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

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.