SPATIAL CORRELATION BETWEEN PHYSICAL PROPERTIES OF SOIL AND WEEDS IN TWO MANAGEMENT SYSTEMS

The spatial correlation between soil properties and weeds is relevant in agronomic and environmental terms. The analysis of this correlation is crucial for the interpretation of its meaning, for influencing factors such as dispersal mechanisms, seed production and survival, and the range of influence of soil management techniques. This study aimed to evaluate the spatial correlation between the physical properties of soil and weeds in no-tillage (NT) and conventional tillage (CT) systems. The following physical properties of soil and weeds were analyzed: soil bulk density, macroporosity, microporosity, total porosity, aeration capacity of soil matrix, soil water content at field capacity, weed shoot biomass, weed density, Commelina benghalensis density, and Bidens pilosa density. Generally, the ranges of the spatial correlations were higher in NT than in CT. The cross-variograms showed that many variables have a structure of combined spatial variation and can therefore be mapped from one another by co-kriging. This combined variation also allows inferences about the physical and biological meanings of the study variables. Results also showed that soil management systems influence the spatial dependence structure significantly.

土壤性状与杂草的空间相关性在农艺学与环境科学领域均具备重要研究价值。对该相关性开展分析，对于阐释其内在意义至关重要，因其影响因素涵盖杂草扩散机制、种子生产与存活特性，以及土壤管理技术的作用范围等。本研究旨在评估免耕（no-tillage, NT）与常规耕作（conventional tillage, CT）体系中，土壤物理性状与杂草间的空间相关性。本研究分析了以下土壤与杂草物理性状：土壤容重、大孔隙度、微孔隙度、总孔隙度、土壤基质通气容量、田间持水量、杂草地上部生物量、杂草总密度、饭包草（Commelina benghalensis）密度以及三叶鬼针草（Bidens pilosa）密度。总体而言，免耕体系下的空间相关变程高于常规耕作体系。交叉变异函数分析结果显示，多数变量存在联合空间变异结构，因此可通过协同克里金（co-kriging）实现变量间的相互制图。此种联合空间变异还可用于推断本研究各变量的物理与生物学意义。研究结果同时表明，土壤管理体系对空间依赖结构具有显著影响。