Use of 15N to study the N fixation, N transfer and yield of intercropped groundnut (A ra ch is h ypogaea L.) as affected by genotype and the root barrier

Abstract

l5N-aided intercropping studies of maize/groimdsiut (Experiment 1), and sorghum/groundnut (Experiment 2) with and without below-ground barriers were conducted. The results revealed that the groundnut variety X-14 was more competitive than Red Spanish and this competitive ability was much higher in association with maize. Root barriers improved the intercropped maize yield in association with X-14 while no root interaction affected on maize yield in association with Red Spanish. Seed and total biomass yield of sorghum in association with X-14 showed a similar trend but those of sorghum when associated with Red Spanish was not affected by intercropping in the presence of a root barrier. Intercropped groundnut derived a higher percentage of N2 (45-55%) from the atmosphere compared to the monocrops (18-35%) without respond to root barrier and groundnut genotype. lsN-aided studies revealed that part of the N2 fixed by intercropped groundnut has been transferred to the associated maize crop. N yield was higher in groundnut sole crop compared to that grown in association with both cereal crops.