Illinois Fertilizer
Conference Proceedings
January 27-29, 1997
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K.B. Ritchie, R.G. Hoeft, E.D. Nafziger, L.C. Gonzini, and J.J.
Warren
Our 3-year no-till study (1993-95) showed good success with starter fertilizers at 7 of the 8 site-years. This success with no-till starter raised the question: How effective will starter fertilizer be in high-residue minimum-till systems that have become common in the last decade?
Two separate studies were established at six locations to evaluate the response
of minimum-till corn to: 1) factorial combinations of N, P, and K banded 2 inches
beside and 2 inches below the seed (2X2); 2) dribbling N fertilizer on the soil
surface near the seed furrow, and 3) the secondary nutrients sulfur, zinc, or
ACA added to a 25-30-0 starter.
Plant weights were increased at 5 of 6 locations by 2X2-banded 25-30-0 and 25-30-20.
At 4 locations, plant weights were higher with a 25-30-0 treatment than with
a 12.5-30-0 treatment. Plant weights were higher with banded N starter than
with surface-dribbled N at McLean and Ogle. Addition of sulfur to the 25-30-0
starter increased plant weight at Ogle, but neither sulfur, zinc, or ACA increased
plant weight at any other location.
Grain yield was significantly increased at 3 of 6 sites by the 25-30-0 and 25-30-20
treatments. Yield increases were better with 25 lbs of N than with 12.5. Sulfur,
zinc, or ACA did not significantly increase grain yields when added to a 25-30-0
starter at any of the locations studied.
Results from this first year of research suggest that the use of starter fertilizer
on minimum-till fields may not be as effective as on no-till fields, but no
direct comparisons between the two tillage systems were made in these experiments.
The 25-30-0 and 25-30-20, which performed well in no-till in previous years,
increased yield the most consistently in minimum-till. Banded starter N tended
to be more effective than surface-dribbled applications. Starter N was more
effective at 251bs than 12.51bs. No consistent benefit was measured from sulfur,
zinc, or ACA added to a 25-30-0 starter.
Addition of starter fertilizer increased no-till corn yield by about 10 bu/acre
at 7 of 8 siteyears in a 3-year study (Ritchie et al., 1996). The most consistently
profitable treatments were a 25-0-0 and 25-30-0 starter banded 2X2 (Hibbard
et al., 1996). After seeing these results, many farmers and crop advisors asked
how effective starter fertilizer would be with minimumtill practices used today
by Illinois farmers. Several studies have shown that although starter fertilizer
hastens corn maturity, it does not consistently increase yields in conventional
tillage (moldboard plow) situations (Bretzlaff and Boone, 1970; Bullock et al.,
1993; Randall and Hoeft, 1988). The purpose of our research was to evaluate
the effect of starter fertilizer combinations on minimum-till corn and to determine
the effect of adding zinc, sulfur, or ACA to starter fertilizer.
Six sites varying in climate, soil type, crop rotation, and soil test values
were established in the spring of 1996 (Table
1). Fields were worked by the cooperating farmers once with a chisel plow
(or equivalent tillage implement designed to leave residue on the soil surface).
The research plots were 10 by 35 feet. Corn was planted with a 2-row planter
at rates near 35,000 seeds per acre (planting dates and hybrid are listed in
Table 2). Plant populations were thinned
to 29,000 plants/acre at the V5 growth stage, and above-ground plant samples
were taken to measure weight and nutrient content. The corn was hand harvested
from an area in the middle of the plot 5 by 15 feet. Corn yields were adjusted
to a 56 lbs/bu, 15.5 % moisture basis.
Nitrogen was applied to all sites at planting time by injecting 28% UAN solution
according to the University of Illinois recommendations (1.2 lbs of N per bushel
of proven yield minus 40 lb/ac legume credit from soybean). Soil tests were
taken in the spring, and P and K were broadcast at rates of 46 lb P205
and 90 lb K20 at the Effingham location. At Gridley, the plots received
46 lb P205 and 1421b K20. The 4-inch soil temperature
was monitored during the first 30 days with a Hobo® temperature logger (Figure
1).
In Experiment 1, we established factorial combinations of N, P, and K banded
2X2 (see Table 3). We also compared N at
rates of 12.5 and 25 lbs/ac banded 2X2 or surface-dribbled. All treatments were
replicated 4 times in a randomized block design.
Experiment 2 compared a 25-30-0 starter with sulfur, zinc, or ACA to a 25-30-0
without these additives (see Table 4). These
treatments were replicated 8 times at 4 locations, and 4 times at 2 locations
(Effingham, Champaign C-CRP rotation) in a randomized block design. One location
in Champaign county followed CRP set-aside ground instead of a soybean crop.
It is important to remember that these results are based on only one year of data.
Plant weights were increased at 5 of 6 locations by 2X2-banded 25-30-0 and
25-30-20 (Table 3). This finding is consistent
with several studies in no-till and conventional-till showing that starter fertilizers
increase early-season plant growth. At 3 locations, plant weights were higher
with a 25-30-0 treatment than with a 12.5-30-0 treatment. Plant weights were
lower at the McLean and Ogle locations when starter N was surface-dribbled instead
of banded (Table 3). Sulfur improved the
young plant response to 25-30-0 starter at Ogle, but sulfur, zinc, or ACA did
not increase plant weight at any other locations (Table
4).
Grain yield was significantly increased at 3 of 6 sites by the 25-30-0 and 25-30-20
treatments (Table 5). Yield increases were
better with 251bs of N than with 12.5. This suggests that a 10-34-0 starter
at 1001bs/ac may not supply enough N; growers using 10-34-0 as a starter should
consider spiking it with UAN solution to increase the N content. There was no
significant difference between banding or surface-dribbling N starter (Table
5). Sulfur, zinc, or ACA did not significantly increase grain yields at
any of the locations studied (Table 6).
Although we measured grain moisture, these experiments were not designed to
focus on the benefits of earlier grain dry-down that starter often provides.
Because we hand-harvest, we try to harvest when the corn is drier (around 20%
moisture). It is likely that farmers who harvest wetter corn might see more
grain moisture decreases when starter is used than we did. Grain moisture was
significantly decreased by 2X2-banded 25-30-0 and 25-30-20 at 3 of the 6 sites
(Table 8). Sulfur and zinc added to a 25-30-0
starter decreased grain moisture more than did the 25-30-0 starter alone at
the Ogle county location (Table 7).
Results from this first year of research suggest that addition of starter fertilizer
may not be as consistent in increasing grain yield on minimum-till as compared
to no-till corn, but no direct comparisons between the two tillage systems were
made in these experiments. The 2530-0 and 25-30-20, which performed the best
in no-till in previous years, increased yield the most consistently in minimum-till.
Banded starter N tended to be more effective than surfacedribbled applications.
Starter N was more effective at 251bs than 12.5 lbs. No consistent benefit was
seen from sulfur, zinc, or ACA added to a 25-30-0 starter.
1. Starter may not be as effective on minimum-till fields as on no-till fields.
2. 25-30-0 and 25-30-20 significantly increased yields at 3 of the 6 sites.
3. 25-30-0 performed better than 12.5-30-0.
4. Sulfur, zinc, and ACA did not consistently improve corn response to a 25-30-0
starter.
Table 1: Soil Test Values, 1996
Table 2: Planting Dates and Hybrind Used, 1996
Table 3: Effect of starter fertilizer on V5 plant weight. Experiment 1
Table 4: Effect of starter fertilizer on V5 plant weight. Experiment 2
Table 5: Effect of starter fertilizer on corn grain yield. Experiment 1
Table 6: Effect of starter fertilizer on corn grain yield. Experiment 2
Table 7: Effect of starter fertilizer on corn grain moisture. Experiment 2
Table 8: Effect of starter fertilizer on corn grain moisture. Experiment 1
Figure 1. Maximum and minimum soil temperatures at 4-inch depth
Bretzlaff, W.G. and L.V. Boone. 1970. Corn yields as affected by row fertilizers,
planting date, and nitrogen level. Illinois Research, University of Illinois
Agricultural Experiment Station, Winter, 1970.
Bullock, D.G., F.W. Simmons, I.M. Chung, and G.I. Johnson. 1993. Growth analysis
of corn grown with or without starter fertilizer. Crop Sci. 33:112-117.
Hibbard, J.D., K.B. Ritchie, J.C. Siemens, and R.G. Hoeft. 1996. An economic
evaluation of using starter fertilizers in Illinois no-till corn production.
p. 67-78. In R.G. Hoeft (ed.) 1996 Illinois Fertilizer Conference Proceedings.
University of Illinois, Urbana, IL.
Randall, G.W. and R.G. Hoeft. 1988. Placement methods for improved efficiency
of P and K fertilizers: A review. J. Prod. Agric. 1:70-79.
Ritchie, K.B., R.G. Hoeft, E.D. Nafziger, L.C. Gonzini, J.J. Warren, and W.L.
Banwart. Nitrogen management and starter fertilizers for no-till corn. p. 55-66.
In R.G. Hoeft (ed.) 1996 Illinois Fertilizer Conference Proceedings. University
of Illinois, Urbana, IL.
1K. B. Ritchie is a Jonathan Baldwin Turner Fellow, R. G. Hoeft and E. D. Nafziger are Professors, and L.C. Gonzini and J.J. Warren are Senior Research Specialists, Dept. of Crop Sciences, University of Illinois.
