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.

Fertilization strategy and application model using a centrifugal variable-rate fertilizer spreader

With the sustainable development of precision agriculture and the steady progress of variable-rate fertilization technology,the centrifugal variable-rate fertilizer spreader has attracted research attention due to its lower incidence of crush damage,high efficiency,and low cost.To improve fertilization accuracy and uniformity,spreading performance tests were conducted using this spreader in accordance with the test methods specified in ISO 5690 and ASAE S341.2,in which particle mass was weighed in a two-dimensional matrix of collection boxes.The effects of fertilization strategies that control the feed gate flow rate and the disc rotation speed on particle distribution,and application rate per unit area and effective swath width,were investigated.A variable-rate fertilization model was developed by analyzing the variation characteristics resulting from an increasing and decreasing application rate,and field experiments were conducted to verify its accuracy.The results indicated that when the feed gate flow rate was 300 g/s,the mean application rate was 26.47 g,the standard deviation is 2.81,and the coefficient of variation of particle distribution is at its minimum value of 14.25%.When the disc rotation speed was 600 r/min,the fertilizer was most evenly distributed with a coefficient of variation of 13.86%,and an average effective spreader swath width of 24.51 m.The proposed variable-rate fertilization model showed a high fitting degree with an S-shaped function curve for both increasing and decreasing distribution rates and the yielding coefficients of determination were more than 0.82 and 0.71,respectively.The average error between the model predictions and the test results was 9.47%,and the coefficients of determination for the increasing and decreasing distribution rates were 0.91 and 0.82,respectively,which confirmed the accuracy of the proposed variable-rate fertilization model.This investigation provided a theoretical basis for traditional empirical fertilization using centrifugal variable-rate fertilizer spreaders,and guides the selection of a multiple trajectory,variable-rate fertilization strategy.

Response characteristics and efficiency of variable rate fertilization based on spectral reflectance

The key technical problem of variable rate fertilization system based on spectrum information was precise variable fertilization in certain area according to the acquired spectrum information.Hysteretic fertilizing is a critical problem in most of current fertilizer equipment.Hysteresis model was built and analyzed in this study to improve the system.Fertilizing tests were conducted on different wheat breeds and the results were analyzed.The tests showed that variable rate fertilization had obvious hysteresis phenomenon with the maximum lag distance of 3.82 m,the minimum lag distance of 1.73 m and average of 3.06 m.Hysteresis phenomenon of the variable rate fertilization system was obviously decreased when implanting a correction time of 2.04 s with the maximum lag distance of 0.61 m.Variable effects varied by different wheat breeds.Variable rate fertilization had an advantage of improving spatial differences of Yangmai-23,and the spatial variability of which decreased by 14.23%.In the small test area,the amount of fertilizer in Zhenmai-168 decreased by 2.84 kg,while the amount of which in Yangmai-23 increased by 3.83 kg.Yield of Zhenmai-168 in small area was lower than that in traditional pattern,but the condition of Yangmai-23 was on the contrary.Valuable information for increasing performance of fertilization in variable rate fertilization system was provided in this paper.