Evaluating the Impact of Crop Layout Changes on N and P Nutrient Balance: A Case Study in the West Liaohe River Basin, China

Zijuan Zhao,Dong Liu,Beilei Fan

doi:10.3390/su13147982

Zijuan Zhao, Dong Liu + Show 1 more

Open Access

https://doi.org/10.3390/su13147982

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Abstract

Regional crop layout has changed significantly due to climate, policy, and other factors, which has impacted farmland nutrient balance. Here, we evaluated the impact of crop layout changes on N and P nutrient balance in the West Liaohe River Basin from 2000–2015. The study area has long been in a N and P surplus state. The unit N surplus exhibited a downward trend and the unit P surplus showed an increasing trend. Significant correlations existed between planting areas and nutrient surplus. The N and P surplus layout was mainly concentrated in the West Liaohe River lower reaches basin. The planting area of wheat must be reduced and the areas of maize and soybean must be controlled to adjust the N and P balance and reduce the environmental pollution risk. Chemical fertilizer and seed inputs are the main sources of N input. Furthermore, combining farming and pastoral farming is conducive to improving N and P use efficiency. Manure can be absorbed by farmland, the ratio of organic and chemical fertilizers can be reasonably set, and chemical fertilizer application can be reduced.

Highlights

It shows that it is feasible to use phenology information for division crop layout, and that the decision tree classification methods can be applied to the extraction planting patterns
We evaluated the impact of crop layout changes on N and P nutrient balance in the West Liaohe River Basin from 2000–2015
We found that the crop planting area showed an increasing trend, and that the spatial layout was consistent with the major tributaries of the West Liaohe River Basin

Summary

Introduction

Protecting cropland and improving cropland quality are the basis for global food security and sustainable agricultural development [1,2]. To promote crop growth and increase crop yields, the use of chemical fertilizers has become the main method for stable agricultural production [3]. Since the 1980s, agricultural production in China has increasingly depended on the use of chemical fertilizers to meet food demands [8,9,10]. In 2014, total chemical fertilizer consumption in China accounted for 31% of the global total [11]. The use of large amounts of chemical fertilizers has greatly increased crop yields. In the case of low N and P use efficiency, excessive fertilization wastes nutrients and causes serious environmental problems such as groundwater pollution, eutrophication of surface waters, decline in biodiversity, water quality degradation, soil acidification, and an increase in greenhouse gas emissions [12]

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