Research On Fertilizer Requirement Pattern And Quality Of Forage Maize In Saline Soil In Shanxi Province

As an important part of the Northern Agro-pastoral Transitional Belt of China,great importance has been attached to Yanmenguan Agro-pastoral Transitional Belt by Shanxi government in recent years.To further promote the development of Yanmenguan Agro-pastoral Transitional Belt.Expanding the planting area of high quality forage crops has become one of the important measures in the further development of Yanmenguan Agro-pastoral Transitional Belt.In order to clarify the biology,nutrient uptake and quality buildup of forage maize in Yanmenguan area,two maize varieties,forage maize Yayu 8 and dual-purpose maize Tunyu 168,were selected for this experiment for the 3414 incomplete fertilizer tests conducted in Xie-zhuang Village,Da-huang-wei Town and Dong-hui-yao Village,Zhen-zi-liang Town of Ying-xian County,Shuo-zhou City,and Mao-zao Village,Mao-zao Town of Huai-ren City.The biology,nutrient demand and quality formation of different types of forage maize were investigated to explore the reasonable fertilizer application techniques for different types of maize used as livestock feed in Yanmenguan area and to provide technological guidance for the development of grass and livestock industry in the region.The results of the three-year multi-location positioning trial are as follows:（1）When the reasonable fertilization was applied,the dry matter accumulation rate of dual-purpose maize used for both human food and livestock feed was higher than that of forage maize before the silking period,and vice versa after flowering,and the optimized fertilization regime for forage maize was N 284-300 kg/hm²,P₂O₅103-120 kg/hm²and K₂O60-64 kg/hm²;the optimized fertilization regime for dual-purpose maize was N 297-325 kg/hm²,P₂O₅122-135 kg/hm²,K₂O 56-66 kg/hm².The forage yield of forage maize was higher than that of dual-purpose maize,and no significant difference was found in economic efficiency of forage yield between these two types of maize.（2）The nutrient accumulation of forage maize was significantly increased when increased nitrogen was applied;deficiencies in phosphorus and potassium limited nutrient accumulation,while excessive phosphorus and potassium fertilizers did not significantly increase nutrient accumulation.The influence of elevated fertilizers on nutrient accumulation rate followed an order of nitrogen>phosphorus>potassium.The nutrient uptake of the two types of maize in the growth period showed a trend of N>K₂O>P₂O₅.When the forage yield was used as the economic yield,the demand for nitrogen in forage maize was greater when compared to dual-purpose maize,while the demands for phosphorus and potassium in dual-purpose maize weres greater than that of forage maize.（3）As the growth period progressed,the content of crude protein in the two types of maize decreased gradually while the accumulated amount increased gradually,and increased N application slowed down the reduction rate of crude protein content.Meanwhile,the contents of neutral detergent fiber and acid detergent fiber increased firstly and then decreased gradually,and the accumulated amount of both gradually increased.The contents of both types of fiber were reduced by increased N application.Increased N application also promoted the relative forage value（RFV）,and the dual-purpose maize had a much higher forage value than that of forage maize in the harvest period.（4）In the forage harvest period,the nitrate-nitrogen content in the topsoil of both types of maize was higher than that before sowing,and then returned to the normal level in the grain harvest period.the content of available phosphorus in the topsoil did not show significant difference before sowing and in the forage harvest period,and decreased slightly in the grain harvest period.When forage yield was used as the economic yield,the demand for potassium was higher in the dual-purpose maize as compared to forage maize.The recommended fertilizer application rate ensured the nutrient demands of maize during the growth period without causing any soil environmental risks.