| Abstrakt: |
The benign interaction between fertilizer application and grain production is of great significance to ensure food and ecological security. Solving the contradiction between reducing fertilizer application and increasing efficiency has become an important issue for the main grain producing areas. Taking 16 cities under the jurisdiction of Shandong Province as the research u-nits, the spatial-temporal coupling pattern and dynamic change process of fertilizer application and grain yield from 2000 to 2020 were discussed. The results are as follows. ➀ From 2000 to 2020, the regional differences between fertilizer application and grain production in Shandong Province showed a fluctuating upward trend. Fertilizer application rate generally showed a decreasing trend of "substantial increase-small increase-substantial decrease" in terms of time, and an increasing trend of "eastern Shandong-central Shandong-western Shandong" in terms of space. The increase of grain yield showed significant EastrWest differentiation. ➁ The spatial coupling between the two was significant. The "high-high" coupling degree was the highest in western Shandong,and the "low-low" coupling degree was higher in central and eastern Shandong. The coupling degree was reduced in 2020 compared with the previous time point ➂ The promoting effect of fertilizer application on grain production followed the law of diminishing marginal return, and the coupling relationship between grain yield and fertilizer application had changed from "both increase of grain and fertilizer " to "both decrease of grain and fertilizer" and "reducing fertilizer application and increasing efficiency". According to the above conclusions, the policy suggestions of fertilizer control with regional differences are put forward. [ABSTRACT FROM AUTHOR] |
