Storage and fractions of organic matter of an oxisol under coffee plantations with different plant spacings

Abstract

This study aimed to evaluate the effect of coffee planting spacing on soil carbon and nitrogen storage and on the contents and distribution of organic matter fractions (light and heavy) of a dystroferric Red Latosol (Oxisol). An experiment installed 11 years ago on an experimental farm of EPAMIG in Machado (Minas Gerais State, Brazil) was evaluated. The treatments consisted of the combination of four spacings between rows (2.0, 2.5, 3.0 and 3.5 m) with three spacings between plants (0.5, 0.75 and 1.0 m). As reference, soil samples were also colleted in a native forest area adjacent to the experiment. For the evaluation of organic carbon (OC), total nitrogen (TN) storage and density fractions of organic matter, soil samples were collected in-between rows (IR) and in the coffee canopy projection (CP). Organic C stocks and C-light fraction contents measured in-between coffee rows are equal to or higher than those verified in the coffee canopy projection. The coffee plant area and stand, and the distance between coffee trees and planting rows had no influence on the soil OC and TN stocks or the other analyzed fractions of soil organic matter.