ARS | Publication request: MICROBIAL ACTIVITIES AND LABILE C AND N IN SOUTH DAKOTA SOILS UNDER PERMANENT GRASS, CONVENTIONAL TILLAGE, AND NO-TILL

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 9, 2000
Publication Date: N/A

Technical Abstract: Agricultural fields in central South Dakota managed in permanent grass, no-till row crops, and conventionally-tilled row crops were studied for microbial activities. Measures focused particularly on microbial means of phosphorus release through beneficial mycorrhizal fungi and phosphatase enzyme activities. Tests included dehydrogenase enzyme activity, short-term mmineralizable (labile) C and N, acid and alkaline phosphatase enzyme activities, and mycorrhizal fungal colonization of roots. All measured parameters of activity and nutrient availability followed the order permanent grass > no-till > conventional tillage. Generally, measures in permanent grass soil were significantly greater than both no-tilled and conventionally-tilled soils. In mineralizable N and mycorrhizal colonization, only permanent grass and conventional tillage were significantly different. Of the measured parameters, only alkaline phosphatase significantly differentiated among all three treatments. These measures suggest that few microbial parameters of soil quality are significantly greater in South Dakota soils converted to no-till management. No-till soils tended to support slightly more activity and labile C and N than conventionally-tilled soils, which may suggest slow or limited enhancement of soil quality.