Variabilidade espacial dos atributos químicos em um cambissolo háplico ta eutrófico típico

Abstract

Innovative technologies, such as the expansion of no-till, integrated production systems, and crop biotechnology, are becoming increasingly important in our country, showing the importance of developing techniques that allow more efficient use of resources. That said, the spatial variability of chemical soil attributes was evaluated in an experimental area at the Federal Rural University of Pernambuco / Serra Talhada Academic Unit (UFRPE / UAST) in soil classified as Typical Cambisolo Háplico Ta Eutrófico Typico, to analyze the spatial behavior of the variables: Phosphorus (P), pH, Potassium (K), Sodium (Na), Aluminum (Al), Calcium (Ca), Magnesium (Mg), Organic Matter (MO), Potential Acidity (H + Al), Sum Bases (SB) and Cation Exchange Capacity (CTC) at pH 7.0. The data were collected in a sample grid divided into 4 plots containing 16 subplots each of 3.75x3m, resulting in 128 simple samples divided into depths from 0 to 10 cm and 10 to 20 cm. The data were analyzed using descriptive and geostatistical statistics using spatial dependence analysis and adjustment of semivariograms using the free software R version 3.5.1. Most of the evaluated attributes had an average coefficient of variation (CV) with the highest CV value found for variable K, 102.79 at the depth of 0-20, and the lowest value for pH, 3.58. Most of the attributes showed a pure nugget effect, which may be the result of measurement errors or because the spacing is greater than necessary to identify the spatial dependence, thus being adjusted to the linear model, among the variables that fit the models, the majority presented weak spatial dependence with the variable SB presenting better spatial dependence.