Abstract:

The study object was Recommend Top-dressed Nitrogen Quantity Based on Chlorophyl SPAD diagnosis of Rice (CSDR) in Different Growth Stage. The different experiment site and CSDR integrate were adopted. The study on CSDR to different nitrogen treatment in Different Growth Stage, reasonable recommend Top-dressed Nitrogen Quantity Based on CSDR was put forward in order to provide scientific proof to reasonable application nitrogen in irrigation area of Ningxia. The study result show that it is close relationship between CSDR in Different Growth Stage and different application nitrogen treatment, CSDR enhanced with application nitrogen increased. The CSDR and yield were close relationship, correlation coefficient (R2)were 0.6696 ～0.9194 before booting stage in different experiment site. Reasonable recommend Top-dressed Nitrogen Quantity Based on CSDR was put forward, application nitrogen was 30～60 kg/hm2when CSDR was 32～35 during tillering –elongation stage, application nitrogen was 45～75 kg/hm2 when CSDR was 35～40 before booting stage, application nitrogen was15～30 kg/hm2when CSDR was40～45 after booting stage, no application nitrogen when CSDR more than 40～45.