Effectiveness of silica application at the panicle formation stage on the rice production

Abstract

The effects of silica application on the yield and quality of rice were compared among the following plots: (A) a new silicate fertilizer A was applied at the panicle formation stage at 12g m^<-2>, (B) a new silicate fertilizer B was applied at the panicle formation stage at 12g m^<-2>, (C) a conventional silicate fertilizer was applied before transplanting as a basal fertilizer at 36g m^<-2>, and (N) no silicate fertilizer was applied. The results obtained were as follows: 1. The relative yields at the experimental plots A, B, C and N were 106, 104, 104, and 100, respectively. The effectiveness of applied silicate ((yield at A, B, or C-yield at N)/the amount of Si applied) for A, B, and C were 2.58, 2.17 and 0.67g m^<-2>, respectably. In addition, higher cost performances were achievd in A and B than in C. 2. The numbers of grains were as follows: 30,400 grains m^<-2> for C>30,100 for A and B>28,900 for N. On the other hand, no significant difference was found in the 1,000-grain weight and the percentage of ripened grains among those experimental plots. 3. The amounts of Si in the leaves plus stems were as follow: 65.0 for A and B(110)>63.0g m^<-2> for C(107)>59.3 for N(100) The amount of Si in the grains were as follows: 35.3g m^<-2> for C(116)>33.2 for A and B(109)>30.4 for N(100) This fact indicates that the top-dressed Si was more effectively used by the rice plant than the basal Si. 4. Total amount of N acquisition and the recovery rate of top-dressed N by the rice plants were higher in Si-applied plots than in non-Si-applied plot. It is likely that the application of Si enhances the N acquisition, resulting in increase of the number of grains.