%K Calcitic lime, Groundnut, Gypsum, Phosphorus, Sandy soil
%A W T Mupangwa
%A F Tagwira
%I Springer
%V 73
%L icrisat5992
%J Nutrient Cycling in Agroecosystems
%N 2-3
%P 161-169
%D 2005
%X Phosphorus and calcium are the major nutrients limiting groundnut production. The objectives were to determine (a) optimum application levels of P and Ca, and (b) compare the effectiveness of calcitic lime (40% Ca, 4.5% Mg) and gypsum (22% Ca, 17% S) as sources of Ca for groundnut grown on sandy soils. Field experiments were established in smallholder farming areas using four levels of P (0, 8.5, 17 and 34 kg ha-1) combined factorially with calcitic lime (0, 200, 400 and 800 kg ha-1) to give 16 treatments. Similar levels of P were combined factorially with gypsum (0, 100, 200 and 400 kg ha-1) to give sixteen treatments. Experiments were laid in a randomized complete block design with three replications. Phosphorus had a significant effect on groundnut yield at the majority of the experimental sites. Application of P at 8.5 kg ha-1 gave the optimum groundnut yield response. The optimum application rates for calcitic lime and gypsum were 200 and 100 kg ha-1. Gypsum and calcitic lime were not significantly different as sources of Ca for groundnut. Soil chemical properties were significantly improved following application of P and Ca sources
%T Groundnut yield response to single superphosphate, calcitic lime and gypsum on acid granitic sandy soil