Assessing the effectiveness of land consolidation for improving agricultural productivity in China

Agricultural production in China is crucial for socioeconomic development and food security. Land consolidation has been regarded as an important way to maintain food security and is highly valued by the Chinese government. However, whether productivity improvements can be achieved through land consolidation is not yet clear. To address this, we propose a straightforward method to assess agricultural productivity changes using remote-sensing data. The normalized difference vegetation index (NDVI) is used to represent yield, as its changes correlate significantly with yield changes. The analysis uses a Moderate Resolution Imaging Spectroradiometer NDVI time series covering a period of 13 years (2001–2013) at a spatial resolution of 250m and data on projects completed in 2006 and 2007. Control sites near the projects are used to eliminate the influence of other factors. The results show that 62.90% and 58.34% of projects in 2006 and 2007, respectfully, were effective at improving productivity, whereas 56.51% and 52.56%, respectfully, effectively stabilized productivity. Generally speaking, 78.67% of projects in 2006 and 78.32% of those in 2007 proved effective at either improving or stabilizing productivity; however, only 40.56% and 34.34%, respectfully, were effective at doing both. Furthermore, it should be noted that areas with effective productivity improvements mainly benefitted from growth in the cropping area and that the annual yield per unit area on project areas decreased within a few years after consolidation. The lack of effectiveness may be caused by problems of engineering, construction, and subsequent management. Governments must thus consider new consolidation projects comprehensively and cautiously before launching them.