红壤稻田种植制度的养分平衡特征

Characteristics of nutrient balance of different cropping systems in paddy field of red earth.

试验研究了湘北红壤稻田系统4种种植制度的养分平衡特征。结果表明,N、P、K养分输出为稻-稻-油种植制度>稻-稻-油(肥)种植制度>稻-稻-肥(紫云英)种植制度>稻-稻种植制度;N盈余量以稻-稻-肥种植制度最大,达18.4kg/hm^2·α,稻-稻-油(肥)种植制度基本维持平衡,稻-稻种植制度表现亏缺,稻-稻-油种植制度亏缺最大,达38.9kg/hm^2·α;4种种植制度P和K均有亏缺,但以稻-稻-油种植制度亏缺量最大,分别为11.2kg/hm^2·α和118.7kg/hm^2·α,稻-稻-肥种植制度亏缺量最小;稻-稻-肥种植制度有机物质归还量最大,有利于有机质的积累,稻-稻种植制度有机物质归还量最小,有机质呈现亏缺状态。

The characteristics of nutrient balance of 4 kinds of cropping systems were studied in paddy field sys-tems of red earth in northern Hunan. The results show that the sequence of nutrient output of N, P and K is the cropping system of rice-rice-rape>the cropping system of rice-rice-rape (green manure)>the cropping system of rice-rice-green manure>the cropping system of rice-rice. The N surplus of the cropping system of rice-rice-green manure is 18.4kg/hm2·a,which is the biggest among 4 kinds of cropping systems. N nutrient of the cropping sys-tem of rice-rice-rape(green manure) is basically balanced. The cropping system of rice-rice shows the N deficit. The N deficit in the cropping system of rice-rice-rape is up to 38. 9kg/hm2·a,which is the biggest. P and K of 4 kinds of cropping systems all show deficient, but the cropping system of rice-rice-rape is the biggest, being 11.2 kg/hm2·a and 118.7kg/hm2·a, respectively, and the cropping system of rice-rice-green manure is the smallest. Returning of organic matter of the cropping system of rice-rice-green manure is the biggest and favourable to accu-mulation of organic matter, and return of organic matter of the cropping system rice-rice is the smallest and shows negative balance in organic matter.