Effects Of Regulate Measures On Growth Metabolism And Soil Condition Of High Yield Poplar

To solve the problem in poplar planting, in aid of agriclutural research achievement, system research were carried out in forest cultivation including key techniques of water and fertilizer regulating, root regulating, plastic mulch, organic fertilizer et al. The study tried to explore the regular of plplar growth, improve the forest fertility and increase the poplar yield. The results were as fellows:1. Water and fertilizer interactive: Under the same water level, the content of chlorolhyll and root activity was increased in application of humic acid compared with inorganic fertilizer. The NR activity was increased in application in earlier stage. Application of humic acid fertilizer decreased the Gs and Tr, increaed the WUE and ABA under low water condition; however, it is increased the Gs and Pn, decreased the content of ABA significently in regular and high water level.With the increasing of water level and application of humic acid, the content of IAA GA and ZT increased in varying degree in leaf and root. Application of humic acid also enhanced the activity of active oxygen elimination and the osmoregulation.Under the same water level, the poplar total absorbtion of N,P,K was increased by application of humic acid compared with inorganic fertilizer, therefore, the contents of nitrate nitrogen and available P,K were low in soil, but it can increased the content of ammonium nitrogen, which might reduce the loss of N from soil. The application of humic acid also increased the contents of total C, humic acid,fulvic acid and the ratio of humic acid to fulvic acid,polyphenol oxidase enzyme and urease enzyme.Application of humic acid have little effect on weight of root,stem,leaf and total weight of poplar under low water treatment, have significent effect under regular and high water treatment however, and high water treatment increase the most.2. Plastic membrane mulch: Plastic membrane mulch treatment increased the SOD POD activity, decreased the content of MDA. Protein are degradation slow, and Pro and free amino acid are low in mulch treatment, It can be concluded that plastic membrane mulch can decreased the degree of cell membrane lipids peroxide, increased the cell membrane stability, and put off the poplar aging. Compared with no mulch treatment, plastic membrane mulching can decrease the loss nitrate nitrogen and increased the utilization ratio of N in treatment. It also can increased the available P, K and organic matter by 46.60%,6.09% and 35.60% respectively, and can increased the bacterium, actinomycetes, fungus and microorganism by 144.73%, 63.45%, 10.07% and 101.65% respectively.As for the amount of growth, compared to no mulch, plastic membrane mulching increased DBH,tree height and volume of timber by 30.15%, 10.75% and 33.93% respectively, and also increased the NPK content in root,stem and leaf. It is thus clear that the application of plastic membrane mulch have active effects in poplar growth.3. Root cutting: Root cutting can increased the activity of SOD, decreased the MDA content. MDA are higher in four side root cutting than in two side root cutting. The souble protein and free amino acid are decreased in the near root cutting and four side root cutting. As for the Pro, four side root cutting are higher than CK, two side root cutting lower than CK.Nitrate nitrogen are higher than CK in 60cm root cutting, and lower than CK in 80cm and 100cm. Root cutting decreased the ammonium nitrogen and available P. Under the same root cutting distance, two side root cutting have lower nitrater nitrogen and ammonium nitrogen, but have higher available P than in four side root cutting because root secretion have activation on soil P. Root cutting also can increased the activtity of catalase and urease, and decreased the activity of polyphenol oxidase, increased amount of bacterium, actinomycetes, fungus and microorganism, and four side root cutting superior to two side root cutting.Root cutting obviously increased the DHB and tree height. As for volume of timber, the 8-2 treatment is the best, the second were10-2 and 10-4, 6-2,8-4 and 6-4 were in th last. But all root cutting treatment have higher yield than CK. Root cutting also increased the nutrient content of root stem and leaf. Thus it can be concoulded that reasonable root cutting is feasible to increase poplar yield.4. Organic fertilizer: Application of organic fertilizer can increased the leaf SOD activity, decreased the MDA content. It was also incresed the souble protein and souble sugar, decreased free amino acid in later stage, therefore, organic fertilizer can decrease the degree of cell membrane lipids peroxide, increased the cell membrane stability.NPK have no obvious law in different fertilizer treatment. But application of organic fertilizer increased the contents of total C, humic acid and fulvic acid, correspondingly the ratio of humic acid to fulvic acid and the value of E4/E6 was increased. This can be inferred that organic fertilizer can increased the activity of soil humus. Application of organic fertilizer also can increase the activity of catalase, dmylase and urease, and decreased the activity of polyphenol oxidase, increased amount of bacterium, actinomycetes, fungus and microorganism.As for the amount of growth, compared to inorganic fertilizer, the application of organic fertilizer increased DBH, tree height and volume of timber by 40.68%, 38.41%, 35.08% and 33.60% in 1,2,4,3 respectively, CK are the lowest by 28.14%. It is thus clear that the application of organic fertilizer have the significent facilitation on poplar growth.