Illinois Fertilizer
Conference Proceedings
January 25-27, 1999
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R.G. Hoeft, E.D. Nafziger, L.C. Gonzini, J.J. Warren, E.A. Adee,
L.E. Paul, and R.E. Dunker1
Slower germination and early-season plant growth of no-till corn have prompted
farmers and researchers to look for innovative, low-cost techniques that would
allow them to retain the advantage of no-till while overcoming these disadvantages.
Earlier work funded by FREC has clearly shown that the addition of a starter
fertilizer that contains N and P will increase no-till corn yield on most fields
(Ritchie et al., 1996). However, even with use of this yield-enhancing treatment,
early-season growth on no-till fields is still slower than on conventionally
tilled fields.
Cooler soil temperatures and wetter soils associated with no-till fields are the primary factors responsible for the slower early-season growth. In an attempt to overcome these adverse factors, farmers have developed a system called strip tillage that allows them to apply their N in the fall, while at the same time creating an improved environment for spring planting. Special application equipment moves the residue from the row area, applies ammonia, and covers that application band with a small ridge in which next year's crop will be planted. Creation of the ridge allows the seed row area to dry sooner in the spring and since the residue has been removed, soil temperatures should approximate those in conventional tillage.
While strip tillage has been successfully used by several farmers, questions exist that can be answered only through a scientifically designed study. These questions include:
1. Is the benefit from strip tillage associated with the improved seed bed (which is warmer and drier), from the presence of N in a band near the seed, or from both?
2. Will starter fertilizer in combination with strip tillage result in yield equivalent to that under conventional tillage?
3. Is placement of ammonia directly under the row a safe and effective method of N application?
4. Does fall strip tillage remove the advantage provided by starter fertilizer?
While there is considerable data on the impact of ammonia fertilizer placement, only limited data exists on the impact of strip tillage on yield (Pedersen et al., 1997), and this project did not explore the impact of ammonia with the strip tillage. Therefore, this project offers an opportunity to provide no-till producers with new research information to use in their decision making process. Refinement of strip tillage techniques offer the potential for producers to obtain the benefits of no-till while overcoming the disadvantage associated with high residue over the row.
The objectives of the project are to:
1. Evaluate the effect of strip tillage with and without ammonia application in the fall as compared to conventional tillage (two-pass tillage in the spring after ammonia application).
2. Evaluate the effect of starter fertilizer on strip tillage and on conventional tilled land.
Experiments were established in the fall of 1998 at Urbana, DeKalb, and Monmouth, Illinois. The previous crop at each location was soybean. A split-plot experiment with tillage as main plot and a factorial combination of time of ammonia application by ammonia placement as subplot was established. Treatments consisted of chisel plow, no-till, and strip till; two times of ammonia application (fall and spring), and two ammonia placement positions (under row and between row). Each experimental unit was eight rows by 50 feet. When the corn is planted in the spring, four of the eight rows of each plot will receive a 2 x 2 placed starter application of 21-19-0, and the other four rows will receive no starter. At Urbana, two additional treatments will be established in the spring to evaluate the effect of ammonia placement under the row versus between the row on spring strip tillage.
To facilitate treatment application, a four-row , two-bar applicator was built (Figure 1). The front movable bar contains row cleaners in front of each of the four knives. The bar moves to allow the knives on the front bar to be positioned to apply the ammonia under the row for the appropriate treatments and to be slid over 15 inches to apply the ammonia between the row for the remaining treatments. The back bar contains ammonia (mole) knives and ridging equipment for strip till treatments. When conventional and no-till treatments are being applied, the rear bar is hydraulically lifted to avoid soil contact.
Figure 1. Side and rear view of experimental strip-till applicator.
1 R.G. Hoeft and E.D. Nafziger are Professors; L.C. Gonzini, IT Warren, and E.A. Adee are Senior Research Specialists; and L.E. Paul and R.E. Dunker are Agronomists, Dept. of Crop Sciences, University of Illinois.
Pedersen, W.L., R.E. Dunker, C.A. Bradley, D.S. Mueller, and J.C. Siemens. 1997. Evaluation of fall and spring strip-till as an alternative to no-till for corn. Agron. Abstr. p. I 11. Amer. Sec. Agron. Madison, WI.
Ritchie, K.B., R.G. Hoeft, E.D. Nafziger, W.L. Banwart, L.C. Gonzini, and J.J. Warren. 1996. N management and starter fertilizers for no-till corn. In R.G. Hoeft (ed.) Illinois Fertilizer Conference Proceedings. Univ. of IL., Urbana, IL. pp 55-65.
