Preparation And Characteristics Of The Slow Release Sulphur Fertilizer Containing Multiple Nutrient Elements

Two slow release sulfur fertilizer containing multiple nutrient elements (MNSRF-1andMNSRF-2) were synthesized with thiourea, aldehyde (formaldehyde or isobutyraldehyde) andpotassium dihydrogen phosphate as raw material under the chemical reaction. They have metthe orientation of "slow release","diversity","efficient","green" of the developing worldfertilizer.The slow release sulfur fertilizer containing multiple nutrient elements (MNSRF-1) wassynthesized with thiourea, formaldehyde and potassium dihydrogen phosphate as raw material.Its cold water solubility is19.0%~22.0%, hot water solubility is70.0%~74.0%. Its nutrientscontent of N, S, P, K are23.8%,34.8%,3.9%,3.8%. The optimal synthesizing process ofMNSRF-1was obtained through orthogonal and optimization experiments. The structure ofMNSRF-1was characterized by infrared absorption spectrum (FITR) and nuclear magneticresonance spectroscopy (1H-NMR,13C-NMR,31P-NMR), and its molecular was analyzed bygel permeation chromatography (GPC). The nutrient release characteristics in water ofMNSRF-1was studied by water dissolution rate method and the nutrient release kineticsmodel was established. The results have showed MNSRF-1has the very good slow releaseperformance, its nutrient release characteristic curve was inverted "L" type. The nutrientrelease characteristics in different water content in the soil were studied by soil culturemethod on MNSRF-1, the results show that the cumulative nutrients release rate of MNSRF-1have increased with the increase of soil moisture content. Under the condition of soil moisturecontent is60%, effective state nutrient content in the soil is higher. It showed MNSRF-1notonly promoted the growth and development of rapeseed, but also improved the remaining soilfertility by rape pot experiment. The slow release sulfur fertilizer containing multiple nutrient elements (MNSRF-2) wassynthesized with thiourea, isobutyraldehyde and potassium dihydrogen phosphate as rawmaterial. Its cold water solubility is8.0%~11.0%, hot water solubility is96.0%~98.0%. Itsnutrients content of N, S, P, K are22.7%,31.5%,1.6%,1.6%. The optimal synthesizingprocess of MNSRF-2was obtained through optimization experiment. The structure ofMNSRF-2was characterized by infrared absorption spectrum (FITR) and nuclear magneticresonance spectroscopy (1H-NMR,13C-NMR,31P-NMR), and its molecular was analyzed bygel permeation chromatography (GPC). The nutrient release characteristics in water ofMNSRF-2was studied by water dissolution rate method and the nutrient release kineticsmodel was established. The results have showed MNSRF-2has the very good slow releaseperformance, its nutrient release characteristic curve was inverted "L" type.