1 Humification of organic materials could be enhanced by composting.

2 Both humification and decomposition are impeded.

3 The humification coefficient of the wheat straw determined with the nylon bag method was 12.25 %.

4 Humification coefficient did not changed proportionately with temperature and rainfall and was multiply influenced by environmental factors, especially soil properties.

5 The improvement of soil fertility could make the humification degree of free humus in soil and its complexes decrease, and furthermore, result in type change.

6 The content of methyl functional group of humus is an important index to evaluate the humification of soil.

7 The final process in organic matter decomposition is known as humification.

8 Transformation and bioavailability of selenium in soil depends , to a certain extent, on the humification processes.

9 The amounts of total organic carbon, biomass C, heavy fraction C, extractable humus (HE) and loosely-combined humus and the humification degree were higher in steppe chernozem than in wind-blown soil.

10 Steppe soil had higher amounts of total organic carbon, biomass C, heavy fraction C, HE and different combined humus than sunflower wind-blown soil, but humification degree had no obvious difference.

11 The plant residue with more lignin has a higher humification coefficient. As the residue containing more N is more favorable to the formation of soil microaggregate.