At the ripe stage of upper leaf, the seemingly nitrogen mineralized was above 10kg/hm2in the field of Fenggang, but it was below Okg/hm2 in the field of Jinsha.

• 在上部叶成熟落黄期的，土壤表观氮素矿化量凤冈试验田在10kg/hm~2以上，而金沙却出现了氮素固持现象。