Soil Loss Mitigation by Applying Animal Waste Slurry

Abstract

The application of excreta wastes is beneficial for soil conservation, especially in degraded soils and soils being susceptible to erosion. In this study animal dung was used as a resource for protecting soils against erosion. The objective of this study is to measure the effectivity of animal waste slurry for mitigating soil loss in leptosol from Mixteca Region, Mexico. For this purpose, a splash erosion model and a surface runoff model were used. Splash erosion model consisted in stainless steel cores of 1.0 cm long with inside diameter at 1.1 cm. Soil was placed inside at a dry density of 1.0±0.1 g/cm³. Fifty drops of artificial rain were dripped into the soil inside the core and soil loss was measured. On the other hand, surface runoff model consisted of a plot of 91 cm x 3.15 cm x 1.4 cm, with a triangular section. Soil was filled in with the same dry density of raindrop model and 1.2 cm³/s of deionized water was supplied during one hour on a 12 degrees’ slope. Discharge was collected every ten minutes and soil loss was measured. As treatment for both models, animal waste slurry was used. Horse dung was collected in the Horsemanship Club of Tokyo University of Agriculture and passed through a sieve at 212 μm in order to obtain slurry. 2 treatments were set up: the first was cattle slurry incorporated with soil and the second was crust formed with animal waste slurry; and control. Soil losses were compared among these 2 treatments. Raindrop experiment results showed that the addition of slurry decreased significantly soil loss rate from 6.4% to 1.3% in slurry incorporated cores and 0.2% in formed bio-crust cores. The same tendency was observed in the slope model experiment, where the application of slurry reduced significantly the soil losses from 558.6 g/m² to around 60 g/m² in both plots where slurry was added. Therefore, it can be concluded that the application of animal waste slurry was effective to reduce significantly soil losses by protecting the soil against kinetic energy of raindrops, as well as against shearing force of runoff on a 12 degrees’ slope in leptosol soil of Mixteca Region.