Productivity and quality of intercropped maize (Zea mays L.) + cowpea [Vigna unguiculata (L.) Walp.] fodder as influenced by nitrogen and phosphorus levels

Cereals grown in association with legume crops may utilize some nitrogen fixed by legumes, resulting in enhanced forage yield and quality. To work out precise requirement of N and P in fodder maize and cowpea intercropping, a field experiment was laid out during summer seasons of 2008 and 2009 in randomized block design with eight treatments consisting of different nitrogen and phosphorus combinations. Results indicated that maximum plant height, stem girth, leaves/plant, fresh weight/plant, total green fodder (412.7 q/ha) and dry matter yield (111.5 q/ha) of maize + cowpea were recorded with 67.5 kg N + 60 kg P2O5/ha which was significantly better than all combinations of half RDF maize or RDF cowpea but was at par with 90 kg N + 30 kg P2O5/ha (RDF maize), 67.5 kg N + 30 kg P2O5/ha and 67.5 kg N + 45 kg P2O5/ha. The highest crude protein content and IVDMD of maize (8.8% and 62%), cowpea (18.7% and 66.2%) was also observed with 67.5 kg N + 60 kg P2O5/ha. Maximum crude protein yield of maize and cowpea was recorded with 67.5 kg N + 60 kg P2O5/ha. The study indicates that higher yield of quality maize and cowpea fodder in mixture can be realized with 67.5 kg N + 30 kg P2O5/ha.