Changes of rice yield and soil physicochemical properties in long-term dry seeded rice-barley double cropping.

摘要

Changes of rice yield and soil physicochemical properties of the dry-seeded rice-barley double cropping system were investigated for 10 years from 1990 to 1999. Generally, seedling stand was more unstable in the rice-barley cropping system regardless of barley straw addition or removal than in the rice single cultivation as indicated by higher standard deviation of seedling stand across year. Rice yield in rice-barley double cropping cultivation was increased due to barley straw application starting from the second year, recording 2 to 19% increase (average of 9% for 10 years) due to higher spikelet number. Protein content and Mg/K equivalent ratio were similar among the barley straw applied field, rice single crop and barley straw removed plots.Also, amylose content was not significantly different among cropping patterns. Physicochemical properties of soil was improved by applying the barley straw; soil porosity was higher and content of organic matter and cation exchange capacity of Ca increased but those of Mg and K did not differ.