No-till is attractive

Corn producers looking for an opportunity to replace a declining hay field may consider the option of planting corn following a first harvest of hay. This late-planted corn crop is traditionally aimed at silage production, and may in fact allow for earlier planted corn that had been intended for silage to be shifted to grain corn production. In some areas of the province, with proper hybrid selection, the late-planted crop may be targeted for grain corn production. With time, and heat unit accumulation, being the limiting factors this corn crop needs to be planted as quickly as possible following hay harvest. For this reason the option of no-tilling the corn crop into the hay stubble is very attractive. In addition, many of the soil structural and erosion control benefits fostered by the previous forage crop will be enhanced and/or prolonged by using a no-till system.

Research Results

Research in Ontario, conducted by the University of Guelph, examined corn silage yields from several different cropping systems in a study conducted near Woodstock in 1988 and 1989. In this work a five-year-old sod (75 % alfalfa) was converted to corn production using both conventional tillage and no-till systems following the removal of a hay crop (as haylage) in early June. Yields obtained from these two tillage systems are outlined in Table 1. Silage yields were equivalent between conventional and no-till in 1989 but no-till yielded dramatically less than conventional tillage in 1988. Rainfall was 7% of normal during June of 1988 and this resulted in no-till planting conditions that caused low plant stands and poor early growth. Success of the no-till corn planting following hay harvest in 1989 was attributed to adequate soil moisture during, and subsequent to, the planting operation.

Table 1. The effect of corn planting systems following early June hay harvest on corn silage yields. Woodstock, Ontario.
Corn planting system
Corn silage yields @ 65% moisture
Conventional tillage (following hay harvest)
No-till (following hay harvest)
Planting date
June 2
June 8

Aflakpui, T. Vyn, G. Anderson, D. Clements, M. Hall and C. Swanton. University of Guelph.

Similar studies to those in Ontario were conducted by the University of Wisconsin (M. Smith, P. Carter and A. Imholte) during 1985 to 1987 and had somewhat similar results. In their study, no-till corn grain yields following an early season hay harvest where comparable with yields obtained by plowing in only one out of the three years. The successful no-tilling occurred in the year that had June rainfall that was above average. In the other two years of the experiment no-till corn yields averaged 46 bu/acre less than those obtained with conventional tillage.

Factors You Can Control

If you are determined to plant corn following a hay harvest in early June and rain has been limiting the lower risk alternative is certainly one, which includes some tillage prior to planting. This tillage does nothing to conserve moisture or soil structure but it may be essential for good seed to soil contact and early corn root exploration in these relatively hard, dry soils. This is a common phenomenon in Ontario. We can measure higher soil moisture in no-till soils, compared to plowed ground but if dry weather comes early the corn plants cannot get established a root system which allows for exploration of the soil profile. In these cases no-till performs poorer than plowed ground. Even though your no-till ground has conserved more moisture the roots cannot get at it.

However, in years like this one were soil moisture is adequate it appears that no-till corn can do well in these sod fields providing we can get it established and off to a good start. Here are some suggestions:

  1. This operation will require above average planter unit down pressure and overall planter mass. No light-weights recommended.
  2. Some tight sods, especially those with a lot of grass in them cannot be suitably worked with a three coulter system common to many no-till planters. The resulting strip is clumpy, air filled and not conducive to germination or early plant growth. You may want to try a single coulter along with trash removing wheels for a firmer, cleaner seedbed.
  3. Chemical control of the sod and other weeds is critical. Apply a recommended pre-harvest treatment to the hay crop and/or herbicides during pre-emerge or post-emerge windows of the corn crop.
  4. Select a hybrid with a heat unit rating suitable for the delayed planting date and intended use (silage or grain). Late planted corn may be at greater risk to corn borer damage so a Bt hybrid is recommended.