Submitted to: International Soil Conservation Organization Conference Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2004
Publication Date: 7/4/2004
Citation: Stott, D.E., Diack, M. 2004. Changes in surface soil physical, chemical and biochemical properties under long-term management practices on a temperate mollisol. International Soil Conservation Organization Conference Abstracts, July 4-9, 2004, Brisbane, Australia. 2004 CD ROM. Interpretive Summary:
Technical Abstract: With the progressive degradation of agricultural soils, there is a new emphasis on developing methods that are sensitive to changes in the condition of soils and their resilience to stress. This study relates soil physical, chemical and biological property changes under various long-term management systems. The study was conducted on a 16-year experimental field where several tillage and crop rotation combinations were available. The 16-ha field site was located in West Lafayette, Indiana, USA. The dominant soil was classified as a fine-silty, mixed, superactive, mesic Typic Endoaquoll. The climate is temperate, with a continental pattern of summer rains, averaging 970 mm/yr. The sealing index, as a measure of aggregate stability, decreased with decreasing tillage intensity, while soil penetrability increased. However, infiltration rate was highest in the chisel-disk system, with the no-till system exhibiting the lowest rates of infiltration. Total carbon and nitrogen, microbial biomass carbon, cold-water extractable dissolved organic carbon, and the enzyme activities were significantly greater in conservation systems as compared to conventional tillage practices. Enzyme activities measured, including ß-glucosidase, arylsulfatase, and fluorescein diacetate hydrolase, were sensitive to both changes in tillage and in cropping management with strong correlations with the physical parameters measured. This research shows that soil enzyme activities should provide a quick, sensitive indication of changes occurring in the soil physical structure.