EROSION, CROP PRODUCTIVITY AND PROFITABILITY OF TWO SOILS OF THE STATE OF OAXACA

Abstract

Few studies have been made in México on soil erosion effects on crop productivity and profitability, in order to develop management practices for land use sustainability. The objective of this study was to determine the effects of topsoil removal on corn (Zea mays L.) stover and grain yields, and net returns in two soils of the State of Oaxaca, one classified as Calcaric Faeozem and the other as Rendzic Leptosol. After removing 0, 5, 10, and 20 cm of topsoil, corn was planted under the conventional tillage system. Plant height, and grain and stover corn yields decreased 14, 40, and 30 %, respectively, with removal of 20 cm of Faeozem topsoil; whereas the corresponding figures for Leptosol soil were 78, 100, and 87 %. The annual rate of corn yield reduction estimates were 3.4, and 70.0 kg ha-1 year-1 at Faeozem, and Leptosol soils, respectively. The corresponding estimates for the annual rate of reduction of net returns were $ 3.10, and $ 61.00 (Mexican pesos) ha-1 year-1. Negative effects of erosion on crop productivity and profitability were in accordance with soil characteristics.