Nutritional portfolio of maize and cowpea fodder under various intercropping ratio and balanced nitrogen fertilization

Abstract

Cereal–legume mixture may be a viable option to improve forage yield and quality. Furthermore, nitrogen requirement may also varying according to proportion of legume component. Therefore, the present study was carried out to evaluate the effect of different intercropping ratios and nitrogen levels on productivity and nutritional quality of fodder maize (Zea mays L.) and Cowpea (Vigna unguiculata L.). The experiment was laid out in split plot arrangement with three intercropping row ratios of maize: cowpea (1:1, 2:1 and 1:2, respectively) in main plot and five nitrogen levels (0, 30, 60, 90 and 120 kg N/ha) in sub plot. Highest total green fodder, protein and ash yield in 2:1 ratio whereas maximum ether yield was reported in 1:2 intercropping ratio of maize and cowpea. However, the maximum crude protein, ether extract, ash content and lowest NDF, ADF and ADL of maize and cowpea, respectively were obtained under 1:2 intercropping ratio of maize and cowpea. Among N levels, highest total green fodder, crude protein, ether and ash yield and as well as their content in green forage of maize and cowpea were recorded with the use of 120 kg N/ha. However, cowpea responded significantly upto 60 kg N/ha only. The lowest NDF, ADF and ADL of maize and cowpea were found when these crops fertilized with 120 Kg N/ha. A significant interaction between intercropping ratios and N levels was reported in terms of yield. Thus, it can be concluded that nitrogen rates 90, 120 and 60 kg/ha found suitable to achieve maximum fodder yield in 1:1, 2:1 and 1:2 (maize: cowpea) ratios, respectively.