Precision Farming Profitability Chapter 5: Increasing Cost Effectiveness of Weed Control By Case Medlin, Jess Lowenberg-DeBoer

Figure 1. Many perennial weeds, such as johnsongrass, exist as distinct patches in fields. Control of johnsongrass in a soybean crop is relatively easy with herbicides, but could be expensive if treating the entire field. Precision Farming Profitability, p. 45

Figure 2. Lightbar Precision Farming Profitability, p. 45

Precision Farming Profitability, p. 46 Ted Biehl, Urbana, IN “ Site-specific farming has explained a lot of situations about what is going on in the field, but it has created an immense amount of work for the farmer and the dealer to analyze this data.”

Precision Farming Profitability, p. 47 Keith Anderson, West Point, NE “Cost-wise I don’t think I saved any money. But as for weed control, it worked real well.”

Table 1. Cost and benefit examples for GPS guidance and foam marker use on a 1500-acre farm. Precision Farming Profitability, p. 49

Table 2. The rates of most soil applied herbicides vary dramatically based on soil texture, soil organic matter, soil pH, soil cation exchange capacity, or a combination of these factors. Site-specific application of these herbicides may result in fewer cases of crop response and improved weed control. Precision Farming Profitability, p. 50

Figure 3. Soil factors can vary significantly across a large production field. Many herbicides are safest to the crop and most effective on the weed when applied at specific rates. Therefore, VRT applications based on soil pH, soil O.M., or soil texture variability should be very beneficial in the future. Precision Farming Profitability, p. 51

Precision Farming Profitability, p. 52 Kent Brewer, Clinton County, IN “Producers cannot afford crop injury, extra herbicide expense, or yield reduction due to poor weed control. VRT herbicide applications will be essential to profitability in the future.”

Precision Farming Profitability, p. 53 David Eshelman, Cass County, IN “The savings from variable-rate herbicide application are well worth the equipment modification cost.”

Precision Farming Profitability, p. 54