Production limits analysis of rain-fed maize on the basis of spatial variability of soil factors in North China

Abstract

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.