Grain Sorghum vs. Corn in Drought and Heat Conditions: Part V
This continues a series of Sorghum Tips discussing production yield of grain sorghum vs. corn in relation to dryland and limited water conditions as well as water-use efficiency of grain sorghum vs. corn. Previously in Part IV I demonstrated a relative albeit simplistic comparison of yield vs. seasonal water use for grain sorghum vs. corn which emphasized two points:
- What is the incremental change (increase) in yield per unit of available water?
- How much available water does it take to produce the first bushel of grain?
Although corn generally yields more per unit of water than grain sorghum—once sufficient water is present to achieve grain yield for each crop—the important consideration for grain sorghum, however, is that grain sorghum can produce grain yield at moisture levels (lower) that corn cannot. K-State Research & Extension frequently and generally notes in Kansas that when corn yields fall below 100 bu/A that sorghum generally becomes the more favorable cropping option.
But what about the price of the corn or grain sorghum you receive in the market (this Tip’s discussion)? And what about the cost to produce the corn or grain sorghum (the next TGSA Tip)? These factors will influence the simple comparison I portrayed in the Part IV tip, which was based only on yield.I have reconstructed the original graph in Part IV to now reflect crop value of grain sorghum and corn using the same yield per inch as before. I have used $4.50/bu for corn and $4.00/bu for grain sorghum (approximate High Plains contract prices as of February 2014), but of course these prices change: 1) in absolute value (prices per bushel go up and down), and 2) the price differential varies (and may be closer together on the Texas Gulf Coast?)
Remember, the above figure is based on crop value. Due to corn’s higher price and higher yield per unit of water, you can see that compared to the previous tip—which is yield only—the relative positioning of the lines on the graph favor corn over grain sorghum in that the “cross point” of crop value has moved to the left, from ~20” to ~15”. This is for our educational comparison. High relative prices for corn shift this red line to the left for corn. So strictly on crop value, corn is favored more.
But any Texas producer knows this is not the whole story! We know grain sorghum costs less to produce.
As noted before the above graph is another singular (and not the whole story) means to compare grain sorghum vs. corn. How may this relative comparison change significantly in favor of grain sorghum even though corn yield per 1” of water and corn grain prices are higher?
So stay tuned for my next Sorghum Tip considerations:
- What effect do production costs for corn and grain sorghum have in terms of profitability in response to water use?
- How would you portray the risks of growing corn vs. grain sorghum on this type of graph?