Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.
Injection or incorporation application treatments other than broadcast almost always reduce odor during and immediately after application and have a neutral or beneficial effect on crop yield. Although the amount of odor reduction among various injection and incorporation treatments may be similar, the level of surface residue cover reduction is different. For land areas where erosion is a concern operating an application system with no more than an appropriate amount of soil and residue disturbance should be strongly considered. Costs of using injection or incorporation equipment are on the order of $0.001 to $0.003 per gallon applied depending on the type of equipment and annual volume applied. Additional application costs for using injection or incorporation equipment even in the upper end of this range are typically not greater than the cost of a secondary tillage pass. The choice of injection or incorporation style should be strongly influenced by balancing the needs for odor control, residue cover maintenance, and fertilizer placement for the subsequent crop.
Factors affecting costs include the initial cost of the application toolbar, annual usage rate, and increased tractor power requirement to pull the injection device. Calculated costs are associated with either a custom annual application volume of 20 million gallons or private application volume of 3 million gallons, 5- (custom) or 15- (private) year equipment life, and application with a double-disc or narrow knife system. Costs of using a double-disc or narrow knife application toolbar are in the range of $0.001 and $0.002 per gallon, respectively, for the higher-volume custom applicator example. Costs are $0.0015 and 0.003 per gallon, respectively, for the lower-volume private applicator example. Costs of using additional tractor power are roughly one-third to one-half of total costs at the smaller annual application volume, but over three-fourths of costs at the higher application volume. Diesel fuel was valued at $3 per gallon. If the pass of a field tillage implement is eliminated (e.g., strip tillage) because of application, costs of injection or incorporation may be balanced by savings in the cost of the tillage pass.
H. Mark Hanna1, Steven K. Mickelson1, Steven J. Hoff11Iowa State University
Point of Contact:
H. Mark Hanna, firstname.lastname@example.org
The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.]