Potential use of polyacrylamide (PAM) in Australian agriculture to improve off and on-site environmental impacts and infiltration management

Polyacrylamide (PAM) has been sold in the United States since 1995 for reducing irrigation-induced erosion and enhancing infiltration. PAM's soil stabilizing and flocculating properties have also substantially improved runoff water quality by reducing sediments, N, ortho and total P, COD, pesticides, weed seeds, and microorganisms in runoff. The first series of practical field tests of PAM was conducted in the U.S. in 1991. Chemical companies, working with "early adopter" farmers, began farm testing of PAM in 1997 in Australia. Australian farmer results have been mixed because of lack of familiarity with PAM chemical and physical attributes, lack of research focused on Australian conditions and a resulting lack of support capability from extension or other public conservation or water management infrastructure. PAM has chemical and physical properties that impart a steeper learning curve than most other typical agricultural chemicals. Nonetheless, in Australian tests of PAM, sediment, nutrients, and pesticide reductions exceeded levels achieved by traditional conservation farming' methods (Waters et al., 1999a,b).