Role of Oat-Clover Intercropping in Dry Matter of Fodder Yield and Soil Nitrogen Sustainability in Semi-Arid Area of Iraq

Abstract

A field trial was carried out including different Oat (Avena sativa L.): Clover (Trifolium alexandrinum L.) sowing ratios (100%:0%, 75%:25%, 50%:50%, 25%:75%, and 0%:100%). Parameters of dry matter (DM) of two cuts, land equivalent ratio (LER), aggressivety (A), and soil nitrogen sustainability (SNS), were calculated. Obtained results showed the sowing ratio of 25:75 superior in DM for the 1st cut, while 75:25 gave the highest DM at the 2nd cut. As for the total fodder yield of the two cuts, results presented solo-cropped oat with the highest score and the lowest appeared with the treatment of solo-cropped clover. The sowing ratio of 25:75 recorded the Highest LER was obtained at 25:75 ratio, on the other hand, the ratio of 75:25 gave the lowest LER, outperformed the total of the two cuts, the sowing ratio of 50:50 recorded the highest “A” significantly outperformed the sowing ratio of 75:25, which recorded the lowest. In general, it was found that oat had the advantage in the ability to compete compared to clover, where oat recorded positive values of A, while clover recorded negative values that differed significantly from 0 for all sowing ratios in both the two cuts and their sum. The conclusion from this study is that the cultivation of oat and clover intercropped with the mentioned sowing ratios was useful for land use and nitrogen sustainability, under the conditions in which the study was conducted.