Study on the ecological effect of crop residues burned or incorporated in fidd in North Central Irrigated Area of China

Results from the experiment show that mulching wheat-straw on the soil in summer contributes to preserve soil moisture,1ower soi1 temperature，increase microbe amounts in the surface soi1 and benefits the growth of the maize and the plot yield．Burning crop residues in field can obviously improve the content of available soil nutrients． Mulching wheatstraw on soil surface can inhibit the emergence of weeds，while burning can kill the seeds of weeds．Not all pests increase and diseases become worse because of the incorporation of crop residues．Plot yield with crop residues burned decreases compared to that of crop residues incorporation．