-venti (L.) Beauv). The aim of this study was to investigate the selected morphological characteristics and chemical composition of A. spica-venti from different cultivation fields in Poland, depending on the macronutrient content of the soil. The average pH values of the soil samples, and the average concentration of nitrogen (N) and phosphorus (P) in the samples were statistically different between study sites. In turn, the concentration of potassium (K) was at the same statistical level. The average values of N, P and K concentrations in the straw of A. spica-venti (% dry matter) in particular study sites were not statistically different. The mean values of the examined morphological features of A. spica-venti did not differ statistically between the individual test sites. Overall, there was no significant impact of the habitat on the chemical composition and morphology of the A. spica-venti occurring naturally in arable fields. However, an increase in soil abundance in some macronutrients (mainly K) may positively affect the morphology of this weed as opposed to an increase in nitrogen concentration in the soil, and an increase soil pH. The lack of significant influence of soil conditions and location of APESV sites on the morphology and chemical composition of the weed indicates that it has high plasticity and is able to thrive under varying habitat conditions. Full article

Alfalfa (Medicago sativa L.) is a perennial leguminous plant, with a strong tap root system that plays an important role in alfalfa’s adaptation to drought stress. However, a better understanding of root functional traits and how these root traits are related to whole plant responses in order to improve pasture productivity under water deficit. Two greenhouse experiments were conducted: Experiment 1 used three alfalfa cultivars and four levels of soil water content treatments to investigate herbage productivity, growth point density, residual shoot weight, and root weight. Experiment 2 assessed relationships among root-sourced abscisic acid (ABA), root system architecture and plant biomass in response to water deficit. The results demonstrated that root system was used as a useful tool to improve tolerant and adaptation when alfalfa copied with lower levels of soil water content. On average, maintaining 60–65% soil water-holding capacity alfalfa had the highest herbage accumulation (6.7 g DM pot-1), growing point density (46.5 pot-1), and residual shoot biomass (1.8 g DM pot-1). At the level of water stress, Medicago sativa L. cv Zhaodong (ZD) and cv Aohan (AH) tended to exhibit a herringbone branching pattern with less root tips, root forks, altitude, and magnitude than cv Golden empress (GE). Principal component analysis and structural equation modeling revealed that root-sourced ABA positively regulated the altitude and magnitude of root system architecture, root tips and root forks, and was closely associated with plant root biomass and herbage biomass. It was concluded that these findings can contribute to developing optimum irrigation strategies and help alfalfa breeders in the development of new cultivars with improved drought tolerance based on root system architecture, plant hormone, and plant growth. Full article

This research was carried out in order to demonstrate that mulching the ground helps to conserve water, because agricultural sustainability in dryland contexts is threatened by drought, heat stress, and the injudicious use of scarce water during the cropping season by minimizing surface evaporation. Improving soil moisture conservation is an ongoing priority in crop outputs where water resources are restricted and controlled. One of the reasons for the desire to use less water in agriculture is the rising demand brought on by the world’s growing population. In this study, the use of organic or biodegradable mulches was dominated by organic materials, while inorganic mulches are mostly comprised of plastic-based components. Plastic film, crop straw, gravel, volcanic ash, rock pieces, sand, concrete, paper pellets, and livestock manures are among the materials put on the soil surface. Mulching has several essential applications, including reducing soil water loss and soil erosion, enriching soil fauna, and improving soil properties and nutrient cycling in the soil. It also reduces the pH of the soil, which improves nutrient availability. Mulching reduces soil deterioration by limiting runoff and soil loss, and it increases soil water availability by reducing evaporation, managing soil temperature, or reducing crop irrigation requirements. This review paper extensively discusses the benefits of organic or synthetic mulches for crop production, as well as the uses of mulching in soil and water conservation. As a result, it is very important for farmers to choose mulching rather than synthetic applications. Full article

Ebb-and-flow subirrigation (EFI) is a water-saving and environmentally friendly irrigation method that can effectively improve water use efficiency and promote plant growth. In this study, we elucidated the effects of ebb-and-flow subirrigation on the protein levels in tomato roots in comparison with top sprinkle irrigation (TSI) and used an integrated approach involving tandem mass tag (TMT) labeling, high-performance liquid chromatography (HPLC) fractionation, and mass-spectrometry (MS)-based analysis. A total of 8510 quantifiable proteins and 513 differentially accumulated proteins (DAPs) were identified, of which the expressions of 283 DAPs were up-regulated, and 230 DAPs were down-regulated in the EFI vs. TSI treatment comparison. According to proteomic data, we performed a systematic bioinformatics analysis of all the identified proteins and DAPs. The DAPs were most significantly associated with the terms ‘metabolic process’, ‘anchored component of membrane’, ‘oxidoreductase activity’, ‘phenylpropanoid biosynthesis’, and ‘biosynthesis of secondary metabolites’ according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes enrichment (KEGG) analysis. The 272 DAPs were classified into 12 subcellular components according to their subcellular localization. Furthermore, the activities of SOD, POD, CAT, GR, and APX in tomato roots were remarkably increased under EFI, while the MDA content was decreased compared with TSI. Correlation analysis among activities of enzymes and their related DAPs showed that 30 DAPs might be responsible for the regulation of these enzymes. The results showed that ebb-and-flow subirrigation could induce a series of DAPs responses in tomato roots to be adapted to the new mode of water supply. Full article

Biochar application has been considered as a promising solution to address the effects of modern agriculture on climate change. However, there is a lack of research on the biochar application of greenhouse gas emissions based on poor soils in Korean agricultural land. Therefore, this study aimed to evaluate the effects of biochar application according to different soil characteristics on soil organic carbon (SOC) improvement and greenhouse gas reduction. The incubation experiments were conducted for 49 days and used different feedstock (barley straw and poultry manure) and biochar application rates (0, 5, 10, and 20-ton ha⁻¹) in four soil characteristics (upland, U; greenhouse, G; converted land, C; reclaimed land, R). The results of this study showed that the SOC increased significantly in all soils after biochar application. The increasing SOC rate was the highest in poor soil. Biochar 20-ton ha⁻¹ treatment significantly reduced N₂O emissions by 33.2% compared with the control. Barley straw biochar significantly reduced N₂O emissions from all soils. Barley straw biochar decreased approximately 74.5% of N₂O emissions compared with poultry manure biochar. Poultry manure biochar improved SOC and reduced N₂O emissions in poor soil. However, in poultry manure biochar treatment in U and G soil, N₂O emissions increased. In conclusion, barley straw biochar application was found to suppress N₂O emissions and improve the SOC in all soil characteristics of agricultural land. In addition, the soil carbon storage effect and N₂O reduction effect of biochar were the highest in poor soil. Thus, the biochar application can be a potential agricultural practice for improving soil quality and decreasing N₂O emissions in domestic agricultural soil. Full article

Supplemental lighting is common in northern countries or during winter greenhouse tomato production. We investigated the effect of supplemental lighting treatments on cherry tomato (‘Jun-Ama’) yield, productivity (light-use efficiency (LUE) and energy-use efficiency (EUE)), and fruit quality under high irradiance (average greenhouse daily light integral (DLI) = 14.5 mol m⁻² d⁻¹). Supplemental lighting treatments contained average DLIs of 2.7, 4.9, and 7.6 mol m⁻² d⁻¹ for interlighting, toplighting, and inter- + toplighting, respectively. Supplemental LED lighting increased fruit yield by 18, 41, and 40% with inter-, top-, and inter- + toplighting, respectively, compared with the control. Interlighting increased fruit number (+11%), and top- and inter- + toplighting also increased the fruit number (+26%, +27%) and weight (+10%, +10%), respectively. LUE and EUE were comparable between inter- and toplighting, while inter- + toplighting decreased LUE by 21 and 38%, and EUE by 38 and 31% compared with inter- and toplighting, respectively. All LED supplemental treatments significantly increased total soluble solids compared with the control. Total acidity and lycopene content were unchanged in all treatments. In conclusion, LED supplemental lighting with inter- or toplighting improved cherry tomato yield and quality, but inter- + toplighting was inefficient under high irradiation. Full article

The growing demand for water by the population and industry, as well as water scarcity due to climate change, has created a need to reuse treated water for agricultural purposes. In this context, the European Union, through its Regulation (EU) 2020/741, establishes minimum requirements for wastewater reuse, specifying that reuse for agricultural purposes can help to promote the circular economy and reduce the need for fertiliser use by setting high-quality standards. The aim of this article is to study whether the treated water from a pilot plant with membrane bioreactor technology operating with real urban wastewater from the city of Granada (Spain) satisfies the quality standards required for its reuse for agricultural purposes, as well as assessing the use of other resources produced during wastewater treatment, such as biogas and biostabilised sludge. This plant works in four cycles of operation at two different hydraulic retention times (6 and 12 h) and different concentrations of mixed liquor (2429–6696 mg/L). The pilot plant consists of a membrane bioreactor where there are four ultrafiltration membranes working in continuous operation and a sludge treatment line working in discontinuous mode. Subsequently, a tertiary treatment of advanced oxidation process was applied to the treated water for a time of 30 min, with different concentrations of oxidant. The results showed that the effluent has sufficient quality to be used in agriculture, complying with the characteristics established in the European legislation. Furthermore, the biostabilised sludge and biogas can be potentially reusable. Full article