Effect of Low Rates of Nitrogen and Phophorus Fertilizers on Growth and Yield of Intercropped Pigeonpea with Sorghum in Makurdi, Nigeria

Abstract

Nitrogen (N) and phosphorus (P) are the most limiting nutrient elements in the soils of the tropics.  A field experiment was conducted at the Teaching and Research Farm of the University of Agriculture, Makurdi during the 2013 and 2014 cropping seasons to determine the influence of low rates of nitrogen and phosphorus fertilizers on the performance of pigeonpea intercropped with sorghum. The treatments comprised of two cropping systems (sole and intercropped pigeonpea with sorghum) in factorial combination with two nitrogen rates (10, 15 kg/ha), two phosphorus rates (20, 30 kg/ha) and N + P (N10P20, N10P30, N15P20, N15P30) and the check (N0P0) laid out in Randomized Block Design. The treatments were replicated three times. Results indicated that intercropping decreased pigeonpea nodule number and root weight at 50%flowering, dry pod and grain weights at harvest. The combinations of N and P fertilizers produced significantly higher nodule number, root weights, dry pod and grain weights of pigeonpea than either N or P alone in both cropping systems.  N10P30 produced significantly higher dry grain yield of pigeonpea than all other treatments, except N15P20 and N15P30. Sorghum grain yield was highest at N15. These results showed that low rates of N and P has potential for the production of intercropped pigeonpea with sorghum. The significant interaction between cropping systems and fertilizer indicated further research needs for intercropping systems as distinct from monoculture.

Key words: nitrogen, phosphorus, pigeonpea, sorghum, intercrop