Dry and wet weather management of sub-surface tile drains
From design to installation to management, the Aug. 1-2 drainage management field day has plenty to offer.
If manure hauling to harvested small grain stubble is on your to-do list for the coming weeks, heed precautions, especially on tile drained lands. The dry soil has benefits of reduced compaction from heavy manure hauling equipment but the down side can be that very dry clay soil can exhibit cracking that can allow very liquid manure to follow these cracks and reach subsurface tile lines rather than soaking into the soil. This is an extreme condition but one that requires attention and precautions.
If sub surface drained soil does have dry cracks, avoid hauling any manure, especially liquid, until after a rain has caused the soil to swell and cracks are gone. If manure must be hauled, surface tillage may break the cracks enough to block flow to drains. Break soil cracks and disrupt macro-pores with tillage prior to manure applications. Do not assume that manure injectors create enough disruption to prevent flow to sub-surface tiles. Be sure that whatever form of tillage achieved the goal. More aggressive, shallow tillage may be better than chisel type tools on wide spacing. Reduced manure rates will also help. But, if you do haul on such fields, even with precautions, be sure to get off the tractor and check tile outlet point during hauling to see if the tactics are working. If any manure water is running out the outlet, stop hauling and take measures to block the tile flow that is occurring. Tile stops inside the lines can work and or blocking the ditch to stop the flow moving out of control. Any manure release should be reported to the spill hotline immediately at 1-800-405-0101 where procedures for appropriate control and clean up can be provided.
Check soil conditions before thinking about hauling. Check tile outlets, before, during and after applications. Also check outlets again after the first rainfall occurs.