Author
Zobeck, Teddy | |
BADDOCK, MATTHEW - Griffiths University | |
Van Pelt, Robert - Scott | |
Tatarko, John | |
Acosta-Martinez, Veronica |
Submitted to: Aeolian Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/15/2012 Publication Date: 9/1/2013 Citation: Zobeck, T.M., Baddock, M., Van Pelt, R.S., Tatarko, J., Acosta Martinez, V. 2013. Soil property effects on wind erosion of organic soils. Aeolian Research. 10(1):43-51. Interpretive Summary: Histosols (also known as organic soils, mucks, or peats) are soils have more than 20 % organic matter in half or more of the upper 30 inches. Forty four states have a total of 52 million ac of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss in crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA-Natural Resources Conservation Service (NRCS) as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to calibrate and validate estimates of wind erosion of organic soils using WEPS. A field portable wind tunnel was used to generate air-borne particles and dust from agricultural surfaces for soils ranging from 17% to 67% organic matter (OM). The soils were tilled and rolled to provide a compacted, but loose surface. Blowing dust and sand were measured using an sampler at the wind tunnel exit. Dust samples were analyzed for physical and chemical properties. Particle density of the sand-sized material varied with OM content. The lowest OM soils had the highest dust concentrations. The soils with the highest amount of wind-erodible particles present (51-74%) had distinctly higher dust emissions compared with the other soils (<43% wind-erodible particles). These results demonstrate the following: 1) Surface soil organic matter content affected how wind eroded the soil and their dust emissions. 2) Differences in dust emissions can be linked to soil properties. 3) Simple matnematical models based on one or more soil properties can be used to estimate dust emission from organic and organic-rich soils. Technical Abstract: Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss in crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA-Natural Resources Conservation Service (NRCS) as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to calibrate and validate estimates of wind erosion of organic soils using WEPS. A field portable wind tunnel was used to generate suspended sediment and dust from agricultural surfaces for soils ranging from 17% to 67% organic matter. The soils were tilled and rolled to provide a consolidated, friable surface. Dust emissions and saltation were measured using an isokinetic vertical slot sampler aspirated by a regulated suction source. Suspended dust was sampled at a frequency of once every six seconds in the suction duct using a Grimm optical particle concentration and size analyzer. The larger dust samples were analyzed for physical and chemical properties. Particle density of the saltation-sized material (>106 microns) varied with OM content from 2.41 g cm-3 for the soil with the lowest OM content to 1.61 g cm-3 for the soil with highest OM content. The lowest OM soils produced the highest dust concentrations both during initial blow-offs and when abraded. The soils with the highest fraction of wind-erodible aggregates (51-74%) had a distinctly higher dust emissions compared with the other soils (<43%). The dust emissions from the four high OM soils (>25% OM) was not significantly increased by the introduction of abrader. These results demonstrate the following: 1) Surface soil organic matter content affected wind erodibility and dust emissions. 2) Variations in dust emissions can be linked to soil properties. 3) Abrasion did not significantly increase dust emission rates from high OM soils due to their high mechanical stability. 4) Simple models based on one or more soil properties can be used to estimate dust emission from organic and organic-rich soils. |