东北黑土地产能时空演变及其提升对策

东北黑土地产能变化的时空演化规律研究对于保护东北黑土地、保障国家粮食安全具有重要意义。基于MODIS-EVI数据,利用阈值法以作物最优生长时长(MAD)表征黑土地产能,揭示2010～2018年东北黑土地产能的时空演变及提升潜力。结果表明:①东北黑土地产能整体由中南向西北递减,以作物最优生长时长2～4级为主,种植集中区主要分布于松嫩平原东部及三江平原中西部地区; ②东北黑土地产能2010～2018年总体表现为先上升后下降的趋势,70%左右的黑土地产能保持稳定,产能显著提升的黑土地占3.99%,产能显著下降的占24.88%; ③东北黑土地产能提升潜力整体处于中等水平,空间上呈现“西高东低”状态,具有较大提升潜力的耕地较少。基于上述研究结果,参考黑土地保护的梨树模式、龙江模式,针对黑土地出现的“变薄、变瘦、变硬”等问题,提出了东北黑土地产能提升与保护的政策建议。

Spatio-temporal Evolution of Black Cropland Productivity in Northeast China and Its Promotion Countermeasures

Research on the spatio-temporal evolution patterns of black cropland productivity changes in Northeast China is essential to protect black cropland and ensure food security in China. Basing on MODIS-EVI data, the threshold method was used to characterize the productivity changes of black cropland in Northeast China by the most active day(MAD). The spatio-temporal evolution and productivity improvement potential of black cropland in Northeast China were revealed. The results show that ① the overall black cropland productivity decreases from the middle-south to the northwest of Northeast China, with crop MAD major levels being 2 to 4, and the planting concentration areas are mainly distributed in the eastern part of Songnen Plain and the central-western part of Sanjiang Plain; ② the overall black cropland productivity in Northeast China shows a trend of increasing and then decreasing during 2010 to 2018; among them, about 70% of black cropland productivity remains stable with a significant increase of 3.99% and a significant decrease of 24.88%; ③ the overall improvement potential of black cropland productivity in Northeast China is in a medium level, and its spatial distribution is “high in the west and low in the east” with less black cropland having more improvement potential. Basing on the above research results, and regarding the Lishu model and the Longjiang model, the policy suggestions for improving black cropland productivity and protection were proposed to solve the problems of “thinning, leaning, and hardening” of black cropland.