Soil Organic Matter and Grain Yield of Rainfed Maize in Luvisols of Campeche, México

Abstract

The organic matter is an important soil component, due its favorable effects on soil physical and chemical properties and, by consequence, on crop yields. So, the objective of this work was quantify the changes through the time of soil organic matter in rainfed maize ( Zea mays L.) system, in a period of 30 years of continuous crop and in relation to system of natural vegetation system, and also the effects of these changes on the crop yield, in Luvisols soils of State of Campeche, México. In production cycle of 2004, 53 farmer plots in rainfed maize system of different land use time and five sites of forest natural vegetation system were sampled for soil, to quantify physical and chemical properties of soil, and it was taken data about climate, system management and crop yield. The data were analiced by regression analysis, considered the organic matter as function of land use time and factors of soil and management of system, and the crop yield as function of soil organic matter and factors of soil, climate and management of system. The soil organic matter diminished from 5.68% in forest natural vegetation system to 3.59% after 16 - 30 years of cultivation, and the soil annual incorporation of vegetative mulch (weeds and stubble of maize) increased the organic matter from 0.14% after 1 - 5 years to 0.46% after 16 - 30 years of cultivation. Without fertilization, the diminution of soil organic matter caused 907 kg ⋅ ha − 1 less of maize yield, and the fertilization with 200 kg ⋅ ha − 1 of diamonic phosphate (36 kg ⋅ N ⋅ ha − 1 and 92 kg P2O5 ha − 1 ) increased the maize yield 1224 kg ⋅ ha − 1 after 1 - 5 years and 1421 kg ⋅ ha − 1 after 16 - 30 years of cultivation, but not compensed less maize yield of 711 kg ⋅ ha − 1 due the diminution of soil organic matter.