第十章土壤养分循环 ATMOSPHERIC N GAS 3.800000bion BIOSPHERE Atmospheric Plant and animal wastes decaying organisms nIc fixation plants bacteria en in proteins) 30 million 44 milhon 760 billion 4ml‖on Denitrificaton IGNEOUS ROCKS 14 000 0co b llion uman PEDOSPHERE 140 billion Nitrate Impact (NH4) NO3) To groundwater and oceans第十章 土壤养分循环