In precision agriculture, suitable soil moisture and nutrient levels are important for crop production. Therefore, studying the spatial variability in soil moisture and nutrient, and their impact on crop yield is essential. In this study, spatial variability in soil mechanical composition, bulk density, water content and nutrient content in north China along with its impact on crop yield is investigated. Results show that soil mechanical composition and bulk density respectively exhibited moderate and weak spatial variation at the 0–80 cm soil depth. Soil moisture and NH4+-N contents at the 0–80 cm soil depth showed moderate spatial variation, while soil NO3−-N content showed a moderate spatial variation from the seedling stage to the filling stage and a strong spatial variation from the milk-riping stage to the maturing stage. The maximum attainable yield was achieved under the optimum soil moisture, NH4+-N, or NO3−-N contents for the whole growth period and each growth stage. At high soil water condition, both soil NH4+-N and NO3−-N contents were found to be significantly different between the high and low yield areas, while at low soil water condition, only soil NO3−-N content affected the crop yield significantly. At either low or high soil NO3−-N level, soil NH4+-N content in high-producing areas was significantly lower than that in low-producing areas. Excess fertilization was found in the experimental area. This study can provide a scientific basis for developing appropriate crop irrigation and fertilization management practices to obtain high yield.

中文翻译：

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基于土壤因子空间变异性的华北雨养玉米生产极限分析

在精准农业中，合适的土壤水分和养分水平对作物生产很重要。因此，研究土壤水分和养分的空间变异性及其对作物产量的影响至关重要。本研究调查了华北地区土壤机械组成、容重、含水量和养分含量的空间变异及其对作物产量的影响。结果表明，土壤力学成分和容重在 0~80 cm 土层深度分别表现出中等和较弱的空间变化。0~80 cm土层土壤水分和NH4+-N含量呈中等空间变异，而NO3--N含量从苗期到灌浆期呈中等空间变异，从乳熟期呈强烈空间变异。阶段到成熟阶段。在最佳土壤水分、NH4+-N 或 NO3--N 含量下，整个生育期和每个生育阶段的产量最高。高土壤水分条件下，高产区和低产区土壤NH4+-N和NO3--N含量均存在显着差异，而低土壤水分条件下，仅土壤NO3--N含量对作物产量影响显着. 无论是低还是高土壤NO3--N水平，高产区土壤NH4+-N含量均显着低于低产区。试验区发现施肥过多。本研究可为制定适当的作物灌溉施肥管理措施以获得高产提供科学依据。或整个生育期和各生育阶段的 NO3--N 含量。在高土壤水分条件下，高产区和低产区土壤NH4+-N和NO3--N含量均存在显着差异，而在低土壤水分条件下，仅土壤NO3--N含量对作物产量影响显着. 无论是低还是高土壤NO3--N水平，高产区土壤NH4+-N含量均显着低于低产区。试验区发现施肥过多。本研究可为制定适当的作物灌溉施肥管理措施以获得高产提供科学依据。或整个生育期和各生育阶段的 NO3--N 含量。在高土壤水分条件下，高产区和低产区土壤NH4+-N和NO3--N含量均存在显着差异，而在低土壤水分条件下，仅土壤NO3--N含量对作物产量影响显着. 无论是低还是高土壤NO3--N水平，高产区土壤NH4+-N含量均显着低于低产区。试验区发现施肥过多。本研究可为制定适当的作物灌溉施肥管理措施以获得高产提供科学依据。只有土壤 NO3--N 含量显着影响作物产量。无论是低还是高土壤NO3--N水平，高产区土壤NH4+-N含量均显着低于低产区。试验区发现施肥过多。本研究可为制定适当的作物灌溉施肥管理措施以获得高产提供科学依据。只有土壤 NO3--N 含量显着影响作物产量。无论是低还是高土壤NO3--N水平，高产区土壤NH4+-N含量均显着低于低产区。试验区发现施肥过多。本研究可为制定适当的作物灌溉施肥管理措施以获得高产提供科学依据。