Submitted to: Journal of Environmental Quality
Publication Type: Other
Publication Acceptance Date: 10/24/2003
Publication Date: 10/20/2004
Citation: Acosta Martinez, V., Zobeck, T.M. 2004. Enzyme activities and arylsulfatase protein in dust generated under laboratory conditions from agricultural soils. Journal of Environmental Quality. 33:1653-1661. Interpretive Summary: Dust created by wind erosion of agricultural soils can affect human health, and the quality of air and soil. Thus, it is important to locate the sources of dust to apply appropriate agricultural practices that reduce soil erosion and the production of dust. Dust generated from soils under laboratory conditions will allow comparisons of the properties of dust and its soil source in order to select which dust properties are a good fingerprint of their soil source. We generated dust of different sizes (27 and 7 microns) from soils that have been under different agricultural practices, and compared enzyme activities and protein content of the dust and its soil source. The enzyme activities and protein content of dust reflected the agricultural practices of its soil source. In addition, dust from different soils showed differences in their protein content and enzyme activities. These results indicate that measuring protein content and enzyme activities of dust can be a good fingerprint of its soil source.
Technical Abstract: Little is known about the potential of enzymatic processes, which are sensitive to soil type and management, for the characterization of dust properties. These measurements may have potential to identify the soil source of dust that may allow the application of appropriate corrective measures in the source site. Dust (27 and 7 microns) was generated under controlled laboratory conditions from agricultural surface soils (0-5 cm) in West Texas, USA. The soils were sampled from continuous cotton (Gossypium hirsutum L.) or cotton rotated with peanut (Arachis hypogaea L.), sorghum (Sorghum bicolor L.), rye (Secale cereale) or wheat (Triticum aestivum L.), and under different water management (irrigated or dryland), and tillage (conservation or conventional) systems. Both dust samples showed activities of beta-glucosidase, alkaline phosphatase and arylsulfatase, which are related to cellulose degradation, phosphorus and sulfur mineralization in soil, respectively. Enzyme activities of dust samples were significantly correlated to the activities of the soil source with r > 0.74 (P <0.01). Therefore, as found for the soils in a previous study, dust generated from a loam and sandy clay loam showed higher enzyme activities compared to dust from a fine sandy loam. In addition, dust from soils with a history of crop rotations and conservation tillage showed higher enzyme activities in comparison to dust from soils with a history of continuous cotton and conventional tillage. The same trends were observed with arylsulfatase protein content in dust, which was 0.27- 1.09, 1.54-3.83, and 1.82-5.46 mg per kg soil in the fine sandy loam, sandy clay loam and loam, respectively. Results provide indications that the enzyme activities and protein content of dust have potential as a fingerprint of its soil source.