Water and Erosion Management with Multiple Applications of Polyacrylamide in Furrow Irrigation

Abstract

Polyacrylamide (PAM) in furrow irrigation water eliminates 94% of runoff sediment. Higher infiltration (15-50%) can result in upperfield uverirrigation. We hypothesized that PAM would lengthen advance time, but that interactions with flow rate and wheel-track (WT) Ihrrows would occur, influencing erosion and infiltration with potential for improved water management. A 2-yr study conducted on 1.5% slope Portneuf soil (Dnrinodic Xeric Haplocalcid) was irrigated with 10 g tn-1 PAM in advancing 23 L min-1 furrow streams (reduced to 19 L min-1 after advance) (PAM treatment, 11) or without PAM (control, C). Initial inflows in 1994 were 23 L min-1 (normal flow rate, N) or 45 L min-1 (high flow rate, H) with or without PAM. The application of PAM at 23 L min -1 (PN) increased 2-yr mean advance time 33% and reduced runoff soil loss 88% compared with controls (CN). Polyacrylamide applied at 45 L min-' (PH) reduced advance time 8% and soil loss 75% compared with CN, whereas untreated 45 L min-1 inflows (CH) cut advance time 42% but raised soil loss 158%. The CH and PH raised infiltration 11 and 35% more than CN respectively. Polyacrylamide halted erosion in all furrows, but in WT furrows had no effect on advance time and Bide infiltration effect after two or three irrigations. This is mainly attributed to erosion and deposition increasing control-furrow wetted perimeters; accumulated PAM may also slightly affect seal conductivity. Polyacrylamide raised aggregate stability from 54

Polyacrylamide for Surface Irrigation to Increase Nutrient-Use Efficiency and Protectwater Quality

“…This material has demonstrated a remarkable ability to stabilize dry soil aggregates under rapid inundation and flow shear, flocculate fine soil particles suspended in flows, and coarsen aggregate size characteristics in the furrow system. These PAM-induced impacts result in reduced furrow erosion and increased infiltration (Terry and Nelson, 1986;Lentz, 1995;Sojka et al, 1998b). Barvenik (1994) concluded that anionic PAM applications in irrigation furrows posed little threat to organisms or the environment.…”

Polysaccharides as safer release systems for agrochemicals

“…Beside, water-holding capacity, hydrogels also improve the physical properties of soil by enhancing soil permeability and infiltration rates, reducing irrigation frequency, reducing compaction tendency, stopping erosion and water runoff, increasing plant performance, increasing soil aeration, delaying dissolution of fertilizers (improving fertilizer retention in soil), increasing sorption capacity or favoring the uptake of some nutrient elements by the plants and increasing microbial activity. All these properties, directly or indirectly, are beneficial to plants (Fonteno and Bilderback 1993;Bouranis et al 1995;Ben-Hur and Keren 1997;Sojka et al 1998;Akhter et al 2004).…”

“…These workers have observed that these polymeric matrices (hydrogels/beads) have good water-holding capacity. Hence, this property can further be exploited for water management during agricultural activities (Fonteno and Bilderback 1993;Bouranis et al 1995;Ben-Hur and Keren 1997;Sojka et al 1998;Akhter et al 2004). Bajpai and Giri (2003)have observed the decrease in release rate and release amount of KNO 3 with increase in crosslinker concentrations in (CMC-g-poly(AAm) hydrogels.…”

Managing Runoff Water Quality from Recently Manured, Furrow‐Irrigated Fields

“…Polymer application increased the soil aggregate stability and decreased soil dispersion, particularly during the rapid wetting event that occurs in furrows when the fl ow is initiated (Lentz et al, 1992). Sojka et al (1998) reported that WSPAM treatment nearly doubled the percentage of water-stable aggregates present in treated furrow soils relative to untreated soils. By reducing entrained sediment in the furrow stream by 99%, WSPAM greatly reduced the soil mass and surface area that was exposed to the fl owing water.…”

“…By decreasing sediment loads, WSPAM limited the dissolution, diff usion, and desorption reactions, which release soil-associated DOC and nutrients into the furrow stream. Th e polymer's soil-stabilization properties also promote increased furrow infi ltration, particularly in freshly formed furrows (Lentz et al, 1992;Lentz and Sojka, 2000;Sojka et al, 1998). Th e resulting decrease in mean runoff volume, compared with control furrows, contributed to the decrease in runoff component mass losses.…”