Agriculture

Bacterial symbionts are widespread in insects and other animals. These microbes play crucial roles in many aspects of insect physiology and biology, including immunity, nutrition and confronting plant defenses. In the present study, we isolated and identified the bacterium Burkholderia cepacia BsNLG8 from the brown planthopper (BPHs), Nilaparvata lugens, a devastating pest of rice crops worldwide. Plate confrontation assay indicated that BsNLG8 significantly inhibited the growth of phytopathogenic fungi. In addition, the BsNLG8 strain demonstrated the ability to produce siderophores, which explains its antagonistic mechanism. Lastly, we explored the nicotine degradation ability of BsNLG8 using in vitro and in vivo methods. In vitro, HPLC analysis results showed that BsNLG8 could significantly reduce the concentration of nicotine in the medium at 36 h. Moreover, microinjection of BsNLG8 in axenic BPHs increased the survival rate of the host on nicotine-containing rice seedlings. These findings could serve as the basis of future research in deciphering the interaction between host and symbionts. Full article

For decades, nations around the world have been promoting irrigation expansion as a method for improving agricultural growth, smoothing production risk, and alleviating rural poverty. Despite its apparent advantages, suboptimal adoption rates persist. According to the existing literature, determinants of irrigation adoption are often highly dependent on cultural, contextual, and/or local institutional factors. Yet, studies from diverse geographies identify a consistent set of factors. Thus, to be able to make generalizable inferences from such studies, a global geographic representativeness assessment of irrigation adoption studies was conducted to determine whether identified factors influencing irrigation were the result of geographic, epistemological, or disciplinary biases. The results indicate that multiple geographic biases exist with respect to studying farmers’ irrigation adoption decision-making. More research on this topic is being conducted in regions that have little to a high percentage of irrigation (>1%), are readily accessible, receive moderate amounts of average annual rainfall, and have moderate amounts of cropland cover. The results suggest the need to expand research efforts in areas with little to no irrigation to identify constraints and help accelerate economic growth, poverty reduction, and food and livelihood security for rural communities in these regions. Full article

Fruit morphological and anatomical characteristics are essential in the taxonomy of Apiaceae. Daucus L. is one of the most important genera of the family Apiaceae, as it contains the cultivated carrot, a crop of great economic importance, and about 40 wild species that could serve as potential sources of genetic diversity for crop improvement. However, the taxonomic and phylogenetic relationships among these species have not yet been fully clarified. In this study, we comparatively investigated the fruit morphology and anatomy of 13 Daucus taxa and four closely related non-Daucus species using light and scanning electron microscopy to evaluate the taxonomic value of these characteristics. A wide range of variations was observed in the fruit morpho-anatomical characteristics across the taxa and revealed several diagnostically valuable features, thus proving to be taxonomically useful. For Daucus, the observed differences included the fruit size (2.1–8.4 mm), shape (from ellipsoid to oblong), and weight (0.079–1.349 g/100 fruits), as well as the fruit surface sculpturing and some anatomical characteristics, i.e., the presence/absence and size of vittae, the shape and size of vascular bundles, and the shape of exocarp cells. This study contributes to a better understanding of the relationships among the genus Daucus. Full article

The mechanized sowing operation of corn breeding can improve test accuracy and efficiency and speed up the test process. In view of the problems of low flexibility, high price, and poor sowing quality of the current seeder in corn breeding experiments, the critical components of a hand-pushing corn plot precision planter were optimized. Through the analysis of the relative motion between corn seed and the hole seed-metering wheel, the hole diameter range and hole depth range of the hole seed-metering wheel were determined as 13~19 mm and 6~12 mm, respectively. The chamber structure was optimized to improve the seed filling performance under the condition of a small number of seeds. The angle range between the connecting plate and the horizontal line (ACP) and the angle range between the back plate and the horizontal line (ABP) were 35~55° and 40~70°, respectively. EDEM was used to simulate the seeding circumstances of hole seed-metering wheel with different holes sizes. The optimal combination of hole diameter and depth under different seeds’ sizes and the appropriate angle combination of ACP and ABP were obtained through the orthogonal test. The results of the simulation experiment showed that the optimal hole diameter–depth combinations of the small, medium, and large corn seeds were 13–8, 15–10, and 17–8 mm, respectively. The angle ACP and the angle ABP were, respectively, 45°and 70°. The soil bin test was carried out to further verify the actual seeding effect and the influence of the rotating speed of hole seed-metering wheel on seeding. The results showed that when the rotating speed of hole seed-metering wheel was less than 16.0 r/min, the qualified seeding rates and the double seeds rates of the small, medium, and large corn seeds were higher than 90% and 85%, respectively. The missing seeding rates were 0%. The variation coefficients of plant spacing were less than 5%, indicating good stability of plant spacing, which met the design requirements. The study results can provide a theoretical reference for the optimization design of maize breeding equipment in a plot. Full article

Anthracnose is a major disease of walnut, which seriously reduces the yield and quality of walnut in Yunnan province. Therefore, it is necessary to explore and find a biological control agent for the prevention and control of anthracnose disease. In this study, an endophytic Bacillus WB1, with broad-spectrum antibacterial activity was isolated and screened from healthy walnut roots. The strain WB1 was identified as Bacillus siamensis WB1 based on morphological characteristics, physiological and biochemical tests, and 16S rRNA gene sequence analysis. Bacillus siamensis WB1 produces siderophores and indole-3-acetic acid and solubilizes inorganic phosphate. The strain WB1 not only showed a significant inhibition effect on fourteen phytopathogens, but also showed obvious inhibition on the spore germination of Colletotrichum acutatum. Meanwhile, strain WB1 can code genes for the production of antifungal lipopeptides and generate extracellular hydrolytic enzymes (protease, β-1, 3-glucanase, cellulase, and amylase). In addition, WB1 activated the systemic resistance of the host plant by enhancing the activity of defense enzymes, including phenylalanine ammonia lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO). The results of greenhouse assays also revealed that B. siamensis WB1 can effectively reduce the occurrence and severity of walnut anthracnose disease. These results also indicated that B. siamensis WB1 is a potential biocontrol agent for walnut anthracnose. Full article

Tobacco mosaic virus is the etiological agent of one of the most critical diseases limiting chili pepper production. Various practices have been used to manage the disease, e.g., the use of resistant varieties and interference with the vector through chemical control. However, these practices are not helpful once the virus has been established in the plant. There is still no effective method for the sustainable management of the disease; therefore, exploring new options is required. Currently, some studies have reported the activity of TiO₂ NPs against viruses in plants, although not against TMV in chili pepper. The present work aims to determine a possible direct action of TiO₂ NPs against TMV and if there is a relationship between the amount of virus and symptoms. The application of TiO₂ NPs at 150 μg/mL in infected pepper plants reduced symptoms and viral load and improved the morphological characteristics compared to the control. Incubation of 150 µg/mL TiO₂ NPs with the virus for 6 and 8 h before infection decreased viral concentration significantly after infection compared to the control. In this work, it is reported, for the first time, that the use of TiO₂ NPs is a novel practice for the control of TMV in chili pepper. Full article

The fertilization rate is adjusted through the regulation of opening length and the rotational speed for bivariate fertilizer applicators. It is essential to optimally determine the control combination according to the target fertilization rate and further improve the control performance of fertilization operation in precision agriculture. In this study, a novel decision-making capability optimization scheme of control combination and PID controller parameters is proposed to improve the feasibility and practicability of variable fertilizer applicators. Firstly, EDEM is adopted to acquire the minimum allowable opening length and the proper gap between the spiral blades and the discharge cavity wall, and then calibration experiments are implemented to establish the fitting model of fertilization rate using polynomial fitting. Secondly, the modified sparrow search algorithm (SSA) with chaotic operator and mutation section of the DE algorithm is used to optimize the control combination utilizing the accuracy, uniformity, and adjustment time as the evaluation criteria. Moreover, the tent mapping bat algorithm (TBA) is applied to tune the PID controller parameters for enhancing the accuracy and response speed of the fertilization-rate control system. Compared to the PID controller based on the bat algorithm (BA), traditional PID controller, and fuzzy PID controller, the rise time of the PID controller improved by TBA decreases by 0.018 s, 0.09 s, and 0.038 s, respectively, and the average steady-state deviation of that drops by 0.02 kg ha⁻¹, 1.45 kg ha⁻¹, and 0.19 kg ha⁻¹, respectively. In addition, under the condition of the same controller, compared with SSA, GA, and MOEA/D-DE, the average accuracy of the proposed decision-making algorithm decreases from 1.9%, 2.5%, and 3.5% to 1.8%, the average uniformity drops from 0.52% and 0.48% to 0.47%, and the average adjustment time declines from 0.99 s, 1.48 s, and 1.34 s to 0.5 s. It can be concluded that the method proposed in this study performs better in terms of accuracy and adjustment time but exhibits no apparent effect on the improvement of uniformity. Full article

The application of the conventional vibrating screen to the separation of the black soldier fly (BSF) sand mixture has several problems (e.g., high rate of impurity and low efficiency). A two-stage sieve surface vibratory sorting device with combined planar and curved surfaces was investigated, and its critical operating parameters were determined. Moreover, a coupling simulation model of the sieve surface and the larvae–sand mixture was built based on the characteristics of the BSF breeding process, and its critical operating parameters were optimized. Next, the Plackett–Burman test was set to determine the significant factors for the separation of two-stage sieve surface vibrations as amplitude and curved height. The process of crushing separation of frass aggregates and the process of collision transport of BSF larvae were studied through simulation, and the actual test stand was built for parameter verification tests. The preferred parameter combinations comprised 0.012 m amplitude and 0.007 m curved surface height at the impurity rate of 2.34% and the insect injury rate of 5.65%, as well as 0.013 m amplitude and 0.005 m curved surface height at the impurity rate of 3.15% and the insect injury rate of 4.3%, respectively, thus conforming to the requirement of separating BSF larvae–sand mixture to reduce the impurity and prevent larvae injury. The results of this study can lay a basis for the structural improvement and operational parameter adjustment of the BSF larvae–sand mixture separation device. Full article

Minimization of the possible harmful effects of soil pollution on agricultural production and food safety are the major challenges in modern agriculture. There is great scientific interest in the detailed understanding of the physiology of lead uptake and toxicity in Zea mays, together with the search for approaches to minimizing Pb accumulation in tissues. The aim of the present study was to explore the possibility of reducing Pb accumulation in Z. mays plants cultivated in Pb-contaminated soil, by means of vermicompost amendment. Z. mays plants were cultivated at three soil vermicompost amendment rates (10, 20, and 30%), with the addition of 1000 mg L⁻¹ of Pb in the form of Pb(NO₃)₂ or an equivalent amount of nitrogen in the form of NH₄NO₃. Additional nitrogen had a significant stimulatory effect on plant growth and physiology, but only for control plants, and at a low vermicompost amendment rate. Independently, Pb had an insignificant negative effect on plant growth and biomass partitioning, but significantly negatively affected the mineral nutrition of Z. mays plants. At a 10 and 20% soil vermicompost amendment rate, the Pb concentration in plant leaves and roots decreased by 65%, while plant biomass increased four to five times in comparison to soil-grown control plants, together with accelerated flowering. It was concluded that vermicompost is one of the most promising soil amendments for reducing heavy metal uptake and accumulation in crop plants, while also being an efficient organic fertilizer. Full article

In this study, a pot autofeeding device for a biodegradable pot tray was developed. The tensile strength and bending strength were measured to identify the physical properties of the biodegradable pot tray. As a result of the measurement, the tensile strength and bending strength of the biodegradable pot tray were 0.06 and 0.17 times smaller than those of the plastic pot tray. Therefore, a new type of pot tray extraction mechanism was designed, considering the physical properties, dimensions, and geometry of the biodegradable pot tray, and it was applied to the pot autofeeding device. The developed pot autofeeding device consists of a pot slot, pot-separating blades, pot holders, air cylinders, and a conveyor device. It can supply 240 pot trays per hour to the seeding process without deformation or damage to the biodegradable pot tray. Full article

Recycling waste, such as rice straw and water treatment residuals, is important to reduce harmful effects on the environment and to improve canola yield and soil quality in degraded soils. Nanotechnology for the production of nanomaterials from biochar and water treatment residues will be a future revolution for improving soil quality and increasing canola yield in degraded soil. Therefore, this study aims to identify the properties of some recycled nanomaterials, such as nanobiochar (nB) and nanowater treatment residue (nWTR), and their effect on the biological activity and productivity of canola in degraded soils. The results showed that the nWTR and nB contain many functional groups and minerals, and they also have high negative zeta potential. The addition of the studied soil amendments significantly improved microbial biomass carbon (MBC) and biological activity, which played a major role in increasing canola yield. The highest dehydrogenase (DHA) and catalase (CLA) activity was found in nWTR-treated soil at 50 mg kg⁻¹, with increases of 32.8% and 566.7% compared to the control, respectively. The addition of nB greatly improved the growth of canola plants in the soil. This was evident from the increase in the weight of seeds, the weight of 1000 grains, the number of pods per plant, and the highest increase was for nB added at the rate of 250 mg per kg⁻¹ soil. The addition of 50 mg kg⁻¹ of nWTR gave the best results in seed yield by 150.64% compared to the control. These results indicate that recycled nWTR and nB are some of the best waste recycling treatments, in addition to good soil health, in increasing soil biology and canola yield in degraded soils. In the future, research on recycled nanomaterials should examine the residual effect they have on yield, soil quality, and soil fauna in the long term. Full article

The abundant biomass growth of aquatic macrophytes in wetlands is one of the major concerns affecting their residing biota. Moreover, the biomass degenerates within the wetlands, thereby causing a remixing of nutrients and emission of greenhouse gases. Therefore, it is crucial to find sustainable methods to utilize the biomass of aquatic macrophytes devoid of environmental concerns. The present study investigates the utilization of the biomass of three aquatic macrophytes, including the lake sedge (CL: Carex lacustris Willd.), water hyacinth (EC: Eichhornia crassipes Mart. Solms), and sacred lotus (NL: Nelumbo nucifera Gaertn.) to produce oyster (Pleurotus ostreatus var. florida) mushrooms. For this purpose, different combinations of wheat straw (WS: as control) and macrophyte’s biomass (WH) such as control (100% WH), CL50 (50% WH + 50% CL), CL100 (100% CL), EC50 (50% WH + 50% EC), EC100 (100% EC), NL50 (50% WH + 50% NL), and NL100 (100% NL) were used for P. florida cultivation under controlled laboratory conditions. The results showed that all selected combinations of wheat straw and macrophyte biomass supported the spawning and growth of P. florida. In particular, the maximum significant (p < 0.05) growth, yield, bioefficiency, proximate, and biochemical parameters were reported using the WH substrate followed by CL, NL, and EC biomass, which corresponds to the reduction efficiency of the substrate parameters. Therefore, the findings of this study reveal that the biomass of selected aquatic macrophytes can be effectively utilized for sustainable mushroom cultivation while minimizing the risk associated with their self-degeneration. Full article

Due to water scarcity and harsh climate, Saudi Arabia and its neighboring countries rely heavily on fresh food imports from distant lands and have higher per capita expenditures on vegetable imports compared with USA and China. Aquaponics can supply fresh food throughout the year and may complement conventional agriculture in Saudi Arabia to help the objectives and policies defined by the government for food and water security. In this spirit, an Aquaponics farm is being constructed in the desert-coast climate to study the feasibility. A detailed SWOT analysis is performed for a commercial farm which reveals that the advantages of Aquaponics in the Saudi market outweigh the weaknesses. Preliminary experiences show that such ventures require high capital costs and synergistic collaboration of engineering, agriculture, business, and geology. Full article

The present study aimed to evaluate the effects of recycling ash from Amazonian biomass on the fertility of a dystrophic Yellow Latosol. For this purpose, a laboratory incubation experiment was performed with Yellow Latosol using four increasing doses of ash (8.75, 17.5, 35, and 70 Mg ha⁻¹), three incubation times (20, 40, and 60 days), two positive treatments (13 Mg ha⁻¹ lime and 2 Mg ha⁻¹ phosphate fertilizer), and one control soil. The chemical analyses of the soil revealed that the application of increasing doses of ash positively affected the pH values and significantly increased the availability of the nutrients P, K, Ca, and Mg, the levels of which were adequate for the soils and main crops of the state of Pará, Brazil. The input of these nutrients and the moderate increase in pH contributed to the increase in base saturation and thus reduced the potential acidity of the soil and neutralized Al³⁺. Therefore, recycling ash from Amazonian biomasses in agricultural or forest soils may represent a sustainable and integrative alternative that balances the management of industrial waste and the fertility of acidic and nutrient-deficient soils in the state of Pará. Full article

The use of wood-derived materials in soilless substrates for horticultural crop production is increasing; however, there is little information about the effects of wood on the incidence and severity of soilborne diseases of container-grown plants. The objectives of this research were to compare three differently processed wood substrate components blended with sphagnum peat and to investigate the effect of the peat:wood blend ratio on damping-off disease caused by Rhizoctonia solani using radish as a model system. In objective one, raw sphagnum peat was blended with three types of processed pine wood, screw-extruded, twin disc-refined, and hammer-milled, at a volumetric ratio of 70:30 and compared to a 70:30 peat:perlite mix. Radish plants grown in the hammer-milled wood and disc-refined wood had significantly lower damping-off disease severity compared to plants grown in the peat–perlite control. In objective two, sphagnum peat was blended with the three types of processed wood at a volumetric ratio of 90:10, 80:20, and 70:30 and compared to a 70:30 peat–perlite mix. The effect of the blend ratio varied by wood processing type. Higher percentages of Forest Gold and pine tree substrate resulted in lower disease severity. In both objectives, radish plants grown in any of the substrate treatments containing wood infested with R. solani tended to have lower disease severity compared to plants in the control. Results of this study indicate that the blending of processed pine wood-derived components into peat may enhance the natural suppression of damping-off disease of radish. Further research is needed to elucidate the mode of action of wood-derived materials on disease suppression in container-grown crops and to study the effects for other plant pathogens and crop species. Full article

To improve the working accuracy and anti-interference capability of the steering operation of an automatic tractor, this paper investigates the tractor steering system. In response to the current problems of high steering resistance during tractor field operations and the low service life of the drive shaft of conventional electric steering wheel solutions, an electro-hydraulic coupled power-assisted solution combining EPS and HPS is proposed. The combination of the EPS system’s high control accuracy and sensitive steering operation and the hydraulic power system’s large steering torque greatly reduces the power of the power motor and battery performance requirements, optimizing the power transmission scheme to achieve green and energy-saving purposes. Secondly, the research is focused on the influence of external disturbances on the stability of the steering system during tractor operation, and a combination of model predictive control and sliding mode control is used to study the steering system control strategy. It is finally demonstrated through simulations and experiments that it can compensate for the disturbance of the system control parameters by external disturbances, has the ability of MPC to handle input constraints and maintains the advantages of SMC robustness. Full article

Serious economic damages in many regions of the world were caused by the changes in agroclimatic resources during the last 2–3 decades. The Balkan Peninsula is much affected by the temperatures rising, changes in the distribution of precipitation, and the increasing frequency of extreme events—basically, droughts and frosts. Bulgarian agriculture is developed under various agrometeorological conditions. The climate of the country is characterized by the atmosphere and soil moisture deficit in the time of active crop vegetation and yield formation. The aim of this research is to assess the changes in agrometeorological conditions for the growth of the main grain crops and the possibilities for reaction through agro-technologies. Furthermore, the features of contemporary varieties and hybrids of spring and autumn cereals will be taken into account. The next important factor is the specific requirements for hydro-thermal conditions at different phenological phases of agricultural crop development, i.e., sums of the temperatures and precipitations. Agro-technologies react to tendencies in changing agrometeorological conditions. For the adaptation of agro-technologies, the maximum use of natural agroclimatic resources should be included in activities for overcoming unfavorable conditions, as well as the increased frequency of extreme events. A detailed assessment of the agrometeorological conditions is necessary to choose the suitable agro-technology activity. The analysis of the main meteorological elements—temperatures, precipitations, air humidity, wind speed, and solar radiation for thirty years (1986–2015) was used to assess the changes in agrometeorological conditions on agricultural lands in Bulgaria. Appropriate agro-technical activities for growing the main grain crops are proposed in accordance with the observed changes. Full article

In this paper, we present a high-accuracy model for blueberry yield prediction, trained using structurally innovative data sets. Blueberries are blooming plants, valued for their antioxidant and anti-inflammatory properties. Yield on the plantations depends on several factors, both internal and external. Predicting the accurate amount of harvest is an important aspect in work planning and storage space selection. Machine learning algorithms are commonly used in such prediction tasks, since they are capable of finding correlations between various factors at play. Overall data were collected from years 2016–2021, and included agronomic, climatic and soil data as well satellite-imaging vegetation data. Additionally, growing periods according to BBCH scale and aggregates were taken into account. After extensive data preprocessing and obtaining cumulative features, a total of 11 models were trained and evaluated. Chosen classifiers were selected from state-of-the-art methods in similar applications. To evaluate the results, Mean Absolute Percentage Error was chosen. It is superior to alternatives, since it takes into account absolute values, negating the risk that opposite variables will cancel out, while the final result outlines percentage difference between the actual value and prediction. Regarding the research presented, the best performing solution proved to be Extreme Gradient Boosting algorithm, with MAPE value equal to 12.48%. This result meets the requirements of practical applications, with sufficient accuracy to improve the overall yield management process. Due to the nature of machine learning methodology, the presented solution can be further improved with annually collected data. Full article

The implementation of the 10-year fishing ban compensation policy in the Yangtze River basin is the first practice of the river ecological compensation project in China, which has a milestone value to protect China’s ecological sustainability and boost green development. Based on the survey data of 212 retired fishing households in Ma’anshan city, this paper constructs a livelihood capital evaluation system, coupled with coordination model and mobility matrix to analyze the policy effect on participants’ livelihood from the changes of livelihood capital amounts on structure and mobility. The key results are threefold. (1) Policy implementation has significantly raised retired households’ livelihood capital index; (2) The households livelihood capital coupling coordination degree has significantly improved, and the capital structure has transitioned from imbalanced to coordinated; and (3) Households’ livelihood capital exhibits a high mobility, and the gap between rich and poor has been narrowed. This paper theoretically contributes to the research on ecological compensation by providing a more comprehensive perspective of policy effect analysis, and it can also provide a micro level empirical basis for policymakers to optimize the follow-up fishing ban policy. Full article