PRODUCTION OF ROOT-DERIVED MATERIAL AND ASSOCIATED MICROBIAL-GROWTH IN SOIL AT DIFFERENT NUTRIENT LEVELS
PRODUCTION OF ROOT-DERIVED MATERIAL AND ASSOCIATED MICROBIAL-GROWTH IN SOIL AT DIFFERENT NUTRIENT LEVELS
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DOI：
10.1007/bf00257647
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发表时间：
1987-01-01
影响因子：
6.5
通讯作者：
VANVEEN, JA
中科院分区：
文献类型：
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作者：
MERCKX, R;DIJKSTRA, A;VANVEEN, JA
玉米植株在含有 14CO2 的大气中、两种不同矿物质营养水平的沙土中生长 42 天。发芽后28、35和42天测量芽、根、土壤和土壤微生物量的14C和总碳含量。在较低营养水平下，芽和根的相对生长速率在35天后下降，但在较高营养水平下相对稳定。在前一种处理中，所有收获时，总固定 14C 的 2% 作为残留物保留在土壤中，而在较高的养分水平下，42 天后保留高达 4%。在较低养分水平下，14C 融入土壤微生物生物量在 35 天后接近其最大值，但在较高养分水平下继续增加。一般来说，根际微生物量、14C含量和荧光假单胞菌数量之间存在良好的一致性。根际荧光假单胞菌的数量在较低营养水平下35天后达到最大，并在较高营养水平下继续增加。土壤中残留14C占土壤微生物量的比例，在较低养分水平下为28%～41%，在较高养分水平下为20%-30%。 0.5 N K2SO4 可以从低营养土壤中提取 18%-52% 的残留土壤 14C，而从高营养土壤中提取的残留土壤 14C 为 14%-16%。根际微生物的生长似乎直接受到矿质养分消耗的影响，而植物生长和根源材料的相关生产仍在继续。
Maize plants were grown for 42 days in a sandy soil at two different mineral nutrient levels, in an atmosphere containing 14CO2. The 14C and total carbon contents of shoots, roots, soil and soil microbial biomass were measured 28, 35 and 42 days after germination. Relative growth rates of shoots and roots decreased after 35 days at the lower nutrient level, but were relatively constant at the higher nutrient level. In the former treatment, 2% of the total 14C fixed was retained as a residue in soil at all harvests while at the higher nutrient level up to 4% was retained after 42 days. Incorporation of 14C into the soil microbial biomass was close to its maximum after 35 days at the lower nutrient level, but continued to increase at the higher level. Generally a good agreement existed between microbial biomass, 14C contents and numbers of fluorescent pseudomonads in the rhizosphere. Numbers of fluorescent pseudomonads in the rhizosphere were maximal after 35 days at the lower nutrient level and continued to increase at the higher nutrient level. The proportions of the residual 14C in soil, incorporated in the soil microbial biomass, were 28% to 41% at the lower nutrient level and 20%-30% at the higher nutrient level. From the lower nutrient soil 18%-52% of the residual soil 14C could be extracted with 0.5 N K2SO4, versus 14%-16% from the higher nutrient soil. Microbial growth in the rhizosphere seemed directly affected by the depletion of mineral nutrients while plant growth and the related production of root-derived materials continued.