This column isn’t about groundwater or irrigation. It’s not about building a pipeline from the Missouri River. Today’s column is about how area agriculture can maximize the efficiency of precipitation in a climate, which at least in the near term, is short on precipitation. These suggestions have merit, even under more normal conditions.
• Minimize or eliminate tillage – While tillage is effective for weed control and preparing a seedbed, the same objectives can be met without aggressive tillage. The goal is to promote soil structure and accumulate crop residue/organic matter at the soil surface. This achieves two goals. Water isn’t lost through tillage and the residue helps minimize evaporative losses and maximize plant transpiration. And as organic matter slowly starts to accumulate the water holding capacity of the soil increases as does its structure and nutrient holding capacity. However, it can take several years for the benefits of no-till to become apparent. Where is this more difficult (read expensive) or impractical? Under irrigation where you are dealing with large amounts of crop residue and in continuous cropping systems where pest pressure can become a problem. Residue can be baled or removed but that is an additional cost unless you have a market for the residue. This strategy is best adapted to ground using crops rotations as diverse as possible. It is also important when eliminating tillage to correct problem like soil pH before starting.
• Adjusting hybrids/varieties – The fuller the season of the cultivar the greater the yield potential under ideal conditions. Also there is greater potential for a train wreck when moisture and/or temperature are limiting. Select earlier maturing hybrids/varieties may sacrifice some yield but provides greater security in terms of a sustainable yield.
• Rethink double-cropping – When moisture is adequate, double-cropping enhances income and water use efficiency. When lacking soil moisture it can result in two mediocre or nonexistent crops instead of one acceptable harvest. If intent on double-cropping consider a hay or feed crop that can be harvested earlier and provide an opportunity for soil moisture recharge.
• Minimize stresses – While you can’t make it rain or never have excessively hot temperatures, you can do everything possible to minimize stresses from nutrient deficiencies and pests. Proper fertility and pest control are more critical under a yield-limiting environment than under an excellent one.
• Crop selection – Where possible, it may be wise to rethink your crop selections. Dryland grain sorghum instead of corn. As canola varieties become better adapted to this area, consider adding canola acreage to the mix for the rotational benefits. Hybrid pearl millet instead of more traditional feed crops.
There are more ideas than space allows but there are many things to be done to help cope with limited water resources. While they may not be easy or cheap, they may be necessary to cope with an erratic climate.