Variabilidade Espacial E Correlação Dos Atributos Do Solo Com Produtividade Do Milho E Da Soja

Abstract

O emprego de técnicas de agricultura de precisão, associadas a análises geoestatísticas, possibilita mapear a variabilidade espacial existente em um campo de produção. O conhecimento da variabilidade é importante ferramenta na tomada de decisões quanto ao manejo da área, uma vez que possibilita que este seja realizado de forma localizada. O estudo foi realizado em um talhão da Fazenda Planalto, localizada no município de Maracaju – MS, com o objetivo de avaliar a variabilidade espacial e correlação entre os atributos químicos e granulométricos do solo e a produtividade do milho e da soja. Foi utilizada uma grade amostral contendo 187 pontos, utilizando-se 10 amostras simples de solo por ponto amostral. Não foi detectado dependência espacial para o cálcio, alumínio, acidez potencial, soma de bases, ferro e zinco. As melhores estimativas em locais não amostrados foram obtidos para a areia e argila. A produtividade da soja apresentou forte dependência espacial e se correlacionou positivamente de forma forte com o fósforo e moderada com o magnésio. Palavras-chave: Latossolo; dependência espacial; Glycine max; Zea mays. Spatial variability and correlation of chemicals and physical soil attributes with corn and soybean yield ABSTRACT: The use of precision farming techniques, associated with geostatistical analysis, makes it possible to map the spatial variability in a production field. The knowledge of variability is an important tool in decision making regarding the management of the area, since it allows it to be carried out in a localized manner. The study was carried out in a plot of Fazenda Planalto, located in the municipality of Maracaju - MS, with the objective of evaluating the spatial variability and correlation between the chemical and granulometric attributes of the soil and the corn and soybeans yield. A sampling grid containing 187 points was used, using 10 simple soil samples per sample point. No spatial dependence was detected for calcium, aluminum, potential acidity, sum of bases, iron and zinc. The best estimates in unsampled locations were obtained for sand and clay. The soybeans yield showed strong spatial dependence and was positively correlated strongly with phosphorus and moderately with magnesium. Keywords: Oxisol; spatial dependence; Glycine max; Zea mays.

Sampling density to detect spatial dependence of potassium, calcium and magnesium in sandy soils

“…Several studies on spatial variability mapping of soil chemical attributes with emphasis on potassium, calcium, and magnesium carried out with different types of soils, crops, and sampling densities presented CV values ranging from moderate to very high, corroborating the results of this study (CARVALHO et al, 2018;FIGUEIREDO et al, 2018;LIMA et al, 2018;NOETZOLD et al, 2018;MATIAS et al, 2019;LEANDRO JUNIOR et al, 2020;GELAIN et al, 2020;GELAIN et al, 2021;SANTOS et al, 2021, SANTOS JUNIOR et al, 2021CORRÊA et al, 2022).…”

Efficiency and quality of soil sampling according to a sampling tool

“…The clay content data showed classical homogeneity, given by the coefficient of variation. Low CV values for clay content are commonly observed in the literature (Feitosa et al, 2019;Gelain et al, 2021) and are intrinsically linked to the source material of soil formation (AbdelRahman et al, 2021).…”

“…The lowest coefficients of variation (CV%) were observed for pH and CEC, indicating that these variables were the most homogeneous in the soil. Low CV values for pH are commonly found in soils (Oliveira et al, 2020;AbdelRahman et al, 2021;Gelain et al, 2021). The homogeneity of the pH is related to the subtle slope of the area and the parent material from which the soil is formed (AbdelRahman et al, 2021).…”

“…The results for P, K, and S showed coefficients of variation (CV%) greater than 20%. Evaluating different sampling arrangements, Gelain et al (2021) observed that the increase in the dispersion of P and K is due to the successive application of fertilizers in the sowing furrow. This causes large variations in nutrient content over short distances, especially in the case of P, which is not very mobile in soil.…”

Variabilidade espacial dos componentes produtivos da cultura da soja

“…O efeito pepita puro ocorre quando a distribuição da variável na área é aleatória, ou quando distância mínima entre os pontos amostrais é superior à distância da dependência espacial. Dependendo do arranjo amostral, ocorre mudança dos modelos teóricos ajustados, demonstrando que há grande influência do arranjo amostral na análise geoestatística dos dados (Gelain, Bottega, Motomiya, Oliveira, 2021).…”