This NebGuide describes how using a furrow firming wheel improves furrow irrigation performance. Nearly half of the irrigated acres in Nebraska are furrow irrigated. Higher pumping costs, water restrictions and water shortages are all factors encouraging efficiency-improving irrigation practices.
Deep percolation is the loss of water below the root zone.
The amount of deep percolation caused by irrigation is difficult to estimate unless irrigation application is measured or the soil moisture content monitored. Deep percolation both reduces irrigation efficiency and increases the cost of pumping. In addition, chemicals applied to the soil surface to control pests and improve production can leach below the rootzone and into the groundwater. Uniform application of water using furrow irrigation is difficult to achieve. As water advances down a field, the opportunity time, or the time water has to infiltrate the soil, is greater at the upper end of the field than the lower.