Study On The Effects Of Plastic-film Mulching And Fertilization For Forage Maize In The Northwest Plateau Of Hebei Province

With the forage maize named White Dent, the experiment including the effects of plastic-film mulching, nitrogen-phosphorus interaction and potassium effects research was conducted on the arid shoaly land experimental field of Zhangbei Experimental Station Agricultural University of Hebei from May to September in 2004. By field survey and experiments in laboratory, the thesis expatiated the effects of plastic-film mulching, nitrogen-phosphorus interaction, single potassium for forage maize in the northwest plateau of Hebei Province. The main results are as followed:The biomass and nutritive value yield of forage maize was increased enormously by plastic-film mulching. In the nitrogen-phosphorus interaction experiments the biological production, crude protein, ether extract, cruder fiber and lignin was increased by 29.3%, 32.6%, 30.1%, 38.2%, 4.2%, respectively and in the single potassium experiment increased by 28.0%, 36.8%, 42.7%, 32.0% and 51.8%, respectively compared with those without mulching.Not only the soil temperature of cultivated layer was increased 1.83 ℃ by plastic-film mulching, also the water use efficiency was increased 5% for changing the invalid evaporation into effective transpiration of plant. The effects of increasing temperature and preventing evaporation created an appropriate condition for the maize growing in the cold and droughty prophase and promote forage maize to uptake the nutrient in the soil for growth. The plant height, stem width, leaf area index, and the percent in the whole plant of N, P₂O₅, and K₂O were improved significantly compared with that without plastic-film. Plastic-film mulching created necessary base for metabolizing rapidly.The regression equations for the biomass and the yield of nutritive value including crude protein, ether extract, cruder fiber and lignin with the different nitrogen and phosphorous application rates were established by computer optimization. Rational ratio of nitrogen and phosphorous could increase the nitrogen, phosphorous and potassium content in the plant, improve the characters of nutrient growth, biomass and nutritive value yield. The...