QUANTIFYING SOIL TILTH FOR WHEAT AND Faba bean CROPS USING TILTH INDEX

Abstract

One of the factors critical to seed germination and plant development is good tilth. This study was conducted to calculate the tilth index (T1) under different tillage practices and two crops, wheat and faba bean in order to determine the optimum tilth index value for maximum yield of wheat and faba bean crops. Tillage practices applied were traditional tillage by different chisel ploughing passes {two (P2), four (P4), six (P6) and eight passes (P8)} and moldboard plough (Pm). Tilth index was calculated following the model suggested by . Five soil physical properties, soil bulk density, cone index, aggregate uniformity coefficient organic matter content, and plasticity index were determined for each tillage system to quantify (T1) according to the model. The calculated values of the tilth index were varied with tillage practices. The tilth index increased as ploughing passes increased. Tilth index increased from 0.52 to 0.67 under (P2) and (P8), respectively. However, the highest value was obtained with the moldboard plough (0.71).Yield of wheat and Faba bean also varied according to the tillage practices and to the (TI) values. The highest yield of wheat was obtained with (Pm) treatment which corresponds to (TI) value of 0.71, while Faba bean yield increased with (P6) treatment which corresponds to (TI) value of 0.59.It is concluded that the tilth index can be used to describe the physical conditions of the soil and as an indicator for the most effective tillage practices that achieve the maximum yield for a certain crop.