Study of planting density and optimized fertilization on super rice Y Two Optimal Number 2

The result to study planting density of super rice Y two optimal number 2: the suitable planting density of Y two optimal number 2 were 180 000～220 000 plants/hm2.Using three elements secondary saturated D-optimal design research fertilization model,yield increasing effect and fertilization net benefit of super rice varieties.The result showed: when using N,P2O5,K2O(N∶P2O5∶K2O=1.00∶ 0.50∶1.02) were 275.0 kg/hm2,135.0 kg/hm2 and 280.0 kg/hm2,the best predicted yields were 10 370.0 kg/hm2.The increasing rates of N,P,K were 63.3%,fertilization net benefit was 6 442.0 yuan/hm2.While fertilization insufficient,the biggest affect of yield and fertilization benefit increase first was N,second was K,last was P,but excessive fertilization,the reduce of the yield first was N,second was K,last was P.The reduce of the fertilization benefit first was P,second was N,last was K.