Effect of tillage treatments and different amounts of crop residues on rainfed chickpea yield in Kermanshah Conditions

Abstract
Conservation agriculture reduces soil erosion and increases long-term yield by increasing organic matter. Experimental was conducted in order to evaluate the tillage system (T) and crop straw rates (S) effects on seed yield of chickpea Adel cultivar under rainfed conditions in the wheat-chickpea rotation. This experiment was conducted in a split plot based on a randomized complete block design with three replications in three cropping seasons 2017-20 in the dryland agricultural research sub-institute. The tillage system was in the main plots including conventional tillage (CT) (moldboard plow + disk harrow), minimum tillage (MT) (chisel + disk) and no-tillage (NT) (direct drilling), and crop straw rates were in sub-plots including no-straw (S1), 30-50 (S2) and 50-70% (S3) straw. Results revealed that the main effect of T was significant for the grain yield (P<0.05). The highest grain yield (1034 kg. ha-1) was obtained from MT which indicated an increase of 10 and 24% compared to CT (936.7 kg ha-1) and NT (833.7kg ha-1), respectively. The effect of S was significant for plant height (P<0.01), and grain yield, straw yield and biological yield (P<0.05). The highest grain yield was obtained from S1 with 990.6 kg ha-1, which was not significantly different from S2 with 953 kg ha-1. The highest grain yield and biological yield were obtained from MT × S2 with 1136 and 2433 kg ha-1, respectively. Therefore minimum tillage with 30-50% crop residues in the field could be used to improve yield productivity and stability of chickpea under rainfed conditions.