Study On The Utilization Of Large-scale Piggery Slurry In Machine-transplanted Rice

In recent years, the rapid development of the scale of livestock and poultry breeding has brought huge economic benefits to our country, but at the same time, the unreasonable discharge of livestock and poultry dung also caused great pressure on the environment. The pollution of livestock and poultry breeding has become a problem to be solved in the present stage of environmental protection, which is the key to the sustainable development of livestock and poultry breeding in the future.Wheat-rice double cropping is the primary planting format in Jiangsu, and the rapid development of machine-transplanted rice technology has made it become a mainstream way of planting, so it has universal significance to do a research on the utilization of large-scale piggery manure in machine-transplanted rice.Taking Huaidao5 as the experimental material, This experiment included 12 treatments with three repetitions for each treatment, including one unfertilized blank treatment (CK1), one local conventional fertilisation treatment (CK2), one pig slurry-only treatment M, and nine treatments receiving the combined application of pig slurry and nitrogen fertiliser, the randomized block design was employed. For basal application of fertiliser, pig slurry was applied by 45m3·hm-2, 67.5m3·hm-2, and 90m3·hm-2; in the panicle fertiliser stage, pig slurry was applied by 60m3·hm-2, 90m3·hm-2, and 120m3·hm-2, in the tillering stage urea was applied by 187.5kg·hm-2.In this study, pig slurry was applied in the production of rice to investigate the effects of slurry on nutrition absorption, yield and quality of rice, further more to find the optimum rate of pig slurry. The results showed that:1. During the jointing stage, the number of tillers decreased firstly and then increased with increasing slurry application, high quantity of slurry is helpful to improve the tiller number.In the point of SPAD value, the more amount of slurry manure caused the larger SPAD value, which was beneficial to the nitrogen absorption.2. From the point of production, the combined application of slurry and nitrogen fertiliser in reduced dose could produce equal or higher yield than conventional fertilisation, with a increase by 10.84%. The highest yeild was the treatment that combined with base fertilizer 90 m3·hm-2 pig slurry,120 m3·hm-2 and 187.5 kg·hm-2 urea, up to 10448.3 kg·hm-2.3. From the point of nutrient absorption and distribution, the accumulation of dry matter of rice plant and NPK content and NPK. accumulation amount were increased with the increasing slurry application. They all reached the highest when combined with base fertilizer 90 m3-hm"2 pig slurry,120 m3·hm-2 and 187.5 kg-hm-2 urea. Nitrogen harvest index, nitrogen use efficiency for dry matter production and nitrogen use efficiency for rice production declined with increasing slurry application amount in the heading stage.4. In terms of quality, the quality of the grain would be better with increasing slurry application. Compared with the conventional fertilization, the milling quality of grain basically did not change, but the appearance quality, nutrition quality and cooking quality were improved.5. The contents of Pb and As in rice reached the highest at every growth stage, when combined with base fertilizer 90 m3·hm-2 pig slurry,120 m3·hm-2 and 187.5 kg·hm-2 urea. The levels of Cd, Hg and Cr reached the highest at every growth stage when using conventional fertilization (CK2). On the basis of identical pig slurry as base fertilizer, the content of Pb and As elements increased with the increasing slurry application in heading stage, but the content of Cd, Hg and Cr elements were just the opposite. Compared with conventional fertilization treatment, the substitute ferlitizer of pig slurry not only did not make a significant increase in the content of heavy metal elements in grain, on the contrary it made the content of Cd, Hg and Cr elements fall.The contents of Pb, Cd, Hg, Cr and As in grains of every treatments were lower than the maximum levels of contaminants in foods (GB 2762-2012),so under the condition of this experiment, the grains were safe. Therefore, considering thoroughly, the treatment that combined with base fertilizer 90 m3-hm-2 pig slurry,120 m3·hm-2 and 187.5 kg·hm-2 urea was the best fertilizing program.