On-Farm
Research
Research Results
Evaluation of Zone-tillage and a Polymer Seed Coating for Corn Production
Erie County, 2002
Ron Hoover, On-Farm Research Coordinator
Joel Hunter, Crawford County Extension Educator
Sjoerd Duiker, Soil Management Extension Specialist
Jim Neuberger, Grain Producer, Erie County
On-farm cooperator, Jim Neuberger planting corn into test plots.
Rationale
The reader is referred to the overview of the potential for zone-tillage in Pennsylvania and the reasons for conducting comparative research on it under a separate heading on the same webpage.
Recent developments in polymer seed coatings have resulted in the release of several products. These coatings are designed to prevent imbibition (seed soaking) when seeds are planted into soils that are too cool for optimum germination and early growth. This polymer moisture barrier can allow producers to plant earlier than recommended without suffering the ill effects of planting into cold soils. There are several ways in which a producer might benefit from earlier planting. The planting season is made longer by starting earlier in the spring. This can reduce the anxiety of the spring planting rush, allowing the producer to more easily complete planting during the time when greatest yields can be realized. It might also enable a producer to use the equipment over more acres. Perhaps the greatest benefit from earlier planting is to allow the producer to plant when weather and soil moisture will permit planting without damage to soils, into an ideally formed and closed seed furrow, possibly ahead of a wet period that prevents the timely planting of the crop.
Objective
- To evaluate zone-tillage ahead of corn planting as a possible means of increasing corn grain yields, when compared to no-till planting, and
- To evaluate field performance of polymer-coated corn seed for plant population and yield on medium-textured northwestern PA soils.
Site Conditions
- Cooperator:
- Jim Neuberger
- Location:
- Fairview, York County, Pennsylvania
- Soil type:
- Howard silt loam
- Previous crop:
- soybean
- Fertilizer:
- 225 lbs/A of 17-17-0 with Zn
- 150 lbs/A of ammonium nitrate
- Variety:
- Fielders Choice X2003
- Planting date:
- April 17, 2002
- Seeding Rate:
- 29,000/A
- Herbicides:
- Princep @ 1.5 lbs/A (2001)
- Python @ 0.96 oz/A
- Bicep II @ 1.6 qt/A
- 2,4-D @ 1.2 pt/A
- Banvel @ 0.5 pt/A
- Induce @ 1% spray volume
- Harvest Date:
- October 15, 2002
Methods
The test consisted of a replicated two factor comparison of no-till (commercially available no-till planter) versus zone-till planting and of polymer protected (Intellicoat by Landec Ag) compared to non-protected seed of the same hybrid. A field on which soybean was grown during 2001 was selected as the test site. The field was nearly level. A two-by-two factorial, randomized complete block design with four replications was utilized for the experiment. Approximately 320 feet of field width was used for the test site. An individual plot consisted of eight planted rows that extended the length of the field (between 900 and 1100 feet). The four combinations of two tillage treatments (no-till or zone-till) and two seed treatments (polymer-coated and non-coated) were randomly assigned to plots. Zone-tillage was accomplished with the use of a 4-row Unverferth Zone Tiller® tractor drawn trailer implement as an operation separate from corn planting one day before the entire test site was planted with a 4-row no-till corn planter. Row spacing was 30 inches. A border area of four or more rows was maintained on each side of the test area.
Ten weeks after planting, when plants were found with six or seven leaf collars, four lengths of 100 feet of row were marked and all plants were counted. These counts indicated the percentage of planted seed that had reached mid-maturity and would likely be present at harvest.
Ten weeks after planting, when plants were found with six or seven leaf collars, four lengths of 100 feet of row were marked and all plants were counted. These counts indicated the percentage of planted seed that had reached mid-maturity and would likely be present at harvest.
Results
Corn in Erie County is usually planted between mid April and late May. For at least two weeks prior to planting, daytime air temperatures were unseasonably high. The experiment was planted early with the expectation that cool conditions would return prior soon after planting and that emergence differences between polymer coated and non-coated seed would be observed. Conditions remained warm and corn in all treatments had emerged by early May. The polymer treated corn emerged one to two days later than the non-treated. There were no visible differences in rate of emergence between the tillage treatments. The crop was subjected to several weeks of cold and wet conditions beginning in early May that ended with three consecutive mornings of frost during May 18 to 20. Soil moisture ranged from plentiful to excessive during the period. Between early June and corn maturity, precipitation at this site was less than average and temperatures were often several degrees F higher than average. Several periods of moderate drought stress were observed.
Plant population counts in late May found no differences between the tillage treatments, but a small significant difference that favored the polymer seed coating was observed. The trends were carried through to harvest as grain yields followed a similar pattern. Crop yields were markedly lower than historical averages for the area, most likely due to the various periods of crop stress.
| 1 Grain yields are adjusted to 15.5 % moisture. 2 Rows on 30-inch spacing. 3 LSD significant at P>0.10 level. |
||
| Treatment | Corn Populations (June 28, 2002) (plants per 100 feet of row 2) |
Grain Yield1 (bu/acre) |
|---|---|---|
| Tillage | ||
| No-till | 152.4 | 100.0 |
| Zone-till | 148.2 | 98.3 |
| F-ratio | 1.4 | 1.6 |
| LSD (0.05) | NS | NS |
| Seed Treatment | ||
| Polymer-coated | 153.7 | 100.7 |
| Non-coated | 146.9 | 97.6 |
| F-ratio | 3.8 | 5.20 |
| LSD (0.05) | 6.5 3 | 3.06 |
| C.V. (%) | 5.0 | 3.0 |
Grain quality, as determined by visual assessment, was very good. There appeared to be no difference in kernel size, the fraction of cracked grain, and amount of fines exiting the combine bin.
Summary
The crop at this site was subjected to moderate drought stress during several phases of the growing season. Lack of rainfall and higher than average temperatures both contributed to the stress situation. This was reflected in grain yields. While the observed level of moisture stress is not uncommon in this region, it may have influenced the results obtained from this trial. The reader should be cautioned when interpreting and using only these results when making future decisions regarding the use of zone-tillage.
Much of the potential for zone-till to improve the seedbed environment of a corn crop is associated with the ability of zone-till to incorporate some surface residue. Incorporation is facilitated by shallow tillage that loosens soil several inches deep, thus reducing possible surface compaction. Loosened soils exchange gas more readily and are able to dry and warm more quickly. Also, less light-colored residue on the surface allows solar radiation to reach and be absorbed by the darker soil which compounds the warming effect. The residue at this site, soybean stubble, was not very thick. Much had already decomposed during the mild winter and spring prior to corn planting. Additionally, the aggressive sweeping action of the row cleaners and incorporating potential of coulters on modern no-till planters made it difficult to visually see differences between the treatments after the field was planted. On moderately well drained, medium textured soils with small amounts of easily incorporated residue, there may be minimal opportunities for zone-tillage to improve upon the seedbed environment that is produced with modern no-till planters.
The small improvements in both plant populations and grain yield due to the polymer coating on the corn seed is interesting. The greatest advantage of polymer coating the seed is to enable growers to plant earlier during the season, lengthening their window of opportunity to plant, possibly when soils are too cold for seed germination and corn growth. Prolonged exposure to the soil microorganisms can lead to seed decay and poor stands. The corn in this experiment was planted and was emerged during relatively warm conditions. Cold and wet weather arrived after emergence. An improvement in both population and yield when the growing season followed the pattern observed in 2002 was unexpected and warrants further investigation.
Acknowledgements
The authors are grateful to Unverferth Manufacturing Company for the use of their zone-till cart and to Landec Ag for providing the Intellicoat polymer coated and non-coated seed for this trial.