Study On Coupling Effect Of Water And Fertilizer Under Mulched Drip Irrigation Of Maize In Semiarid Region Of Northeast China

As an advanced and efficient water-saving irrigation technology,drip irrigation under the membrane not only can effectively save irrigation water,but also has the advantages of saving fertilizer,reducing the destruction of soil structure and increasing crop yield.Northeast China is the main grain producing area,Heilongjiang is the largest food producing province in China,and maize is the main food crop in Heilongjiang Province.However,the frequency of spring drought in the western part of Heilongjiang Province is high.The drip irrigation technology under the membrane can effectively increase the soil temperature,prevent spring drought and low temperature chilling,and ensure crop emergence and root growth.This paper conducts field trials on maize under drip irrigation under film in the western region of Heilongjiang Province to determine the optimal irrigation and fertilization levels suitable for local conditions.The experiment adopts the optimal design of D416,sets 5 levels of 3 factors of nitrogen fertilizer application,phosphate fertilizer application and potassium fertilizer application,sets 4levels of this factor of irrigation water quantity,and sets up no-film treatment and irrigating treatment of CK to form test treatment.The soil moisture content and maize growth traits in the plots were regularly monitored during the maize growth period,and the maize yield was measured at the time of harvest.Through statistics and analysis of experimental data,the coupling laws of water and fertilizer under drip irrigation conditions under the membrane and its influence on corn growth were preliminarily determined.The resulting as follows:1.Nitrogen,phosphorus and potash fertilizers have effects on plant height,stem diameter,leaf area,and other physiological indices.The application of nitrogen fertilizer has the greatest impact on various growth traits.The gain effect of mulching on various growth traits of maize was most obvious from the jointing stage to the tasselling stage.The relationship of the rate of photosynthesis in corn growth stage is:jointing stage>filling stage>tasseling stage.The leaf area index of corn is negatively correlated with the photosynthesis rate of corn leaves.2.During the growth period of maize,the change trend of soil water content in 0~80 cm deep soil layer is roughly as follows:seedling stage and jointing stage remain stable,tasselling stage and filling stage fall rapidly,mature period slightly rises.The water consumption of corn increased with the increase of irrigation volume,and the water consumption during the tasseling period was the largest and the water consumption during the mature period was the smallest.Film covering can significantly reduce water consumption during maize growth period.3.Within the scope of the experiment,the degree of influence of various factors on maize yield from big to small was as follows:nitrogen fertilizer,phosphate fertilizer,potash fertilizer,and irrigation volume.The amount of irrigation water has a negative effect on corn yield,and the remaining factors have a significant positive effect on the maize yield.4.Under the condition of drip irrigation under the film,the water use efficiency(WUE)of maize is between 2.11 kg/m~3 and 3.53 kg/m~3,which decreases with the increase of water consumption.Film covering effectively improves water use efficiency.5.The rainfall during the growth period of maize in the experimental year is 386.0 mm,which is a middling drought year.In this year,maize under drip irrigation under the film has a water saving of about 1308 m~3/hm~2 compared with the surface irrigation.The maize yield is increased by about 20.4%compared with the middle and low-yield fields,and increased by about 10.8%compared with the middle-high yield fields.6.Comprehensive consideration of yield,water use efficiency and economic efficiency,to determine the appropriate level of irrigation and fertigation for maize film under the drip irrigation in the region:the amount of nitrogen fertilizer is 225 kg/hm~2,the amount of phosphorus applied is88 kg/hm~2,the amount of potassium fertilizer is 90 kg/hm~2 The irrigation volume is 335 m~3/hm~2.