Effect of Intercropping on Nitrogen Fixation of Three Groundnut (Arachis hypogaea L) Genotypes in the Guinea Savanna Zone of Ghana

Abstract

An experiment was conducted on the research farm of the Savanna Agricultural Research Institute (SARI), Nyankpala, in the Guinea savanna agro-ecology to study the nitrogen fixation performance of three groundnut genotypes (Jenkaar, Kpanieli and Nkosuor) intercropped with maize (Obatanpa variety). The experiment was laid out in randomized complete block design with four replications. Treatments evaluated were sole groundnut, sole maize, single-row groundnut intercropped with single-row maize (G1M1), double row groundnut intercropped with single-row maize (G2M1), single-row groundnut intercropped with double-row maize (G1M2) and double-row groundnut intercropped with double-row maize (G2M2). Data collected included canopy width, number of branches plant-1, above ground dry matter, residue and seed N, stover yield and stover N             (kg N ha-1). The results showed that with the exception of Kpanieli, intercropping significantly (P<0.05) reduced the growth parameters and nitrogen fixation of the groundnut genotypes. Row patterns that allowed more space and light penetration significantly (P<0.05) improved nitrogen fixation. Even though all three groundnut genotypes performed within the reported levels with regard to nitrogen fixation, the Kpanieli genotype intercropped with maize using the double row groundnut-single row maize (G2M1) pattern was more beneficial.