Good drainage is always important, but it is especially so during cloud bursts, which some Illinois landowners have been experiencing the past few weeks.
Bob Frazee, University of Illinois Natural Resources educator, says the old axiom "When it rains – it pours" has pretty accurately described the rainfall which has occurred throughout many areas of Illinois during the 2008 growing season. Some farmers get a little, some get a lot.
Frazee suggests that now is an excellent time for landowners to make notes and take photographs of damage at the exact location of ponds and wet spots. Record these on a map of the farm. This will assist district soil conservationists, drainage engineers, and contractors to help design and install needed drainage improvements.
According to Frazee, excess water is the principal problem on over 3 million acres of Illinois cropland. Farmers and landowners need to carefully examine the low areas and wet spots that plague some of their fields. Although many soils are naturally well-drained, others must be drained artificially to make them suitable for profitable crop production.
The growth of most crops is sharply affected by continued saturation of a substantial part of the root zone or by ponded water on the surface. Although the water itself may not kill the plant or its roots, saturation of the root zone results in a deficiency of oxygen and accumulation of toxic gases. Frazee emphasizes that even a short period of oxygen deficiency can reduce water and nutrient uptake and root respiration, and can cause a buildup of toxins that kill cells and roots and eventually the entire plant.
According to Frazee, there are three primary objectives of drainage for most Illinois soils:
1: To provide a proper balance of soil, water, and air in the root-zone to encourage optimum plant growth.
2: To increase the yield or quality of a crop, or to improve the soil environment to allow production of a higher-valued crop.
3: To provide better conditions for planting and harvesting the crop. These objectives all depend on a lowered average water table, the first function of a drainage system.
Draining soils removes excess water from land by means of surface or subsurface conduits. Frazee suggests that a good "rule of thumb" is that a drainage system should be capable of removing water from the soil surface and lowering the water table to about 12 inches beneath the soil surface in 24 hours and to 21 inches in 48 hours.
The first step to take in evaluating a drainage problem should be to schedule a meeting with agency staff at the county NRCS and FSA Offices. It is crucial that a Wetlands Determination be obtained from these agencies for each individual field. If the affected field is not impacted by the federal wetlands designation, the landowner may want to investigate both surface and sub-surface options with a local land improvement contractor.