The Status and Countermeasure of Nitrate Pollution Under Double Crop- ping Systems in China

The multiple cropping is the main agricultural production pattern, including double cropping of rice in south China and double cropping of wheat and corn in north China. Household investigation, typical farmland survey and county statistics inspection were performed to analyze the status and countermeasure of nitrate pollution in China. The result showed that the nitrate rate of underground water was slowly increased, but it was not above the standard of WHO. Under the multiple cropping of winter wheat-summer corn, the nitrate level of irrigation well water had raised year after year since 1991. Some countermeasures should be taken to avoid the nitrate content of underground water, such as increasing the fertilizer use efficiency by taking agronomic measures, according to the local conditions, a reasonable allocation and application of fertilizer and others.