Experimental Study On Rice Straw Stubble Burying Device In Saline-Alkali Land

The saline-alkali land in the Songnen Plain of Northeast China is one of the three major saline-alkali areas in the world.It is characterized by’dry hard,wet sticky’,resulting in low utilization of soil resources.Planting rice in saline-alkali land is an effective measure to control and improve soda saline-alkali land.The reuse of straw returning to the field is of great significance to the ecological restoration of saline-alkali land.In view of the low efficiency of the mechanized rice straw returning device,a new type of agricultural machinery is developed to solve the problem of straw wrapping in the rice straw returning operation parts in soda saline-alkali land,so as to realize the improvement of saline-alkali soil and greatly improve the production efficiency.In this paper,a pressure burying device for rice straw stubble in saline-alkali soil is designed.The device is passive and consists of a grass pressing roller with a damper and a stubble returning roller.The key components of the burying device were optimized by reasonable design to improve the burying rate of straw and stubble.The main research contents and conclusions are as follows:1.The research and analysis of rice straw returning technology and the study of soil physical properties,physical properties of rice straw and mechanical properties of straw in saline-alkali soil.The physical properties of soil in saline-alkali land were measured.The soil bulk density of the test field was 1.18g/cm~3,the soil moisture content was 27.85%,the soil porosity was 48.73%,and the soil p H value was 9.1.The physical and mechanical properties of straw in the experimental field were studied.The stubble height of rice straw was 398mm,the average plant spacing was 17.24mm,the straw density was 396.8plants/m~2,the surface straw amount was 750.52g/m~2,the straw moisture content was 58.04%,and the cutting force per unit diameter of rice straw after soaking was 35.7N/mm.2.The design and manufacture of rice straw stubble burying device in saline-alkali land.The design parameters of the device and the key components were determined and the three-dimensional solid modeling of the device was completed by Solidworks software.The ANSYS Workbench static finite element simulation software was used to analyze the straw cutter of the frame and the straw roller,which provided the necessary reference for the development of the device.3.Field experiment and analysis.The diameter of the circular slurry returning hole,the slip rate and the number of grass-pressing horizontal knives were selected as the test factors for the three-factor and three-level test.The optimal operating conditions were analyzed by Design-expert software:the diameter of the slurry returning hole was 65mm,the slip rate was 18%,and the number of grass-pressing horizontal knives was 10.The relevant performance indicators of the device were tested and verified.The test results were as follows:the straw burying rate was 95.47%,the stubble burying rate was 94.89%,the burying depth was 16.08cm,the burying stability was 94.68%,the surface leveling was 2.14cm,and the slurry solubility was 84.03%.The test device can complete the multi-process of straw stubble burying and pulping at one time,realize the effect of rice straw burying and salt resistance,improve the burying rate of straw and stubble,realize the combination of saline-alkali land measures and rice straw reuse technology,and improve the efficiency of mechanized straw returning to field.