| Summary: | 博士 === 國立中興大學 === 農藝學系 === 90 === Field experiments were conducted to investigate the effects of application rates, stages, management of soil moisture regime, and long term application of organic fertilizers on the soil and growing of rice. The objective of this study was to find suitable application rates and stages of organic fertilizers.
Experimental results revealed that, the application of organic fertilizers had higher organic matter content than that of chemical fertilizers in improving the fertility of soil. The effect of chicken composts was higher than that of rape seed meal on the soil. Organic fertilizers used in the second crop, the soil redox potential was lower than that of chemical fertilizer, and induced excessive trace elements on the vegetative stage of rice. Thus, caused poor tillering and lower grain number per panicle as compared to that of chemical fertilizer.
Under well control of blight, three kinds of treatments including (1) Rape seed meal 4 tons/ha served as base fertilizers, (2) Rape seed meal 2 tons/ha served as base fertilizers and 2 tons/ha served as top-dressing, and (3) Rape seed meal 2 tons/ha served as base fertilizers, 1 tons/ha served as top-dressing, and 1 tons/ha served at panicle initiation were practiced. On the first crop, rice yields of three kinds of treatment were higher than that of chemical fertilizers. On the second crop, under well control of blight, four kinds of treatments including (1) Rape seed meal 2 tons/ha served as base fertilizers and 2 tons/ha served as top-dressing, (2) Rape seed meal 2 tons/ha served as base fertilizers, 1 tons/ha served as top-dressing, and 1 tons/ha served at panicle initiation, (3) Chicken composts 12 tons/ha and rape seed meal 2 tons/ha served as base fertilizers, and (4) Chicken composts 12 tons/ha served as base fertilizers, and rape seed meal 1 tons/ha served as top-dressing were conducted. Rice yields of four kinds of organic fertilizers showed no significant difference yield as compared to that of chemical fertilizers.
Stepwise regression analysis revealed that crude protein content in grain is the main factor affecting the eating quality of cooked rice. Total organic fertilizers served as base fertilizers, had lower crude protein content and better eating quality in milled rice as compared to that from chemical fertilizer. Rape seed meal served as base, top-dressing, and panicle initiation fertilizers, had a higher nitrogen recovery and yield of rice as compared to that from chemical fertilizer, and resulted in a higher crude protein and poor eating quality.
Treatments of 0.03 Mpa and 0.06 Mpa soil moisture tension during grain filling stage reduced crude protein content of rice grain. The high soil moisture tension reduced nitrogen absorption of rice and produced higher quality rice.
|
|---|
