Effects of different cultivation modes on yield and nitrogen absorption of double cropping super rice.

Using super early rice variety Chunguang No.1 and super late rice variety Ganxin 688 as experimental materials,the author studied the effects of different cultivation modes on the yield and nitrogen absorption of rice,which was transplanted by seedling-throwing mode.The results showed that the yield of both early rice and late rice cultivated by different modes had the following order: precise and quantitative cultivation mode(PQCM) and three-high and one-guarantee cultivation mode(THOGCM) three-control cultivation mode(TCCM) conventional cultivation mode(CCM).The number of effective spike,ear-bearing percentage,setting rate and 1000-grain weight of rice in treatment THOGCM were higher.The effective spike number of rice in treatment PQCM was maximum,but its ear-bearing percentage was lower.In comparison with CCM,the PQCM,THOGCM and TCCM could enhance the biomass,total nitrogen accumulation and nitrogen utilization rate of double cropping super rice,and THOGCM obviously reduced the nitrogen requirement for 100 kg grain production.