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The rhizosphere microbiota plays a critical and crucial role in plant health and growth, assisting plants in resisting adverse stresses, including soil salinity. Plastic film mulching is an important method to adjust soil properties and improve crop yield, especially in saline–alkali soil. However, it remains unclear whether and to what extent the association between these improvements and rhizosphere microbiota exists. Here, from a field survey and a greenhouse mesocosm experiment, we found that mulching plastic films on saline–alkali soil can promote the growth of soybeans in the field. Results of the greenhouse experiment showed that soybeans grew better in unsterilized saline–alkali soil than in sterilized saline–alkali soil under plastic film mulching. By detecting the variations in soil properties and analyzing the high-throughput sequencing data, we found that with the effect of film mulching, soil moisture content was effectively maintained, soil salinity was obviously reduced, and rhizosphere bacterial and fungal communities were significantly changed. Ulteriorly, correlation analysis methods were applied. The optimization of soil properties ameliorated the survival conditions of soil microbes and promoted the increase in relative abundance of potential beneficial microorganisms, contributing to the growth of soybeans. Furthermore, the classification of potential key rhizosphere microbial OTUs were identified. In summary, our study suggests the important influence of soil properties as drivers on the alteration of rhizosphere microbial communities and indicates the important role of rhizosphere microbiota in promoting plant performance in saline–alkali soil under plastic film mulching. [ABSTRACT FROM AUTHOR]

Farmland irrigation is an essential foundation for good crop growth, while traditional farmland irrigation techniques cannot fully consider the impact of factors such as natural precipitation and crop transpiration on crop growth, which can, to a certain extent, result in poor irrigation decisions and a complex farmland environment that cannot be monitored promptly, thereby reducing farmland production efficiency. This study designs a farmland irrigation control system based on a composite controller. Firstly, an irrigation control method is proposed to establish a prediction model for future rainfall and crop transpiration using historical meteorological data. The composite controller is designed based on the prediction model to realize an irrigation control operation with an irrigation value as the control quantity, a water and fertilizer machine, and a solenoid valve as the actuators. Secondly, an intelligent irrigation control cloud platform based on Java language is designed to monitor farm information and irrigation operation records in real-time to facilitate visual management. Finally, the prediction accuracy is high, based on the prediction model results, which can provide a specific reference basis. The superiority of the proposed controller is verified by simulation using MATLAB/Simulink. The results show that the proposed controller can be well suited for nonlinear control systems and has good control performance while ensuring high tracking accuracy, strong robustness, and fast convergence. [ABSTRACT FROM AUTHOR]

The sugarcane lifting–cutting System (SLS) is the core component of the sugarcane harvester, and the influence of its stalk lifting height on the mechanism of perennial root-cutting damage is still unclear. The test was conducted with the vertical height of centroid (VHC), forward velocity, and cutter rotational speed. Numerical quantification of perennial root based on the cutting breakage effect and cutting breakage grade (CBG) classification was used as the evaluation index. The test results showed that the VHC had a highly significant effect on the CBG of the perennial root. The CBG of the stalk decreased significantly with the lifting height. The average CBG was greater than 2.0 when the stalk lifting height was severely collapsed. The CBG ≤ 1.6 was considered qualified, and the requirements were met when the VHC of the stalk was about 0.85~1.0 m at a forward velocity of 1~3 km/h. The inverted angle of the stalk being lifted was selected to be 45° as the evaluation standard to measure the qualified lifting of the spiral sugarcane lifter. This study provides technical support for the optimal design and selection of operating parameters of the sugarcane harvester. [ABSTRACT FROM AUTHOR]

The traditional fertilizer application methods have serious problems of environmental pollution and soil degradation due to low utilization rates in the Huang–Huai–Hai Plain of China. In this study, the conservation tillage strip-hole layered fertilization method was proposed and a precision strip-hole layered fertilizer subsoiler was designed. To meet the requirements for deep tillage strip-hole layered fertilizer application, theoretical analysis and parameter calculations were first carried out on the fertilizer application type hole wheel, and then the main factors affecting the fertilizer application effect of a strip-hole layered fertilizer shovel were analyzed. The effect of forwarding speed, angle of fertilizer tube installation (AFT) and angle of unloading fertilizer (AUF) on the middle and lower layers of the fertilizer distribution length (FDT) and fertilization amount deviation stability coefficient (FADSC) was studied using the discrete element method (DEM). The three-factor three-level full-factors test design method was adopted. Simulation results showed that the FDT and the FADSC increased as the forward speed increased; the FDT decreased as the AFT and the AUF increased; an increased FADSC was observed at a middle angle of the AFT and the AUF. The minimum FADSC was obtained for a combination of parameters with a forward speed of 2 km/h, the AFT of 35° and the AUF of 60°, corresponding to the FADSC of 2.49% in the middle layer and 2.93% in the lower layer while satisfying the FDT condition. The results of the field trials showed that the FADSC was 11.36% and 12.42%, respectively, an increase of 8.87% and 9.49%, respectively, compared to the simulation results, validating the simulation model. The new way of fertilizer application methods and a theoretical basis were provided for the design of hole application machinery. [ABSTRACT FROM AUTHOR]

As a critical component of the sugarcane harvester, the primary function of the crop dividers is to lift the lodged sugarcane (LS) and reduce the loss rate of the sugarcane harvest. In this study, a rigid-flexible coupling simulation method is proposed to improve the lifting efficiency of the crop dividers on severely LS and analyze the nature of interaction between the sugarcane stalk and the crop dividers. The model's accuracy was verified using field experiments, and the operational performance of the crop dividers on sugarcane in different lodging postures was investigated. The results showed that the curve of the vertical height of the center (VHC) fluctuated more and slipped with highest frequency during the lifting process of side and forward LS. The speed of VHC was fastest during the lifting operation of side LS. The effect of side angle on the lifting effect of sugarcane was significant; the qualified values of the VHC of sugarcane being lifted in different lodged postures were: side and reverse lodged > side lodged > side and forward lodged. The coupling method and experimental results described in this paper can provide guidance for the optimal design and field operation of the crop dividers. [ABSTRACT FROM AUTHOR]

RNA editing plays a key role in organelle gene expression. Little is known about how RNA editing factors influence soybean plant development. Here, we report the isolation and characterization of a soybean yl (yellow leaf) mutant. The yl plants showed decreased chlorophyll accumulation, lower PS II activity, an impaired net photosynthesis rate, and an altered chloroplast ultrastructure. Fine mapping of YL uncovered a point mutation in Glyma.20G187000, which encodes a chloroplast-localized protein homologous to Arabidopsis thaliana (Arabidopsis) ORRM1. YL is mainly expressed in trifoliate leaves, and its deficiency affects the editing of multiple chloroplast RNA sites, leading to inferior photosynthesis in soybean. Taken together, these results demonstrate the importance of the soybean YL protein in chloroplast RNA editing and photosynthesis. [ABSTRACT FROM AUTHOR]