Southeast Kansas has been in a severe drought for most of this year’s growing season. Poor crop and pasture yields have led to limited feed options and increased forage price tags for cattle producers.
The year 2012 offered very similar conditions. One option many Kansas producers found was to ammoniate wheat straw.
Wheat straw is widely considered a poor forage that is better served as bedding, but research conducted by Kansas State University shows ammoniating bales can greatly improve protein content and digestibility. Wheat straw typically tests around 3.3% crude protein and 31% in-vitro dry matter digestibility (IVDMD). Ammoniation rates of 1.5% (lbs anhydrous ammonia/dry matter lbs wheat straw) can increase crude protein content to 8.6% and IVDMD to 42%. An ammoniation rate of 3% increased crude protein to 10.8% and IVDMD to 46.2%.
The process of ammoniating wheat straw is not overly complicated. An area large enough to hold the stacks of bales will need to be cleared, with some soil pulled away to be used later. Bales should be gathered in rows and stacked in a pyramid (three bales on the base, two on the second level and one on top). The entire stack should be covered with a black plastic sheet, about 6 to 8 mm thick. A 40’ x 100’ sheet can cover 12 rows of pyramid-stacked bales. The edges of the plastic should hit the ground and be covered with loose soil to seal the bales inside the plastic. Any holes in the sheet will need to be patched with tape. Next, a pipe (6 – 8 ft. long) should be placed on the ground and inserted into the center of the stack. Attach the pipe to the anhydrous tank and slowly empty
Once the stacks of bales are covered, it is time to let the anhydrous ammonia go to work. The ammoniation process is dependent on heat, so the straw will be ready to feed sooner with warmer temperatures. Average temperatures above 86° will need to be sealed for one week, temperatures between 59–86° need to remain sealed for two to four weeks, and temperatures below 59°need to remain sealed for up to eight weeks. The October 2021 average daily high and low temperatures at the Kansas Mesonet Station near Uniontown, were 71°and 51°, respectively. With expectations of a warmer than average October, we could expect the ammoniation process to take around 4 weeks if started the first week of October.
Now, what is the cost?
Any producer who fertilized his pasture or crop ground this past spring knows that fertilizer prices have gone through the roof, especially compared to 2012, when producers were using this alternative feed source.
THE PRICE of anhydrous ammonia at Midwest Fertilizer in Iola was $1,206.67 as of Sept. 28. That equates to $0.60/lb. A 40’x100’ sheet of black plastic can seal a row of 12 pyramids. Assume a tightly wrapped wheat straw bale (tightly wrapped bales work better for ammoniating) weigh on average 1,100 lbs. 72 total bales, at 90% dry matter, means you will have roughly 35.64 dry tons of wheat straw to ammoniate.
1.5% rate will require 1,069.2 lbs. anhydrous ammonia
1,069.2lbs x $0.60/lb = $641.52 = $18/dry ton wheat straw
3.0% rate will require 2,138.4 lbs anhydrous ammonia
2,138.4lbs x $0.60.lb = $1,283.04 = $36/dry ton wheat straw
Anhydrous ammonia will not be the only cost associated with this process. Let’s assume another $15/dry ton wheat straw to account for fuel, the plastic sheeting, labor, and other miscellaneous costs. This will bring our cost of ammoniating wheat straw to:
1.5% rate: $33/dry ton wheat straw
3.0% rate: $51/dry ton wheat straw
