Two Pass vs Single Pass No-Till

        Two pass no-till is an oxymoron; however, it is a term used, and a BM practice (in our area), allowing participants to access USDA and Ecology money as an incentive to try no-till for erosion control.  I have never been a fan of the practice, feeling that success would be erratic and it may be an inoculant against no-tilling.  That question is still not answered.

       For nearly 40 years I have listened to researchers talk about what it takes for maximum yields, whether it be a conventional tillage, or no-till system.  There are many factors that go into high yields but two are always part of the list.  They are:
                ---Place seed in soil (not residue).  Most crop cultivars grow through and among residue without any growth issues as long as the seed is placed in soil.  All the issues I have heard about have been with seed being in close contact with decaying residue.
                ---Cotyledons need to emerge within three days of each other.  Thirty-five plus years ago I first heard a speaker (and several since), mention that seed can lay in the ground for some time; however, when conditions allow the seed to germinate, cotyledons emerging within three days of each other comprise 90% of a crops yield.  You can imagine how this be the case.  All plants compete for sunlight, nutrients and water.  If one gets a jump start of four or more days, that plant develops roots and leaves before the other plants in it's sphere of influence, and takes the lion share of everything.  The plants emerging later will be starved to some extent, and can actually degrade the overall quality of the crop.
       Operations associated with 2 pass no-till systems in our area just don't meet the two parameters mentioned above, of seed placement for timely emergence.  A lot of N is lost in a surface application of fertilizer unless the operation can be timed with a rain, --this results in most fertilizer being shanked 4-6 inches into the ground.  Shanked fields are rough and cloddy and residue, if there is any, is left clumped.  Drills normally used for conventional tillage systems are then rolled over these rough fields dropping seed erratically in/on the ground and residue.  If the stars line up right you can get a decent looking crop started; however, most look bad.  To improve emergence, harrows or packers have been allowed and still qualify for two-pass operations.  In my mind these operations then become reduced tillage operations.  Reduced tillage systems do reduce water erosion in a lot of cases, but still, they are not nearly as effective as a high disturbance one pass no-till drill system, in either plant emergence or soil erosion.

COVER-CROP INFORMATION

       A good article in No-Till Farmer (June 18th, 2018 edition) on the experience of John Stigge.  Stigge no-tills corn, soybeans, wheat, oats, milo and raises livestock on 2000ac near Washington, KS.  He has cover cropped ground for many years.  Real progress has been made to soil health in the past 5 years, after years of trial and error, and some notable failures.   He has found that grazing cover-crops have given him positive income when grain has not, and that grazing has accelerated microbiology.   Here are some points he expressed that I found pertinent.  Keep in mind this is KS, with a much longer growing season than we have in the Inland Northwest.
     ---Three main species work synergistically!  He states that brassicas, legumes and grasses work together supporting soil biology and providing nutrients for cash crops.  He has found that using the three together has been the secret to getting the results he wants.
     ---Use of Grasses in mixes!  Stigge finds grasses are an essential foundation to cover-crop mixes.  He likes annual ryegrass as it's relatively inexpensive, grows extensive, deep root systems, and are easy to terminate.  After starting to use annual ryegrass, his OM started to jump.
      Cereal rye is used by many no-tillers.  He states that those looking for cover, but have to put up with late seeding dates, go this route but he found cereal rye problematic and quit using the cultivar.  (my note:  I have found only one other article expressing a concern using cereal rye, --and I know it is problematic.  We are still rouging cereal rye out of our fields after 70+ years since it's introduction.  That one article cautioned, to use cereal rye seed that the supplier can certify being one cereal rye cultivar, and not a mix of 5 cultivars that is commonly sold as cereal rye.  Growth habits vary with each type of cultivar. )

<---pic shows cereal rye plant in WW.  65 years ago you could hardly see the wheat for the rye.  Today, we still walk our fields and find a few stalks of rye.  If you miss a year, you have a bigger problem the next year.  
         Stigge also noted that cereal rye, once it hits boot stage has the value of compost from a grazing standpoint.
        Oats are a great soil conditioner and hold their grazing value through it's life cycle.  Stigge likes using oats, vetch, peas, and a brassica for weed control in his organic program.  After it dies he grazes calves through the winter with no additional feed.  He once rolled out a bale of alfalfa and they used it for bedding, not interested in eating any of it.
    ---Use of Legumes in mixes!  Stigge includes a legume in all his mixes.  They are expensive but very important part of his mixes and about half the mix cost.  They not only sequester free N in the soil but support rhizobia bacterium to fix N, and feed mycorrhizal fungi that serve as the transportation network bringing nutrients from plant to plant.  Legumes also aid in the formation of globulin which is important for soil aggregation.  Vetch (seeded in summer or early fall) is a good spring grazing cultivar if you don't have to terminate to early.  He likes Naomi Wooly Pod vetch, a variety from Australia.  It will start nodules after seven days.  He likes cow peas and they all die with one 37F night in either spring or fall (probably not an option for us where we will reach that temp, or lower, nearly every month of the year).  Stigge likes flying on crimson clover with annual ryegrass.  Berseem clover is for warm season use.  He has found Sunn hemp is good.  Seed is becoming more available and with better inoculants.  It does require heat though to perform well.  Sunn hemp builds a lot of N and has a tap root that goes deep.
      ---Use of Brassicas in mixes!  He has found that brassicas bring up nutrients from deep in the profile and make them available to cash crops.  Their exudates break off calcium, sulfur and other minerals from phosphorous compounds to make them more available.  He likes mustards and radishes, and particularly the bayou kale-rapeseed cross.  This cross has an exceptional root structure.  This cross also brings in a lot of leaf eaters, but they quickly are countered by predator bugs, so don't apply insecticides.  Stigge finds that Daikon radish is great for loosing top soil but the leaves are bitter and livestock don't like it until after a frost.

Scraper Issue with the CrossSlot Drill

         The consumables on a CrossSlot opener include a scraper for each side of the disc.  The purpose of this scraper is to prevent seed from catching on the disc and being drawn back to the surface.  We have not been able to use the scraper because of it's tendency to catch residue and foul the opener.  We have a lot of surface residue, and we farm across slopes of ≤ 40% which exacerbates the problem.
         We have always used the cast chrome blades because they are significantly cheaper than the blades with carbide inserts.
         The fix:  --  Using Blades with Carbide Inserts. 
        Because of our past experience with one cast chrome blade with carbide inserts, we put new blades with carbide inserts on all the openers at the beginning of 2018 season.  We also put all the scrapers back on the seed side of the openers.
        The spring planting is done, -- SUCCESS!   We had less operating down time, with better seed placement using these new blades.  This spring the seeding condition was grueling.   We seeded into all combinations of wet to too wet soils and varying amounts of surface residue.  Kye avoided, where possible, seeding through standing water.  Did we eliminate all plugging of openers? --NO!, --but there was never any consideration of removing the scrapers.  The pace of work picked up compared to the past.   Our seed placement and emergence shows improvement to the point we need to consider dropping seeding rates.  
        This is an expensive opener to maintain compared to our hoe drills in the past, but it's versatility, and ability to seed/emerge a crop in any residue and field condition, is outstanding.  If one figures all the costs that goes into field preparation to emerge a successful stand, the CrossSlot is the least expensive, and the lowest disturbance no-till drill commercially available today.

<---This pic shows the CS opener with the notched disc, the spring plate, the left blade with the carbide inserts, and the scraper.  This blade has run one season showing little to no wear.  By looking closely you can see a short black object hanging down in front of the blade.  There is a hole just below the spring plate that allows material (residue) to enter the void designed for the seed.  This material has the potential of stopping the seed drop.  Several years ago a local custom operator (Jon Olson) spotted the problem and developed a plastic shield to cover that opening.  It works great and we are using the shield.

<---This pic shows two sets of cast chrome blades (w/o carbide inserts) positioned bottom to bottom.  On the left is a new pair, and on the right is a used pair.  The leading edge for both pair is on your left.  Notice the wear on the bottom leading edge of the used blade.  We have found that this wear gradually gets to the point where dirt is allowed to enter the void designed for the seed drop.  It's easy to see this condition when you remove the blade.  There will be a plug of dirt that falls out, or is molded to the blade.  The void designed  in the blade is open on the back (trailing) edge, so the condition won't necessarily stop seed flow, --you will however, have poor seed positioning, leaving the seed near or on the soil surface.

<--- This pic shows the cast chrome blade with two carbide inserts.  One on the lower portion of the leading edge (to your right) and one on the front portion of the leading edge on the bottom wing.  The bottom insert stops the wear on the short wing preventing dirt from entering the void designed for the seed drop.
       Notice the geometry is different from the cast chrome blade without the inserts.  We don't fully understand what is happening here, but, between the geometry difference, and the carbide protected wear surfaces along the leading edge and the bottom wing area, we are now able to seed and use the scrapers as intended.
       One blade with carbide inserts has run on this drill since 2014 and is the only blade that ran the whole time with the scraper.  We have been told that we will have grooving and excessive disc wear using the carbide.  We have not seen that yet.  We have replaced all the disc's due to wear that thinned the blade which caused cracking and breakage from the stress of weight, and hillside operation.

Rotate DS w TILLAGE ??

 

    Left pic:  --one pass low disturbance             Right pic:  --a good no-till drill in tillage
                     drill in undisturbed field.                                     prepped field.
        
 For many years I have heard farmers express a willingness to include a "no-till" practice within a tillage system.  It blows my mind every time I hear it, --these are two completely different (maybe polar opposite) systems.  To me it's like mixing oil and water, --a mess.

Advantages:

        --The potential for soil erosion from water, wind and tillage is significantly reduced during the period that the soil is not tilled.  Un-tilled soil allows old root systems to remain intact along with the surface residue.  These elements resist erosion.  Any tillage that follows negates this advantage.   As years of no-till add up, and as you move from high disturbance to low disturbance no-till, the advantage of no-till increases, --meaning: as time passes and you gain knowledge on soil biology and apply that knowledge, your soils will gain health and productivity instead of continuing to degrade under a tillage system.

Disadvantages:

       --You may expand the number of weed species in your field.  There is a weed shift with no-till.  China Lettuce and Russian Thistle can be problem weeds in chem-fallow. Every plant type has a preferred environment.  Changing that environment by introducing no-till, or diversifying crops, or even reducing the number of tillage passes will change weed types and populations.  Those of us experienced in no-till use that fact and exploit it in our management of the system.

       --You will probably need additional N.  If you take soil samples and use an N budget, it will include a factor for N production that relates to the percent of OM in the sample.  Tillage stokes the furnace; making N, by mixing oxygen (air) with fuel (OM) and soil temperature to break down the OM.  Without tillage this process is slowed way down by not introducing oxygen (air) into the soil profile, creating less N from the soil source.  It varies, but somewhere around 3-7 years of continued no-till, N release becomes similar to tilled soil.  When you start building your soil OM, than you can start reducing your commercial applied N, and other plant nutrients.

THE BOTTOM LINE:

      When you finally quit making excuses and admit to yourself that the productivity of the land you are stewarding is being flushed down the creek and/or blowing away and decide to change, --CHANGE!!!

      Start slowly, --take a field that is large enough to bring in a custom no-tiller to do your seeding, dedicate the field to no-till, and learn the system.  Expand across the remainder of your operation as soon as you get some comfort level with the system.   Don't make comparisons with your tilled fields.  These comparisons only slow down the process of positive change.  It is a proven fact that tillage destroys soil productivity, and unless you change, your soil will become dirt, and unproductive.  It's just a matter of time.  In a little over a 100 years we have lost ~50% of our soils natural productivity. Evidence of this happening sticks out all over the Palouse Hills region by observing the skimpy/no crop on some ridge lines. Change has never been easier than it is now.  Most no-till issues have been experienced and solutions found, --meaning: no-tillers are experiencing fewer problems as their experience and knowledge increases.  Most experienced no-tillers I have been around are quite willing to talk about their experiences and help others.

FUTURE:

      No-till controls the bleeding by stopping erosion through protecting the soil surface and building back soil structure.  You can accelerate building soil productivity by increasing soil biology, --a subject beyond this post.