Effects Of Slow-Release Fertilizers On Yield Formation And The Uptakes Of Nitrogen, Phosphorus And Potassium By Aerobic Rice

A field trial was carried out in Xibeiwang village during 2003. The trial was to study the effects of different fertilizer treatments on yield and nutrients uptake of Han dao 297, the nutrients change of slow-release grain fertilizers and the N utilize efficiency, the other trial was to study the effects of different planting density on Han dao 297 yield and components factors of yield. There were four fertilizer treatments including Acidic slow-release grain fertilizer treatment (ACFB), neutral slow-release grain fertilizer (NCFE), coated slow-release fertilizer (SRNF), optimizing fertilizer model (Opt) and one no fertilizer treatment (CK) in fertilizer trial. The main results were given below:1 , The yield of aerobic rice was 4t/hm². ACFB gave significantly higher yield than NCFE, SRNF and CK. Compared with Opt, there was no significant difference.2, At tilling stage, there were much more soil NO₃^--N and available K in ACFB and NCFE treatments than in CK; at heading, there was much more soil NO₃^--N and available K in Opt treatment than in ACFB , NCFE and CK; at maturity, there were much more soil NO₃^--N and available K (except in NCFE) in the fertilizer treatments than in CK treatment. Except ACFB, there were much more soil Olsen-P in the fertilizer treatments than in CK treatment at tilling; with rice growing, there were no significant difference between the fertilizer treatments and CK treatment.3, When plant growing, the total N, P and K contents in both slow-release grain fertilizers decreased. There was faster release velocity of NCFE than of ACFB. There were resembling results in available nutrients changes of both slow-release grain fertilizers.4, ACFB, NCFE and Opt treatments facilitated plant assimilating N at early growth stage of aerobic rice; with plant maturity, Opt still facilitated plant assimilating N. ACFB and Opt treatments facilitated plant assimilating P at tilling of aerobic rice; at maturity, there were no significant difference between the fertilizer treatments and CK treatment. At tilling and maturity, ACFB and Opt treatments facilitated plant assimilating K; at heading, the effect of fertilizer was little on K assimilation .5 , In fertilizer trial, the utilization rate of nitrogen fertilizer in aerobic rice was about 36%⁵2%.There was no obvious difference among ACFB, NCFE and SRNF treatments. The utilization rate of nitrogen fertilizer of Opt treatment was higher than that of three slow-release fertilizers significantly.6, The 1000-grain weight is a varietal character of aerobic rice 297 in the fertilizer trial.