Effect of Water-Filled Pore Space on Carbon Dioxide and Nitrous Oxide Production in Tilled and Nontilled Soils

摘要: 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 US locations averaged 62% at time of sampling, whereas that for plowed soils was 44%. This difference …