Agronomics101

Going further under the microscope of Macro-to-Microaggregates

I wrote on the 4th of February on this site some details of how Strip-Till is complimentary to developing more stable macroaggregates, those that are between 1.0mm up to 4.0mm in size and maybe larger.  Within that structural unit I displayed a closeup of an oat root with a cottony mass around the bright white root growing through a small soil ped.  Let us delve a bit closer to see some more.

Macro-Micro-Primary sized units of soil structure with key features highlighted.

All of this is to say, what we soil scientists are getting to know more about and I want to offer you what some of  those important facts are:

The image on the far-left depicts how roots and microscopically fine mycorrhizal hyphae along with roots interconnect the soil and help hold smaller particles of silt, sand and clay together to form granular, crumb or fine subangular blocky structural units. The image in the middle gives a close-up of the microaggregate, spores in close enough proximity to the root that they can spear the root with an appressori and inject its rNA into the root and begin the formation of its symbiotic relational organism (called an “arbuscle” – tree-like form) within the root interior cells to feed itself and feed the host root.  As this all occurs the hyphae can extend outward from the root up to 10cm in length.  This hyphae stores a thick glyco-protein within the hyphal tubular walls, when the fungal hyphae die or dessicate it is this extremely sticky glue-like substance glomalin that aids in tightly holding organic particles along with microbial debris to soil clay and silt particles.  This complex substance can last up to 21 years. Scientists have found from soil sampling at various depths, glomalin is in and along old root channels to the depth of 140cm (55 inches) [1].

In the diagram above, on the far right side, microbial sized debris is pointed out.  These materials are the sites where soil organic carbon (SOC) exists and stored to provide easily available nutrients and also hold up to 400 times its weight with water.  This SOC is very important to bacteria for their food source of carbon.  Earthworms that consume small mouthfuls of soil bacteria, nematodes, amoeba, all who hide in these crevasses and nourish the earthworm.  As the worm passes the material through its gut it too excretes stable microaggregates with mucous-like substances that can release to other bacteria foodstuffs.  These materials can stabilize soil structural units with specific chemical and electronic bonds.  With Strip-Tillage as a once-a-year minimal disturbance will aid mixing this some in the upper 6 to 11.5 inches and cause minimal disruption in the storing of soil carbon.  The glomalin substances can mix and stick more particles together along with a redistribution of the fungal spores to find more roots and restart the infection of more roots and continue the cycle.  Strip-Till does not turn or tumble soils such as a disc or moldboard plow will.  That kind of tumbling effect dries the soil out, exposes spores, soil carbon, mycorrhizae fragments to the atmosphere, dries them out and will cause rapid oxidation – losing the important substances that help the health and stability of soils.  Many times worms are exposed, their tunnels and home burrows are broke open and the cut or torn-in-two worm may die or try to burrow down and again and then die.  Yes strip-till disturbs the earthworms in the till-zone.

My studying of the till-zone after the strip-till implement pass (over the past 10 years) has shown me the strip-till pass is much less destructive and earthworms can recover in 7 to 14 days, still sense where their tunnels are and continue existing.  Due to our tilling of less than 33% of the total soil matrix across a 20 foot zone by 10 inches deep and not turning it over I believe we are aiding the building up of soil health.  Even “direct seeding” efforts can cause some set back of the fungal/bacterial interaction.

I will keep digging into what Strip-Tillage can do to aid soil health to remain strong, viable and accumulating soil carbon.  Stay tuned to us here at precisiontillage.com and we will provide a ‘below the boot on the ground look”.

 

 

References used:

  1. Glomalin: an arbuscular mycorrhizal fungal soil protein.   Pradeep Kumar Singh, Meenakshi Singh, and Bhumi Nath Tripathi;   Found in: Protoplasma (2013) 250:663–669
  2. Mycorrhizal Symbiosis, S.E Smith and D.J. Read, Second Edition, Academic Press, 1997.
  3. Plant-Environment Interactions., R.E. Wilkinson, Second Edition, Marcel-Dekker AG, 2000.

Orthman/Ohio State University Offers an Approach to a New Tomorrow

Precision Seeding

The team of specialists at Ohio State University under Dr. John Fulton are studying the values of how a Strip-Till Systematic approach to alleviating compaction, providing an ideal seedbed and then setting up the tillage zone with precision placed nutrition works.  This last season [2018] at the Molly Caren Center which is just west of Columbus, OH some 10-12 miles just off I-70 and at the Clark County, Ohio research facility, Fulton and staff demonstrated and have published their results in their 2018 eFields Report (which is out electronically and in published forms).  We at Orthman are providing an 8row-30 inch 1tRIPr along with a Salford twin bin 10 ton steerable fertility cart, with flow control apparatus and technical expertise as they study placement [shallow/medium depth/deep and broadcast], and variable down-force rates on the planter in the strip-zone compared to other systems approach.  And I do say – the results show great promise for growers in the Eastern Corn Belt and westward to consider a system that can save money, labor, fuel, trips across the field, water, soil erosion concerns lessened, an emphasis on applying phosphorus products, fertilizers applied in more crop appropriate quantities, and potential yield improvements.

I do want to direct your eyes and fingers at the computer to check out www.agcrops.osu.edu/people to touch base with Ohio’s Extension folks another way is to reach out to Dr. Elizabeth Hawkins who is a major part of the eFields Program; hawkins.301@osu.edu.  One can download the report if so desired  by going to https://digitalag.osu.edu/efields/efields-reports. It may behoove folks who are in the eastern Indiana, Western Ohio to Michigan region to make it to one of the four upcoming public review meetings being held to go over the 2018 results/studies: February 13th 9:00 to Noon EST Clinton County Extension office, Wilmington, Ohio or February 20th, 9:00-Noon EST, at Robert Fulton Ag Center, Wauseon, OH; February 27th, 4:30-8:30pm EST at RG Drage Career Conference Center, 2800 Richville Dr. SW, Massillon, OH and last one – February 28th, 9:00-Noon EST at Upper Valley Career Center, Adult Applied Technology Center, Piqua, OH.  There is a host of great studies and data presented in the eFields report.  Let me tease you with some information I gleaned quickly as I have gone through the 195 page report.

eFields Strip-Till Fertilizer Placement Study
   study located at Molly Caren Ag Center, London, OH
Treatments: Harvest Grain Moisture % Yield    (bu/acre)
Broadcast-NoTill 17.3 214.0
Broadcast-ST 13.6 210.0
Shallow(0-3″) 16.9 218.0
Medium(3-6″) 17.0 216.0
Deep (6-9″) 17.0 216.0
   Rate of P2O5 was 150lb/ac in all plots
Amt of precip during season 24.1 in.

Changes may not seem all that huge but efficiency of the P products do show that there can be an advantage to placement.  There are other locations across the U.S. that depict the placement can and is greater than this year at OSU.  Watch for those results with your own eyes.

We at Orthman Mfg are very pleased to be working with Ohio State University’s Department of Food, Agricultural and Biological Engineering to bring this and other studies to you.  Check out the report and/or visit with the Extension offices that are having these meetings right here quick.

Mike Petersen, Lead Agronomist-Orthman Manufacturing, Inc.

Scientists determine why long term N-fertilization aids in biological activity of soils

Here it is winter, January 2019 in the Northern Hemisphere, soil microbes are either asleep or dormant in most soils below the 41 degree Fahrenheit point.  I want to scratch at your brains to consider some of the biological importance of aerobes and anaerobes; whether they are cyanobacteria, fungi, nitrogen consumers, phosphate or potassium decomposers, or sulfur digesting workers in high residue environments.

When high carbon to nitrogen ratio (C:N) grown crops [corn and small grains with ratios of 45:1 up to 80:1] are in long term crop rotations with conservation tillage practices, we in Agriculture see Total N fraction (TN) of the soil generally improve up with proper N fertilization.  All that is to say as you add forms of nitrogen into each years cropping system; both the fungal biomass and microbial biomass increase proportionately up.  Some may say with a resounding duh.  Well stay with me for a moment.  In long term studies some over-the-pond researchers concluded a 23 year study of small grain rotations, they studied to determine which enzymes and/or organic reagents derived from the microscopic  world tell you how Total Nitrogen  and  stable macroaggregates (those >2mm in size) can continue to climb in percent of the sand-silt-clay-SOM fraction.  All of these stable aggregates relate to improved soil health.

<<< Image of actinomycetes in a large colony

When this happens your soils are more healthy, less erosive to water and wind erosion and will have more sites to hold nutrients.   From that 23 year study the scientists found the fungal and fungi-like populations such as Actinobacteria made up of in the order of abundance in soils, the common genera of actinomycetes are: Streptomycetes (nearly 70%), Nocardia and Micromonospora with Actinomycetes, Actinoplanes, Micromonospora and Streptosporangium being 15%.  All of these one celled creatures are involved in the breakdown of cellulose, chitin, lignin, fats, lipids, and some proteins from the remaining crop residues and roots.  Some of who I just mentioned are anaerobic and do better in more moist No-Till environments compared to aerobic conditions where more tillage is involved.  These organic compounds [N-acetyl-β-D-glucosaminidase, β-glucosidase, Phosphatase and Sulfatase] are some of the major components released by fungal populations and Actinobacteria to breakdown the cellulosic materials and tough lignin materials.  All four of those compounds are released from higher populations of the fungi and Actinobacteria to aid in storage of N and stabilizing of carbon on the macroaggregates.

Wow that was a mouthful of large graduate school level microbiologic words that mean what?  These one celled microbes with flagella or whip-like tails  [Actinobacteria] facilitate movement in the soil solution and to move around on root surfaces. They are very good at breaking down complex cellulosic matter and making the N as an plant available component of those soil organic carbon materials, readily available to the existing crop/plant or subsequent plants.  However they are mostly anaerobic or facultative anaerobic based, [live in low oxygen soil environments] which is not a good season long environment for roots and root respiration.  These bacteria that act similar to fungi are important but some of them are pathogenic too.  They can cause root rots, be precursors to fungal pathogens, pink root issues, dampening off and a host of other things.  Soils that may be overly compacted, shallow water table, ponded, slow to very slow internal drainage in the first 24 inches, all can turn bad in a short period and create untold problems due to the wrong microbial families that take over.  However, Actinobacteria are important in the soil ecology to break down carbon based materials into valuable components for plant and soil life.

What does this have to do with Precision Tillage, Strip-Tillage and you?  For you that ever had to deal with wet soil conditions this spring, summer and fall – I wanted you to be aware of such conditions can exist and who is lurking under the corn leaves, stalks, and cobs.  Strip-Tillage may fit into your 2019 management program.  For you that have compaction due to harvest traffic that created ruts, smeared soils and holes where you took four hours to get the grain cart out of the field; soil conditions that squeezed oxygen out of the soil – issues I spoke of are happening and strip-tillage has a place.  Now this is not all bad ladies and gents.    Soils need to have a mix of all the aerobes, facultative anaerobes, anaerobes to enrich the spectrum of making nutrients available.  Too many of the anaerobic miniature critters and we can see way too many negatives.

I will go into some more of the good miniature creatures in a subsequent blog article.  Thanks for reading.

References I used and may serve your further reading:

Functional Predictions of Microbial Communities in Soil as Affected by Long-term Tillage Practices
Janani Hariharan, Aditi Sengupta, Parwinder Grewal, and Warren A. Dick*, Agricultural &
Environmental Letters, Research Letter published via ResearchGate on-line

Long-term effects of nitrogen fertilization on aggregation and localization of carbon, nitrogen and microbial activities in soil; YidongWang a,b, Zhong-LiangWang a,b,⁎, Qingzhong Zhang c, NingHud, ZhongfangLi d, Yilai Lou c,⁎⁎, Yong Li a,b, Dongmei Xue a,b, Yi Chene, ChunyanWue, Chris B. Zou a,f, Yakov Kuzyakov a,g; Science of the Total Environment Journal homepage: www.elsevier.com/locate/scitotenv

Growth of saprotrophic fungi and bacteria in soil, Johannes Rousk1,2 & Erland Baath 1, Microbiology Ecology

Mike Petersen

Why from the soilsview we see vertical disruption of compaction important.

The two images: Heavy residue and me digging to expose the compaction alleviation effects of the 1tRIPr were done in the fall before all field conditions went south. 

As a soil scientist and investigator of “the dirt”, I have studied, poked, prodded, dug shallow to down deep to really get the view of why we see vertical tillage with a shank tool do the job to disrupt and remediate soil compaction.  Let me help you get your head wrapped around what must happen to alleviate soil compaction in the upper 11 inches of the soils on your farms.

First, we drive over the soils in a horizontal fashion, whether tractor, trucks, heavily loaded grain carts, big combines, tractor and disk tools (even those VT machines) that can and do insert compaction unless it is bone dry.  Common occurrences for some of you, we bring out the disk or field finisher to dry out the soil – a smear, sliding action with a vibrating down pressure that breaks down soils to smaller units and squeezes the soil making a lateral thin zone of soil particles like pages of paper stacked on top of one another.  Heavy carts or truck such as during silage harvest, push big forces of pressure downward to where that energy is dissipated squeezing pores and oxygen out making the density of the soil at that depth (let’s say it is 9 inches below the soil surface), at that depth roots encounter resistance to moving downward or water slows to a near stop to move down.  Root growth for many of our row crops are impeded when they encounter 140 psi of resistance and greater.  Early in the life of a corn plant for instance, the seedling root  system does not have much strength, power to extend away from the seed. When it encounters dense soils at the 4 inch depth and that zone of resistance is 2 inches thick – wow that baby plant is in for a work out.  The plant has a finite amount of energy apportioned to its growth potential at the root tips to grow downward by the pull of gravity.  When stopped or slowed to a crawl, the plant cannot not adequately sustain its need for water and nutrients such as phosphorus, zinc, manganese and iron (all needed in the first 15-20 days after emergence). Immediately energy levels drop and the plant resorts to falling off its potential.

 
Big_shankwork_1tRIPr_4PTcom

Figure 1. This graphic depicts the action of the Orthman 1tRIPr implement. Soil compaction is pervasive in many, many fields in the U.S. and causes yield losses, retards downward water penetration, soil surface runoff issues. The “red bolts” that extend upward and out from the shank away from the tillzone crack the soils minimizing ‘potted soil effects’.

So a tool that works to fracture, shatter and have a up and out at near 45 degrees of zig-zag ripple effect (towards the soil surface) into adjoining area of soil space on either side of the shank. It does not explode the soil and cause it to heave and roll out soil material, that will not really help change compacted soils. Whoa, do not go to “I need to get a subsoiling ripper tool to tear, rip, snort, explode soils from stem to stern”, that is not what I am advocating. We want you to be controlled and do this in a specific zone for the new coming to be planted crop.  That is exactly what the Orthman tool is designed to do.

The 1tRIPr is set to go right under the bottom of the compacted layer(s) then pulled at 4 to 5.5mph to lift, fracture and ripple the zone in a tapered U shaped zone.  The open end of the U is right where a grower will follow with his/her planter.  We do not want to cause a sidewall smear alongside the shank or at the underneath side of the point.  We ask folks to check their soil moisture content at the depth the tool needs to be run.  Best moisture conditions are when you can just ball the soil in your hand, toss up 8-12 inches and catch it and it breaks, it is time to go to work.  That is 35-50% moisture depleted of field capacity.  When too wet the job you are wanting to accomplish will not be quite as effective.

Newer Nitrogen Tools for We Strip-Tillers – Options to Consider!

For many of you, and for us at Orthman Research Farm near Lexington, Nebraska we are planning the pre-plant tillage operations of the spring 2013 to be underway very soon. Tillage via strip-till methods will be our way, but how about many of you as you consider the fertilization part of the puzzle? How will that be happening for you?
Just recently we attended a good set of meetings in Reno at the Western Fertility Conference to hear recent findings and interact with industry and research scientists about some gains in fertility management for row crops, small grains, and orchard/fruit crops. The issues of ground water contamination, overland flow issues getting into the major water course of the Mississippi River and major river systems of the West are challenging the way we growers must consider our operations. You all have heard about well waters reaching levels of nitrate in the water that surpass drinking standards not only for human infants but even livestock due to leaching and other contamination processes. Being good stewards now is very wise, but we are coming against issues of the past 65+ years of intensive farming with nitrogen sources.  After WWII and thoughts that “if a little is good than a whole bunch is that much more better.” Yeah bad grammar but it was an addage that numerous growers thought and employed. Now we pay for it and have to be that much more on top of our game.
The good folks I met, listened too and spoke with in Reno, NV are saying there are Nitrogen products on the market that will give better and sustained release to the crops root system over a longer period of time and resist the change from first introduction into the soil profile to convert to Nitrate and leach away before the roots have a chance to access to it in the soil solution. Products such as ESN™ being a granular urea coated with micro thin polymer, yes it is a dry product. This method of release can aid in slowed access to the urea-N product so it does not leach away, gobbled by the microbes or become mineralized so quickly that the plant root starves for N when called for by the growing above ground plant.
ESN™ is an Agrium product which responds to soil temperature and soil water content. Another product out on the market is Nutrisphere-N™ by SFP that works a bit differently than ESN™ but offers another management alternative for growers on how N releases into the soil environment. For the strip-till grower these products offer advanced ways to accomplish higher management of your N-fertility and feed the plant incrementally. Agrotain™ by Koch Industries, then there is Instinct™ by Dow are other products out there that all should be aware of so N management is not a willy-nilly part of how we furnish the corn, wheat, grain sorghum, dry edibles, cotton, peanuts, etc what is needed. As we learn more about these products from trials in each of our regions or even on a neighbors ground – we can better feed the crops we grow with the Nitrogen.
It was in the conference that we learned that especially with veggie crops N is in big demand for a short period and timing is everything. Consider maize/corn, we know it has three major calls if you will when N is in demand. Dump a hugeload prior to planting like 300 pounds per acre 30-90 days ahead of planting, do you really think it is going to sit still and not move deep or get fixed in the organic colloids or onto the clay complex or move off the surface if surface applied? Here is when these slowed release agents/products come into play to offer new solutions to our old loss problem. A little further study can really help you gain when and which product can work in your soils environment whether you have dry, wet, cold or what ever conditions.
In the strip-till system where the soils off to either side of where we strip-till 10 inches deep can be 2 to 8 degrees Fahrenheit colder, more moist if not wet and cause issues of root N-uptake and maybe even yield reductions early because the availability is just not there. You pour on N via anhydrous ammonia and expect because it is cooler that it will be there when the roots get to it, wow that could be an issue. It is a cheaper form of lots of N but is it the right one when any of it volitalizes or gets converted too soon? Cavities in the soil, shanked in and you may see it escaping, warmer than 50 degrees, dry soils – all issues and 20+% is poof, gone and that price differential just evaporated. Placing a charge of 250-300lbs/acre and then a couple-three inches of rain and the stuff will move even in clay loam soils 10-25 inches deeper than where you placed it. In some environments folks, the roots may never reach that and it is lost to never be had. Yes the same can happen to high rates of N via liquid products.

This day and age we are called to be better managers and come out of the shell the old way Daddy did it and move to spending time to educate how we can do better and wiser. Allocate time to have products be within reach of the roots when the demand for N is there will take new skills when we place it with the strip-till tool that we make called the 1tRIPr or another tool is very important. We, Mark and I at Orthman Farms are using some of the above products and getting positive responses that these products yield good results in grain and healthier crops. Check back with us or go to your agronomist or fertilizer dealer and learn about these products.

In California the watchers and monitoring agencies are clamping down on how fertility is managed, in Delaware and Maryland the environmental agencies by law demand fine-toothed control of N-P fertilization. In segments of the Central and Eastern Corn Belt states fall applications of N products are restricted and certain watersheds are being monitored and evaluated to stating growers may only apply 70lbs/acre (as an example) of N for a 200 bushel/acre corn crop. That is quite restrictive – yes? Other environments we can still be applying high amounts of N but to what cost? As a soil scientist and agronomist for Orthman Manufacturing I am going the route of top flight management with better products that will feed the plant incrementally. It has paid off and we encourage the same with the checking into the use of these good products that I named as a few of them to start with.
We will one day maybe feeding the corn we plant only half of what we have conventionally tilled into the soils and still yield 300 bushel/acre corn regularly. It has been done in the past three years in the Western Corn Belt under intensively managed irrigated corn. Instead of 300-350lbs N/acre researchers applied 140-150lbs/acre. Consider the dollars savings alone folks.

All of us who grow crops to reac a production goal know it takes fertilizers, either commercial or with use of manures.  We know our dollars stretch only so far and our water is stretching us to be better about how we grow crops.  We encourage you to place those nutrients in the soil precisely, with the understanding how much will the plant need and when.  Using the Strip-Tillage tools manufactured at Orthman is a great choice to put this all in motion.  Please contact any of us on the Sales, Marketing and/or Agronomy Team here at Orthman.

Strip-Tilling with Liquid Fertilizers for Early to Mid-Season Growth

BEST USE OF CROP RESIDUES ADDS SOIL CARBON

In 2012 and now 2013… Retention and Best Use of Crop Residues Adds Important Soil Carbon

By Michael Petersen, Lead Agronomist for Orthman Manufacturing, Inc.  January 2013

 

Many of us in the Conservation Tillage movement agree that as much of the past crop aftermath left on the soil surface as possible and not mixed in to the soil surface layer provides tremendous benefits both short term and long. All of us who advocate Strip-Tillage and Direct Seeding know that residues provide food for beneficial microbes, protozoa, earthworms, mites.  We know that this carboniferous material improves water holding capacity and nutrient capacity – SOC (soil organic carbon) can hold up to more than 150X its weight in water.  The exchange capacity to hold specific nutrients positive and negative charges is extremely high but material is mobile.  SOC is vital to stabilizing soil aggregates and feeding mycorrhizal fungi which release a sticky polysaccharide compound called “glomalin” that glues soil aggregates together so they can resist raindrop impact and wind sorting.  The SOC in the surface 1-3 inches resists soil crusting especially after hard rains and then baking sun.

Here in the States we have adopted better and wiser conservation measures to simplify and drastically reduce the types of pre-plant tillage which was inverting and burying prior year residues but exposing years and years of prior stored carbon and much of it was oxidizing away and above.  Modelers and scientists have calculated that with practices such as Strip-Till and Direct Seeding growers can store tons of carbon in the surface 1 to 4 inches with the return and slow breakdown of crop aftermath.  But what about all those roots, root exudates, lignin and cellulosic materials from 0 to 6 or 7 feet in places?

Here at Orthman Manufacturing, Inc we have observed rooting magnified SOC with the conservation tillage strategy of Strip-Tillage due to in part a quicker start in the spring to maximize the number of roots expressed below ground.  We have followed that up with observed soil pits to measure corn roots in a continual strip-till program that promotes deeper expansion into the soil due to roots propensity to follow the cooler soil temperatures as the season heats deep into the soil profile.  We also have gained information from studies accomplished at the University of Georgia (1999-2001) that corn is known to extend vertically at specific soil temperatures as well as its lateral root development.  Gaining more root dimension in linear length we know that those of us who raise corn can accumulate more grams of dry matter below ground to depths mentioned above.  That in turn adds soil carbon to the soil profile.

…SOC is vital     to stabilizing soil aggregates and feeding mycorrhizal fungi….

We have measured in eastern Colorado in loam and silt loam textured very deep soils under corn; 38,100+ linear inches of corn roots with deeper rooted corn hybrids, other not quite as prolific rooted hybrids we have measured 9,500 to 20,000 linear inches.  The estimate for the grams of carbon materials is far and above the grams of material remaining after the ear of corn is harvested. It is our contention as we have exposed nearly a quarter mile of roots under one corn plant that was planted into a strip-tilled environment and precision fertilized we are gaining loads more soil carbon material than what is possible with full width (inversion) tillage systems every year.  To give you for example, when we first started the strip-till methodology at Lexington, Nebraska in 2007 our soil samples from the first four inches was 2.1 to 2.3%. This spring when we sampled again, in very near proximity we had 2.7-3.1% SOM.  We do not graze the corn stalks with cattle which can reduce corn residues by 50% on the soil surface.  We leave our standing stalks 13 to 20 inches tall and we do not shred come spring.  It is our contention that the longer and taller stalks keep winter winds from blowing residues away and off into the adjoining fields or barrow ditches. We have estimated tonnage of corn residues after harvest of 5.5T/acre to 7.8T/acre and very little of it leaving the property.  Maintaining this quantity of aftermath has its concerns but we have more water stored, more carbon returning into the surface, increased population of microbes, and we have old roots decomposing slowly to become humus – the treats for those burrowing insects and soil microbes.

 

 

In our long term studies at the Irrigation Research Foundation which lies just north of Yuma, Colorado, we observed from 2001 to 2008 a change in SOM from 1.51% to 2.66% in 7 years with strip-tillage. Now remember that is only being measured in the upper 10 cm (4 inches) of the soil profile.  It is also important to note the elevation at Yuma is 4100+ ft compared to Lexington at approximately 2300 ft above sea level.  As observed in the high plains of Colorado the residues are reduced by UV during the winter months due to the non-cloudy winter days and lack of snow cover.  An accelerated oxidation of the carbon materials remaining is quite evident.

 

NEWS FROM DOWN UNDER…More Roots Gain SOC

Scientist Hulugalle in New South Wales, Australia has conducted some very sound measurements and reported this in Agriculture Today, April 2010 regarding what returns of carbon came from roots in two cropping systems.  “We measured corn root growth in back-to-back corn and a cotton-corn rotation sown on one meter (~40inches) beds during the summers of 2007-08 and 2008-09”.

“Total carbon added from corn roots averaged 5.0T/ha/yr with cotton-corn and 9.3t/ha/year with back-to-back corn,”  noted Dr. Hulugalle.

In other soil measurements Hulugalle determined that corn on corn accumulated 770 g C/m2/ yr or for those of us here in the States that is 1.7lbs of carbon per 10.7 square feet per year or 0.16lb C/sq.ft. per year.  This was published in a Short Report on the Plant Root website 2010.

Much of the research and determined rates of carbon storage here in the U.S. has looked at the surface layers of the soil.  Some limited research has gone into determining how much soil carbon is stored with switchgrass, a near-permanent crop and the rate is quite high.  These studies are part of the biofuels industry look at how the cellulosic material can be beneficial to ethanol production and as an ecologically sound system.

RECENT EUROPEAN RESEARCH EFFORTS… More Roots = More Carbon Stored

Kätterer, T., (2011) writing in Agriculture Ecosystems and Environment observed in a review on the relative contribution of root versus shoot material to soil organic matter formation, that researcher Rasse et al. (2005) concluded that results from in situ experiments indicate that root contribution to soil organic C per unit C is, on average, 2.4 times higher than of shoots. Data ranged from a minimum of 1.5 to a maximum of 3.7, compiling results from maize, hairy vetch and alfalfa. However, in the review by Rasse et al. (2005), and studies by Barber (1979) and Plénet et al. (1993), it was assumed that the annual input of fresh root C through root exudation, turnover and cell sloughing into soil was equivalent to that of the ‘measurable root biomass’ (i.e. 100%). In the calculation by Bolinder et al. (2007), root exudation, turnover and cell sloughing was assumed to be 65% of the measurable root biomass. This is consistent with Swedish research results from a long-term (1979-88) project on agroecosystems, Ecology of arable land – the role of organisms in N cycling by Andrén et al. (1989).

The main hypothesis tested in Katterer’s research, that roots contribute relatively more to uncontrollable soil organic matter than aboveground residues, He concluded that there is strong evidence from his experiments that roots contribute more to relatively stable soil C pools than the same amount of shoot-derived plant material does.

 

 

IN CONCLUSION…

 

Our work in South Central Nebraska and 16 other locations across the United States confirm that SOC is changing in the positive direction year after year with Strip-Tillage one of the best Conservation Tillage methods going. The information I shared with you provides more proof that we are helping your soil resource be sustainable, yielding well when moisture is coming from above, helps profits, reduces erosion concerns greatly with the use of Strip-Tillage.

 

We will be writing more and giving you more information as time marches on in 2013 as to the benefits of Strip-Tillage.

Corn is about to go into a feeding frenzy… for water and Nutrients

The holiday we all have a load of respect for, July 4th is upon us and the heat is putting corn, soybeans and cotton crops into some dire stress. It is time for rain, even the irrigators will heartily agree as we all watch the crops suffer and get set back. This should be the time when the crops are going into high nutrient demand with the way the crops genetics and physiology are progressing. So we ask the question, do you have a reasonable nutrient package of materials in the root zone between 7 to 30 inches? Nitrogen demands at this time should be 4.5 to 7lbs/acre/day. Now during stress times, corn is trying to maintain a water balance to cope with heat and desiccation. N uptake as well as P, K, S, Zn all will get shorted which affects growth, photosynthate production and sugars moving in the plants to get ready for flowering and later fruit production (seeds).
For those who have strip-tilled and left last year’s crop aftermath (residues) to shade the ground, limit soil surface water losses, and help cool the soil temperatures you folks have an upper hand. For the grower who still tills the entire surface before planting most likely lost 1 to 3 inches of available water to the tillage passes and evaporative losses. That moisture loss now is crucial. To give you natural rainfall (dryland) growers an idea – in the Western Corn Belt that is $12 up to $45 per inch applied per acre if irrigated. Another excellent reason why strip-tillage is a superb practice to use in what we do as farmers across the United States and elsewhere around the world.