Short-term effects of lime and phosphogypsum reapplication methods on wheat and maize nutrition.

Lime (L) and phosphogypsum (GY) are indispensable inputs in acidic soils that can alter the nutritional status of crops. The objective of this study was to evaluate the nutritional status and productivity of maize and wheat after the application of L and GY. The treatments consisted of a 2 x 4 + 3 factorial, with two forms of L application: surface (SL) and incorporated (IL) to obtain different levels of base saturation (BS%): 44, 60, 70 and 90; additionally three treatments involving the use of GY were evaluated: BS% 60 + 3.71 Mg ha−1; BS% 70 + 3.71 Mg ha−1 and BS% 70 + 7.42 Mg ha−1 of GY. The increase in BS% favored the absorption of magnesium (Mg) (SL and IL) and phosphorus (P) (IL) content in maize. IL increased the contents of nitrogen (N) and sulfur (S) and maize yield compared with SL. GY increased the maize yield by 7.6% compared with the control (BS 44%). Maize productivity correlated positively with calcium (Ca) (0.65), S (0.78) and N (0.54) leaf contents. In wheat, the increase in BS% reduced absorption of potassium (K) (SL and IL) and increased leaf Ca and Mg (IL) contents. Wheat yield correlated positively to leaf Ca (0.61) and S (0.62). Lime incorporation decreased wheat yield. High doses of GY (7.42 Mg ha−1) reduced absorption of Mg (maize and wheat) and K (maize). It is better to apply GY than to till the soil, thus maintaining uninterrupted no-till. [ABSTRACT FROM AUTHOR]