Abstract
An experiment was conducted in the field during the winter growing seasons of 2022 – 2023 and 2023 − 2024 in the western region of Iraq to investigate the effect of three tillage systems, including conventional tillage, reduced tillage and no-tillage, on oat (Avena sativa L.) berseem clover (Trifolium alexandrinum L.) intercropping with seed proportions of 100 : 0, 75 : 25, 50 : 50, 25 : 75, 0 : 100%. A factorial experiment using a randomised complete block design in a split-plot arrangement with three replications was employed. The results showed that conventional tillage recorded the highest dry matter yield, crude protein yield, dry matter digestibility yield, and the best land equivalent ratio for dry matter, with no significant difference from reduced tillage at the same time. Deterioration was observed when no-tillage was applied. The seed proportions of 75% oat to 25% berseem clover produced the highest dry matter yield, dry matter digestibility yield and land equivalent ratio. Seed proportions of 25% oat: and 75% berseem clover produced the greatest crude protein yield. Intercropping achieved land equivalent ratio higher than 1 at all tillage systems with all seed proportions according to the T-test. In conclusion, it is possible to reduce tillage instead of traditional tillage, as this does not cause a deterioration in the yield. Intercropping with all seed proportions had an advantage in exploiting land area.