Evaluation Of Nitrogen Metabolism Ability Of Dominant Grass Species In Apple Orchard And Effect Of Orchard Management On Soil Nutrients

Orchard natural grass can improve the stability of the soil environment.Increasing soil organic matter content and diversity of soil microbial communities in orchard.Achieve efficient use of substance and energy in orchard ecosystems.It laid the foundation for sustainable and efficient production of fruit trees.In this study,we studied the growth and succession of 'Hanfu' orchard grasses under the conditions of grass production and the changes of soil nutrients,microbial population structure and grass nitrogen metabolism enzymes after castration management.Understand the changes of soil nutrients and microbes in grassland,and find out the relationship between grass and soil under mowing management.Provide theoretical guidance for the sustainable and healthy development of the orchard.The main results are as follows:nce for the sustainable and healthy development of orchards.The results as follows:1.A total of 16 different grass species were found in the natural grasses of the orchard,a total of 15 genera from 12 families in 2018.With each change of season grasses vary significantly month alternately.In June.The dominant grass species has changed.Mainly in the Polygonum posumbu?Chenopodium album?Herb of common crabgras.Entering the summer in July,the dominant grass in the apple orchard has Polygonum posumbu ?Chenopodium album?Herb of common crabgras?Common knotgrass.After entering the rainy season in late June,as the rainfall increases,the grass grows stronger and the grass yield increases.The dry weight of the aboveground parts reached 234.16 g·m^-2 and 362.98 g·m^-2 in June and July.2.Determination of the 4 types of grass Seedlings of NO₃^- and NH₄⁺ absorption kinetics parameters.Differences in nitrogen uptake capacity of four species of grass species.Common knotgrass?Herb of common crabgras?and Chenopodium album have higher affinity for NH₄⁺ than NO₃^-.And the affinity of Polygonum posumbu for NO₃^- is significantly greater than that of NH₄⁺.Affinity of different grass species to NO₃^- Chenopodium album>Common knotgrass>Herb of common crabgras>Polygonum posumbu.3.Changes in leaf and root nitrogen metabolism enzymes in four species of grass after mowing treatments conditions.Mowing treatments lead to the metabolic system slows sharply of grass,and cause a decrease in the root activity of the grass species,which is the most obvious decrease on the second day.After the mowing process results in four kinds of roots and Ni R reduced NR activity.Root nitrogen metabolism of diminished capacity.GS and GOGAT activity in Chenopodium album,Common knotgrass and Herb of common crabgrasafter mowing also showed a trend of decrease.It inhibits the assimilation of NH₄⁺.This leads to a decrease in nitrogen metabolism.After mowing treatments an increase of four dominant grass tablets GOT activity.Promotes the synthesis of some essential amino acids.4 kinds of GOT and GPT activity Root advantages of reducing both appear in the first 2d after mowing.It indicated that the transamination effect of the four grass roots after the mowing was weakened,indicating that some amino acids in the leaves were affected after the castration.4.The effects of four species of grass mowing treatment on soil nutrients were mainly concentrated in 0-10 cm soil layer.The effects of different grass species on soil nutrients and microbes after mowing treatment.Mowing treatment indirect effects of soil environment.Thereby causing changes in soil microbial communities.