Effects Of Two Dry-farming Measures On Nitrogen Uptake And Utilization Of Apple Trees In The Hilly-gully Areas

The Loess Plateau in northern Shaanxi has the natural environment suitable for the growth of apple,which is the most promising area for the development of apple industry.However,the Loess Plateau is drier and drier and has some influence on the development of apple industry.Therefore,this paper takes the fruit trees of apple orchard in northern mountain as the research object,and studies the effects of ridge film mulching,rainwater stimulation and fertilization on the uptake and utilization of nitrogen fertilizer in orchard on the basis of previous research on rain and moisture conservation.The soil water distribution before and after the rainy season was studied under different field management.The main conclusions are as follows:(1)The ridge film mulching combined straw mulching,rainwater harvesting field rain and water conservation measures,can improve the orchard soil moisture content,slow soil drought.The soil water content in the roots of fruit trees was 10% ~ 15% higher than that of the control.Before and after the rainy season,the soil water distribution in different soils changed greatly.During the rainy season,the soil water content of 0 ~ 60 cm soil treated with P-C was lower than that of the control,and the treatment was 80 ~ 200 cm higher than that of the control.In short,ridge film coverage,rainwater harvesting field rain and water conservation measures to a certain extent,improve the soil moisture content,but the rainwater stimulation in the rainy season,may lead to deep water infiltration,cannot be absorbed by the tree.(2)Rye treatment(L-M)could increase the utilization rate of nitrogen fertilizer,which was 10% ~ 13% higher than that of the control.The nitrogen use efficiency at N2 level was significantly higher than that of N1 and N3,which was 30.98% and 17.57% respectively.During the annual period,the nitrogen content of fruit leaves showed high-low-high trend,and the Ndff value of the leaves increased with the passage of time.The nitrogen content and Ndff value of leaves treated with N2 were higher than those of N1 and N3 at different fertilization levels.The Ndff value of the fruit was higher than that of other organs,and the Ndff value of the new shoots decreased.However,the L-M and N2 treatments were better than other treatments.(3)The utilization rate of nitrogen fertilizer treated by P-C on the slope land increased with the increase of fertilizer application rate,and the utilization rate of nitrogen fertilizer was 21.32% ~ 27.58%.Leaf nitrogen content and Ndff value increased with the increase of fertilizer amount.The nitrogen content of leaf decreased first and then increased in the annual cycle,and the Ndff value of leaf increased with the passage of time.In the fruit harvest period,the Ndff value of the fruit was higher than that of other organs,followed by the new foliage,the Ndff value of the organ,and the difference was significant.To sum up,ridge film mulching combined straw mulching,rainwater stimulation and infiltration can effectively maintain the soil moisture content of the orchard and reduce the loss of soil water.The typhoon film cover can improve the absorption and utilization of nitrogen fertilizer and promote the growth and development of fruit trees.The application of fertilizer nitrogen fertilizer can effectively improve the efficiency of fertilizer utilization.The absorption and utilization of fertilizer from apple tree on the accretion of sloping land increased with the increase of N1,N2 and N3.