|Green, V - PURDUE UNIVERSITY|
Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2002
Publication Date: November 15, 2002
Citation: STOTT, D.E., GREEN, V.S. PAM CHEMICAL FORMULATIONS: EFFECTS ON EFFICACY. CD-ROM. INDIANAPOLIS, IN: SOIL SCIENCE SOCIETY OF AMERICA ANNUAL MEETING. 2002. Technical Abstract: PAMs are being used to stabilize the soil surface against crusting and erosion. At this time, only a few of the many commercially available PAM formulations have been used as soil conditioners. We designed three studies to determine how polymer charge density and concentration impacted PAM's effectiveness for reducing surface sealing controlling rill and interrill erosion. In the initial experiment, mini-rill flumes were used to examine the polymer effects. Alteration of polymer charge densities was achieved by carboxylation. The parent polymer had a molecular weight range of 5-6*106 g mol-1. Maximum control of rill erosion was achieved when 25-30% of the PAM amide side groups were replaced by carboxyls. The next two studies examined the impact of PAM on interrill erosion. Combinations of 3 polymer sizes (MW: 6, 12, and 18 Mg mol-1) and 3 charge densities (CD: 20, 30, and 40% hydrolysis) were studied. Three soils were used that varied in texture and mineralogy. Soils were exposed to rainfall simulation and infiltration rate was used as a surface sealing indicator. They were also analyzed using a fall-velocity tube to calculate an aggregate stabilization index. All responded well to PAM treatments. PAM increased final infiltration rate by as much as 3-5 fold. All PAM treatments were equally effective on the poorly structured soil, while the better structured soils showed differing preferences, indicating a need to tailor the treatment to the soil type. Understanding the interaction of different soils with various PAM configurations will enable users to select the best PAM product for their specific soil conditions.