Validation of Late Season Cornstalk Nitrate Test under Different Natural and Social Environments for Better Fertilizer Management in China

While the current food security is fulfilled in China, the substantial nitrogen fertilizer use has caused many far-reaching environmental problems. Therefore, reforming the fertilizer management is the key toward sustainable agriculture for 1.3 billion people. The present study is intended to test the applicability of a nitrogen fertilizer management approach for corn production developed in U.S. to regions with different climates in China. Through field work, it was found that the so-called Late Season Cornstalk Nitrate Test approach may have to be adapted to dry continental climate and irrigation water conditions, but meanwhile appeared workable under sub-humid warm temperate continental monsoon climate in China. A hypothesis was made to explain the findings and a simple cure was suggested. Moreover, the importance of applying this approach to China was discussed in relation to GHG emission reduction and national fertilizer subsidy policy. Finally, a new fertilizer management scheme was proposed.