Effects of deep vertical rotary tillage on the grain yield and resource use efficiency of winter wheat in the Huang-Huai-Hai Plain of China

Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_(N)),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_(N) and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_(N) and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.

Strip deep rotary tillage combined with controlled-release urea improves the grain yield and nitrogen use efficiency of maize in the North China Plain

Inappropriate tillage practices and nitrogen(N) management have become seriously limitations for maize(Zea mays L.) yield and N use efficiency(NUE) in the North China Plain(NCP). In the current study, we examined the effects of strip deep rotary tillage(ST) combined with controlled-release(CR) urea on maize yield and NUE, and determined the physiological factors involved in yield formation and N accumulation during a 2-year field experiment. Compared with conventional rotary tillage(RT) and no-tillage(NT), ST increased the soil water content and soil mineral N content(Nmin) in the 20–40 cm soil layer due to reduction by 10.5 and 13.7% in the soil bulk density in the 0–40 cm soil layer, respectively. Compared with the values obtained by common urea(CU) fertilization, CR increased the Nmin in the 0–40 cm soil layers by 12.4 and 10.3% at the silking and maturity stages, respectively. As a result, root length and total N accumulation were enhanced under ST and CR urea, which promoted greater leaf area and dry matter(particularly at post-silking), eventually increasing the1 000-kernel weight of maize. Thus, ST increased the maize yield by 8.3 and 11.0% compared with RT and NT, respectively, whereas CR urea increased maize yield by 8.9% above the values obtained under CU. Because of greater grain yield and N accumulation, ST combined with CR urea improved the NUE substantially. These results show that ST coupled with CR urea is an effective practice to further increase maize yield and NUE by improving soil properties and N supply, so it should be considered for sustainable maize production in the NCP(and other similar areas worldwide).

Computer aided engineering analysis and design optimization of rotary tillage tool components

The computer aided engineering analysis and design optimization of rotary tillage tool on the basis of finite element method and simulation method is done by using CAD-software for the structural analysis.The different tillage tool parts of rotary tillage tools are geometrically constructed as a solid model.The actual field performance rating parameters along with boundary conditions are set in the software for 35 hp and 45 hp tractor.The estimated forces acting on soil-tool interface are fed into software as a loading condition.The resultant effects of loading condition on tillage blade and whole rotavator assembly were obtained from stress distribution and deformations plots.The proposed working results in identifying sufficient tolerance in changing the dimensions of rotavator frame sections and side gear box for removing the excess weight in a solid section and also to raise the weight of blade for a reliable strength.The present working model with tillage blade is analysed to new design constraints with change of its geometry for the maximum weed removal efficiency by presenting its practical results from the field performance.

Design and experiment of spray and rotary tillage combined disinfection machine for soil

A spray and rotary tillage combined disinfection machine for soil was designed to solve the serious problems of plant diseases and insect pests,and it was divided into two operations which were soil disinfection and rotary tillage.The main structure and working principle of this machine were illustrated and analyzed.The reasonable structural parameters of the key parts of this machine were optimized,such as spraying disinfection system and rotary tillage land preparation system.To optimize the working performance and obtain better operation parameters,the orthogonal experiments were carried out to analyze the influences of three factors(forward speed of driving machine,rotational speed of rotary tillage,and working pressure)on the working performance.The mixing uniformity coefficient and the variation coefficient of spraying were selected for evaluating working performance.The range analysis and variance analysis were studied based on experimental data.The results showed that,the mixing uniformity coefficient of spraying was 93.95%and the variation coefficient was 6.01%with a working speed of 3 km/h,rotational speed of 2000 r/min and working pressure of 2.0 MPa.The machine can meet the agronomic requirements of disinfection and plowing,which was designed simply,compactly and strong applicability.The results can provide a guidance and technical support for preventing the plant diseases and insect pests,developing sustainable and ecological agriculture and improving the efficiency of compound cultivation.

Design and test of automatic detection platform for soil fragmentation rate in rotary tillage

As an important index of soil crushing performance of rotary tiller,the soil fragmentation rate is still limited to manual measurement.In this study,an automatic detection platform for soil fragmentation rate was designed,which integrated soil intake,screening,weighing and calculation of soil fragmentation rate.This platform can solve the problem that the index of the soil fragmentation rate cannot be detected quickly and effectively after rotary tillage,which leads to difficulty in field quality evaluation.The platform was mainly composed of a shovel soil module,conveying module,screening module,weighing module and automatic control system,which could realize single-line and multi-point automatic soil fragmentation rate detection.Based on the homogeneous dry slope model,the tilting angles of soil intake and soil feeding after rotary tillage on the platform were determined to be 30.10°and 26.67°,respectively.According to the principle of flow conservation,a rotary circulation screening module was designed to obtain soil particle size grading.A method based on the principle of multi-line and multi-point measurement was developed to detect soil fragmentation rate.The influence of screening speed on screening effect was analyzed,and the reasonable value of screening speed was determined to be 0.5 m/s.A field performance test was carried out in October 2019 to verify the detection performance of the platform.The results showed that,compared with the manual test method,the maximum test error was no more than 11%,the minimum test error was less than 4%,the maximum single test time was no more than 2 min,and the total test time of each test area was no more than 30 min.The efficiency of single-point detection was significantly better than the manual detection,which indicated that the design in this study met the requirements of rapid detection of soil fragmentation rate,and provided a new idea for the automatic detection of quality of rotary tillage.

Experimental Study on Water Saving of Large-scale Mechanized Paddy Field Production Process in Heilongjiang Province

In order to clarify the water-saving technologies and standards in large-scale mechanized production of paddy fields, the water-saving effects and cost-benefit situations of paddy field steeping, seedling transplanting and different land preparation methods were studied. The results showed that the suitable water layer height for the closing period of mechanized operation was 10 cm, which could save water, facilitate weed control, and lead to better effect and the highest yield. The treatment with a water layer height of 1 cm(Huadashui) for the seedling planting operation achieved better quality of seedling transplanting, lower vacancy rate and higher yield and was water-saving. From the perspective of saving water and taking into account the cost of land preparation, the method of steeping and beating the field was better than the method of plowing in autumn and rotary tillage and harrowing in spring, but it was very prone to lodging. From the perspective of high yield creation, the method of plowing in autumn and rotary tillage and harrowing in spring was significantly better than the method of steeping and beating the field. In order to reduce the cost of land preparation, it is recommended to change the way of plowing in autumn and rotary tillage and hallowing in spring to plowing in autumn and rotary tillage in spring or plowing and hallowing in spring to reduce the cost of one time of rotary tillage, and to simultaneously realize deeper plough layer, which is conducive to preventing lodging and obtaining high yield.

Optimization and experiment on key structural parameters of no-tillage planter with straw-smashing and strip-mulching

Accelerate the quality of smashed-straw laying and enhance the effect of seed-bed arranging for no-tillage planter with straw-smashing and strip-mulching in full stubble covered paddy have become imperative in implementing modern conservation tillage.Considering the perfect operating performance(passability and stability)of the developed no-tillageplanter,this study intends to optimize the structure design of smashed-straw diversion device and strip-rotary tillage device.Dynamics equations of smashed straw and kinematics models of rotary blades were established through theoretical analysis,and the principal factors that affecting straw strip-laying quality and seed-bed arranging effect were specified.The influence of out-enlarge angle(η)and slide-push angle(γ)of the diversion device on the coefficient of variation(ζ1)of cover-straw width,and the influence of rotary tillage-blade number(N)and configuration in a singlerotary plane on the broken rate(ζ2)of strip soil were completely analyzed.And then,based on the systematic analysis and integrated scheme,operating performance and field verification tests using the optimized no-tillage planter were thoroughly performed.The results of the performance tests indicated that the out-enlarge angle(η)had a highly significant influence on the coefficient of variation(ζ1),and the slide-push angle(γ)had a significant influence on(ζ1).The rotary tillage-blade number(N)had a highly significant influence on the broken rate(ζ2),and the slide-push angle(γ)had a significant influence on(ζ2).The obtained optimal combination of these key structure parameters through comprehensive analysis wasη=45°,γ=40°,and N=4.Field verification test results indicated that the optimized no-tillage planter achieved mean values of ζ1=10.47%and ζ2=90.95%,which satisfied the relevant operation quality and cultivation agricultural requirement of conservation tillage equipment,and provided technical references for developing the similar no-tillage planter of straw crushing and returning.

Design and experiment of anti-adhesion rototiller based on staggered double-roller scraping

In order to solve the serious problem of soil adhering blade roller in the middle and lower reaches of Yangtze River,the anti-adhesion rototiller based on staggered double-roller scraping(ARSDS)was designed by mechanical scraping methods.The volume equation for scraping the soil adhesion part with staggered rotary blades was constructed.The mechanical conditions for separation of soil adhesion part from blade roller were clarified,and the contact time between rotary blade and soil during rotary tillage was analyzed.By this way,the key parameters affecting soil adhering on and separating from the blade roller were determined,which were rotational speed,cutting pitch and tillage depth.The spatial and temporal trajectory changes for the sidelong section edge of staggered rotary blades were analyzed,so that the rotary blade arrangement was obtained.Combining the discrete element method,selecting the soil adhesion mass on the staggered blade rollers as the response value established prediction model by Box-Behnken design test.For example,taking the tillage depth of 14 cm for wheat cultivation in the middle and lower reaches of Yangtze River,the optimal combination of parameters was determined to be 230 r/min and 10 cm for rotational speed and cutting pitch,respectively.At this time,the soil adhesion mass was 4566.67 g.In the meantime,the process of soil particles adhering staggered blade rollers and rotary blades scraping off the adhering soil were clarified.Field experiments have shown that the operation quality of ARSDS met the requirements of rototiller performance indexes.In the rice stubble field of high water moisture,the soil adhesion mass was 13.455 kg and 38.215 kg for ARSDS and conventional rototiller,respectively,which indicated that ARSDS effectively reducing soil adhesion mass.The research results can provide technical support for the design of rototiller reducing soil adhesion in the agricultural areas of the middle and lower reaches of the Yangtze River.