黑土区农田土壤水分、养分与作物产量多尺度空间变异机制及互作效应研究

Spatial variability of soil water, soil nutrients and crop yield that was educed at a certain scale was very difficult to be applied at other scales, in addition, influence of scale change was also not considered when interaction effect between spatial variability of soil water, soil nutrients and crop yield was studied in previous research. In view of the above mentioned problem, this project chooses a farmland in black soil region as research area, explores spatial variability of soil water, soil nutrients and crop yield at different scales with multi-fractal and geostatistics theroy, studies relation mechanism between spatial variability of soil water, soil nutrients and crop yield and scale, and analyzes change rule of interaction effect between spatial variability of soil water, soil nutrients and crop yield at different spatial scales, finally reveals effect rule of scale on spatial variability of soil water, soil nutrients and crop yield, establishes scale transformation models of parameters that reflect spatial variability of soil water, soil nutrients and crop yield, builds interaction effect model between multi-scale spatial variability of soil water, soil nutrients and crop yield, and constructs a kind of technology mode dividing soil water and nutrients management zones considering scale effect. This project has great significance for solving scale transformation of spatial variability of soil water, soil nutrients and crop yield, revealing effect mechanism of scale change on interaction effect between spatial variability of soil moisture, nutrients and crop yield, and guiding distributed control of soil water and nutrients in farmland.

针对某一尺度上农田土壤水分、养分和作物产量的空间变异性研究结果难以在其它尺度上应用，以及以往研究土壤水分、养分与作物产量空间变异性互作效应时，未考虑尺度变化的影响。本项目以黑土区农田为例，运用多重分形和地统计学等理论，研究土壤水分、养分、作物产量在不同尺度上的空间变异性，以及三者空间变异性表征参数与尺度联系机制，分析不同尺度上土壤水分、养分与作物产量空间变异性互作效应的变化规律，揭示尺度变化对土壤水分、养分、作物产量空间变异性的影响规律，建立土壤水分、养分、作物产量空间变异性表征参数的尺度转换模型，构建土壤水分、养分与作物产量多尺度空间变异性互作效应模型，提出考虑尺度效应的土壤水分和养分管理分区划分技术模式。该研究对于解决农田土壤水分、养分、作物产量空间变异性的尺度转换，揭示尺度变化对土壤水分、养分与作物产量空间变异性互作效应的影响机制，以及指导农田土壤水分与养分的分布式调控具有重要意义。

针对农田土壤水分、土壤养分和作物产量空间变异性的尺度效应以及尺度对土壤水分、土壤养分与作物产量相互关系的影响。以东北黑土区秸秆还田玉米地为例，建立土壤水分、土壤养分和玉米穗质量构成要素的传统统计学、地统计学和多重分形模型，分析空间变异性表征参数与取样尺度的关系，以及造成空间变异性的局部信息；利用克立格插值绘制土壤水分、土壤养分与玉米穗质量构成要素的空间等值线图；利用联合多重分形构建土壤水分、土壤养分与玉米穗质量构成要素的联合多重分形谱，分析土壤水分、土壤养分与玉米穗质量构成要素多尺度相关特征与单一尺度相关特征的差异。结果发现，随取样面积的变化，秸秆还田玉米地不同生育时期土壤水分、不同土壤养分指标、不同玉米穗质量构成要素平均含量、变异程度、空间相关范围、空间相关程度的变化趋势并不完全相同；造成研究区域土壤水分空间变异性的局部信息随土层深度的变化有所差异，研究区域碱解氮的空间变异性由其低值信息引起，有效磷和速效钾的空间变异性由其高值信息引起，研究区域玉米穗粗的空间变异性由其高值信息造成，其他玉米穗质量构成要素的空间变异性都由其低值信息引起；研究区域不同生育时期土壤水分、不同土壤养分指标、不同玉米穗质量构成要素的空间等值线图中都存在明显的斑块结构；研究区域土壤水分、土壤养分与玉米穗粒重在单一尺度和多尺度上的相关特征都有所差异，多尺度分析能更深入的揭示出相关特征。研究结果对于揭示研究区域土壤水分、土壤养分和玉米穗质量构成要素的空间变异性及其互作效应，以及指导土壤水分与土壤养分的分布式调控等具有重要意义。通过项目研究，发表EI论文5篇，录用2篇（SCI源刊1篇，EI源刊1篇）。