Study On Potassium Release Characteristics Of Coated Potassium Fertilizer And Applying Effect Of Fertilizer

Maize is the world’s third-largest planted area of food crop after rice and wheat and itsyield and quality affects the social stability and economic development of our country. Becauseof the limited farmland of our country, increasing corn yield per unit is the only way to increasegrain production in China. Potassium is an important element of corn growth stages.Application of K fertilizer will improve the yield and quality of corn However, because offertilizer is not perfect and reasonable application of technology, the K fertilizer utilization rateis low, the input of soil K content was far below the amount of crops to take, which not onlydestroyed the farmland nutrients balance but also caused the waste of resources. Therefore,development of new type of fertilizer and improve the utilization rate of fertilizer is a focus ofthis research. In order to provide a scientific basis for the production and development of CPFwhich is suitable for maize growth needs, the nutrient release characteristics of coatedpotassium fertilizer and its application effect on corn were researched.(1) Water dissolution rate method was used to research the nutrient release characteristics andthe influence of different external conditions for its nutrient release of three type of coatedpotassium fertilizer (CPF-A、CPF-B、CPF-C). The results show that the incipient dissolutionrate of the three potassium fertilizers (CPF-A、CPF-B、CPF-C) and K2SO4were11.3%、10.4%、10.8%and35.8%respectively. It proved that three kinds of coated potassium fertilizer were allconformed to international standards and their dissolution rate of potassium in the7th day werelower than K2SO4. The incipient dissolution rate and differential dissolution rate of CPF-B werelower than that of CPF-A and CPF-C, therefore the slow-release effect of CPF-B was the best.The research of the effect of the aqueous solution pH, temperature and water ratio on thenutrient release of coated potassium fertilizer showed that the aqueous solution of pH=6.5ismore suitable for the release of potassium and the pH value of the influence of pH on theincipient dissolution rate of CPF-B was less than that of CPF-A and CPF-C. The nutrientrelease rate of the three type of coated potassium fertilizer was positively correlated withtemperature and water ratio. When the soil water content was75%, potassium release of coatedpotassium fertilizer (CPF) was the largest. The three kinds of CPF were suitable for differentsoil environment.(2) JiNong201and XianYu335were selected as experimental varieties. This paper studied theeffect of coated potassium fertilizer on physical properties of maize root and leaf，physical characteristics of plant and content of maize. The results show that:①the root dry weightincreased in the growth period of both varieties, and the biggest increment of root dry weightcame out in the CPF-A treatment;②the root activities showed a single peak cure change in thewhole growth period, and the peak occurred at bell stage. The performance of maize rootactivities under different fertilizer treatments followed the order of CPF-B>CPF-A>CPF-C>K2SO4>CK;③Plant high, stem diameter, Ear length, ear diameter increased with differentCPF treatments and the length of bald tip decreased. It showed that application of the suitableamount of CPF can effectively improve the maize plant biology character. The growth of maizewith CPF-B treatment was better than that with CPF-A、CPF-C、K2SO4、CK. There was nosignificant difference between two varieties of maize.④The soluble sugar and soluble proteincontent in the leaves increased significantly during the growth and jointing stage of maize,which indicated that the release rate in the soil of CPF were relatively consistent with cropgrowth.⑤Dry material accumulation in the upper, line number, number of grains per ear,hundred kernel weight and yield of JiNong201and XianYu335were all increased and the yielddifference reached the extremely significant level. Among different treatment, CPF-B was thebest and the result was basic accord with the results of water dissolution rate method.(3) Compare with maize grain quality (the content of fat, starch and protein) of the twovarieties of maize, it can be concluded that the treatment of applying K fertilizer were betterthan control and treatment of applying CPF is better than that of potassium sulfate.