Don’t Call Me An Expert - This is just the way I do things

Managing Residue in No-Till

By Darwyn Mayer

To start with, a little background.  I returned to the family farm that I grew up on after graduating from NDSU in 1988.  My wife Rachael and I, along with our four children ages 8, 6, 2, and 6 months, farm with my parents Francis and Delila Mayer, north of Mott, N.D. in north central Hettinger County.

Our current crop rotation includes spring wheat, durum, winter wheat, corn, canola, flax, sunflowers, and occasionally peas, barley, buckwheat, and millet in a low disturbance (single disc drill) no-till system.

In the past, residue had to be managed with tillage. Combines were not equipped with chaff spreaders, and choppers could not spread straw the full width of the header. Double disc drills and most hoe drills of the day couldn’t handle the residue, especially from wheat grown on fallow. 

We were having to fall tandem disc the heavy wheat straw just to get the field cultivator and drill through the chaff and straw rows left by the combine .  Two things had to improve.  First, the combine needed to return residue back to the ground evenly. Second, the drill had to be able to handle more residue without plugging.

When it came time to switch to no-till, we tried to solve the combine problem first. In 1995 we installed fine cut choppers on both our rotary and conventional machines. We also needed a chaff spreader on the conventional machine.  The chaff from the rotary machine fed directly into the chopper with the straw. 

In 1996 we planted half the farm with a no-till single disc drill, and by 2001 went to 100% no-till using a single disc air-seeder and a 30” no-till planter.

Today one of the factors we use in determining our crop rotation is the amount of residue out on the field from the previous crops, and how well it is distributed.  The southwest corner of N.D. is on average the warmest part of the state, however there are still two big challenges for no-tilling out here from cold weather.

Our dry climate allows more extremes in high and low temperatures, so the first challenge is late spring frost damage to small seedlings growing through heavy crop residue, which insulates them from warmth coming up from the soil on cold nights.

Canola has caused us the most problems, with flax being the next most sensitive. Using the “amount of residue out there” guideline, it’s safer to plant these crops on higher ground with low amounts of residue.  As crop insurance allows, canola can go on flax or pea ground in our area, which gives it a blacker residue and soil to emerge from.  We’ve never completely lost a flax stand to frost but have had it thinned out considerably in heavy stubble.

Our second cold weather challenge comes from having only around 2,100 GGD units for growing corn.  We are very grateful to see huge improvements in early maturing corn varieties in both yield and stress (cold) emergence scores.  This allows us to use the high amounts of residue we get from winter wheat and sometimes spring wheat and durum to reduce moisture evaporation between 30” rows. Of course, water is the main restriction to corn yield, so slowing evaporation from the soil increases water available for the crop. 

Floating row cleaners are great for warming up soil for both corn and sunflowers.  On fields of very heavy wheat straw residue, we have been able to do two years of row crops, either corn-corn or corn-sunflower.

Setting up next year’s crop starts with managing last year’s residue
We have a lot more no-till success when we can spread residues properly with the combine.  If you have more straw or chaff in one area than another as you harvest down the field, several problems arise by next planting season:

• Planting equipment cannot seed at a constant depth.
• Soils won’t warm up evenly.
• Nutrients will be tied up in streaks.
• Diseases can be more of a problem where residue is heavy.

So farmers and combine operators need to have the proper spreading equipment, and know the various factors that affect its performance. Some of these factors include header type and width, cutting height, mechanical condition and speed of rotation of equipment.  Even the condition of the straw as its spread can make a difference – with today’s aeration systems, more farmers are taking grain earlier, and taking grain earlier leads you into greener and tougher straw.

When our straw spreading doesn’t go well behind the combine, we are more likely to use the 30” planter with row cleaners.  We’ll still see streaks, especially in corn.  Another option is to use a warm season crop like buckwheat or millet to let the soil warm up and residue to decay before planting. 

In the past we’ve used a heavy harrow, but have noticed some disadvantages. Harrowing cannot move chaff rows, and it knocks down some of the standing stubble, thereby reducing snow hold and putting more residue on the ground to seed through.

Also in the past in heavy residue fields, we’ve used a 15” spacing NH3 applicator with lead coulters and ¾” to 1” knives. The drawback here is that it can leave the ground uneven for drilling shallow seeded crops, and there is more moisture evaporation between 30” rows.

I believe residue management is crucial to no-till farming.  Residues can be managed to your advantage with the proper amount of diversity in a system. The extra water that is saved by not tilling, trapping snow, and lowering evaporation has allowed us to diversify to crops and rotations that are typically used approximately 100 miles east of our operation.  All this, along with the decrease in soil erosion and savings in fuel use, is a win-win situation for our farm.

You can contact Darwyn by email at rdmayer@pop.ctctel.com.