Effects Of Different Fertilizers On Nitrogen Absorption,N₂O Emission And Fruit Quality Of Apple Orchards In Weibei Dry Plateau

On Weibei dryland apple orchards of different fertilization measures,no nitrogen CK?nitrogen?,conventional high nitrogen?800 kg/hm²pure nitrogen?,optimization of reduction of nitrogen?400 kg/hm²?pure nitrogen,organic and inorganic NPK?400 kg/hm²pure nitrogen organic inorganic fertilizer 50%each?,four process,determine the regulation pathway and quantitative evaluation on apple orchards N₂O emissions of nitrogen loss of N₂O emissions,clear N₂O emission losses of nitrogen loss,reveal nitrogen optimize reduction and organic fertilizer instead of chemical fertilizer on the influence of nitrous oxide emissions,at the same time on the apple tree of different organs of nitrogen determination,In order to determine the distribution of nitrogen and the loss of nitrogen orchard to do a quantitative analysis,to determine the optimal amount of fertilizer applied to apples and fruit trees to the distribution of nitrogen rules,for the production of reasonable,efficient fertilization measures to provide a scientific basis.Research shows that:?1?the apple expands period is one of the largest,N₂O emissions is mainly due to the high temperature in summer,CK,conventional high nitrogen,optimization of reduction of nitrogen,organic inorganic NPK N₂O emission coefficient of 0.28 to 0.33%,four processing in?November 2018-November 2019?total emissions range?0.95 3.56 kg/hm²?,compared with the conventional high nitrogen treatment,optimize the reduction of nitrogen treatment and organic inorganic NPK treatment significantly reduce N₂O emissions,was reduced by39.88%and 41.57%respectively,the optimization of nitrogen and organic inorganic NPK can reduce N₂O emissions.?2?the length and diameter of all branches of apple trees were measured from January2019 to November 2020.A and b values were determined according to the relative growth formula=a?D²H?b,and the annual biomass growth of the whole tree was estimated.The whole tree biomass growth in 8.95 10.1 kg,large difference of different organs in tree growth accounted,CK,conventional high nitrogen,optimization of nitrogen,organic and inorganic reduction with four processing,trunk growth accounts for 16.3 18.5%of the growth of trees,branches growth was 18.2%-24.8%,leaf growth was 2.3%-2.6%,fruit growth was 42.5%-45%,root growth was 14.1%-16.0%of each processing tree biomass growth amount difference is not big,can be affected by the original nutrients in the soil.?3?the annual nitrogen uptake of the whole tree was 100.91 kg/hm²,106.77 kg/hm²,98.73 kg/hm²and 124.05kg/hm²,respectively,after four treatments of CK,conventional high nitrogen,optimized nitrogen reduction and organic and inorganic application.The annual increase of nitrogen in the whole tree was the highest under the treatment of organic and inorganic application,which was 13.93%and 20.41%higher than that under the conventional treatment of high nitrogen and the optimized treatment of nitrogen reduction.?4?the apple orchards of nitrogen loss under different fertilizer treatments including branches cut?summer and winter cut branches,leaf,fruit,N₂O emissions?,and the carrying out of each part cut from 0.56%to 2.17%of total fertilizer rate,leaf 1.8%4.83%,2.98%8.45%fruit,nitrous oxide,0.44%0.69%,the part of the cumulative loss in 5.78%to 16.14%of total n application rate,in the processing,no significant difference of nitrogen loss,but on the utilization rate of nitrogen fertilizer,organic inorganic NPK treatment better,provides a feasible solution for reducing nitrogen loss.?5?compared with the optimal nitrogen reduction treatment and the conventional high nitrogen treatment,there was no significant difference in fruit weight and fruit shape index.The organic and inorganic fertilizer treatment of soluble solid was 7.06%high in conventional nitrogen,which may be because the organic fertilizer promoted the decomposition of minerals by soil microorganisms and accelerated the absorption of nutrients by trees.The optimal nitrogen reduction treatment for soluble sugar content and the organic and inorganic application of soluble sugar were similar to the conventional high nitrogen treatment,which indicated that the decrease of nitrogen fertilizer did not cause the decrease of soluble solids in fruits.The titratable acid of the fruit is about 0.3%.Organic inorganic NPK treatment the highest content of vitamin C,is significantly higher than other processing,is higher than conventional high nitrogen and optimization of reducing nitrogen treatment increased by 37.47%and 79.68%,respectively,visible,organic fertilizer could change the fruit quality,this is likely to be organic fertilizer application,change the microbial activity in the soil,resulting in the absorption of nitrogen changed the vitamin C content of the apple.The yield of organic and inorganic fertilizer treatment was the highest,which was 37.3t/ha.The yield of organic and inorganic fertilizer treatment was 10.68%and9.06%higher than that of conventional high nitrogen extraction and optimized nitrogen reduction treatment.The combination of organic and inorganic fertilizer will not cause the decline of fruit quality,but also improve the fruit quality.