Abstract
A field experiment designed in a split plot with four replications was carried out at the Agriculture Research Station of King Abdulaziz University, Jeddah, Saudi Arabia to study the response of blue panic (Panicum antidotale L. cv. Australian-110) - alfalfa (Medicago sativa L. cv. Cuf 101 USA) forage production, quality and land and water use efficiencies to three irrigation water regimes and six intercropping mixing ratios. The main plots were 100, 80 and 60% of crop water requirement (WR). Under each water regime six intercropping ratios: IC1 (1 row alfalfa: 1 row blue panic), IC2 (2 alfalfa: 1 blue panic), IC3 (3 alfalfa: 1 blue panic), IC4 (4 alfalfa: 2 blue panic), IC5 (alfalfa sole crop) and IC6 (blue panic sole crop) were investigated. Results revealed that difference in fresh and dry forage yields between the 100% WR and 80% WR treatments were minimal in all cuts. The IC5 produced the least forage yield while IC6 produced the highest compared to all treatments. The IC1 produced the highest forage yield compared with IC2, IC3 and IC4. Irrigation water use efficiency of 80% WR was higher than in 100% WR but fewer than in 60% WR. The highest land equivalent ratio was obtained from IC1. Intercropping ratios increased protein content in forage compared to blue panic sole plantation. Applying 80% WR reduced dry matter yield by 10% while saving 20% of irrigation water. Applying 60% WR reduced dry matter yield by 20.7% while saving 40% of irrigation water.