Sustainable management of land, water, and fertilizer for rice production considering footprint family assessment in a random environment

Abstract

Effective management of land, water, and fertilizer resources for rice production is critical for efficient and sustainable agriculture but is challenging due to the uncertainties associated the resources. The aim of this study is to propose a unified model for simultaneously optimizing crop planting area, irrigation water, and nitrogen fertilizer considering uncertainty. Water, carbon, energy, and ecological footprints are analyzed to jointly evaluate the re-allocation of resource. The proposed model has an advantage in addressing trade-offs of land, water, and fertilizer resources for different irrigation subareas in a cost-efficient, resources-efficient, and environmental-friendly manner, thus helping decision makers track resource utilization and where effort should be made from different perspectives, and also dealing with non-linearity and uncertainty. The model is applied to an irrigation district in northeast China. Results demonstrate that rice production is based on the simultaneous allocation of land, water, and fertilizer resources, but the objectives for the optimization model are conflicting. The model performs best when both water supply and precipitation are at their medium level. Compared with status quo, the value of irrigation water use efficiency increases by 1.6%, and the value of Global warming potential deceases by 7.45%. The allocation of 1.596 × 107 m3 of water can be regarded as a reference amount for water planning, which is obtained by considering possible scenarios of high-low flow level combinations of water supply and precipitation. Results of “footprint family” assessment suggest that improving the efficiency of nitrogen fertilizer utilization is particularly important to reduce greenhouse gas emissions and energy consumption, and indicate that land re-allocation helps improve the utilization of rice straw. The proposed model can help manage agricultural land, water, and fertilizer resources in a sustainable way in a changing environment, and is applicable for similar agriculture-centered regions.