Maize yield response as affected by phosphorus, sulfur and nitrogen as banded applications on a volcanic ash derived tropical soil

Abstract Phosphorus and sulfur deficiencies have been observed on many of the volcanic ash derived soils in Central America. One exploratory experiment was initiated in 1987 to examine maize (Zea mays L.) grain yield response to phosphorus, sulfur and nitrogen applied together on a volcanic ash derived soil in the Pacific coastal plain of Guatemala. Four cycles of yield data were collected in 2 rainy and 2 dry seasons. Treatments consisted of rate combinations of N (0, 100 kg ha‐1 as urea), P (0, 22 kg ha‐1 as triple superphosphate) and S (0, 57 and 114 kg ha‐1 as CaSO4.2H2O) applied together in continuous bands in a randomized complete block design. Residual P and S response was measured during the last two cycles, whereby only urea was applied at a constant rate to all plots. The combined analysis of the first two cycles demonstrated a linear response of yield to applied S when no P was applied (4.95, 5.75 and 5.95 Mg ha‐1 at 0, 57 and 114 kg S ha‐1 respectively), while yield response was quadratic when...