Design And Experiment Of Earthworm-like Multi-function Opener

Insufficient soil moisture content and accumulated temperature of the plow layer during springtime tillage in Northeast China severely restrict soybean root growth and soybean development.Conservation tillage technology is widely used because it can improve soil water storage capacity and promote crop growth.However,the adoption of conservation tillage techniques has resulted in lower soil temperature in the plow layer during springtime tillage,which has affected the growth and development of crops.Therefore,it is important to improve the soil moisture content during springtime tillage while taking into account the increase of soil temperature.As the core components of sowing operation operation,the furrow device has important research significance by directly affecting the physical properties of the seedbed soil and affecting the temperature and moisture content of the seedbed soil.At the same time,the furrow device is installed on the seeding unit and adopts the passive action profile.However,when the surface of operation conditions is undulating,and the soil solidity varies greatly everywhere,It is difficult to ensure the pressure and the depth of furrow remains stable.Therefore,it is necessary to study the furrow device which is suitable for shaping the soil structure of the high-quality seedbed in the no-tillage sowing operation condition while ensuring the pressure of the seed furrow and the opening depth remains stable.The design of the opening equipment—earthworm-like multi-function opener is divided into two parts: the design of the earthworm-like multi-function opener structure and the automatic pressure regulation system.The structure of the earthworm-like multi-function opener can simulate the change of the surface morphological characteristics of the earthworm in the soil,and loose surface soil of cultivated layer to speed up the exchange of heat between the soil and the outside world to increase the temperature of the soil.At the same time,it has a certain ability of profiling.The automatic pressure regulation system can compact subsoil of seed ditch,shape the soil structure with less macroporosity and suitable compaction to enhance the capillary water conductivity of the furrow soil and the improvement of the soil moisture content.This system can be adjusted in real time according to the different surface conditions of the operation to ensure the stability of the compaction.Through the feasibility study of the opener,parameter optimization experiments and regression analysis methods were adopted.Analyses showed that operating speed,scarification mechanism bump height and number of crests of corrugated disk had a significant effect(P<0.01)on average soil moisture content(0-100 mm),average soil temperature(0-100 mm)and average emergence time.The variance analysis of the test results showed that the order of influence of various factors on the average soil moisture content(0~100mm)was as follows: the number of crests,the bump height,the operating speed.The influence of various factors on the significance of the average moisture content of soil(0~100mm)was as follows: the number of crests,the operating speed,the bump height.The influence of various factors on the saliency of the average emergence time was as follows: the bump height,the number of crests,and the operating speed.Earliest average emergence time was taken as main optimization index to obtain the optimal parameters by using MATLAB software based on the analysis of the test results and the model fitting.It was found that the optimal parameters of earthworm-like multi-function opener were as follows: operating speed of 8 km/h,bump height of 6 mm and number of crests of 15.The automatic pressure regulation system is mainly composed of the pressure regulation mechanism,the pressure automatic adjustment system hardware and the pressure automatic adjustment system software.Through the pressure calibration test,the mathematical relationship model between the pressure and the output signal data of the linear displacement sensor is determined.Through the soil trough test,it is found that the automatic pressure regulation system has achieved remarkable results under the preset three kinds of suppression strengths,and can adjust the pressure effectively in real time according to different working surface conditions to ensure the stability of the compaction.Based on theoretical analysis and soil trough test,field comprehensive experiments were carried out.The test results show that compared with the V-type double disc opener,earthworm-like multi-function opener could increase average soil moisture content(0-100 mm)by 2.7%,raise average soil temperature(0-100 mm)by 0.7℃,and advance soybean emergence time by 0.77 d,respectively.Under the three compressive strengths of 1500 N,1600N and 1700 N,the soil moisture content is most effective when the applied pressure is 1600 N.After opening the pressure automatic adjustment system,the opener can adjust the pressure in real time according to the change of soil firmness and the fluctuation of the surface,and the adjustment effect is remarkable.In addition,it can always maintain a high stability to the suppression of the seed trench in the process of operation.