Author
Shouse, Peter | |
Goldberg, Sabine | |
SOPPE, RICHARD - WATER MAN LAB, PARLIER,CA | |
Skaggs, Todd | |
Ayars, James |
Submitted to: Vadose Zone Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/2/2006 Publication Date: 5/1/2006 Citation: Shouse, P.J., Goldberg, S.R., Soppe, R.W., Skaggs, T.H., Ayars, J.E. 2006. Effects of shallow groundwater management on the spatial and temporal variability of boron and salinity in an irrigated field. Vadose Zone Journal. 5:377-390. Interpretive Summary: In some irrigated regions, the disposal of agricultural drainage waters poses significant environmental challenges, and efforts are underway to develop new irrigation water management practices that reduce the volume of drainage generated. One such management strategy involves restricting flow in subsurface drains in an effort to raise the water table and induce the consumption of groundwater by crops. A potential complication with is management approach is that upward groundwater flow may salinize the soil and increase concentrations of phyto-toxic elements such as boron. We found that soil salinity and boron concentrations were found to be highly correlated in the field. The observed spatial and temporal variability in boron and salinity was largely a product of soil textural variations within the field and the associated variations in salt leaching. It appears that the shallow groundwater management program used in this study could be continued and sustained in this field without increasing soil salinity or boron concentrations, and without decreases in yield. Technical Abstract: In some irrigated regions, the disposal of agricultural drainage waters poses significant environmental challenges. Efforts are underway to develop irrigation water management practices that reduce the volume of drainage generated. One such management strategy involves restricting flow in subsurface drains in an effort to raise the water table and induce the consumption of groundwater by crops. A potential complication with is management approach is that upward groundwater flow may salinize the soil and increase concentrations of phyto-toxic elements such as boron. In this study, salinity and boron concentrations were measured over three years in a field that was managed according to a shallow groundwater/drainage reduction strategy. Soil salinity and boron concentrations were found to be highly correlated in the field. The observed spatial and temporal variability in boron and salinity was largely a product of soil textural variations within the field and the associated variations in salt leaching. During the three-year study period, the field changed very little from one year to the next, although within a given year there were fluctuations related to the cropping and irrigation practices utilized and environmental conditions. However, any changes arising during the growing season were erased in the fallow season by winter rainfall and pre-plant irrigations that leached salts from the top 1 m (approximately) of soil uniformly across the field. Overall, it appears that the shallow groundwater management program used in this study could be continued and sustained in this field without increasing soil salinity or boron concentrations, and without decreases in yield. |