农业政策调整下大豆种植格局变化对水土资源消耗的影响评估

目的]通过对政策调整下农作物种植格局变化引起的水土资源消耗变化研究,从资源利用角度为种植格局调整的政策制定提供科学支撑。方法]文章以黑龙江省为研究区,利用系统动力学方法构建大豆种植格局驱动机制模型,并模拟三大作物(即大豆、玉米和水稻)补贴政策情景下的作物种植面积转换;其次,核算三大作物生产中的水土资源消耗量,并获取不同政策情景下大豆与玉米和水稻种植面积转换引起的水土资源消耗变化量。结果](1)黑龙江省大豆、玉米和水稻生产过程中单位面积的水资源消耗排序为“大豆<玉米<水稻”,单位产量的耕地资源消耗排序为“水稻<玉米<大豆”。(2)由于单位面积大豆的耗水量最少、单位产量大豆的耕地消耗量最多,当大豆生产者补贴增加40%时,大豆净增加面积最多(由玉米和水稻转入),因此三大作物生产过程中水资源消耗总量减少最多为2 400万m³,但耕地资源消耗仅增加3.2万hm²。结论]农业补贴调整,不仅可以满足粮食的总体供给,优化作物种植格局、扩大大豆种植面积,进而减少大豆供给的不确定性,还可以实现区域水土资源的优化配置。该文结论可以为...

IMPACT ASSESSMENT OF CHANGES IN SOYBEAN PLANTING STRUCTURE ON WATER AND FARMLAND RESOURCES UNDER AGRICULTURAL POLICY ADJUSTMENT

Food security is being challenged by the COVID-19 pandemic, climate change, population growth, and environmental degradation. Understanding the dynamics of crop planting structure driven by policies and the effect on water and farmland resources are important to address these challenges, which require quantitative evaluation. To provide scientific information for the policy-making of crop planting structure adjustment from the perspective of resource utilization, this paper chose Heilongjiang province as the study area and established a system dynamics model of soybean planting structure in Heilongjiang. Based on the system dynamics model, it simulated the conversion of planting area among soybeans, corn, and rice in Heilongjiang under the subsidy policy for these three crops. Additionally, it calculated the consumption of water and farmland resources in the production of the three crops, and obtained the change in the consumption of water and farmland resources caused by the conversion of planting area among soybeans, corn, and rice under different scenarios of subsidy policy. The results showed that the range of water resources per unit area and farmland resources per unit yield consumption in the production of soybeans, corn, and rice in Heilongjiang from small to large was "soybeans<corn<rice" and "rice <corn<soybeans", respectively. Since soybean consumed the least amount of water per unit area and consumed the most amount of farmland per unit yield, when soybean producer subsidy increased by 40%, the soybean planting area increased the most. Therefore, the consumption of total water resource of the three crops decreased by 24 million m³, but the consumption of farmland resources only increased by 0.032 million hm². In summary, this study reveals that the adjustment of agricultural subsidies can not only meet the overall supply of food, optimize crop planting structure, expand soybean planting area, and then reduce the uncertainty of soybean supply, but also realize the optimal allocation of regional water and farmland resources. Our analysis suggests that the results of this study can provide scientific information for the policy-making under the constraint of optimal allocation of water and farmland resources, and help ensure food security and realize sustainable utilization of water and farmland resources.