土壤水分和养分时空变异性与作物产量的关系

Relationship between spatio-temporal variability of soil moisture and nutrients and crop yield

精确农业使得农田土壤水分和养分的时空变异与产量关系的研究显得尤为重要,这就要求在其研究方法上取得新的进展,以加快精确农业的进程。该文运用传统统计理论和地质统计学理论结合分析了冬小麦苗期、灌浆期的土壤水分和养分变异与产量变异之间的关系。提出用"综合指示率"综合评价土壤的水分和养分状况,并分析了综合指示率的变异与作物产量变异之间的关系。结果表明在67.8m范围内综合指示率与产量之间存在很强的空间相关性,综合指示率越大,产量越高。Kriging估计的空间分布图也表明综合指示率与产量有较好的对应关系,综合指示率能解释产量变异的58.4%,比多元回归结果提高17.4%。多元逐步回归分析和综合指示率与产量的两变量回归分析结果都表明,同时考虑土壤水分和养分的变异能解释产量变异的33.3%～58.4%,比只考虑土壤养分变异时提高0～5.2%,同时考虑苗期和灌浆期土壤水分和养分变异能解释产量变异的41.0%～58.4%,比只考虑其中1个时期提高4.3%～16.5%。综合指示率为表达农田土壤水分和养分时空变异性及其与作物产量的关系提供了一种思路和方法,其分布图不仅是管理者综合评价土壤水分和养分状况的有利工具,而且把它与产量分布图对比,可以为精确农业的实施提供一定参考。

It is very important for the implementation of precision agriculture to study the relationship between crop yield and spatio-temporal variability of soil moisture and nutrients,which requires improving the methods of studying such relationship to speed up the process of precision agriculture.The relationship between crop yield and spatial variability of soil moisture and nutrients at the seedling stage and grain-filling stage of winter wheat was analyzed with both geostatistics and traditional statistics,and a method to integratedly evaluate soil moisture and nutrient status through integrated indicator rate was proposed.The relationship between integrated indicator rate and crop yield showed integrated indicator rate was significantly correlated with crop yield in the range of 67.8 m,and the greater integrated indicator rate was,the greater yield was.Their kriging maps indicated the distribution of integrated indicator rate was similar to that of yield.Integrated indicator rate could explain 58.4%of yield variation which was 17.4%more than the result of multivariate step regression analysis.Both multivariate step regression analysis of soil moisture and nutrients and crop yield and simple regression analysis of integrated indicator rate and crop yield indicated that soil moisture and nutrients could explain 33.3%-58.4%of yield variation which was 0-5.2%more than only considering soil nutrients,and meanwhile soil moisture and nutrients of both seedling stage and grain-filling stage could explain 41%-58.4%of yield variation,4.3%-16.5%more than considering soil moisture and nutrients of either seedling stage or grain-filling stage. Integrated indicator rate provides a method for describing spatio-temporal variability of soil moisture and nutrients and their relationships with crop yield.Its kriging map is a useful tool of integratedly evaluating soil moisture and nutrient status,and provides an available reference for implementation of precision agriculture by comparing with the kriging map of yield.