Abstract

Food shortage and security attracts global attention and at this moment in time, intensive farming has a large impact on agricultural resources. In this respect, multiple cropping is an effective agricultural practiceincreasing the combined yield of crops and agricultural output. Over-cropping however, is a major cause ofcultivated land degradation. The multiple cropping index (MCI) is an important parameter in arable farming systems. It reflects the utilization of water, soil, incoming radiation, as well as other natural resources. Hence, MCI monitoring is an important activity in the resources and food security assessment of agriculture.Therefore, the objective of this paper is to investigate the MCI monitoring method using multi-temporal moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI)data, for the time period of 2001 to 2004 in the study area of Southeastern China. The annual cycle of crop phenology inferred from remote sensing is characterized by four key transition periods: (1) greenup; (2)maturity; (3) senescence and (4) dormancy. The maximum of the NDVI time-series profile for cropland is a proxy for maximum leaf area. Hence, MCI of arable land in Southeastern China from 2001 to 2004 wasmonitored by the acquisition of peak frequencies in NDVI time series profiles. The results showed that the MCI increases from north to south for every year, 41.18% areas of Southeastern China had the largest MCI in 2004. The MCI from the MODIS-NDVI elicit a significant correlation with statistical MCI, and most of the relative errors were less 10%. All these results indicated that the method used to estimate MCI described in this paper is dependable.

Key words: Multiple cropping index, moderate resolution imaging spectroradiometer (MODIS), normalized difference vegetation index (NDVI), phenology, Southeastern China.