Evaluation of Wheat-Chickpea Intercrops as Influenced by Nitrogen and Weed Management

Abstract

Wheat and chickpea are most important crops in dryland farming areas of Iran. Weeds have major impact on chickpea grain yield. This experiment was carried out to increase land use efficiency and weed suppression through intercropping in dryland agricultural research station-Sararood, Kermanshah, Iran during 2008-10. The experimental design layout was factorial split plot based on randomized complete block design with three replications. The main plots contained factorial plots of N fertilization with 3 levels (N1: no fertilization, N2: 60 kg.ha^-1 urea for wheat and 20 kg.ha^-1 for chickpea and N3: Nitragin as a biofertilizer + 30 kg.ha^-1 urea for wheat and chickpea no urea); and weed conditions with 2 levels (weed infested and weed free). The third factor as sub-plots arranged in main plots was cropping patterns with 10 levels (1: wheat Sole Crop (wh.SC), 2: chickpea Sole Crop (ch.SC), 3: wh./ch. Mixed Intercropping (wh./ch.MIC) in 1:1 ratio, 4: wh./ch. MIC in 2:1 ratio, Row Intercropping (RIC) 1row wh.:1row ch., 6: Strip Intercropping (SIC) 5wh.1ch.5wh.2ch, 7: SIC 7wh.:2ch., 8: SIC 2wh.:7ch., 9: SIC 9wh.:4ch. and 10: SIC 4wh.:9ch.). Weed and nitrogen factors didn’t have significant effect on wheat yield and patterns number 5, 8 and 10 produced highest wheat grain yield respectively. Chickpea yield was significantly reduced by wheat when intercropped, but high Land Equivalent Ratio (LER) derived. Effect of weeds on chickpea Grain Yield (GY) was significant and GY in weed infested was nearly half of GY in weed free condition. LER in weed infested condition in both years was higher than weed free condition. Weed dry matter in five intercropping patterns clearly decreased as compare to chickpea sole crop. It is concluded that intercropping can be used as a method to decrease the inputs of wheat and chickpea crops, especially for nitrogen fertilizing and weed control.