This study investigated the soil acidification caused by continuous planting of tea bushes and its influence on the population distribution and community structure of microorganisms, soil basal respiration and activities of 3 soil enzymes (urease, invertase, acid phosphomonoesterase) and related ecological factors in the rhizosphere of 10-, 40- and 90- year old tea bushes, respectively, in Hangzhou, China. Soil pH decreased significantly by 0.57 of a pH unit with the tea bushes’ age, from 10- to 90-year old. Total exchangeable acidity of the soil also increased, ranging from 1119 to 1436 mmol (1/3 Al 3+ + H+) kg−1 oven-dried soil. However, the dominant component of soil total exchangeable acidity shifted from exchangeable H+ to exchangeable Al3+ with increasing cultivation age of the tea bushes. The soil organic carbon and total nitrogen contents, as well as the C/N ratio and soluble phenol content were significantly negatively correlated with soil pH, suggesting an accumulation of organic matter in the root-layer of the tea bush soils caused by the soil acidification. The bio-characteristics of these soils varied with the increasing age of the tea bushes and with soil acidification. Bacteria dominated the microbial community of the root-layer soils and soil microorganisms were not generally affected by soil pH. However, oligotrophic bacteria were obviously inhibited by soil acidification. Soil microbial biomass carbon and daily basal respiration were stimulated by soil acidification and the reverse was true for the metabolic quotient (qCO2). Decline of soil pH enhanced only the activity of soil acid phosphomonoesterase but not the activities of urease and invertase. The numbers of bacteria and actinomycetes in the soils of the 40- and 90-year old tea bushes were only half those in the 10-year old tea bush soil; however, the amount of soil microbial biomass carbon and the potential of daily basal respiration showed a two-fold increase for the 40- and 90-year old tea bush soil, compared with the 10-year old tea bush soil. The metabolic quotient (qCO2) declined as the cultivation age increased. Activities of urease and especially invertase in the root-layer soils declined with increasing tea bush age but, on the contrary, the activity of acid phosphomonoesterase increased.
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- Soil Acidification under Tea Bushes and Its Influence on the Biological Characteristics of a Red Soil
- Springer Netherlands
Systemische Notwendigkeit zur Weiterentwicklung von Hybridnetzen