红壤茶树根层土壤基础呼吸作用和酶活性

Soil basal respiration and enzyme activities in the root-layer soil of tea bushes in a red soil.

对不同树龄茶树根层土壤的呼吸作用 (包括代谢熵 qCO2 )和土壤酶 (脲酶、转化酶和酸性磷酸单酯酶 )活性进行了研究 .不同树龄茶树根层土壤日基础呼吸作用强度 (3 6.2 3～ 5 8.5 2mg·kg-1·d-1)和日代谢熵 (0 .3 0～ 0 .68)都以 40和 90年茶树较为接近 ,分别显著大于和小于 10年树龄茶树根层土壤 ;脲酶活性 (41.48～ 47.72mg·kg-1·h-1)则三者间差异不大 ,虽然随树龄增长而下降 ;转化酶活性 (189.2 9～3 63 .40mg·kg-1·h-1)也随树龄增长而下降 ,并且 10年茶树根层土壤显著大于 40和 90年树龄茶树 ;而酸性磷酸单酯酶活性 (44 4.2 2～ 82 8.3 2mg·kg-1·h-1)相反 ,随树龄增长而增强 .结果表明 ,土壤基础呼吸作用、代谢熵和 3种土壤酶活性都与茶树树龄、土壤 pH、土壤有机碳、土壤全氮、土壤可溶性酚总量。

Soil basal respiration potential, metabolic quotient (qCO 2), and activities of urease, invertase and acid phosphomonoesterase were investigated in the root layer of 10 , 40 , and 90 yr old tea bushes grown on the same type of red soil. The soil daily basal respiration potential ranged from 36.23 to 58.52 mg·kg -1 ·d -1 , and the potentials in the root layer of 40 or 90 yr old were greater than that of 10 yr old tea bushes.The daily qCO 2, ranging from 0.30 to 0.68, was in the reverse trend. The activities of test three enzymes changed differently with tea bushes' age. Urease activity in the root layer of all age tea bushes ranged from 41.48 to 47.72 mg·kg -1 ·h -1 and slightly decreased with tea bushes' age. Invertase activity was 189.29～363.40 mg·kg -1 ·h -1 and decreased with tea bushes' age, but its activity in the root layer of 10 year old tea bushes was significantly greater than that in the root layer soil of 40 or 90 year old tea bushes. Acid phosphomonoesterase activity (444.22～828.32 mg·kg -1 ·h -1 ) increased significantly with tea bushes' age. Soil basal respiration potential, qCO 2 and activities of 3 soil enzymes were closely related to soil pH, soil organic carbon, total nitrogen and C/N ratio, total soluble phenol, and microbial biomass carbon, respectively.