The Growth and Yield Performance of Groundnut (arachis Hypogea )cultivated Under Various Fertilizer Inputs on an Alfisols in the Southern Guinea Savanna Zone of Nigeria

The response of groundnut variety SAMNUT22 to various fertilizer inputs was examined on a field experiment at the Teaching and Research Farm of the Federal University of Technology, Minna during the 2010 cropping season. A total land area of 0.06 ha was cleared, harrowed, ploughed and ridged. Thirty plots of size 4 x 3.5m were marked out at plot spacing of 1m and replicate spacing of 2m. Soil samples were taken randomly from 20 points at a soil depth of 0-20cm with the aid of an auger. Samples taken were bulked to form a composite, air-dried and screened through a 2mm sieve to remove contaminants. Physicochemical properties of sub- samples were determined using the methods described by IITA, 1979. Seeds of Groundnut variety, SAMNUT22 were planted on the 24th of July, 2010 at an inter and intra row spacing of 75cm x 25cm and at the rate of 3 seeds per stand. Seedlings were later thinned to two seedlings per stand at 2 weeks after planting (WAP), prior to fertilizer treatments. There were five fertilizer treatments as follows: SSP at 30 kg P ha-1, Rock phosphate at 30 kg P ha-1, SSP + Urea at 30 kg P ha-1 and 20 kg N ha-1 respectively; SSP + Agrolyzer at 30 kg P ha-1 and 900g ha-1 respectively and the zero fertilizer treatment. All the treatments were arranged in a Randomized Complete Block Design replicated 3 times. Tissue sampling was done destructively within the two inner ridges when the plants were at mid flowering while harvesting was done at physiological maturity. Data collected were statistically analyzed and results revealed that apart from shoot biomass, nodule No, % P in leaf and seed, fertilizer treatments affected growth, nodulation and yield parameters of SAMNUT22 significantly at P<0.05. Plots without fertilizer treatments were not the poorest in response: they recorded the best nodule weight and number and the second-best yield. Plants that were supplied with Rock phosphate gave a significant improvement in leaf number, nodule weight and yield compared with those receiving SSP alone. The inclusion of SSP to Urea significantly improved plant height and leaf number than when plants received zero fertilizer application and SSP alone.