Study On The Relationship Between Water And Nitrogen Of Winter Wheat Mulched With Plastic Film In The West Of Guanzhong

Nitrogen and water are the most important nutrient elements for winter wheat growth.Film is conducive to moisture preservation.In order to develop nitrogen fertilizer and film mulching in winter wheat,it is important to explore the effect of water and nitrogen coupling on winter wheat under plastic film condition.The experiment of water and nitrogen coupling in winter wheat field under film mulching was carried out at the irrigation station of Northwest A & F University in October 2015.Four kinds of film mulching treatments were designed,which were coated with ordinary plastic film,biodegradable film,jointed film and uncoated treatment.Two kinds of level of nitrogen fertilizer is set which is respectively low nitrogen 120kg/hm2 and high nitrogen 180kg/hm2.The effects of different nitrogen application rates on the growth indexes,yield,soil NO3-N and plant nutrient of winter wheat under different film mulching conditions were studied.The conclusion is as follows:(1)Effects of soil water storage under different mulching conditions: There were significant differences in film mulching and non-laminating treatment during the early growth period.There was no significant difference in the treatment of plastic film and plastic film during the whole growth period.In the middle of fertility,the difference of soil water storage in different mulching treatments was similar,which is(M1)>biodegradable membrane(M3)>unplugged masking(M2)>uncoated treatment(M4).In the late growth period,the whole growth period was significantly higher than that of the other three capsules.There was no significant difference in soil water storage between the unfolding film,the biodegradable membrane and the uncoated film.The soil moisture at the whole growth period is the highest in the whole growth period.Before the winter wheat jointing period,the moisture and soil preservation effect of ordinary film and biodegradable membrane is equivalent.Subsequently,the biodegradable film is gradually degraded and broken,and its moisture preservation effect is decreased.However,in terms of the whole growth period of winter wheat,the common film and ridge covered with biodegradable film has a certain effect of preserving moisture and soil.(2)Under different treatments,the plant height,leaf area,dry matter accumulation and yield of winter wheat increased with the increase of soil moisture.They all reached the maximum at the highest water(full growth period M1)and high nitrogen(N2)treatment.Inthe lowest water(no M4)and low nitrogen(N1)treatment,the index is lowest.The highest yield was 11.782 t · hm-2 and the lowest was 9.017 t · hm-2.The plant height,leaf area and dry matter accumulation of winter wheat increased with the increase of soil moisture under different nitrogen application rates.There was no significant difference between the exposed film and the biodegradable film during the whole growth period and the whole growth period.In the late growth period,the performance of the whole growth period is as follows: ordinary membrane> Biodegradable membrane> jointing film> no film treatment.This is consistent with the difference in soil water storage under different mulching treatments.(3)The changes of nitrate nitrogen in 0-200 cm soil layer were similar to those under different treatments of amount of nitrogen and filming in the shooting period.Soil NO3-N content decreased first with soil depth.When reaching a certain value,with the depth of soil nitrate nitrogen content,there is no significant change and the content tends to be stable.The content of nitrate nitrogen in 0-50 cm soil decreased.The content of NO3-N in 50-200 cm was not significant.In the mature period,the trend of nitrate nitrogen content in 0-200 cm depth was increased first and then decreased.There was no significant difference in soil nitrate content at 100-200 cm depth.(4)During the whole growth period of winter wheat,the trend of nitrogen concentration in the plant was increased first,then decrease and later increased.In the heading period,it reached the maximum and in the grain filling period,it began to decrease;in the mature period,it was increased.Under different growth stages and under the same condition,the nitrogen concentration in the plant treated with high nitrogen was significantly higher than that of low nitrogen treatment.Under the condition of same amount of nitrogen application and different films,the different growth period of the law is roughly the same.The rule is as follows:(M1)>biodegradable membrane(M3)>unfolding film(M2)>uncoated(M4).