Impacts of Spatial Zonation Schemes on Yield Potential Estimates at the Regional Scale

Hao Xu,Xiaohu Zhang,Weixing Cao,Fen Huang,Yongchao Tian,Wenjun Zuo,Yan Zhu

doi:10.3390/agronomy10050631

Abstract

Simulations based on site-specific crop growth models have been widely used to obtain regional yield potential estimates for food security assessments at the regional scale. By dividing a region into nonoverlapping basic spatial units using appropriate zonation schemes, the data required to run a crop growth model can be reduced, thereby improving the simulation efficiency. In this study, we explored the impacts of different zonation schemes on estimating the regional yield potential of the Chinese winter wheat area to obtain the most appropriate spatial zonation scheme of weather sites therein. Our simulated results suggest that the upscaled site-specific yield potential is affected by the zonation scheme and by the spatial distribution of sites. As such, the distribution of a small number of sites significantly affected the simulated regional yield potential under different zonation schemes, and the zonation scheme based on sunshine duration clustering zones could effectively guarantee the simulation accuracy at the regional scale. Using the most influential environmental variable of crop growth models for clustering can get the better zonation scheme to upscale the site-specific simulation results. In contrast, a large number of sites had little effect on the regional yield potential simulation results under the different zonation schemes.

Highlights

Yield potential refers to potential productivity, which is entirely determined by temperature and photosynthetically active radiation when nutrients, moisture, soils, cultivars, and other agricultural technological parameters are at optimum conditions [1,2]
To upscale the simulated yield potential of sites to the regional scale by using spatial zonation, previous studies have mostly focused on the use of a single existing zonation scheme, such as climate zonation or agricultural zonation; existing zonation schemes may have negative effects on the regional estimation results because of inappropriate prior information used for the zonation, and as a consequence, homogeneous simulation results were not obtained within the irregular basic spatial units [10]
The Chinese winter wheat production region was used as the study area, and regional yield potential simulation scenarios were established under different zonation schemes using different numbers of sites for site-specific model simulations

Summary

Introduction

Yield potential refers to potential productivity, which is entirely determined by temperature and photosynthetically active radiation when nutrients, moisture, soils, cultivars, and other agricultural technological parameters are at optimum conditions [1,2]. The first upscaling method links a site-specific crop growth model with regional gridded data (rain, temperature, radiation, soil, etc.) and runs the crop growth model for each grid cell, a basic homogeneous spatial unit, to obtain the regional yields [4,6,7,8]. While this method can Agronomy 2020, 10, 631; doi:10.3390/agronomy10050631 www.mdpi.com/journal/agronomy

Methods

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Discussion

Conclusion