Sorghum: A Drought Tolerant Crop Option For 2015

 

As the spring progresses and the weather remains extremely dry across South Dakota, many producers with dry fields or failed winter wheat are faced with difficult decisions. Producers may still be able to hedge some of their risk and opt to seed crops that are considered more drought tolerant.

 

 

Grain sorghum or milo is one that can be successfully grown in many areas of South Dakota. Sorghum is a warm season grass, like corn, and is considered to be relatively drought (or heat) tolerant. While sorghum requires about 6.5 inches of moisture to get to the point where it will produce grain, the production with additional moisture is very efficient, accumulating about 500 lbs of grain or about 9 bushels per acre-inch once that point is reached (see Why Grow Sorghum?). Sorghum has a large fibrous root system that allows it to extract water from very deep in the soil profile, it also has the ability to tolerate water stress at any growth stage to some degree. Another benefit is that sorghum does not enter the high water use period during its life cycle until August. This gives producers a better window to receive some much needed precipitation and rebuild soil moisture.

 

Sorghum offers other benefits; seed is cheaper than corn seed, it is not susceptible to some of the diseases that plague corn such as Goss’s Wilt and it is not affected by corn rootworm or corn borers. If producers are concerned about crop rotation, these benefits would allow producers to go back into sorghum residue with corn or soybeans next year. However, due to the late harvest of sorghum and disease issues, it would not be recommended to seed winter wheat into fields after sorghum.

 

 

If producers are considering a late switch to sorghum, it will be important to check the labels of any herbicides which have already been applied to the fields in question. Ensure that no rotation restrictions exist for sorghum on any products which have already been applied. In many cases residual herbicides have already been applied to fields scheduled to be seeded to sorghum since these products require rainfall for activation. Obtaining adequate moisture to make these products work properly is less likely when they are applied at or after seeding. Post emerge weed control options for warm season volunteer grass control in milo are limited.

 

Another reason that sorghum may be a viable crop option this year is that it can offer producers a chance to get some residue on soils that may not have any now. This will protect the soil surface from wind and water erosion.