Effect of Long-term Fertilization on the Chang of the Contents of Combined Formation of Humus in the Protected Cultivation

The study analyses effect of different fertilization treatments on there kinds combined formation of humus in the long-term vegetable fertilization experimental field. The main results are shown as follows: the treatments of long-term fertilization of organic manure and organic manure combined with chemical fertilizers, content of combined loose-combined humus , tight-combined humus,steady-combined humus and the ratio of loose-combined humus and tight-combined humus are increase with the years growth, but the treatments of long-term non fertilization and long-term fertilization of organic manure ,only the content of tight-combined humus are increase, the content of loose-combined humus and steady-combined humus as well as the ratio of loose-combined humus and tight-combined humus are decrease with the years growth.