Loss of soil from water erosion in the basin Chapala Lake, Michoacan, Mexico

Runoff plot measurements were used to quantify the loss of soil due to water erosion for the Chapala Lake basin, a portion of Michoacan, Mexico. A total of 18 runoff plots were installed which contained the main soil uses that are present in the region: pasture, irrigated crops, seasonal crops, oak forest, and sub-tropical brush. Monthly sampling was performed during the rainy period, from August to October 2012. Most of the loss in soil occurred on plots with seasonal farming, with 630.7 kg ha-1, followed by pastures with 87.9 kg ha-1, and to a lesser extent, oak forest with 3.9 kg ha-1. Taking all of the soil uses together, the total soil loss in the study area was 6593 t ha-1 year-1, and was greater in areas with seasonal crops, with 4019 t ha-1 year-1. Organic matter was a soil component with the greatest loss during the water erosion process, with values between 24.5 and 5.1 kg ha-1 for seasonal crops and pastures, respectively. The macronutrients measured in the sediment also were found to be correlated with the previous factor; the highest N, P, and K values recorded correspond to irrigation crops, with values of 0.9, 0.1 and 2.1 kg ha-1, respectively.