耕地上山撂荒成因及空间优化路径探究——以江西省万年县为例

Research on the Reasons for Farmland Uphill Abandoned and the Path for Space Optimization under the System of Requisition-compensation Balance:A Case Study of Wannian County in Jiangxi Province,China

围绕耕地、林地与建设用地的占补平衡是兼顾粮食安全、生态安全及城市发展需求的土地空间置换制度。然而,“耕-建”占补平衡却造成了大量耕地上山并撂荒的现象,有悖于“藏粮于地”的耕地保护方针。利用二元Logistic回归模型和粮食产能核算模型,剖析山区农业大县万年县补充耕地撂荒特征、成因及粮食产能效应,提出联动“耕-林”占补平衡制度实现空间优化的方案。结果表明:(1)2010~2020年万年县补充耕地呈现上山和细碎化趋势,撂荒率约为14.77%。(2)当补充耕地海拔高度>130 m∩斑块面积<0.2 hm^(2)、或所在村常住人口密度<400人/hm^(2)∩斑块面积<0.2 hm^(2)、或临近耕地交通距离>40 m∩斑块面积<0.2 hm^(2)、或海拔高度>110 m∩临近耕地交通距离>70 m时,撂荒可能性较大。(3)可开垦利用为耕地的林地共3183.39 hm^(2),其中有林地、其他林地、稀疏林地分别占88.25%、9.74%、2.01%。(4)通过上山耕地与稀疏林地置换可弥补撂荒造成的297.48 t粮食产能流失。研究认为,补充耕地撂荒是未考虑土地利用“条件-状态-功能”耦合关系导致空间错配的结果,山区土地整治要联动“耕-林-建”占补平衡制度,实现上山耕地与山下宜耕林地空间置换,优化土地利用状态,实现区域土地多功能协同。

To meet the needs of food security,ecological security and urban development,the Chinese government proposed the system of Requisition-Compensation Balance to swap the spatial position between farmland,forest land and construction land.However,this system also makes a large amount of farmland abandoned,which has violated China’s policy of"Hiding Grain in the Land".The methods of binary logic regression model and grain capacity accounting model were used to analyze the phenomenon,causes,and grain productivity effects of farmland abandoned in Wannian County,a mountainous agricultural county.The study found that:(1)From 2010 to 2020,the supplementary farmland in Wannian County has been uphill and fragmented,and the abandonment rate has reached about 14.77%.(2)The farmland is more likely to be abandoned when its altitude>130 m and patch area<0.2 hm^(2),or permanent population density of the located village<400 people/km^(2) and patch area<0.2 hm^(2),or patch area<0.2 hm^(2) and traffic distance with adjacent farmland>40 m,or altitude>110m and traffic distance with adjacent farmland>70 m.(3)3183.39 hm^(2) of forest land can be reclaimed in county areas,of which forest land,other forest land,and sparse forest land account for 88.25%,9.74%and 2.01%respectively.(4)The replacement of farmland and sparse forest space can make up for the loss of 297.48 t production capacity caused by the abandonment.The study has shown that the abandonment of farmland is the result of spatial mismatch caused by the coupling relationship between land use conditions-state-functions.Therefore,we put forward joint strategies of requisition-compensation balance among farmland,forest land,and construction land in mountainous areas,so that the farmland uphill can be swapped to the place suitable for cultivating by humans.