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引言水田氮素肥力的消耗比旱地少,其主要原因是由于在淹水条件下,微生物能够固定空气中的氮素。水田里的固氮量虽然不如豆料草地,但是远比旱地多。据推测,每年每公顷的固氮量是30-40公斤。因为世界上的总水田面积大约相当于全部农业耕地的10
Introduction Nitrogen fertility in paddy fields is less depleted than in drylands, mainly due to the immobilization of nitrogen in the air by microorganisms under flooding conditions. Although the amount of nitrogen fixation in paddy fields is not as good as bean grass, it is much more than dry land. It is speculated that the annual nitrogen fixation per hectare is 30-40 kg. Because the total paddy field in the world is about the same as that of all agricultural land