Growing wheat behind sorghum
Sorghum offers many options for farmers. Drought tolerant, water-sipping and nitrogen efficient, sorghum provides a summer rotation that has proven to be profitable in the harshest conditions and lucrative when good weather prevails.
Sorghum production has gained interest in recent years as regional grain demands have stoked local swine producers, like Murphy-Brown LLC, to offer competitive markets for sorghum. With the rapid acreage increase in the 2012 growing season, many farmers are getting used to growing one of the world's oldest grains. Additional advantages of sorghum include its ability to tolerate hot, dry weather, a condition that can be challenging for corn acres during pollination. Sorghum also offers a change up in herbicide chemistry, offering a way for farmers to combat the increasing infestations of glyphosate-resistant pigweed and horseweed. Sorghum also works well in a rotation to combat nematode infestations and seems to be less favored by the high deer populations compared to soybeans. As with many sorghum acres, particularly new acreage, many wheat, soybean and cotton farmers are curious as to how sorghum will fit into their enterprise rotation. With most farmers eyeing the high wheat prices, it is likely many double-cropped acres of wheat will follow this year's sorghum crop.
As expected with any double-crop scenario, pros and cons exist. Wheat behind sorghum offers farmers a chance to capitalize on high grain prices twice while taking advantage of increased residue from the sorghum stubble to improve their soils. However, this double-crop scenario could present some typical challenges. Most double-cropped acres--of any crop combination--have the potential to show some yield drag in the second crop from a shorter growing season, reduced profile moisture, and reduced nitrogen availability, while the primary crop (winter or summer) will typically use the lion's share of the water and nutrients. Growers need to make sure to adjust soil fertility, especially when planting wheat after sorghum because sorghum removes more nitrogen from the soil than corn or other crops.
Hybrid or variety selection also plays a major role in the performance of a cropping rotation. Additional interactions of herbicide residuals, tillage practices, and organic compounds can complicate or enhance the rotation. The economic balance of double-cropping is trying to make the total of two crops (one short and one regular season) more profitable per acre than a single full-season crop. Depending on the weather, commodity prices and other market drivers, rotations can fluctuate in the dollars generated.
Sorghum still offers many opportunities to become part of a summer rotational cropping system.
"I have been using a wheat and sorghum rotation for 40 years, and it works very well for my farming system," said Dodge City, Kan., farmer Greg Shelor, chairman of the Sorghum Checkoff crop improvement committee. "With modern technology, such as no-till and seed treatments, we typically see very little yield drag (2 to 4 bushels per acre) on no-till wheat behind sorghum and no measurable yield drag on our conventional tillage operations when wheat follows sorghum."
If you are considering planting wheat following your sorghum crop, then below are a few management techniques sure to make your wheat-sorghum rotation a success. The following is a list of best management practices.
Tips for wheat after sorghum
--Make sure pre-plant nitrogen, phosphorus, potassium and sulfar are at the high end of recommended levels.
--Burying sorghum residue with tillage can help reduce allelopathy if present.
--Use glyphosate to kill the sorghum prior to harvest. This will stop regrowth and may help reduce potential allelopathy if present.
--If planting no-till wheat, remember to increase your seeding rate over conventional till rates.
--Strictly monitor wheat tiller development. Growers are encouraged to check tiller density around growth stage 25 and apply an early N split if needed.
--Higher nitrogen rates for wheat at growth stage 30 should be considered to overcome nitrogen tied-up in sorghum residue. Tissue testing to determine optimal spring nitrogen rates is highly recommended.