Effects Of Different Fertilizing Treatments On Soil Enzyme Activities And Plant Growth In Peach Orchard

The effects of fertilization and soil managements on soil enzyme activities and microbial in peach orchard involved were seldom investigated.Under the condition of different fertilization and soil managements, this research studied the effects of the fertilizing on soil enzyme activities, soil nutrient, soil microbial communities and the plant growth of peach trees. The sensitivity of soil enzymes and soil microorganisms serving as soil quality was furthering explored. We could provide reference to the standard of soil enzyme and microbe and the reasonable management of soil and nutrient in peach orchard. The main results are ass follows:1.All the fertilization treatments improved the activities of soil invertase, urease, acid phosphatase, protease and catalase significantly; At the early stage of the peach tree growth,the soil enzyme activities of bag-controlled release fertilizer were lower than that of ordinary fertilizer.But after that, the enzyme activities of bag-controlled release fertilizer were significantly higher than that of the ordinary fertilizer. The trends of soil available nutrients were same as that of soil enzyme activities. Throughout the growing season, the bag-controlled release fertilizer provided nutrients steadily and incessancily. Significant correlations existed between soil enzyme activity and soil nutrient content, all soil enzyme activities and alkaline hydrolysis nitrogen content were significantly positive correlation; Catalase, sucrase and available phosphorus content were significantly positive correlation. All the processings of fertilizer enhanced the total nitrogen, total phosphorus and total potassium content in peach leaves. Furthermore, the promotion effect of bag-controlled release fertilizer was better than ordinary fertilizer. Compared with ordinary fertilizer and CK, bag-controlled release fertilizer treatment increased chlorophyll content and net photosynthetic rate of leaves significantly.New shoot increment of the bag-controlled release fertilizer was lower but stems were thicker than ordinary fertilizer.2. The study of fertilizers and different materials compounding was found that, the treatments of fertilizers + BSFA+ sorbitol and all matter added improved the activity of soil invertase. BSFA、sorbitol 、sodium nitrophenolate and Na HS reduced the activity of invertase compared with fertilizers. Compared with single fertilizing,all treatments improved the activity of soil urease except Na HS.Among these, the result of fertilizers + BSFA+ sorbitol was the best. The treatments of fertilizer + sodium nitrophenolate and fertilizer + Na HS reduced theactivity of catalase compared with CK. The treatment of all matters adding made the activity of protease highest; fertilizing improved the activity of proteinase, and every material improved the activity of protease.3. We made use of organic fertilizer, BSFA and activated carbon to repair contaminated chromium soil at pots.The results showed that, the activities of soil invertase, ureast,phosphatase and catalase at chromium contaminated soil were lower than that of no contaminated soil. With the increase of chromium concentration, the activities of enzyme reduced. When it was slight chromium pollution（1mg/kg）, increased the activities of soil invertase, urease, acid phosphatase and catalase in the early; The effects were better than that of and BSFA. When the soil was severe chromium pollution（2mg/kg）, organic fertilizer and activated carbon increased the activities of soil invertase, urease and catalase.4. The experiment was conducted to study the influences of soil enzyme activities and microorganism community in the soil of 2-year seedlings,planted in pots at different fertilizing amount. We found that, with the increase of fertilizer rate, effective nutrient content in soil increased. Within 50 days after fertilization, the activities of soil invertase and ureast of 1.33 g/kg treatment were highest; 50 days later, the activities of soil invertase and ureast of 2.75 g/kg treatment were highest. soil acid phosphatase of 2.28 g/kg treatment were highest in the first 50 days after fertilization; 50 days later, the activities of acid phosphatase of 2.75 g/kg reached the maximum. The activities of catalase of 1.33 g/kg were the highest within 60 days after fertilization. Bacteria of fertilization had great changes compared with no fertilizer. The advantages of soil bacteria genera were Subgroup_6norank, Xanthomonadaceae_uncultured and Chitinophagaceae_uncultured and so on. With the increase of fertilizer rate, the scale of Subgroup- 6- norank reduced, while the scale of Chitinophagaceae_uncultured, Xanthomonadaceae_unculture and bacillus increased. The advantages of soil fungi genera were Cystofilobasidiaceae-unclassified, Gibberella and Trichocomaceae-unclassified and so on. The structure and composition of soil fungi were different for different fertilization treatments. The leaves nutrient contents of fertilization were higher than that of without fertilization; and with the increase of fertilizer, nutrient contents increased. The plant new shoots showed the same trend as the nutrient contents. The leaf net photosynthetic rate of 26.6 g/tree were the highest and chlorophyll content of 2.28 g/kg were the highest.5. We studied the variation trends and correlations of soil nutrient and soil enzyme activities, which under the conventional fertilization and management level, on 15 different peach-orchards. Results showed that, alkali phosphorus and potassium satisfied the demandsof the peach trees in most areas except nitrogen, some areas lacked soil organic matter. In different regions, the activities of soil enzymes were significant difference except protease. In northwest region, the average activities of soil catalase, invertase and urease were the highest, but the activity of phosphatase was thelowest. In the northeast and southwest,the activities of catalase, invertase and urease were lower, but the activity of phosphatase was higher in northeast China. Between soil nutrient and soil enzyme has a great relationship, soil enzyme activities were influenced greatly by nutrients.