冬小麦生育期内农田土壤速效养分的时空变异研究

The Spatio-temporal Variability of Soil Available Nutrients at Field Scale during the Growing Season of Winter Wheat

了解土壤养分的时空间变异特征,可以为作物不同生育阶段的田间精准管理提供科学的依据。以江苏省姜堰市西华农场为例,运用地统计学方法详尽地分析了冬小麦播前及不同生育阶段农田土壤速效养分(速效N、P、K)的时空变异特性。结果表明:不同时期各土壤变量大部分都由趋势、剩余残差的空间相关部分和随机部分组成;不同生育阶段3个土壤变量都具有中等以上空间结构性;碱解氮(AN)的分布格局在冬小麦播前和主要生育期内变化不大;速效磷(AP)苗期和孕穗期空间分布较相似,空间连续性也强,而播前和乳熟期的连续性稍差,出现较多斑块;速效钾(AK)在前三个时期分布较相似,与乳熟期分布有较大差异。作物生育期内土壤养分空间分布随时间存在程度不同的变化,从经济和环境两方面考虑,田间管理应兼顾时间和空间变异,才可能做到真正精准管理。

The spatio-temporal variability of soil alkali-hydrolyzable N （AN） , available P （AP） and available K （AK） in a winter wheat field on Xihua farm of Jiangyan in Jiangsu province was analyzed with geostatistics. The results indicated that most of soil variables at different stages were composed of the trend, the random component and spatial component. All of soil variables were moderate-highly spatially dependent. There were little change of AN before sowing and at different growing stages. Spatial distributions of AP at the seedling stage and the booting stage were similar and AP at the two stages was spatially correlated than before sowing and at the stage of milky ripeness. Spatial distributions of AK were similar at the seedling stage, the booting stage and before sowing and were different from the stage of milky ripeness. Spatial distributions of soil nutrients changed with time to various certain extents during the growing season of crop. In order to improve economic performance and environment, both temporal variability and spatial variability of soil properties should be taken into account for precision management.