Published November 10, 2007 | By admin
November 10th NEWS – Strip-Till in 2007 Sets a Precedence
Early in the year, in a leading farm magazine, a sound article brought up the case for growers to consider what might be the major mistakes in strip-tillage and how to avoid them. Several of those interviewed and asked responded to help you know what to stay away from. That is good material. We here at Orthman would like to offer a number of items that inform positives when using Strip-Till technology and systems. Many of these you may know, however it does not hurt to bring them up again.
Till where one needs to
With strip-till we are tilling a zone where the seed is to be placed and fertility is placed, not 100% of the soil to a depth of 6 to 10 inches which is expensive, may dry the soil out far too much (those in the Western Corn Belt must be conscious of this fact to get their crop up and going), activate/germinate weed seed, and may initiate soil erosion. Each tillage pass can see 0.5 to 0.7inch moisture lost to evaporation. When irrigating that is $3.50 to $12.00 per acre lost.
Strip-till allows for vertical tillage action in the strip with a reduced potential to damaging soil structure. Vertical tillage can and does aid downward water movement, breaking of lateral soil compaction, and greatly reduce the smashing/tumbling effects in rollover, full-width tillage such as disking, moldboard plowing, and chisel-disc operations.
Better placement of fertilizers
With strip-till, growers can apply nutritional needs right in the pathway of the root growth. Roots like to grow in the presence of nutrition not hunting and gathering which takes away from yield potential and full plant growth.
When broadcast fertilizers are spread across the soil surface maybe only 15% effective at best, we feed far too many weeds and not enough of the roots being grown for the corn, soybean, cotton, potatoes, grain sorghum or peanuts. What you are losing out to weeds gobbling up nutrition and what you paid good dollars to raise should concern all of us. Precision placement with your strip-till implement can allow you to reduce your fertilizer bill 25 to 40% over broadcast rates. In this day and age of $600 per ton for nutrition sources that is significant lowering of input costs.
Placing fertility in the root zone for the first 45 to 55 days after emergence sets the stage for what will happen during pollination, seed set and final yield. Our seven years of study in eastern Colorado and central Nebraska has proven that over and over again. This year we measured as much as 30 bushel/acre improvements with well placed fertility (within 1 inch accuracy) with the seed placement on the average it was 14.5 bushel/acre.
Storage of soil carbon and organic matter build-up
In a strip-till system, especially corn-on-corn, we have observed 900+ pounds (unpublished carbon data with Dr. Ronald Follett, USDA-ARS) of actual soil carbon stored in the upper 4 inches of the soil surface. With larger and better root systems which we have observed in our long term cooperative effort studies in eastern Colorado at the Irrigation Research Foundation (IRF) roots extending deeper and more prolific with strip-till compared to conventional tillage systems, we are storing much more carbon material.
With more extensive vertical and lateral roots in corn, measuring up to 1360 ft of roots per plant in strip till, we fully expect soil carbon quantities to accumulate more and more. How are your roots doing?
Spring soil warm-up has positive effect
In strip-till many researchers and growers have measured 2 to 8°F warmer soils in the upper 3 to 4 inches of the strip-tilled area compared to what is lying under residue. That occurs due to the darker soils absorbing radiant sunlight, the reflecting wavelengths coming off the lighter albedo residue and into the absorbing darker colored soils. In the northern tier of the U.S. that has big consequences to reaching your yield goals. When soils are wet in the spring, open strips can dry quicker, gain heat and affect seed germination and stand.
Strip-till maximizes GPS guidance
When one considers how to be accurately placing seed in the zone and fertility below the seed at planting time has value “ the most accurate signal using triangulation in RTK systems has incredible value. Consider it too beyond the tractor, strip-till rig and planter. The application of herbicides and other pest management products, less waste, targets are hit on a higher percentage of the time, a grower gains confidence, possibly can use less active ingredient to get the job done. These all can pay out quickly.
Our second year of monitoring what RTK can do with fertility placement with seed placement in eastern Colorado has given a boost of 4-5% in 2006 and now 10-13% in 2007 in yield. That makes us all turn our heads and watch “ yes?
Earthworm activity in strip-till definitely rivals no-till
In side-by-side studies in western Kansas, southwestern Nebraska and eastern Colorado we have observed more earthworms active and moving in and out of the strip-tilled zone compared to conventionally tilled ground and within 5% of the number of active earthworms in No-Till after three years. Earthworm numbers are 10 to 30 worms per square foot in strip-till and 17 to 30 worms per square foot.
We have observed five to 12 times more red and brown wigglers, along with more nightcrawlers in the strip tilled fields. When allowing the root crowns to remain intact and moving over 15 inches in a 30 inch row crop system with strip-till, earthworms have more food source to work with, propagate, and survive. As the summer heat comes on, earthworms burrow below 18 inches to escape heat/desiccation and afterwards return to near surface in the months of September-November and do their work when the soil temperature cools. In the spring (fall strip-tilled) earthworms move in and out of the vertically tilled zone eating cellulosic materials with ease. This we have observed at the IRF for the last 5 years (2002-2007).
Significantly less wind and water erosion
USDA-NRCS has made erosion measurements to determine the effectiveness of standing residues in strip-till and have measured soil losses to be 0.8 to 1.2 tons/acre/year in soils with erosion indices of I-86 and I-134. Soils with I-86 and less, they have determined erosion rates are less.
During the extreme wind storms of mid-May 2004 in northwestern Kansas when the big rolling cloud of dust covered the Colby area, thousands of acres had to be replanted. The ground strip-tilled and no-tilled survived fine, keeping input costs down by more than $50/acre. In 2007 at the Texas A&M Stiles Research Foundation farm near Thrall, Texas (north of Austin 40 miles) the heavy rains of May washed badly, losing >10tons/ac/year topsoil just during that month. The no-till and strip-tilled field sized plots still had erosion but less than 1/3rd of the amount was lost compared to conventional tilled plots.
Substantially less compaction
Due to the fewer trips across the field with strip-till and the vertical tillage performed, this system of strip-till reduces the impact of re-insertion of load compaction. With advent of GPS steering technology, growers can keep their traffic on solid ground, plant and allow the crop roots to grow in a better prepared root zone. It has been said by numerous scientists studying soil compaction, that the first pass after major tillage will cause soil compaction all over again. One-pass strip-till with planters attached is a premier method to greatly reduce soil compaction. Not all growers can or want to farm with one-pass strip-till we know that. Two-pass strip-till remains a very effective way to combat soil compaction, reduce fuel consumption, labor costs and time inputs over the field.
Reduction in input costs
As just mentioned, strip-tillage reduces fuel consumption a growing concern with diesel climbing towards $3.00 per gallon even on farm fuel. At our research facility near Lexington, Nebraska this year (2007) we kept fuel consumption to 2.15 gallons/acre including the harvest operation. During a study with growers in four states (NE, CO, KS, & TX) the years 2001-2005 these growers kept records of diesel fuel consumption for tillage, planting, spraying and harvest; we saw rates of fuel consumption 2.0 to 2.8gal/acre with strip-till compared to conventional (disk-rip/disc/field finisher) operations 6.4 to 9.1gal/acre. That is 55 to 68% less fuel burned. At todayâ€™s prices that is $5.50 to $7.70 per acre for strip-till versus $16.50 to $24.75 per acre at $2.75 per gallon fuel costs. That tells us loads.
If considering side-dress fertilizer applications and pre-plant, strip-till can still be cost effective at keeping diesel consumption down.
For the irrigating grower, less water needs to be applied/pumped
Our observations of digging root pits during the growing season and measuring roots, Mike Petersen, Agronomist with Orthman Manufacturing, Inc says â€œwe have measured at the IRF up to 5500 more cubic inches of soil explored and roots extracting moisture in strip-till system farming over conventionally tilled ground.â€ That is a great deal of potentially stored soil water available to the plants root system, Mike says between 1.5 and 2 gallons of water per plant. More water can lead to higher sustained yields in all row crops. When an irrigating farmer considers the price of pumping from underground aquifers at $7.50 to $17.50 per acre to pump one acre inch, even the naturally rain fed grower sees the cost savings and benefits. Why? The old rule of thumb states that for every inch after the first 10 inches of moisture the roots access, in corn we can yield 12 more bushels. In irrigated farming we can see 12 to 22 more bushels per inch.
It is natural with some of your landlords you may hear objections even from your own relatives when strip-till is being considered the way to go in 2008. These are some of the facts which we feel really point towards strip-tillage as a sound way to farm. Consider it, farming with 4 to 7 tillage passes before planting eats dollars beyond what many growers have to spend and this strip-till method offers a light in the tunnel.