Study On Multiple Cropping And Processing Technology Of Silage Corn

At the view of current shortage of high-quality roughage and the lack of a suitable stubble crop for the short-season crops such as fresh corn, potato, wheat and et al in insufficient double cropping region, a cultivation pattern of multiple cropping was proposed to use silage corn as the stubble crop of short-season crops. Taking screening of appropriate silage corn varieties as the breakthrough point, combining the methods of field trail and laboratory experiment, high yielding cultivation technology and processing and utilization methods of multiple cropping silage corn were studied, and an analysis and evaluation were done on use of resources and comprehensive benefits of three multiple cropping patterns in which silage corn was used as the stubble crop. The result of two-years-research was shown as:1. Compared with one-quarter spring corn, the energy production efficiency, accumulated temperature production efficiency, precipitation productivity, net increased energy, production, output value and pure benefits of the three multiple cropping patterns of potato to green silage corn, filmed fresh corn to green silage corn and wheat to green silage corn were markedly improved. The pure economic benefits of the three multiple cropping patterns were 25462 yuans, 22993 yuans and 14216 yuans per ha. respectively, which were 136.5 %,113.5% and 32.0% higher than that of the one-quarter spring corn respectively.2. According to the adaptability of corn variety to climatic conditions of summer planting and the criterion of high-quality corn silage, three silage corn varieties fit for multiple cropping, Zhengdan958, Gaoyou4515 and Xianyu335, were screened out.3. The growth and development characteristics, dry matter accumulation, yield and dry matter content of silage corn as well as effects of climatic conditions on silage corn were cleared, and the sowing time limit of silage were determined. The sowing time limit of Zhengdan958 and Gaoyou4515 were both no more later than July 19. The regression equations of silage corn yield to active accumulated temperature were established. For Zhendan958, the regression equation of fresh yield to active accumulated temperature was as y = -8x 10^-5x² + 0.3349x - 278.1(r=0.998), that of dry matter yield to active accumulated temperature was as y = 0.0233x - 25.921(r=0.9968). For Gaoyou451, that of fresh yield to active accumulated temperature was as y =-8 x 10^-5x² + 0.3153x - 251.24(r=0.9968), that of dry matter yield to active accumulated temperature was as y = 0.0185x - 17.188(r=0.9968).4. The yield increasing mechanism and potential as well as suitable planting density of two plants per hole were revealed. At the same planting density, compared with single planting, the colony structure of bunch planting was improved, its main agronomic traits and photosynthesis characteristics were enhanced, but yield increase was not significant. Increase of bunch planting density can lead to aggravation of competition between individuals, decline of some agronomic traits like plant height, stem width, leaf area per plant, and photosynthesis characteristics like leaf photosynthesis rate, stomatal conductance, transpiration rate. At the same time, because of the colony advantage, with increase of planting density, the change of yield per area showed a trend of conics, decrease after increase. The most appropriate bunch planting density was 100000 plants per hektare, at which, fresh yield and dry matter yield were the most, 69.61t/hm² and 20.26t/hm² respectively. When the density was over 120000 plants per hektare, yield decreased because colony advantage could not offset the impact on individual development.5. The effects of nitrogen and phosphorus fertilizer on multiple cropping silage corn were understood further, the reasonable fertilization amount was put forward. Under the soil condition with middle or more organic matter, middle nitrogen content, and lack phosphorus, fertilizer application of middle nitrogen and high phosphate was benefit to agronomic traits and yield, but that of high nitrogen and high phosphorus may caused corn plants grew too strong, colony canopied and closed, which resulted in premature senescence, decrease of ear length, rows per ear and grains per row, and even yield. When fertilization amount of nitrogen (N) was 250 kg/hm², and that of phosphorous (P₂O₅) was 100 kg/hm², the fresh yield was the mostly 61.08 t/hm², when fertilization amount of nitrogen (N) was 200 kg/hm², and that of phosphorous(P₂O₅) was 100 kg/hm², the fresh yield was secondly 60.99 t/hm². If taking both yield and economic benefits into account at the same time, the second fertilization methods was more reasonable.6. The silage effects and nutritional value of different silage methods such as single silage and silage without ear of silage corn at different maturity degree, mixed silage of silage corn with alfalfa, and mixed silage of silage corn with dry straw, were determined. When the silage corn sowed on from July 5 to July 12 was ensilaged by whole plant, the silage grade was one, and silage effect was the best. The content of crude protein, crude fat, crude fiber, crude ash, extract without nitrogen, and et al basically reach or approach the standard of high-quality silage. When the silage corn sowed on July 12 was ensilaged by whole plant, silage grade and nutritional value were lower, if ensilaged by removing ear, the content of crude protein, crude fat, extract without nitrogen decreased, and that of crude fiber increased, and silage grade was 1-2, which was also more successful. The silage grade of mixed silage of silage corn with alfalfa can reach 1-2, which was better than that of single silage of alfalfa. On the view of nutritional value, when the proportion of alfalfa reached 1/2 of the whole silage materials, the crude protein content can reached 14.49%, which was 2.3 times that of single silage of silage corn. Mixed silage of corn and alfalfa integrated the advantages of both gramineae and leguminosae forage, effectively solved the problems that it is not easily to succeed for single silage of alfalfa and protein content was very low in single silage of silage corn. The silage grade of mixed silage of silage corn with straw may reach 1-2, which was better obviously than that of single silage of straw. On the view of nutritional value, when silage corn accounted for 1/2 of the whole silage materials, the crude protein content was 7.49%, and that of crude of fat was 1.40%, which were different significantly from that of single silage of dry straw. Mixed silage of silage corn with dry straw can improved nutritional quality of dry straw, which is an effective method to solve the problem of shortage of silage and raise the level of roughage.