Effect of Gel-Based Controlled Release Fertilizers on Crop Yield and Nutrient Use Efficiency.
Ding Hong and Zhang Yu-shu. Institute of Soil and Fertilizer, Fujian Academy of Agricultural Sciences, Pu-dang, Fuzhou, 350013, China
New gel-based controlled release fertilizers were developed by mixing and processing nitrogen, phosphorus and potassium fertilizers with natural and semi-natural organic materials and inorganic materials. These gel-based fertilizers were easily produced, had lower price than coated controlled release fertilizers, and expressed better physical and chemical properties. To verify the effect of the fertilizers on increasing crop yield and improving fertilizer use efficiency, some field and pot experiments were conducted. The experimental results were as follows: (i) In a pot experiment to compare with common fertilizers (mixed with urea, potassium chloride and ammonium phosphorus acid) the gel-based controlled release fertilizers showed significant positive influence on agronomical, physiological and biochemical characteristics of maize plants (include plant height, stem diameter, leaf number and area, root activity, chlorophyll content and photosynthetic rate, protein content of leaf, NR activity etc.), increased dry biological yield of maize by 26.8%~42.3%, and improved nitrogen use efficiency by 17.0%~31.7%, phosphorus efficiency by 8.0%~16.0%, and potassium efficiency by 4.6%~18.3%. (ii) In a field experiments, the grain yield of maize increased by 3.5%~34.4% and the biological yield by 4.2%~35.7% with gel-based controlled release fertilizer treatments compared to common fertilizers treatments at experiment sites in Jiangxi and Anhui provinces. Nitrogen, phosphorus and potassium use efficiency improved by 2.5%~26.0%, 1.2%~22.7% and 3.5%~25.4%, respectively. The biological yield of Chinese cabbage increased by 5.8%~16.8%, nitrogen, phosphorus and potassium use efficiency improved by 4.3%~11.4%, 2.9%~13.2% and 5.9%~16.1%, respectively at an experiment site in Fujian province. The economical yield of sweet potato increased by 11.8%~33.7%, nitrogen, phosphorus and potassium use efficiency improved by 0.8%~9.5%, 0.3%~2.3% and 11.8%~24.4%, respectively at a site in Fujian province. In wheat and peanut crops gel-based controlled release fertilizer also showed better effects of yield-increasing and improving fertilizer use efficiency. (iii) Experimental results of nutrient release from fertilizers showed that nutrients (N, P and K) in gel-based fertilizers were leached more slowly out into the soil than common fertilizers.