Análise espacial e temporal da erosão laminar pelo método dos pinos

Abstract

A low cost and easy application method to quantify how much soil has been lost due to water erosion is erosion pegs, which are used to evaluate soil surface changes and to estimate soil losses. The objective of this study was to estimate soil losses by means of erosion pins arranged in an irregular mesh.Sample units of 13 meters by 8 meters in an area of Haplic Cambisol, belonging to the Experimental Field Risoleta Neves, Agricultural Research Company of Minas Gerais (Epamig), São João Del-Rei (MG) were submitted to three different managements: bare soil (US), sugarcane (SC), and naturalized pasture (NP). Data were collected during 30 weeks with the aid of geostatistics in order to verify the occurrence of spatial and temporal phenomena associated with soil surface height. Kriging estimate values were used for non-sampled units. For this, with the help of GeoR software, semivariograms were constructed in each period of data collection. Thus, there was absence of spatial dependence by means of the Pure Nugget Effect model at some dates for all types of coverings. There were variations in the nugget effect as well as in the extent and level on different dates. The values of soil losses of the treatments with missing and reconstituted data were similar to each other and were close to the values of losses found in the literature for Haplic Cambisol and above tolerance limits for the state of Minas Gerais.