The spatial-temporal coupling pattern of grain yield and fertilization in the North China plain

Abstract

CONTEXTKnowing the spatial-temporal relationship of historical grain yield and fertilization in various regions provides a solid base for promoting rational fertilization strategies. However, the interaction pattern between grain yield and fertilization over large areas and long time periods from the spatial-temporal coupling perspective has been rarely explored. OBJECTIVEThis study focused on the spatial-temporal coupling pattern of grain yield and fertilization in the North China Plain to propose reasonable fertilization strategies referring to practical experience and to increase grain yield while preserving the agricultural system. METHODSUsing the North China Plain as an example, we applied a method integrating global spatial autocorrelation, geographically weighted regression, and geodetector to reveal the spatial-temporal coupling relationship between grain yield and fertilization based on data from 1990 to 2015. RESULTS AND CONCLUSIONSGrain yield consistently increased but differed significantly among prefecture-level cities. Of cities with a rice, wheat, and corn yield, 49.09%, 45.46% and 47.27%, respectively, were below the average in the North China Plain. The application rates of nitrogen (N), phosphorus (P), and potassium (K) fertilizers first increased and then decreased, especially N fertilizer. The N:P2O5:K2O ratio developed from 1:0.31:0.08 to 1:0.38:0.22. The cities' application rates of N, P, and K fertilizer were 49.09%, 54.55%, and 63.64% lower than the average in the North China Plain, respectively. The effects of N, P, and K fertilizers on rice, wheat, and corn yields differed significantly among cities and along with time changing. The combined application of N fertilizer with P or K fertilizer was better than that of a single fertilizer, depending on the crop. The uneven regional grain yield and fertilization in the North China Plain indicated that a significant increase in grain production can be achieved by promoting grain yield in low-yielding areas through regionally balanced fertilization. For this purpose, an enhanced formulated fertilization strategy based on on-site and time-specific soil testing should be applied, considering the crop variety, climate, and irrigation. SIGNIFICANCEThis paper highlights the significance of formulating reasonable fertilization strategies through understanding spatial-temporal patterns between fertilization and grain yield. Our findings emphasize the importance of rationally balanced fertilization based on on-site and time-specific soil testing; such a strategy could be beneficial for securing food safety while maintaining the sustainability of the agriculture system.