Abstract:

To study the effect of long-term (over ten years) straw returning on the nutrient content of the topsoil and crop yield, long-term comparative experiments of wheat straw returning were carried out from the summer of 2009. Results showed that the topsoil nutrients’ content and crops’ yield increased significantly, the annual average increase of soil organic matter was 0.333 g/kg, the annual average increase of alkali-hydrolyzed nitrogen content was 2.2 mg/kg, the annual average increase of available phosphorus content was 1.3 mg/kg, the annual average increase of available potassium content was 3.8 mg/kg, the annual average yield increase of wheat was 144 kg/hm², and the annual average yield increase of maize was 207.6 kg/hm². The long-term location experiments could track the crop yield variation of wheat-maize rotation, and provide an overall package of reference for promoting crop straw returning technologies and further research on soil environment for agricultural production.

Key words: straw returning, location test, topsoil, nutrient, yield