【作者】 邬奇峰；

【导师】 姜培坤；

【作者基本信息】 浙江林学院 ， 森林培育， 2007， 硕士

【摘要】 板栗是中国南方重要的经济林种,近年来,随着板栗林栽培集约化程度的不断提高,出现了严重的土壤退化现象。为研究板栗集约化栽培对土壤生物化学性质产生的影响,开展了不同集约栽培历史板栗林土壤生物学性质;同时布置了不同除草方式对板栗林土壤生物学性质的影响,不同施肥对板栗林土壤生物学性质的影响和不同绿肥修复对板栗林土壤生物学性质的影响的研究。通过研究得出如下结果:1、板栗集约化栽培对土壤生物学性质产生的影响,采集了不同栽培历史的板栗林土壤样品,采用氯仿熏蒸法和Biolog法分析了土壤微生物量碳和微生物多样性,同时与天然灌木林进行了比较,结果表明:板栗林集约化栽培5、10、20年后,土壤微生物量碳含量比天然灌木林下降了15.89%、49.16%和55.13%,并达到显著差异。板栗林集约栽培初期,土壤微生物量碳占总有机碳比率与天然灌木林无显著差异,到集约经营10年时,比率明显下降,但集约经营10年后,比率又趋于稳定。灌木林改为集约栽培板栗林后,土壤微生物群落功能多样性呈下降趋势,反映土壤微生物碳源利用能力的AWCD值,板栗集约经营5年、10年、20年后分别只是灌木林的79.26%、63.20%和68.50%,并差异达显著水平。反映土壤微生物多样性的Shannox指数和McIntosh指数,集约栽培板栗林也显著低于天然灌木林。综合AWCD值和多样性指数,可以看出,板栗林集约栽培头10年,土壤微生物群落功能多样性下降趋势明显,10年后则变化不大。总之,随着板栗林集约栽培时间的延长,土壤质量明显下降,但到10年后趋于稳定。2、板栗林不同除草方式对土壤生物学性质的影响,布置了不同除草方式试验。研究结果表明:传统的翻耕除草方式不仅可以改善土壤养分状况,而且可显著增强土壤磷酸酶、蔗糖酶及过氧化氢酶的活性,明显增加土壤微生物量碳和水溶性有机碳含量;而除草剂除杂草处理,土壤3类酶活性和土壤微生物量碳、水溶性有机碳含量明显下降,对土壤的健康质量和生物学肥力有严重影响。兼顾土壤保持和土壤质量,采用刈割除杂草方式对林地土壤质量维持和板栗生长均较有利。3、施用不同肥料对板栗林土壤性质的影响,布置了肥料试验。研究结果表明:无论施用有机肥还是施用化肥处理,与不施肥比较,土壤水解氮、有效磷及速效钾的含量都有显著提高,并随着化肥施肥量的增加,土壤有效养分含量明显上升。施用有机肥显著提高了土壤磷酸酶和蔗糖酶活性,并随着有机肥用量的增加,土壤磷酸酶和蔗糖酶活性明显上升。有机肥也明显增加了土壤水溶性有机碳和微生物量碳的含量。4、不同绿肥种植对板栗林土壤性质的影响,布置了绿肥种植田间试验。试验结果表明:黑麦草、白三叶、大绿豆及黑麦草、白三叶、大绿豆3种混播4个绿肥处理的土壤全氮和有机质含量均明显高于不播绿肥的空白处理;种植绿肥也显著增加了土壤酶活性和土壤水溶性有机碳及微生物量碳的含量。比较4个播种绿肥处理发现,种大绿豆对提高土壤全氮、有机质含量和土壤酶活性效果最好。但种绿肥在当年对土壤水解氮、有效磷和速效钾含量无显著影响。更多还原

【Abstract】 Chinese chestnut (castnea mollissima) forest is an important economic forests that has been intensively managed in southern China recently. Consequently, soil quality was getting worse and worse with the intensive management (IM). In order to clarity the effects of intensive management of Chinese chestnut on soil biological properties by studing soil biological properties of Chinese chestnut stands with different history. Three site-specific experiments were conducted to study the influences of different ways of cleaning weeds, different types and various rate of fertilizer, different green manures on the biological properties of soil. The results obtained were summarized as follows:1.Soil biological properties of Chinese chestnut stands with different history were tested using chloroform fumigation and Biolog .Three soil samples from natural shrubbery were collected as control. It was shown that compared with shrubbery, microbial biomass carbon(MBC) of soil under Chinese chestnut stand with 5,10 and 20- year’s IM decreased by 15.89%,49.16% and 55.13% respectively, and significant difference(P<0.05) among one to another has been observed. The proportion of MBC out of total organic carbon (TOC) of soil under Chinese chestnut stand was measured no significant difference with soil under natural shrubbery during first 5-year of IM, however, it decreased apparently until 10-year’s IM and then kept constant afterward. Soil microbial functional diversity measured by average well color density (AWCD) declined greatly by conversion natural shrubbery into IM Chinese chestnut stands. Compared with shrubbery, AWCD value of soil under Chinese chestnut forest decreased by 79.26%, 63.20% and 68.50% respectively after 5, 10 and 20-year’s IM, with significant difference(p<0.05). Index of Shannox and McIntosh reflecting soil microorganism diversity were lower in IM Chinese chestnut stands than that under natural shrubbery. Combining AWCD value with diversity indexes, it can be concluded that soil microbial functional diversity of IM Chinese chestnut stands had decreased noticeably during the first-10 year’s IM, but no change has been observed afterward, suggesting that a new and special soil microbial communities has been formed after 10-year’s IM of Chinese chestnut stands. Soil quality closely related to soil organic and biological properties may decline with intensive management being conducted.2. Intensive management on Chinese chestnut (castnea mollissima) forest with weeds being cleared away is popular, however, it can be predict that soil qualities must have changed as a result. The objective of this study is to test the effects of weeds clearing way on soil properties by conducting a field trial under Chinese chestnut forest. The soil under Chinese chestnut with weeds being plowed into deep soil showed stronger activities of Phosphatase, Sucrase and Hydrogen peroxidase, and so did the soil microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC)comparing with control which having received no any attention. The converse situation has been observed under Chinese chestnut with weeds being cleared away by using herbicide. Considering the fact that soil plowing must result in soil erosion at some extent, the way of weeds being cut but not plowed into deep soil was recommended when farmer managed Chinese chestnut in subtropical zone where precipitation is high.3. Fertilization has become useful way to improve the yield. The objective of this study is to find out the effects of different types and various rate of fertilizer on soil available nutrients and biochemical properties by one year field fertilizer trial. It was found that soil available N,P and K positively response to the increase of fertilizer rate. Organic fertilizer had a positive influence on activities of soil phosphatase and sucrase, and still positive improvement was observed for soil water-soluble organic carbon(WSOC) and microbial biomass carbon (MBC). It was concluded from this trial that the practice of fertilization enriched the soil available nutrients and organic fertilizer has better effect on soil biochemical and biological properties than mineral fertilizer.4.The objective of this study is to test the effects of green manure on soil nutrient and bio-properties under chestnut plantation. A manure trial with planting rye grass, white clover, green gram, the mixture of three of them, and control with no any vegetation (CK). It was found that soil total organic carbon (TOC) and total nitrogen (TN) were much higher (P<0.05)in Chinese chestnut plantation planted with green manure compared with control and the similar tendency was true for soil microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC). Comparing the treatments with different types of green manure, green gram was among the best to improve soil TOC, TN and enzymatic activities, however, there was no improvement to observed respect to soil available N, P, and K after one year manure trial.更多还原