Gypsum and potassium effect on corn yield and exchangeable bases to an acid soil in la Frailesca, Chiapas

Abstract

Objective: To evaluate the residual effect of gypsum in corn crops 2 years after application, in a previously limed soil, as well as the result of a new addition of gypsum combined with potassium in La Frailesca, Chiapas.

Design/methodology/approach: Composite factorial: initial arrangement (2017) with four levels of gypsum (0, 1.25, 2.5 and 5 t ha^-1) and four levels of potassium (0, 60, 120 and 180 kg K₂O ha^-1). In 2019, the plots treated with gypsum were divided into two, adding the same amount of gypsum applied in 2017 to half of each of them, and leaving the other half to evaluate the residual effect to the initial treatment. The potassium doses were the same as the original ones. Corn kernel yield, pH, exchangeable bases, and percentage of aluminium saturation were measured at depths of 0 to 7 and 7 to 14 cm from groun level.

Results: The greatest effect on yield was obtained with 2.5 t ha-1 of gypsum applied in 2017 without significant increases with higher gypsum doses. The exchangeable calcium content and pH increased, but the magnesium, potassium and aluminum in the soil decreased.

Limitations on study/implications: The assumed of Asphalt Stain Complex was diagnosed.

Findings/conclusions: The authors point out the need to be careful when recommending gypsum as an amendment; an excessive application generates an imbalance in the exchangeable potassium and magnesium of the soil, so the incorporation of these should be considered in the fertilization plan.