Author
SELLERS, BRENT - PURDUE UNIVERSITY | |
Hickman, Michael | |
HE, BINGHUI - PURDUE UNIVERSITY |
Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 1/15/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Soil amendments have been shown to increase water infiltration rates and stabilize soils against erosion. Practical application of this amendment technology requires understanding of how the amendments affect herbicide leaching and efficacy. Amendments that increase infiltration may also concurrently increase herbicide leaching. The primary objective of this study was to evaluate the effects of three soil amendments polyacrylamide (PAM); synthetic gypsum (89 percent Calcium Sulfate produced as a byproduct of coal fired electric generation); and agricultural grade lime on herbicide leaching and efficacy. Field experiments were established at two locations in Indiana, in a randomized complete block, split plot arrangement. Soil amendments were applied to the whole plots and herbicide rates were applied to the subplots. Treatments included PAM at 20 kg/ha, gypsum at 1000 kg/ha and lime at a rate to furnish equivalent Ca as the gypsum. Gypsum and PAM were also co-applied as one treatment. Herbicides were atrazine and acetochlor applied at full and 75 percent of the label recommended rates. Weed control efficacy was significantly reduced by using the 75 percent application rate, however, there were not effects on efficacy from soil amendments. Leaching of atrazine and acetochlor was not affected by soil amendment treatments on this Raub silt loam soil. The amendment applications appear to have no effect on herbicide efficacy or leaching in this trial. The impact of repeated, long-term usage of these amendments has yet to be determined. |