Intercropping maize (Zea mays L.) and cow pea (Vigna unguiculata L.) as a whole-crop forage: Effects of planting ratio and harvest time on forage yield and quality

Sole crops and intercrops of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) at eight planting ratios of maize:cowpea (100: 100, 50:100, 100:50, 25:75, 75:25, 50:50, 0: 100 and 100:0) and two harvest times (milky stage and doughty stage) were evaluated for quality characteristics of dry matter digestibility (DMD), crude protein (CP), neutral-detergent fiber (NDF), acid-detergent fiber (ADF) and water-soluble carbohydrate (WSC) concentrations and ash content. This experiment was carried during over two years (2007 and 2008) on Research Center, University of Zabol, Iran. Results indicated that optimum forage quality from milky stage was obtained. Maize and cowpea intercrops were higher in total forage dry matter digestibility (DMD) than maize or cowpea grown as sole crops. Cowpea intercropped with maize led to increased forage quality (CP and DMD concentration) compared with sole-maize, and higher WSC concentrations compared with sole cowpea. The highest crude protein content was obtained by harvest time in milky stage (15.2%). It is suggested that maize-cowpea intercrops may have considerable potential as a high quality.