Better management practices can counter deterioration of ground water quality. From 1991 through 1996 the influence of improved irrigation practices on ground water pesticide contamination was assessed at the Nebraska Management Systems Evaluation Area. Three 13.4-ha corn (Zea mays L.) fields were studied: a conventional furrow-irrigated field, a surge-irrigated field and a center pivot-irrigat...

prediction of weed emergence timing would help minimize crop yield loss and reducing herbicide use by optimization of the timing of weed control. therefore, seedling emergence evaluation was conducted in different irrigation levels (40, 60, 80, 100 percent of crop water requirement and furrow irrigation) to develop a thermal time seedling emergence model for amaranthus retroflexus l. in sunflow...

Slow infiltration rates constrain effective and economical irrigation in some sandy loam soils in California. Polyacrylamide (PAM) has increased soil infiltration in some areas, especially in soils high in clay or silt. Field trials near Fresno, CA, with PAM failed to show improved infiltration. Laboratory experiments were conducted to investigate PAM effect on infiltration of various quality w...

Polyacrylamide (PAM) use in irrigation for erosion control has increased water in®ltration and reduced soil erosion. This has improved runo€ water quality via lower concentrations of nitrogen, phosphorous, and pesticides, and decreased biological oxygen demand. Since non-toxic high molecular weight anionic PAMs removed clay size sediment particles in ̄owing water, we hypothesized that PAM would...

farmers in the indus basin, pakistan have generally switched to groundwater for additional water supplies due to the irregular supply of irrigation water; currently over 50% of the agricultural land in the basin is at least partially irrigated by tube-wells. these wells pump fresh groundwater, which essentially is the result of massive leakage from irrigation canals into the originally saltwate...

The perturbation to the momental figure of Ganymede by the impact basin Gilgamesh was modelled, and it was found that the format, ion of the basin could have significantly reoriented the satellite. Global trends of groove orientation suggest that groove sets formed in reactivated zones of weakness, which were created by tidal despinning and furrow formation. The paleo•ole n which despinning occ...

abstract this study addresses two dimensional infiltration from irrigated furrows. the basic approach is to develop a two-dimensional infiltration as a combination of the corresponding one-dimensional vertical and an edge effect. the edge effect is the difference between the cumulative infiltration per unit of adjusted wetting perimeter and the corresponding one-dimensional infiltration. this a...