Effects Of Controlled Release Compound Fertilizers On Growth Of Cotton

Many studies showed that nutrient release rate of controlled-release fertilizers (CRFs) was accordant with plant nutrient uptake, which could significantly improve the nutrient use efficiency of the fertilizers. In recent years, many studies reported the effects of CRFs on rice, wheat and other field crops, but less reports about the application on the cotton were issued. Now, fertilizers using on cotton were mainly instant soluble fertilizer, so it was significant to apply CRFs on the cotton for the ecological environment and the increase of cotton output. To this question, the experimental study of controlled-release fertilizer technology with the law for cotton fertilizer controlled release fertilizer made from mixing, cotton controlled-release fertilizer, and ordinary fertilizer for comparison. In order to provide a theory of scientific applications and extend on cotton, the different amount of CRFs on cotton and the effect of yield were studied in this study. The main findings and conclusions were as follows:1. Field experiment results showed that the height, stem diameter and the leaf area of cotton treated by CRFs were greater than that of common compound fertilizers (CCFs) treatment. The NO3--N, NH4+-N, solu-P, solu-K of the soil treated by CRFs were greater than those of CCFs, but the difference was insignificant. The node, boll, of plant with CRFs treatments was significant greater than that of the cotton treated by CCFs. the yield difference of three CRFs treatments was insignificant, the yield of CCF treatment increased with the application rate increasing, the difference of lower CRFs treatment and higher CCF treatmentwas was insignificant, it can get the same output when the application rate reduced.2. The pot experiment's results showed that, compared with the CCF, the CRF significantly increased the contents of NO-3-N, NH4+-N, available P and available K in the soil. The chlorophyll readings, plant height of the cotton treated by CRFs were greater than that of CCFs. The node, boll, yield of plant with CRFs treatments of any rate was insignificant greater than that of the cotton treated by CCFs. Though the application rate of CRF treatments was less than CCFs treatments in the experiment, the yield of the cotton of the CRFs treatments was still higher than that of CCF treatments. And the rate of increased cotton yield of CRFs was 113.05%, 34.54% respectively, compared with pure N CRFs 0.2, 0.4g/kg soil. The CRF showed its advantages of controlling release nutrient, increasing yield and reducing nitrogen application rate.3. The cotton applied CRFs after two years growed better than the CCFs treatment, and biomass of the plant treated with CRFs accumulated more than the CCFs treatment, the yields treated by CRFs were 47.05g/pot, 49.94 g/pot and 24.62 g/pot, and the increasing rate were 29.72%,46.96% and 34.51%, compared with the yields 36.2 g/pot,33.98 g/pot和18.30 g/pot treated by CRFs.