Effects of Polyacrylamide and Gypsum on Seedling Emergence
Investigators (most current known information)
Polyacrylamide is known to improve soil structure and therefore may be useful for improving seedling emergence in arid lands where crusting of dry soils often impedes emergence. Series of studies were conducted in Israel and Texas to test the effects of Polyacrylamide (PAM) on seedling emergence. Gypsum and other factors were tested in combination with PAM. In the Israel studies PAM (20 kg/ha) + gypsum (5 Mg/ha) significantly improved emergence of onion seedlings on soils with an ESP of 3%, but had little effect at a higher ESP level or on cotton emergence. In the Texas studies PAM (10 kg/ha) with or without gypsum failed to improve seedling emergence of wheat; and, PAM failed to improve emergence of forage grasses. Subsequent studies indicated that PAM (10 kg/ha) altered the distribution of water in soil columns, causing the surface cm of soil to be drier, and depths of 3 and 5 cm to be wetter than those of control columns. This surface drying may account for the inconsistent response of seedlings to PAM. Further studies revealed that PAM and cactus extract similarly improved water infiltration properties of two soils, and that PAM reduced evaporation from soil columns. Because PAM may result in drier soil surfaces, optimal management of PAM to improveseedling emergence must take into account the depth of seed placement.
Articles in Journals
Gardiner, D., P. Felker and T. Carr. Cactus extract increases soil water infiltration rates. (in press)
Gardiner, D.T. and Q. Sun. 2002. "Infiltration of wastewater and simulated rainwater as affected by polyacrylamide." Journal of the American Water Resources Association 38:1061-1067.
Gardiner, D. and A. Kalaskar. 2001. "Effects of polyacrylamide on soil water content following a rainfall event." In Annual Meeting Abstracts (CDROM, Charlotte). American Society of Agronomy, Madison WI.
Gardiner, D., T. Carr and R. Morgan. 1999. "Soil water distribution following polyacrylamide application." Presented at the Agronomy Meetings. Salt Lake City UT.
Gardiner, D., P. Felker and T. Carr. 1999. "Cactus extract increases water infiltration rates in two soils." Communications in Soil Science and Plant Analysis.
Gardiner, D., Q. Sun, E. Mendez and T. Carr. 1998. "Improving water infiltration and ameliorating soil crusting with polyacrylamide." In Tropic Hydrology. American Water Resources Association, 167-172.
Gardiner, D. and T. Carr. 1998. "Polyacrylamide application affects soil moisture distribution." Agronomy Abstracts. American Society of Agronomy, Madison WI.