Decisions on whether to grow for silage, earlage, or grain confront California corn producers and dairymen, but a Fresno County farm advisor has some guidance for comparing the costs of producing each.
Shannon Mueller recently told a corn production meeting in Tulare that cultural practices hinge on the grower's perspective and objective.
Growing for the dairy, she said, customarily involves silage or some earlage but rarely grain, and the goal is for yield and quality.
“However,” she added, “if you are growing for somebody else, the goal is to maximize dollar returns per acre, and your profit is based on the relative price for corn and the yield potential of the field.”
Comparing the advantages and disadvantages of each of the utilizations, Mueller said silage offers higher yield and energy content than other hay crop forages, along with the option for single, double or triple cropping.
However, silage also has high transportation costs and requires large storage space.
The energy value of earlage is almost equal to that of rolled corn, and quality depends on the amount of leaf and stalk. At the same time, earlage moisture (a consideration in formulating rations) is lower than silage even though it costs less to haul.
In addition, there are bagging costs and possibly greater risk of economic losses in storage.
Grain corn has high energy, but that is offset by high cost, competition with corn for ethanol production, a longer production season, and currently limited harvest equipment availability.
When does the decision on which to produce need to be made? Mueller said if it is made prior to planting, cultural practices can be adjusted to suit each use.
“But the decision can also be made at time of silage harvest. If you can't get the price you want for silage, earlage or grain are still options.”
Mueller's sample production costs for the three uses are similar, but significant differences occur in harvesting costs. Silage and earlage are typically sold as a standing crop with the buyer paying the harvesting costs.
For grain, the grower pays for production and harvesting, with the buyer paying for the commodity and often doing the hauling.
Typical costs for silage harvesting are $8 per ton, plus $1 per ton for covering and hauling — at 30 tons per acre, the total is $270 per acre.
Earlage harvest is $18 per ton, plus $6 per ton for bagging and hauling, and at 10 tons per acre the total is $240 per acre.
Grain corn harvest costs come to $12 per ton, and $10 per ton for hauling, so at 5 tons per acre, the total is $110 per acre.
In each case, additional hauling costs are based on adding per ton per mile charges if the haul distance is greater than 2 to 3 miles.
Mueller said she had no answer for how pricing should be determined, but she offered some approaches. It may be on the value of the feed compared to hay forage. It may be based on the relative value of grain for ethanol. Or it may be calculated from the cost of production.
“There are additional considerations that are difficult to apply a dollar value to,” she said.
These include double or triple cropping with silage, an additional irrigation for silage or grain, bagging costs for earlage, harvest equipment availability, incorporating crop residues after harvesting earlage or grain, corn stunt problems in earlage or grain, and the long-term relationships between growers and buyers.
In offering some perspectives on the amount of nitrogen a corn crop needs, Marsha Campbell Mathews, Stanislaus County farm advisor, said a 5-ton grain crop requires 250 pounds per acre, about the same as a 30-ton silage crop.
However, she added, the grower may not need to apply as much for grain, because the grain corn will remobilize some of the nitrogen and potassium from lower leaves and stalks.
The two elements will also both remain in the stubble to be reused by the following crop. With silage, the entire plant is removed.
In determining how much nitrogen needs to be applied, the grower has to consider the amount used for roots, leaves and grain, the amount removed at harvest, an extra amount to accommodate losses, and how much is lost to leaching. Soil tests will help guide in calculating exact amounts.
As a rule of thumb, she said, growers should plan to put on 120 percent of the amount removed by the crop when using commercial fertilizers and about 150 percent of the amount removed by the crop when using manure fertilizer.
For grain corn, about 80 percent of the nitrogen is taken up by the time of tasseling, but when grown for silage, the corn will take up about 66 percent of the nitrogen by that stage, and some nitrogen may need to be applied after tasseling.
Nitrogen losses to leaching vary by soil type, but nitrate losses after a single irrigation can average 40 percent from the top 3 feet of soil and 67 percent from the top 1 foot of soil.
To compensate for losses in the top 1 foot or so, she said, 25 to 30 units of nitrogen can be added to the water. For losses in the top 36 inches, split applications can be made where there is potential for leaching.
“The trick is to put only what the crop can use from one irrigation to the next. In our part of the state, that is generally between 30 and 80 pounds of nitrogen per acre in each of five irrigations.”
Irrigation uniformity, Mathews cautioned, is critical when water-run applications are made.
Carol Collar, dairy farm advisor for Tulare County, said sorghum, produced either as grain or forage, is a viable alternative to corn, particularly in a season when water is in short supply.
After recent trials at a Lemoore dairy she concluded that nutritional value of both sorghums was slightly lower than that expected from corn silage and yields were lower than historical corn yields.
“Corn is a better choice,” Collar said, “but if water is expensive or limited, if soil conditions are not good for corn, or if disease is an issue, sorghum can be a very good alternative.”