Response of Digitaria setivalva to nitrogen, phosphorus, potassium, magnesium and calcium on Ebini sandy loam, Guyana
1970
Chesney, H.A.D. (Ministry of Nat'l Dev. and Agric. (Guyana). Res. Div.)
Soil samples were taken from each plot before first fertilization, and then at 2, 4, 8 and 12 weeks after this and subsequent fertilizer applications. Chemical analysis was done on the samples. Ca and N at all sampling intervals and the NCa interaction at some intervals significantly affected the soil pH; N and Ca constantly had significant effects on the KCI acid content of the soil at both depths (0-15, 15-30 cm). Application of Ca reduced the KCI acid content in both soil horizons available Ca++ (0-15 cm) was significantly increased by the application of limestone and decreased in the presence of N. In the lower horizon, Ca++ concentration was generally lower but was increased by application of Ca and decreased at a few intervals by the application of N. Available P (0-15 cm) was significantly increased at all sampling intervals by application of p. In the lower horizon only P affected the available -P concentration. Applied K significantly influencd soil K+ at all sampling intervals, increasing after each application but decreasing with time. In the lower horizon it was decreased by the application of N
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