Abstract: Tests of the whole maize straw incorporation and the smashed ones were conducted on tideland of semi-arid area of Quzhou, Hebei Province. The tests are composed of seven different treatments. By one year's period of test, it indicates that the process of decomposition of straw in the field is divided into three stages. In the early stage, the decomposition rate of the smashed straw is faster than that of the whole in the field. But the gap between the two rates is diminished after wheat turns green. The coefficient of huminification is not affected by the measures of adding use of nitrogenous fertilizer,spraying EM and so on.

Key words: stoichiometric model, in vitro fermentation, hydrogen, ruminal methane, carbohydrate.