@article{icrisat5992, title = {Groundnut yield response to single superphosphate, calcitic lime and gypsum on acid granitic sandy soil}, publisher = {Springer}, author = {W T Mupangwa and F Tagwira}, pages = {161--169}, year = {2005}, volume = {73}, journal = {Nutrient Cycling in Agroecosystems}, number = {2-3}, keywords = {Calcitic lime, Groundnut, Gypsum, Phosphorus, Sandy soil}, url = {http://oar.icrisat.org/5992/}, abstract = {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} }