Assessment of Soil Compaction Bulk Density Indices and Cone Index in Different Moistures and Depths for Application in Precise Tillage

Abstract: Soil compaction arising from excessive and improper use of tractors and agricultural equipments caused reduction of pores, water absorption, crop yield and increase in density, soil resistance and soil erosion. Soil compaction models are suitable instruments for predicting soil compaction due to agricultural activities. In order to define these models, local variations of parameters associated with soil compaction is required; therefore, measurement of these parameters is the developing approach. In this research, the compaction created on the surface of the soil due to passing of agricultural equipments was studied and its effect on wheat root growth and development was assessed. For this purpose, soil compaction indices including bulk density and cone index in different parts of the farm were determined for moisture contents of 8, 13, 18 and 23 % and for depths of 0-10, 10-20, 20-30 and 30-40cm. After zoning the changes, soil compaction maps were drawn to manage the farm’s tillage operation and compaction functions were developed for different depths and conditions of the soil. Data variance analysis indicated that in both plowed and unplowed soil. There is a significantly negative correlation between cone index and soil moisture; also, a significantly positive correlation between bulk density and soil moisture. The cone index exhibited a significant negative relationship with bulk density for both types of soil in depth of 0-30 cm; whereas, the same relationship was significantly positive for