Spatial variability of macronutrients in a crop of conilon coffee in the north of Espírito Santo

ABSTRACTThe soils in the state of Espírito Santo, Brazil (ES) display low natural fertility, which often limits the production of the crops due to the deficiency of some elements. However, they have a high potential for agricultural production when the chemical limitations which are present are overcome. The aim of this study was to describe the spatial variability of the macronutrients calcium (Ca), magnesium (Mg), phosphorus (P) and potassium (K) in a crop of conilon coffee (Coffea canephora Pierre) located in the rural area of the city of São Mateus, ES. The experiment was carried out on a crop, planted at a spacing of 1.8 x 1.0 m (5,555 plants ha-1). A rectangular grid of 61.6 x 20.0 m (1,232 m2) was considered, with 60 sampling points, spaced 5.6 m apart between rows and 5.0 m within each crop row. At each point in the sampling grid, soil samples were collected at a depth of 0.00-0.20 m. All the macronutrients under study displayed a strong spatial dependence. The greatest range of spatial dependence was observed for Mg (32.4 m) and the smallest for Ca (8.1 m). Study of the spatial variability of the chemical properties of the soil by geostatistics, using kriging, proved to be an important tool in understanding the spatial distribution of macronutrients in the soil, and may be crucial in aiding the decision making that helps to attend the nutritional requirements of the conilon coffee crop.

摘要：巴西圣埃斯皮里图州（Espírito Santo，以下简称ES）的土壤自然肥力普遍偏低，常因部分营养元素缺乏限制作物生产。但若克服其存在的化学限制性因素，该区域土壤具备极高的农业生产潜力。本研究以位于ES州圣马特乌斯市（São Mateus）郊区的科尼隆咖啡（Coffea canephora Pierre）种植园为研究对象，旨在探明其中大量营养素钙（Ca）、镁（Mg）、磷（P）及钾（K）的空间变异特征。试验种植的咖啡株行距为1.8×1.0 m，种植密度达5555株/公顷。本试验采用61.6×20.0 m（总面积1232 m²）的矩形采样网格，共设置60个采样点，行间采样间距为5.6 m，行内采样间距为5.0 m。在每个采样点采集0.00~0.20 m深度的土壤样品。所有被测大量营养素均表现出强烈的空间依赖性，其中空间依赖范围最大的为Mg（32.4 m），最小的为Ca（8.1 m）。采用地统计学结合克里金（kriging）法分析土壤化学性质的空间变异，是解析土壤大量营养素空间分布特征的重要手段，可为满足科尼隆咖啡种植的营养需求提供关键决策支撑。