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In order to rehabilitate the eroded pastures in semi-arid regions, to improve less fertile dryland, to increase the diversity and sustainability of agro-ecosystems, to prevent the wind and water erosion of soil, and produce suitable rainfed forage yield, a research study was conducted on the mixed cropping of agropyron and alfalfa grass. Positive interaction among these species not only may affect the quality and quantity of forage and the optimal use of environmental factors, can inhibit surface runoff by increasing organic matter content, and hence soil infiltration rate.

The current study was initiated in the experimental station of Tatar located in Arasbaran following mixed and row cropping of alfalfa and wheat-grass The experimental station is situated within the north latitude of 39 degrees1', and east longitude of 46 degrees 50'. The altitude of the station varies between 300 to 700 m with the annual precipitation ranging from 350 to 400 m.

The experiment was laid out under rainfed conditions as a randomized complete block design with the five treatments in four replications. Treatments included pure cultivation of alfalfa, a combination of 75% alfalfa and 25% agropyron, a combination of 50% alfalfa and 50% agropyron, a combination of 25% alfalfa and 75% agropyron, and pure cultivation of agropyron. The area of each plot was 10.5 m(2) (2.10 x 5 m), that by eliminating marginal rows, ultimate harvested area of each plot reduced 7 m2. The cultivation and harvesting date were October 28(th), 1995 and June 30(th), 1996 respectively.

Obtained results from analysis of variance revealed significant F values among treatments with p less than or equal to 0.05. Cultivation of pure agropyron produced the highest yield during the first year of experiment. The obtained yield from the treatment of (75% agropyron and 25% alfalfa) ranked second place after the treatment of pure agropyron. Rest of the treatments produced less yield as compared of 25% alfalfa and 75% agropyron. The higher yield of pure agropyron and mixed cropping at the first year of experiment as compared to the pure cultivation of alfalfa, might be related to the adaptability of agropyron to dry conditions and the further application of 50 kg ha(-1) of urea.