Increasing multiple cropping for land use intensification: The role of crop choice

Land use intensification increases crop production without reclaiming new cropland from natural ecosystems. In addition to the yield-improving approaches, scientists began to assess the multiple cropping potential as an alternative for intensification. These existing assessments largely focused on the number of multiple cropping frequency (MCF) while ignoring the crop growth duration (GD) required by a complete cropping circle, which may bring uncertainty on the estimates. In this study, we aim to address such uncertainty by comprehensively considering the relation between MCF and GD. Selecting Jinxian county, Jiangxi Province, as a study area, we use time-series remote sensing imageries to observe MCF and GD, and to estimate the region’s annual growing season (GS) by aggregating the crop-specific GDs corresponding to the MCF. We further apply scenario analysis to understand how crop choice. i.e. longer GD v.s. shorter GD, would influence the exploitation of GS and thus the multiple cropping potential. Results show that without considering GD, 33.63% croplands have the potential to harvest another time and 64.84% cropland could have two-extra harvests, which would result in the harvested area increased by + 163.31%. However, if GD is considered, this potential is estimated much lower in overall and is varied greatly across crop selection scenarios. In the most close-to-reality scenario, roughly 40% croplands have no potential to make extra harvest, because the GS in many areas have been largely exploited and the remaining GS is insufficient to sustain another complete crop growth. Our study shows that crop choice plays an important role in measuring and exploiting the multiple cropping potential, which provides implications for China’s “agricultural supply-side structural reform” through sustainable land use intensification.