Study On The Decomposition Characteristics Of Tea Tree Pruning Materials Under Different Methods Of Returning To The Field And Their Effects On Soil Fertilit

Tea,as an important economic crop in Guizhou province,produces a large number of tea tree pruners every year.Tea tree pruning treatment is given priority to with returning,in order to explore the tea tree pruning the decay characteristics of content and its influence on soil fertility,this research adopts the nylon mesh bags method to carry out the tea tree pruning the decomposing and test,in view of the tea tree pruning set the surface coverage(T1),buried 20 cm(T2),adjusting the carbon and nitrogen ratio(T3)and add the decomposing agent(T4)returning four ways,To investigate the degradation characteristics of tea tree clippings and their effects on soil nutrients under different returning methods.The results show that:(1)The decomposition rate of tea tree pruning was first fast and then slow.In the field test,the decomposition rate of tea tree pruning was 33.6% after 90 days.From 90 days to 180 days,decomposition stagnation;After the anniversary,the decomposition rate was 43.9%.The nutrient release rates of tea tree pruners were different.After 30 days of experiment,the carbon nutrient release rate was 39.1%.After the anniversary,the carbon release rate was the lowest,64.9%.The release rates of nitrogen and phosphorus were 87.0% and 83.3%,respectively.Potassium nutrient release was slow first and then fast,and the highest nutrient release rate was 92.1% after the annual.The decaying rate of pruned leaves was significantly higher than that of stems,and the decaying rate of leaves was 2.4% and 7.3% higher than that of mixed stems and stems,respectively.The nutrient release rate was different in different parts of tea tree pruning.The release rates of carbon,nitrogen and potassium were leaf > stem-leaf mixture > stem,while the release rates of phosphorus were stem > stem-leaf mixture > leaf.(2)Compared with surface mulch(T1)treatment,all treatments could significantly improve the decomposition rate of tea tree pruning,and buried 20 cm(T2)treatment had the best speed increase effect.Compared with surface covering(T1)treatment,the decomposition time of 20 cm deep(T2)decreased by69.9% and 61.1% in field and basin tests,and the decomposition time of 95% decreased by 32.3% and10.6%.The nutrient release rate of tea tree pruning was increased by different returning methods.After annual decomposition,the carbon release rate of each treatment was 6.2%,4.9% and 10.2% higher than that of surface mulch(T1),respectively.The nitrogen and phosphorus release rates of tea tree pruning were the best when buried at 20 cm(T2),which were 3.9% and 1.9% higher than that of surface mulch(T1)after annual decomposition.The nutrient release of potassium was the fastest in different returning modes.(3)Tea tree pruning had a great influence on soil nutrients.The influence of tea tree pruning on soil p H decreased first and then increased.Soil total p and total K were significantly increased,and surface cover(T1)increased by 20.7% and 31.5% compared with blank control(CK).The increase of soil available P was only limited to the early and middle stages of decomposition,and the addition of decomposing agent(T4)increased 108.2% compared with blank control(CK)for 180 days.The increase of soil available k was only limited to the early stage of decomposition,and the surface cover(T1)increased by 13.8%compared with the blank control(CK)on 30 days of experiment.After annual decomposition,soil organic matter in each treatment increased by 14.6%,7.4%,12.7% and 12.3% compared with blank control(CK),respectively.It had no obvious effect on soil nitrogen.(4)Tea tree pruning had a significant effect on the activities of β-1,4-glucosidase(BG)and acid phosphatase(ACP)enzymes and soil microbial biomass carbon,but had a minor effect on the activities of n-acetyl-β-d-glucosidase(NAG)and soil microbial biomass nitrogen and phosphorus.After annual decomposition,the BG activity of adding decaying agent(T4)increased by 103.2% compared with blank control(CK).The ACP activity of surface mulching(T1)increased by 134.8% compared with that of blank control(CK).Soil microbial biomass carbon under all treatments was significantly higher than that of blank control(CK),and increased by 38.9%,109.4%,226.8% and 50.3%,respectively,compared with blank control(CK).In conclusion,tea tree pruning can significantly increase soil organic matter,phosphorus,potassium,microbial biomass carbon and soil enzyme activities.Deep burial,c/N ratio adjustment and addition of decaying agents could accelerate the decaying of tea tree prunings,but deep burial had a better effect on the decaying of tea tree prunings and the nutrient release was faster than other treatments.Therefore,deep burial is a more suitable way for tea tree pruning to return to the field.