Abstract:

To evaluate the application effect of organic fertilizer instead of chemical fertilizer and to provide scientific basis for formulating reasonable fertilizer cultivation measures, the effects of different proportions of organic fertilizer instead of nitrogen on soil fertility, rice yield and rice quality were studied by field location monitoring. The experiment site was located in the experimental base of Hunan Academy of Agricultural Sciences, Gaoqiao Town, Changsha County, Hunan Province, and four treatments were set up: NPK; 15% organic fertilizer replacement treatment (15M); 30% organic fertilizer replacement treatment (30M); 60% organic fertilizer replacement treatment (60M). After rice harvest, soil pH, total nitrogen, alkali-hydrolyzable nitrogen, total phosphorus, available phosphorus, total potassium, available potassium of 0-20 cm soil layer and rice yield and rice quality were measured. The results showed that the average annual yield followed the order of NPK<15M<30M<60M, the yield of 60M was significantly higher than that of NPK and 15M, increasing by 15.99% and 8.71%, respectively. Compared with NPK, 60M increased rice gum consistency, amylose and protein content by 4.72%, 7.15% and 10.67%, respectively. 30M and 60M increased soil total nitrogen, organic matter, alkali-hydrolyzed nitrogen, available phosphorus and available potassium contents. Partial substitution of organic nitrogen fertilizer for chemical nitrogen fertilizer could promote rice yield and improve rice quality by increasing soil organic matter and total nitrogen content. Under the experimental conditions, 60% organic fertilizer was the best substitute treatment.

Key words: organic fertilizer instead of chemical fertilizer, rice yield, rice quality, soil fertility