EFFECT OF WATER-FILLED PORE-SPACE ON CARBON-DIOXIDE AND NITROUS-OXIDE PRODUCTION IN TILLED AND NONTILLED SOILS
EFFECT OF WATER-FILLED PORE-SPACE ON CARBON-DIOXIDE AND NITROUS-OXIDE PRODUCTION IN TILLED AND NONTILLED SOILS
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DOI：
10.2136/sssaj1984.03615995004800060013x
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发表时间：
1984-01-01
影响因子：
2.9
通讯作者：
DORAN, JW
中科院分区：
文献类型：
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作者：
LINN, DM;DORAN, JW
由含水量和总孔隙度确定的土壤孔隙空间充满水的百分比（充满水的孔隙百分比，%WFP）似乎与不同耕作制度下的土壤微生物活性密切相关。土壤培养在实验室中，在60%粮食计划署支持最大的好氧微生物活性所确定的CO2生产和O2吸收。在田间，美国4个地点的表层免耕土壤（0 - 75 mm）的WFP %在取样时平均为62%，而翻耕土壤的WFP %为44%。这种差异%粮食计划署反映在3.4和9.4倍以上的CO2和N2O的生产，分别从表面免耕土壤在24小时内相比，翻耕土壤。在75至150毫米的深度，%粮食计划署值增加免耕和翻耕土壤，平均约70%的免耕相比，50至60%的翻耕土壤。翻耕土壤中CO2的产生通过增加%WFP而增强，导致耕作处理之间CO2产生的差异很小或没有差异。然而，在免耕条件下，一氧化二氮的产量仍然较大。大量的N2O产生的N-施肥的土壤，无论耕作的做法。CO2和N2O的产生主要与耕作处理的WFP %有关，尽管在某些情况下，土壤水溶性C和NO3-水平也很重要。免耕和翻耕土壤之间的相对好氧微生物活性的计算，基于%粮食计划署相对于最大活动在60%的差异，表明粮食计划署值30至70%之间的CO2和N2O生产的线性关系。低于60%WFP，水分限制了微生物活性，而高于60%，好氧微生物活性明显降低，这是由于通气量减少的结果。
The percentage of soil pore space filled with water (percent water-filled pores, % WFP), as determined by water content and total porosity, appears to be closely related to soil microbial activity under different tillage regimes. Soil incubated in the laboratory at 60% WFP supported maximum aerobic microbial activity as determined by CO2 production and O2 uptake. In the field, % WFP of surface no-tillage soils (0-75 mm) at four USA locations averaged 62% at time of sampling, whereas that for plowed soils was 44%. This difference in % WFP was reflected in 3.4 and 9.4 times greater CO2 and N2O production, respectively, from surface no-tillage soils over a 24-h period as compared to plowed soils. At a depth of 75 to 150 mm, % WFP values increased in both no-tillage and plowed soils, averaging approximately 70% for no tillage compared with 50 to 60% for plowed soils. Production of CO2 in the plowed soils was enhanced by the increased % WFP, resulting in little or no difference in CO2 production between tillage treatments. Nitrous oxide production, however, remained greater under no-tillage conditons. Substantially greater amounts of N2O were produced from the N-fertilized soils, regardless of tillage practice. Production of CO2 and N2O was primarily related to the % WFP of tillage treatments although, in several instances, soil-water-soluble C and NO3- levels were important as well. Calculations of relative aerobic microbial activity between no-tillage and plowed soils, based on differences in % WFP relative to maximum activity at 60%, indicated linear relationships for CO2 and N2O production between WFP values of 30 to 70%. Below 60% WFP, water limits microbial activity, but above 60%, aerobic microbial activity decreases apparently the result of reduced aeration.