Soosan Barati, Mehdi Bassiri, Mohamadreza Vahabi, Mohamadreza Mosadeghi,
Volume 13, Issue 1 (5-2019)
Abstract
The effects of plant density and water stress on leaf water potential and soil water content of Medicago sativa and Bromus tomentellus were studied. A greenhouse experiment was conducted at the Isfahan University of Technology. The experiment included 18 treatments, three crop compositions (M.sativa, B. tomentellus or a mixture of the two), two plant density levels (2 and 4 plants), three watering regimes and four replicates, arranged in a completely randomized block design. Results showed that leaf water potential of M. sativa and B. tomentellus decreased significantly (p < 0.05) with increasing drought stress and plant density in all treatments. The leaf water potential values of the studied species were different. In mixed cropping, the leaf water potential of B. tomentellus was more negative than M. Sativa due to its drought resistant. Also, with increasing soil depth, soil water content decreased in mixed cropping compared to M. sativa mono-cropping and B. tomentellus mono-cropping. B. tomentellus with fibrous root system could only absorb surface soil water content but M. sativa with a well-developed taproot system could absorb a greater amount of soil water content of deep soil. Therefore, the two species functioned complementarily and increased the efficiency of the mixed cropping.
