抄録
Saving irrigation water and increasing crop productivity are critical issues in Egypt. A field experiment of intercropping system was conducted with the purpose of minimizing evaporation from soil surface in the Nile Delta. Monoculture of maize, cowpea, soybean, intercropping of maize/cowpea, and maize/soybean were compared. In intercropping plots seeds of maize and leguminous crops were sown on the same ridge alternately by zigzag planting. Leaf area index (LAI) of canopies, SPAD value of maize leaves, biological yield and grain yield, water use efficiency (WUE), and land equivalent ratio (LER) were investigated. Establishment of cowpea plants was extremely poor which indicated that cowpea was not suitable to the highly compacted soil. Canopy of maize/soybean had higher LAI (3.2) than maize-mono (1.7), which is a positive indicator to minimize the evaporation. SPAD values of maize leaves increased by intercropping with leguminous crops. However, grain yield of maize and soybean decreased by 34 % and 48 %, respectively, when intercropped. Although the production of individual crop was reduced by intercropping, the system slightly improved the total land productivity (LER = 1.16). WUE of maize/soybean was similar to maize-mono, but higher than WUE of soybean-mono plot. Considering maize as a main crop, since intercropping with soybean covered soil with higher LAI and improved LER, the zigzag intercropping system has possibility to reduce evaporation and maintain the crop productivity especially for the small scale farmers in the Egyptian Nile Delta.
