Five-year research summary using PAM in furrow irrigation

摘要: A previous conference paper (Sojka and Lentz, 1996) presented an historic perspective some general results of PAM investigations conducted at the USDA-ARS Northwest Irrigation Soils Research Laboratory in Kimberly, Idaho. This paper presents experimental methods and summarizes results from those studies, conducted over a five year period. Studies initiated since 1991 determined best mode application. established PAM's effectiveness under different furrow irrigation scenarios and sought to define its potential environmental impacts (Lentz, et al., 1992; Sojka 1993, Sojka et al., 1994; 1996; Trout et 1995). Kimberly ARS field experiments initially determine the application method that most efficiently effectively controlled furrow-irrigation induced soil loss infiltration. We investigated the following application parameters: PAM form — dry granular, stock solution. oil emulsion PAM type polymer charge type, charge density, molecular weight Application method standard: PAM added water, nonstandard: PAM applied soil Application strategy timing, rate, period application Irrigation water quality —effect of water's total salt or sodium adsorption ratio on effectiveness Experiments that examined effects of processes are presented in separate paper (Lentz and Sojka, 1996). series studies documented usefulness over range furrow-irrigated field conditions. was tested different soils, slopes, using different inflow rates irrigation waters. Several studies examined PAM's environmental impacts. We first developed an analytical procedure for measuring PAM concentration to document fate to furrow inflows. permanent PAM field site established to study effects long-term applications on soil properties. microbiology (Warwood Kay- Shoemake, 1996), productivity and solute leaching. Another experiment documented s influence field runoff water-quality. Finally, plot treated with excessive additions was used determine potential for acrylamide-monomer accumulation in crop-tissue (Barvenik al., 1996).