几个典型华南人工林土壤的养分状况和微生物特性研究

为了了解华南主要树种对土壤肥力的影响,分别用土壤化学分析方法、稀释平板法和酶分析法对相似立地条件的杉木林、马尾松林、湿地松林、马占相思林和尾叶桉林的凋落物养分、土壤养分、微生物数量及酶活性进行了研究。结果表明,5种林分中,杉木林的凋落物储量最大,凋落物的养分储量较大,为94.08kg hm-2。5种林地均呈强酸性。杉木林的土壤肥力较高,有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量分别为25.54 g kg-10、.96 g kg-1、0.37 g kg-11、2.04 mg kg-1、64.42 mg kg-1、1.87 mg kg-1、41.88 mg kg-1,但是土壤微生物数量小;马尾松林、湿地松林凋落物的养分储量小,土壤养分含量较低,土壤肥力低;马占相思林有效地改善了土壤化学性质,凋落物的养分储量在5种林分中最大,达106.2 kg hm-2,土壤肥力高,有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量分别为23.42 g kg-1、0.93 g kg-1、1.28 g kg-1、15.29 mg kg-1、69.32 mg kg-1、1.98 mg kg-1、76.88 mg kg-1,微生物数量大,酶活性强;尾叶桉林的土壤有机质、N和P含量低,K含量高,微生物数量小和酶的活性较低,土壤肥力低。

SOIL NUTRIENTS AND MICROORGANISMS IN SOILS OF TYPICAL PLANTATIONS IN SOUTH CHINA

Nutrients in litters and soils,amount of microorganisms and activity of enzymes in soils of plantations of Cunninghamia lanceolata,Pinus massoniana,Pinus elliottii,Acacia mangium and Eucalyptus urophylla similar in geographic conditions were studied using soil chemical analysis,dilution flat and enzyme analysis methods in order to get a better understanding of influences of some main tree species in South China on soil fertility.The soils of the five plantations were rather strong in acidity.Among the five plantations,the Cunninghamia lanceolata plantation had the largest amount of litters,which were also rather rich in nutrient reserve,about 94.08 kg hm~(-2).Consequently,its soil fertility was relatively high,with soil organic matter,total N,total P,total K,alkali-hydrolyzable N,available P and available K being 25.54 g kg~(1),0.96 g kg~(-1),0.37 g kg~(-1),12.04(mg kg~(-1),)64.42 mg kg~(-1),1.87 mg kg~(-1),41.88 mg kg~(-1),respectively.However,the soil was low in amount of microorganisms.Pinus massoniana and Pinus elliottii litters were low in nutrient content,and their soils were resultantly low in nutrient contents and soil fertility.The Acacia mangium plantation effectively improved soil chemical properties and its litters had the highest nutrient reserve among the five plantations,about 106.2 kg hm~(-2).Its soil fertility was the highest among the five plantations,with organic matter,total N,total P,total K,alkali-hydrolyzable N,available P and available K reaching 23.42 g kg~(-1),0.93 g kg~(-1),1.28 g kg~(-1),15.29 mg kg~(-1),69.32 mg kg~(-1),1.98 mg kg~(-1) and 76.88 mg kg~(-1),respectively,and its amount of soil microorganisms and activity of enzymes were also great.The soil in the Eucalyptus urophylla plantation was high in K,but low in soil organic matter,N,P,amount of soil microorganisms and enzyme activity,and thus resulting in low soil fertility.