Making Corn after Corn Work
For Ivan and Brian DeJong of Youngfield Farms the challenge to grow corn after corn has been met head on, and so far they like what they see.
Growing corn after corn seems implausible in today's market. How can you afford to apply extra nitrogen fertilizer, pay for rootworm control, take a 10 bu/ac reduction in yields due to the rotation effect and probably be forced to do more tillage?
The DeJongs of Blackstock, Ontario see the picture quite differently, especially when they look at their soils. They are convinced that on their lighter soils that corn after corn is improving soil aggregate stability, raising organic matter content, and boosting yields compared to soybean dominated rotations. The other factor is that they need corn for feed, have their own drier and elevator system and they obtain some additional margin by drying and handling their own crop.
Long term tillage trials in Ontario and Corn Belt states have traditionally shown that if you want to stay in continuous corn and grow it no-till you might anticipate a 15% yield reduction compared to corn rotated with soybeans. Research also suggests that this gap could be narrowed if you were prepared to let the mouldboard plow loose on your continuous corn ground. The DeJongs have recognized the need to do some tillage but have opted for a Great Plains Turbo-till coulter system. (Figure 1). Originally they ran it in the fall but could see little benefit to this operation, so now they perform two passes in the spring ahead of the planter and leave the corn stalks untouched in the fall. On their medium to light textured soils, this prepares a good seedbed while leaving the fairly high residue levels (Figure 2). And at 40' wide and 7 MPH they can cover a lot of acres in a day.
Figure 1 |
Figure 2 |
Ivan and Brian attempt to plant in the areas between last years corn rows where the residue cover is naturally lower. Trash cleaners on the planter are operated quite aggressively to aid in eliminating residue (Figure 3). "We have seen the effects of planting into trash, and it is not favourable, so we try quite hard to plant into a residue free zone" comments Brian. "In the future, we hope to go to GPS steering on the planter tractor to keep new corn rows and old corn rows 15 inches clear of each other all the time", adds Brian. Their corn planter includes a tow-behind air cart that delivers dry fertilizer in a band containing 90 lbs/acre of 11-52-0 and 10 lbs/acre of 0-0-60.
Figure 3 |
Root worm control has not been a big issue for the DeJongs. They have switched to the high rate of seed applied insecticide (Poncho 1250) in those fields where they have noticed or expect problems, otherwise all corn gets the low rate seed applied (Poncho 250) and no additional insecticide.
Ivan recognizes the need for additional nitrogen in a corn after corn scenario compared to corn after soybeans but tries to keep it focused on economics. "When the new OMFRA N calculator (see Table 1) suggested 142 lbs N/acre that was just about what we felt comfortable with", states Ivan. "We also believe that as organic matter and soil structure improve, so will the corn plant's ability to use N efficiently", adds Ivan.
| Table 1. Corn Nitrogen Rate Calculation (Youngfield Farms) | ||
| Factor | Input |
N Rate Adjustment (lbs N/acre) |
| Soil Texture | Sandy loam |
+ 34 |
| Yield Expectation | 165 |
+ 127 |
| Crop Heat Unit | 2700 |
+ 2 |
| Previous Crop | Corn |
0 |
| Price Ratio Corn @ $3.00/bu Nitrogen @ $.45/lb N |
8.5 |
- 21 |
| Total N Recommendation | x |
142 |
| Applied as Starter | x |
- 10 |
| Additional Pre-plant N | x |
132 |
The DeJongs are also one of 42 co-operators in the Nitrogen Rate Validation project being supported by OCPA, Agricorp, and OMAFRA. This involves using the N rate recommended by the N Calculator and comparing it to higher rate strips in the field. In this field they end up with corn after corn growing with 142 lbs N/acre versus adjacent strips with 172 lbs N/acre. Nitrogen (UAN) is applied via the self-propelled sprayer, equipped with a 120' boom (Figure 4). They spray the UAN directly on to corn stalks in the pre-planting period. Concerns over N losses due to volatilization with this process are minimized by performing the spring tillage passes as soon after N application as possible.
