Spatial distribution of soil attributes and macronutrients in banana leaves under the application of limestone

ABSTRACT The aim of the present study was to evaluate the spatial variability of the chemical attributes of the soil and macronutrients in leaves by means of the geostatistic analysis of a soil cultivated with banana in an area with two different methods of applying corrective. The study was carried out in the district of Cristino Castro, Piauí, where 21 soil samples were collected at a depth of 0.00-0.20 m from an area of incorporated limestone, and 21 samples from an area without limestone on the surface, giving a total of 42 duly georeferenced points. The following were analysed in the soil samples: pH, OM, P, K+, Ca2+, Mg2+, Al3+, H +Al; and the sum of bases, cation exchange capacity and base saturation were calculated. The Ca2+, Mg2+, K+ and P content was determined in leaves collected from the same locations as the soil. The results were investigated using analysis of variance, descriptive analysis and geostatistics, and by interpretating the levels of the chemical attributes of the soil and plants. The chemical attributes and nutrient content of the leaves showed a significant variation in the study areas. The use of geostatistics allowed zones with different patterns of behaviour to be identified, which can help in the specific management of soil correctives and fertiliser using precision agriculture. The spatial variability of Ca2+ in the soil was similar to the variability of the nutrient in the banana leaves.摘要 本研究旨在通过地统计分析方法，评估采用两种不同土壤矫正剂施用方案的香蕉种植地块中，土壤化学性状与叶片大量营养素的空间变异性。本研究于巴西皮奥伊州克里斯蒂诺·卡斯特罗镇区开展：在掺混石灰的地块采集21份0.00~0.20 m深度的土壤样品，在未施加地表石灰的地块采集21份土壤样品，共计42个带有完整地理坐标的采样点。对土壤样品的pH值、有机质（Organic Matter，OM）、P、钾离子（K+）、钙离子（Ca²+）、镁离子（Mg²+）、铝离子（Al³+）及H+Al指标进行了分析，并计算了盐基总量、阳离子交换容量与盐基饱和度。在与土壤采样点位一致的植株叶片中，测定了钙离子（Ca²+）、镁离子（Mg²+）、钾离子（K+）与P的含量。本研究采用方差分析、描述性分析与地统计学方法，并结合土壤与植株化学性状水平开展解读，对试验结果进行了分析。研究区域内的土壤化学性状与叶片养分含量均存在显著空间变异性。通过地统计学分析可识别出具有不同养分变化模式的区域，可为精准农业框架下的土壤矫正剂与肥料精准管理提供支撑。土壤中钙离子（Ca²+）的空间变异性与香蕉叶片中该养分的变异性表现一致。