ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 50 Number 3
Response of Digitaria setivalva to nitrogen, phosphorus, potassium, magnesium and calcium on Ebini sandy loam, Guyana. II–Effect on some chemical properties and nutrient status of the soil
The changes in some chemical properties and the nutrient status of Ebini sandy loam following the application of N, P, K, Mg and Ca to Digitaria setivalva were measured over a 12 month period. The annual rates of application were 332, 200 208, 28 and 1120 kg/ha of N, P, K, Mg and Ca respectively. pH in the 0 to 15 and 15 to 30 cm horizons was lowered by the application of N (ammonium sulphate) and increased by Ca (calcitic limestone). The effect of lime on pH was reduced in the presence of N. Ca2+ in the soil was increased by the application of lime and sometimes P (triple superphosphate), but decreased by the application of N. Truog-P in both horizons was increased by the application of P and decreased by the application of N. Phosphorus increased gradually over the experimental period. Exchangeable K+ was increased in both horizons by the application of K (potassium chloride). This increase was, however, relatively small compared to the amount of fertilizer K applied. K was decreased by the application of N, especially in the 15 to 30 cm horizon. No changes in total N in the soil were observed.