Study On Preparation And Slow-release Properties Of Early-rice Seed-coating Fertilizer

Rice is an important food crop, its output directly affects our country’s food security, fertilizer is one of the main ways of improving rice’s yield. The traditional fertilizer’s nutrient utilization rate is low, it not only causes a serious waste of resources, but also has caused serious environmental pollution.In recent 60 years, many countries have researched slow/controlled release fertilizer, has made certain social, ecological and economic benefits; our country has listed it as a key area for the current priority development, but our country’s research on slow/controlled release fertilizer is still at the primary stage of its’development, compared with the developed countries, a large gap. Global existing slow/controlled release fertilizer only works on traditional fertilizer’s structure modification or coating process, fertilizer is far away from the crop root, easily by rain leached, nutrient utilization rate increases not significantly, application range is very limited, mainly used for lawn, vegetables, fruits and other high-value economic crops, rarely used for field crops.Aiming at the deficiency of existing slow/controlled release fertilizer, this article based on the nutrient release theory of controlled release fertilizer and the coating principle of seed coating agent,on the basis of having successfully created the coated controlled-release fertilizer and rice seed coating agent, put forward and created new fertilizer-- rice seed-coating fertilizer, fertilizer wrapped directly on the seed surface, changed the traditional way of carrier and application of fertilizer, the nutrients of rice seed-coating fertilizer is very close to rice roots, to maximize nutrient utilization, to solve the existing mainly problems of slow/controlled release fertilizer.This article applied the hybrid rice and early rice seed-coating fertilizer as the main raw materials, by single factor and orthogonal experiments to explore the method of preparing early rice seed-coating fertilizer, looking for relatively simple production and coating process, developed a special slow-release fertilizer can be used on rice, the slow- release properties, physico-chemical properties and application effect were further determined, in order to improve our country’s rice fertilizer nutrient utilization, save fertilizer resources, reduce environmental pollution, and national grain abundant engineering, provides a new way and technical support, to provide a scientific basis for the creation, performance evaluation and application of new field crop fertilizer, like rice. The main conclusions were as follows:1. The single factor and orthogonal experiments results showed that:the preparation conditions of the early rice seed-coated fertilizer:the fertilizer ZFZ-5 amount was 10%, seed road-rate was 50.0%; coating-agent YCP-8 amount was 0.1%, filler amount was 40%, coating method was A-B (filler-fertilizer), drying time of coated seeds was 40min.2. The slow-release properties of early rice seed-coated fertilizer results showed that: the initial dissolution rates of early rice seed-coated fertilizer were N fastest, then K, P slowest. The initial dissolution rate reflects the quality level of scientific design and coating technology of seed-coated fertilizer.If the initial dissolution rate is very high, reflects slow-release property of designed seed-coated fertilizer is wake, coating technology is poor.The results of the initial dissolution rates and differential dissolving rates showed, the three kinds of nutrients’release trends of early rice seed-coated fertilizer were gentle. This is because the coated seed soaked in the water, with the hinder of coating film and filler, the moisture diffusion into the interior of fertilizer is slow, so it needs time to make the water be full of all the kernel, then the nutrients slowly release driven by concentration pressure. The cumulative release curve of early rice seed-coated fertilizer showed, its release trend was gentle parabola. Also showed under the premise of reducing the waste of fertilizer resources, the supply nutrients of seed-coated fertilizer were consistent with the demand for nutrients during early rice growth. So the slow-release properties of designed early rice seed-coated fertilizer were good, early rice coated by it, can significantly reduce the release rate of fertilizer nutrients, slow down the resource waste and environmental pollution caused by the excessive using of fertilizer, can ensure the gradual release of nutrients, improve the utilization rate of fertilizer, and promote the growth of rice.3. The physico-chemical properties,storage properties and application effects of early rice seed-coated fertilizer results indicated that:the pH of early rice seed-coated fertilizer was 6.90, slightly acidic, and conducive to the growth of early; viscosity was 9.23 mPa·s-1, moderate viscosity could achieve uniform coating effect, and easy adhesion between coated seeds; film-forming was middle, film was uniform; the short forming time which only need 7.50 minutes illustrated the coating film on the coated seeds surface fast curing and the coated seeds easy to dry; the coating split-time in the wate was 6.50min, illustrated the seed-coated fertilizer can play on the nutrient slow release, and don’t influence seed germination;the coating uniformity could up to 95.00%, indicating that the fertilizer was evenly attached to seeds surface, and the coating film was uniform, the slow-release properties were good, he coating expulsion rate was 9.20%(less than 10%), indicating that the early rice seed-coated fertilizer could be firmly attached to the seed surface, not falling; the storage properties were good, easy to storage and transport; the application effects were good, contributed to the rice seedling quality.