On-Farm
Research

Research Results

Evaluation of Zone-tillage for Corn Production

York County, 2002

Ron Hoover, On-Farm Research Coordinator
John Rowehl, Capital Region Extension Educator (Cumberland County)
Sjoerd Duiker, Soil Management Extension Specialist
Harold and Dean Miller, Grain Producers, York County

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.

Objective

  1. To evaluate zone-tillage ahead of corn planting as a possible means of increasing corn grain yields, when compared to no-till planting, on medium-textured southeastern PA soils.

Site Conditions

Cooperator:
Harold and Dean Miller
Location:
Stewartstown, York County, Pennsylvania
Soil type:
Chester
Previous crop:
soybean
Fertilizer
250 lbs/ac of 15-15-15
30 gal/ac of 30 % UAN solution
Variety:
NK N70-D5 (111 day)
Planting Date:
April 25, 2002
Seeding Rate:
29,000/A
Herbicides:
Glyphosate @ 1.5 pt/A
Bicep @ 2 qt/A
Harvest date:
October 4, 2002

Methods

The test consisted of a replicated comparison of no-till (commercially available no-till planter) against zone-till planting of corn. A single field on which soybean was grown during 2001 was selected as the test site. The field was sloping and planted rows followed the contour lines of the slope. A randomized complete block design with four replications was utilized for the experiment. Approximately 120 feet of field width was used for the test site. An individual plot consisted of six planted rows that extended the length of the field (approximately 1350 feet). Tillage treatments (no-till or zone-till) were randomly assigned to plots. Zone-tillage was accomplished with the use of a 6-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 12-row no-till corn planter. Row spacing was 30 inches. A border area of eighteen rows was maintained on each side of the test area.

Five weeks after planting, ten randomly selected plants were observed for leaf collar appearance. These measurements were utilized as indicators of rates of early plant development.

A self-propelled combine equipped with six-row head was used to shell the grain. All six rows of each six-row plot were harvested and grain was transferred to a dump truck positioned on large capacity wheel weighers. Grain moisture of at least three subsamples per plot was measured with an electronic grain moisture meter. Harvested plot lengths were recorded and used to calculate plot area. Each plot was nearly 0.5 acre. Grain weights were corrected to 15.5 % moisture and 56 pound bushel weights were assumed for all grain. Yields were expressed as bushels of 15.5 % grain per acre.

Results

Most corn in this region of Pennsylvania is planted between early April and early May. This experiment was planted just before the onset an extended period of cold and wet weather. Soil moisture was plentiful but soil temperatures were only slightly above thresholds for corn growth and development during a two and one-half week period shortly after planting. Between early June and corn maturity, precipitation at this site was less than average. Also, temperatures were often two to eight degrees F higher than average during the same period. Several periods of moderate drought stress were observed. The cold and wet conditions slowed early plant development and there was no difference between treatments for leaf collar appearance rate. An early season survey of plant development showed little difference between the treatments for rate of leaf collar development. An average of 3.35 and 3.53 collars per plant were observed five weeks after planting for the no-till and zone-till treatments, respectively. Likewise, grain yields at harvest also were not different. Grain yields measured 106.7 and 108.8 bushels per acre from the no-till and zone-till treatments, respectively. These yields are at least 30 percent lower than average yields when moisture stress is absent.

Development of plants and yield of shelled corn in York County (Miller) study in 2002.
Treatment Leaf collar counts
(May 30, 2002)
(developed leaf collars per plant)		 Grain Yield1
(bu/acre)
1 Grain yields are adjusted to 15.5 % moisture.
No-till 3.35 106.7
Zone-till 3.53 108.8
F-ratio   1.80
LSD (0.05) NS NS
C.V. (%)   1.9

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 most likely 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.

Acknowledgements

The authors are grateful to Unverferth Manufacturing Company for the use of their zone-till cart for this and other trials.