What are some important features of Potassium and why we fertilize

What is it when you consider the third macronutrient that we talk about fertilizers from mineral sources that intrigues you? The element K (potassium) is the one I am discussing here today.  Yep for you chemistry buffs; Potassium is a chemical element with the symbol K (from Neo-Latin kalium) and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Its molecular weight is 39.089 and has a positive valence of +1.  It is found in crystalline form of orthoclase, predominantly from granitic origin.  It also is a precipitate of certain salt mines from Australia and China.

Potassium mining in Western Australia, evaporative process for sulfate of potash salts, K2SO4   Designated as:  0-0-51-18.

So?  You ask what are some of K’s dominant functions in a plant whether C3 or C4 metabolism?

Potassium has many different roles in plants:

  • In Photosynthesis, potassium regulates the opening and closing of stomata, and therefore regulates CO2 uptake.
  • Potassium triggers activation of enzymes and is essential for production of Adenosine Triphosphate (ATP). ATP is an important energy source for many chemical processes taking place in plant issues.
  • Potassium plays a major role in the regulation of water in plants (osmo-regulation). Both uptake of water through plant roots and its loss through the stomata are affected by potassium. This nutrient plays a huge role in how the stomata cells open and close throughout each day a plant lives.
  • Known to improve drought resistance.
  • Protein and starch synthesis in plants require potassium as well. Potassium is essential at almost every step of the protein synthesis. In starch synthesis, the enzyme responsible for the process is activated by potassium.
  • Potassium catalyzes chemical reactions by regulating > 60 enzymes associated with plant growth. Furthermore, the amount of K present in the cell determines how many enzyme-driven reactions can be activated at any one time.
  • K is necessary to maintain the function of phloem (the vascular tissue that transports sugars and other metabolic products downward from the leaves) and xylem (the vascular tissue that transports water and nutrients from roots to shoot and leaves) transport systems.

The roles of K in plant health is amazing:
K fertilizer is now known to significantly reduce the disease incidence of stem rot and aggregate sheath spot, and negative correlations were found between the percentage of K in leaf blades and disease severity in rice and wheat. K fertilizer is widely reported to decrease insect infestation and disease incidence in many host plants. A French scientist (Perrenoud, S. Potassium and Plant Health, 2nd ed; International Potash Institute: Bern, Switzerland, 1990; pp. 8–10.) reviewed 2449 references and found that the use of K significantly decreased the incidence of fungal diseases by 70%, bacteria by 69%, insects and mites by 63%, viruses by 41% and nematodes by 33%. Meanwhile, K increased the yield of plants infested with fungal diseases by 42%, bacteria by 57%, insects and mites by 36%, viruses by 78% and nematodes by 19%.  I quickly gather from that information that potassium is vital to crop health and should not be taken for granted that certain soil tests values may depict>300ppm K and all is going to be fine and dandy.

Considering Potassium in Plant Metabolism:

Courtesy of: International Journal of Molecular Science; Weng, et.al. 2013

Some scientists have stated and I am one of those, that K is the “Big Sister” to nitrogen in nearly all crops; nut trees, conifers, small grains, large grains ie: maize, peas, lentils, dry beans, garbanzos, sorghums, forages, root crops, vine crops which include tomatoes and so on and so on.  For those of you who had a big sister, what did she do with you when you were 1 to 4 or so? Drag you here to there, haul you around by the hand or hand to the back and softly push forward was the mode.  For those of you who did not appreciate that you know it was annoying or embarrassing.  With K in the plant cells, it smooths the way for N to move into metabolic pathways and get there quickly (a less scientific way of saying the of the protein transport pathways).  To the left is a flow diagram of what critical roles potassium plays in all grains.

In a future blog article I will bring out the major players in the microbial world of bacteria and fungi who is at work to make potassium available to the root.  For now, chew on this information, I realize there are texts and hundreds of scientific articles covering every side to K in plants and having rudimentary information for today will have to do.  Just getting a different perspective on this important nutrient source is the right start.  I know I learned a few great points of how I should look at potassium.

We will discuss some of the prime important times to fertilize with potassium.  The Fertilizer Institute of Canada retains a great deal of research and data on potassium, you may want to go and look at what they have.  Website: https://www.tfi.org/

Phosphorus – What do we do with it and what does it do?

 

The index finger is touching the 2nd most important nutrient for many crops we grow. Phosphorus

Last blog I spoke about placement and the wiser way to put it in a band right in the pathway of the row crops root system.

When you as a farmer place P & K and maybe some other elements such as S and Zn with a strip till rig we are putting it in something of a concentrated zone.  A caveat here – you do not have to apply the same amount as one would if broadcasting the material whether dry or liquid.  How much less you ask?  We have seen a reduction as much as 40% (ie: 90lb/ac or 100kg/ha reduction to 54lbs/ac or 60kg/ha) when banded at 6.5 inches deep (160mm). Today’s price at $19.50/cwt {dry 11-52-0} or $390/ton that can be a savings of 40% or a savings of approximately $7.00 per acre.  And that is just for the phosphorus.  Now folks that does not say it is the exact right thing for you if you are new to deep banding with a strip-till tool.  A good approach is to incrementally ratchet this down first year and so forth in the next season and so on.  Hundreds of seasoned Strip-Tillers have told us at Orthman, they can reach that goal of 40% in three years and maintain depending upon replacement or satisfying plant use needs with both tissue and soil tests.

A question for you.  As you hitch up the planter, are you using a Phosphorus component in your starter products? I ask this because the plant usage of P in the first days after the coleoptile erupts through the seed coat to 15-20 days after emergence N,P,K and other elements consumption is not much.  For P, it might be ~2 pounds per acre.

But where it is, is just what the realtor tells any one of us if we a buying a new home; location, location, location!  Nearest to the seedling root and the best products you can give that infant plant the better.  A salt laden fertilizer – bad idea!  I say that because that brand new tissue that erupted out of the seed is a lot like an infant human child’s skin.  Tissue burns, cellular breakdown, toxicity, pain – it all happens to this infant plant if we burn that seedling root.  Cooper and MacDonald back in 1970 published in Crop Science, that the preautotrophic stage in maize is 14 to 26 days after germination, that time frame is dependent upon air and soil temperatures.  After that short period maize becomes autotrophic, that is when photosynthesis plus root absorption do it all in the way of feeding the plants engine.  But during that time maximum number of leaves is determined and a certain number of other genetic switches are flipped on.  Soil temperatures after 20 days are warming along with daytime ambient temps.  Bacteria and fungi growth and activity is so minimal unless you supercharge it with a biostimilant that it is pretty imperative to have some nutrients close at hand.  This is dependent upon soil pH in the upper 10 inches (250mm) for the soil solution with inorganic or organic forms of P to be readily available.  Phosphorus is most available in pH’s of 6 to 7.  There are those that will tell you that starters are too expensive and they do not give a decent return or yield bump.  I like to say and do, “When your baby boy or daughter was fresh from the hospital did your wife quit feeding him or her?”  Didn’t think so, I ask again; does placement of nutrients have value/importance?  You bet your last dollar you bet on your college football team to win by 6 points over its archrival.

So what does P do in the plant?

Phosphorus in even the very first days out of the ground is beginning to start photosynthesizing.  Light energy is being used to split water to produce molecular O2, reduced nicotinamide adenine dinucleotide phosphate and adenosine triphosphate (Yoshida, 1981) which sends these NADP and ATP through the leaf to enlarge the plant, make it grow to a 12 foot (300cm) tall plant with an ear and kernels.  Note phosphate in those molecules – IMPORTANT!  Thus, phosphorus is essential for the general health and vigor of all plants. Some specific growth factors that have been associated with phosphorus are:

  • Stimulated root development

  • Increased stalk and stem strength

  • Improved flower formation and seed production

  • More uniform and earlier crop maturity

  • Increased nitrogen N-fixing capacity of legumes

  • Improvements in crop quality

  • Increased resistance to plant diseases

  • Supports development throughout entire life cycle

Another set of scientists from British Columbia, our neighbors to the north of us in the States, state this; “Phosphorus is important for all photosynthesis, maintenance and transfer of genetic code, development and growth of all new plant cells, and formation of seed.”  To me that is pretty doggone important.

As I reiterated last week in the Precision Tillage blog, early P consumption is minimal but by the time the sixth leaf collar is exposed the plant starts consuming P.   At what kinds of rates, about 0.42lbs/acre/day by the time it reaches tassle or VT.  Then during the VT to R2 stage the plant ramps up again and calls down to the roots or maybe by a foliar application for more phosphorus.  Nearly all of that rushes to the ear and all the kernels, putting on bushels or tonnes.

By R6 when we are near full starch line and drying down the maize plant has used phosphorus to grow cells of stalk, leaves, collars, tassle tissues, pollen, pollen tubes, cob full of kernels and god ole my favorite ROOTS.  Follow us along as I delve into Potassium in the coming weeks.  K is the big sister to nitrogen, remember that.

 

 

Definition of autotropic – An organism, such as a maize plant capable of synthesizing its own food and cellular growth from inorganic substances using light or chemical energy.

References I used in writing this article:

  1. Fageria, N.K., Baligar, V.C., Clark, R.B., 2006;  Physiology of Crop Production., 345pp, Haworth Press, Birmingham, NY
  2. Cooper, C.S., and MacDonald, P.W., 1970; Whole plant physiological and yield responses of maize to plant density., Crop Sci., 10:136-139
  3. Yoshida, S., 1981; Fundamentals of Rice Crop Science. Los Banos, Phillipines: International Rice Research Institute

Second Installment – Phosphorus, 2nd Most Important Nutrient Right Behind Nitrogen

In the last Agronomic blog I here at PrecisionTillage.com, I began a conversation to look into plant use and efficiency of phosphorus in a fertilization scheme in high production Agriculture.  Phosphorus is ‘the’ second most important nutrient to plant growth for nearly every crop we grow behind nitrogen.

Fig. 1. Estimated cumulative P uptake for maize as a function of grow¬ing degree days (GDDc on the Y-axis) for maize growth with vegetative (V) and reproductive (R) stages shown for “modern hybrids” (adapted from Bender et al., 2013a) and “older hybrids” (adapted from Ritchie et al., 1997).

Fig. 1. Estimated cumulative P uptake for maize  which I will explain throughout this article.

What I am aiming to accomplish in this part, is to offer to the Phosphorus discussion is:  smart placement of said P products, and why we scientists see P placement important in affecting plant growth and ultimately yield be it grain, forage or fiber.  Some of you already know my perspective that roots are such an emphasis to me personally in this discussion, which zone of the rooting profile extracts/takes-up the nutrients (in this case P) and how we can enhance that use and uptake efficiency with the methodology of Strip-Till.

As you observe in this graphic (Figure 1.) to your immediate left in maize that older hybrids dropped off in P uptake at the V10 stage to a small degree and the newer, more recent breeding and selectivity of maize characteristics has given rise in thinking when later P fertilization gives desired outcomes are a little later.  As new longer cellular life functions are bred into the maize hybrids, the P uptake curve changes into latter parts of the plants life.  Early on in the life of the maize plant the uptake of P is (<5lb/ac) now known to be slightly less than observed before (prior to somewhere around 1996-2000) just when genetic modifications were really getting off the ground.  With the successes here in the United States of 400, then 500+ and now {2019} >600 bushels per acre (10.9T/hectare to 13.6T/ha to 16.3T/ha) the P needs and P uptake curve has been altered.  Growers should be changing their thinking and what should be their P fertilizer recommendations.  In some instances the step-by-step approach of incrementally fertilizing for P looks daunting compared to the big juggernaut load prior to planting.  Loading up front with P and the propensity of soil systems to tie-up P appears to me an inefficient way to feed this crop, maybe any row crop we grow.  Especially as you look at V10 and then R2 stages (see black solid line in Figure 1).  I try to wrap my agronomic mind around that amount of maize coming from one hectare or one acre when I think of those kinds of yields – Wow!

Figure 3. Early corn root system with 1st nodal roots emerging with banded nutrients with planter and deeper placed with 1tRIP tool (yellow blotches)

Back to considering Figure 1 folks, I ask this age ole question: have we been carrying out our Phosphorus fertilization practices to feed the soil, the organic matter complex in the soil, as well the unfortunate calcium tie up mechanisms in our Western U.S. soils or – are we seeking to best feed the plant?  Okay, you are giving that some thought, which is good.  Let us next consider the earlier root system of the maize plant (seedling root to Nodal system 1 and then extending to the beginning of nodal stage 2 development).  Where one places nutrients via broadcast and using tillage to mix to feed the very limited number of roots and root hairs, the surface area of all roots in the first 15 days after emergence could make an incredible difference in those days of growth and future days ahead.  [See figure 2]   Then as you consider the placing those nutrients including P as a starter mix in the seed trench or along either side of the trench, associate that with pre-plant placing P by 1tRIPr tool is seen in Figure 3.  In this depiction (Figure 3) the roots can run into an initial amount of addition of nutrients and then as the deeper seedling root obtains the deeper placed materials the root can proliferate and take in another dose.  I will chance repeating myself here; roots have to physically run into nutrients whether liquid or dry for osmosis, diffusion and mass flow to gain access to them.  The two dark background images (Figures 2 & 3) are what one observes at 15-18 days after emergence stage as the soils are beginning to warm above 55 degrees F. at 6 inch depth.  As soils warm at the depth of 6 to 9 inches (15 to 23cm), bacteria and mycorrhizae that live on and in roots do rapidly populate and fungi infect roots. Both bacteria and fungi gain activity, access and breakdown for the plant what we add of nutrients and then the plant roots absorb.  Numerous scientific articles from worldwide research studies (Netherlands, UK, India, Pakistan, Australia, United States to name a few) have looked in depth at how hundreds of bacteria species along with mycorrhizae do feed the plant hosts through the root system.  Mycorrhizae are of prime importance in absorbing P and feeding its host plant very efficiently of which maize is dependent upon.

Figure 2.  Early corn root system with 1st nodal roots emerging, colored dots depict nutrient products after surface broadcast & mixing

 

The maize plant may have 85 to 110 square inches of root-to-soil surface area which I have done the measurements (look again at Figures 2 & 3) at this V3-V4 stage for absorbing water and nutrients.  It is very important that the P products are placed right near the root system to efficiently and effectively supply nutrients to the fast growing plant.  I have to remind myself, that plant roots do not grow upwards towards the surface where broadcast fertilization drops N,P,K etc.  Gravity pulls roots downward – you physically place said products in the pathway of the root growth – Violá!

As the soil temperature warms to 63° then up to 75° the bacteria are ramped up to a near frenzy and are working on converting inorganic P source products or taking it off the organic complex right in that zone of 6 to 9 inches  below the surface – back to Figure 1, we are right in the steep up-climb of the maize plants needs.  We see the roots that are in this zone with their symbionts of fungi and billions to trillions of bacteria working in harmony together.  Up near the soil surface the soil temperature is rising into the 90 degree range and bacteria die back and the fungal hyphae shrivel and die.  Why we to think the plant roots will be effective at gaining access to surface applied and lightly mixed to roots that are dying due to heat and desiccation?  It is about placement folks into where an abundant root system will proliferate and using a tool that helps the grower conserve moisture, allow residue to protect and insulate the soil surface, water to infiltrate better, feed the biological life, use less fuel to prepare the seedbed and a host of other benefits.

All of it works together so beautifully folks.  The amounts of N,P,K we place is your choice.  Fertilizing as a pre-loading the soil up with broadcast rates in a strip till system approach is not the most wise, you are becoming more efficient with strategic placement, please be smart about this.  May this article be helpful to you as you get after it this spring and into the future.  I will be getting Potassium info ready and up and running so you will reading that in the coming weeks.

 

References I used for preparation of this article:

  1. Battini, et.al, 2017, Facilitation of phosphorus uptake in maize plants by mycorrhizosphere bacteria. Scientific Reports in Nature Publishing Group, Scientific Report 2017; 7:4686

2. P.S. Bindraban, et.al. 2019, Exploring phosphorus fertilizers and fertilization strategies for improved human and environmental health., Biology and Fertility of Soils 56:299-317

3.  D.P. Schachtman, et.al., 1998, Phosphorus uptake by plants: from soil to cell. Plant Physiology 116:447-453

4.  A.E. Richardson et.al., 2005, Utilization of soil organic phosphorus by higher plants. Organic phosphorus in the Environment. CABI-Wallingford 165-184

5.  Schnepf, et.al., 2008, Impact of growth and uptake patterns of arbuscular mycorrhizal fungi on plant phosphorus uptake – a modelling study. Plant Soil, 312:85-89

6.  M.J. Harrison et.al., 1995, A phosphatic transporter from mycorrhizal fungus Glomus versiforme. Nature 1995; 378:626-629

7.  S.M. Kaeppler, et.al., 2000, Variation among maize inbred lines and detection of quantitative trait loci for growth at low phosphorus and responsiveness to arbuscular mycorrhizal fungi. Crop Science 2000; 40:358-364

8.  G. Hopkins & Niel Hansen,2019, Phosphorus Management in High-Yield Systems., Journal of Environmental Quality, 48:1265-1280

The Second Most Important Nutrient/Ion to Dominate Our Nutrient Management Programs — Phosphorus. Let’s start with some ideas of products.

All over the globe we as Agriculturists are aware of the challenge to provide the nutrient phosphorus to small grains (ie: wheat, rice, oats, barley, rye) larger grain crops being maize and then broadleaf crops (ie: sunflower, soybeans, dry edible beans). The concern stems from the role P plays in photosynthesis for plant growth then the finite supply of rock phosphate around the world which is running low in North America.
Knowing that, how do we use less or somehow obtain access to the material in solution or tied up in polyphosphate forms or in the resident soil organic matter? Adding animal manures is one option. Another is to add bioenhancers or biostimulants that stimulate the resident mycorrhizal fungi and microbiology. It has been determined that more use of fungicides and certain herbicides, that mycorrhizae and some microbial families have been diminished in the soil. To me that is alarming and I have seen such but was not putting the two factors together. Since so much of the biology of our soils is intertwined it all makes sense.
From that said, there can be additions of mycorrhizae spores and specific families of bacteria that work on resident P compounds in the soil. The addition of microbes can be difficult due to these creatures in a water based product for any long period of time may drown since they are predominantly aerobic; do not survive under water very well. There have been efforts with the seed companies to place a coating on the seed which can include Phosphorus specific bacterial spores and to offer an influx of bacterial activity early for the emerging root system. The jury is still out as to the effectiveness of that in the seed bag. But with personal eyes digging the summer of 2018, I was part of a team for Bayer Crop Sciences to examine maize plots in Iowa and NW Missouri as to the effectiveness of said seed coatings, we did see several plots that had definite size, number and root development over hybrids without the microbes.

May I first move this conversation to using certain mineral based P fertilizers? Dry products; mono-ammonium phosphate (MAP, 11-52-0) and Diammonium phosphate (DAP, 18-46-0), Triple superphosphate (0-46-0), MESZ (10-46-0-1Zn), 40Rock (12-40-0-6S-1Zn); have been used and continue to be used for what is touted as ease of handling large quantities, spreading quickly (for the applicator) and lower costs for liquid P products are yes some more cost. Too often to the grower because he/she is adding quantity the cost factor plays a big role in what to use and then the choice of all dry can be fraught with pitfalls and availability to and for the plant. [[I want to insert a question for you all to think on – Are we fertilizing to always to have it easy for us OR are we fertilizing to feed the plant products that will give the desired result?]] We have seen a huge pitfall in the Great Lakes region in the past 5-9 years of enormous algal blooms (eutrophication) in streams, rivers and the Lakes due to growers going ahead and applying in the winter months on frozen ground. Then along comes the shallow winter thaws and rains and off these products run to water courses, my oh my. Now state rulings are being organized to restrict ill-timed applications as well new conservation programs. Let me give a for instance in Ohio; a specific region of the state growers can participate with financial incentives to change their modes of applying P sources in a big 14 county pilot program. This is all happening this spring in Northern and NW Ohio to lessen the soluble P movements of getting P into the lakes. It is called “H2Ohio”. Deep banding, injecting, timing of tillage and that fits perfectly with the practice of Strip Till. Here at Orthman we are responding to be part of the solution.

The index finger is touching the 2nd most important nutrient for many crops we grow. Phosphorus

In the more moist environments east of the Missouri River or the I-29 corridor and east, dry fertilizers will with time become available in soil solution and in moderately acid (pH 5.6 – 6.0) to neutral (pH 6 – 7.3) soils so the ‘fixing’ of Phosphorus is not so ugly. When pH of the soils rise from 7.4 to 9.0 then the calcium and or sodium ions will complex with the P and it is like going into a prison lockdown, phosphorus can take years to become available. It has been observed by this scientist and many others that most polyphosphate products will become tied up and or slowly release into the latter part of the cropping season and not be available at the critical times. Yields can be reduced and that is not good. Saying that folks, using dry products are not a bad choice but one must be aware of the complexities and limitations with timing and product choices with dry. Turn 180 degrees geographically and head west, the growers in Central Nebraska and Kansas out to the Continental Divide where rainfall is less and less, where soils are higher pH, lower cation exchange capacity, lower soil organic matter levels to the subsoil and free calcium carbonate can run as high as 10% — the dry fertilizers are not as widely used. In many geographic areas dry products are not used at all.

So that leads us to change modes of thinking, considering liquid products – there is a big grocery list of liquids available to the grower these days. Orthophosphate and polyphosphate combination products are used to insert the phosphorus right where the roots can gain access quickly. Some of these products are manufacturer specific. Products with more Ortho; breakdown of N-P-K: 9-24-3, 3-18-18, 9-18-9, 10-34-0, 11-37-0, 15-15-15, 15-15-2, 6-24-6, 7-21-7 and the list is longer. These products applied right in the pathway of the roots by deep banding with a Strip-Till implement is ideal.

In the next segment of this topic I started with, I want to cover how the products get engaged then we will turn to the plant needs for Phosphorus, the action of P getting into the soil and available for plant uptake and who in the biological world is assisting the farmer, crop and soils.

More Nitrogen News – Can We Feed Our Crops Better?

In my continual search and self education for all of our customers and potential customers which are the rest of you, I read in one of my texts; “2006, Physiology of Crop Production.” by N.K. Fageria, who has been a scientist studying rice and maize production more evidence to support more than one form of Nitrogen during the season .  He writes about the energy required to convert NO3 to the more usable form in the maize plant as, ammonium (NH4+).  His data states that the amount of energy in ATP/mol is four times higher for the plant to assimilate NO3 than NH4+, that can be a setback in crop production potential.  Then in another text of mine, according to Tisdale et al. (1993, Soil Fertility and Fertilizers), the rate of NO3- uptake is usually high and is favored by low-pH conditions. NH4+ uptake proceeds best at neutral pH values and is depressed by increasing acidity.  That is pH levels of 5.5-6 and under.  Fageria reports that maize and small grains do best in N  uptake efficiency when the nitrogen sources are mixed between nitrate and ammonium throughout the season.  NH4+ is the N source of choice early in the life of a maize plant.

Feeding the corn plant to produce the most grain as possible takes multiple forms of N.

Now all of this absorption and uptake depends upon the amount of carbon in the soil rhizosphere.  If soils are low in available C such as soils in the Sandhills of Kansas, Nebraska, E. Colorado, the efficiency of N uptake and utilization to create grain will depend upon how the grower takes care of the crop aftermath, tills, where possible and available adding a living plants that root down well to supply an addition of carbohydrates, proteins, nucleic acids and lipids in left over tissues.  We also know that nitrate is more available to the maize plant in better aerated soils.  We also know the factor of nitrate is readily available in soil solution and the plants can access it via the roots as well as the number of soil bacteria that work on nitrate are numerous.  But the genetics of upland plants prefer nitrate for a major portion of the plants lifespan so we have thought that we should us nitrate as the source of N to improve yields.  Something of a conundrum.

So where do we go with all of this?  Early on as I have written before in this blog and many other scientists have written in journals and blogs, NH4+ is preferred in the first 25-30 days after emergence (DAE), then NO3 up until 75-85DAE after that time frame it seems that urea and NH4+ has much value.  You as a grower ask what makes all the difference Mike?  I buy nitrogen in the form of NO3 and call it good, all what you are saying is fooling around to me. My response – I want to inform you that depending upon your growing which crop of grassy-types or broadleaf crop; certain forms of N are more efficiently absorbed, taken into the root and uploaded in the xylem tissues and moved up towards the sink, the ear or florets or pod.  Considering which N source fits the plants physiology is important for you to know how to be as effective as you can be feeding the crop for the optimal yield you can gain.  Not everyone can push 600 bu/ac corn, your climatic factors are never perfect or maybe conducive to such.  I am concerned tho if we add more and more nitrates as the N source of choice we can cause harm to the soil and water ecosystems, cause groundwater pollution for drinking supplies which in turn cause infant blue baby syndrome and eutrophication of rivers, streams and lakes.  To repeat myself then, mixing our N sources can change the plants growth and efficiency, feed it properly and we accentuate yield of biomass and grains.

I will keep digging folks, asking questions of other scientist I rely upon, reading and getting material for you to gain a further understanding that we can grow some amazing crops.  This is one thing I have is some time right now with so many venues and events are shut down for me and many others while we work to remain healthy folks.  Stay in touch and come back to Precisiontillage.com.  As noted on the Home page; you can call me or send an email.  Cell number is 1.970.302.1442 or email – mpetersen@orthman.com

Importance of Nutrient Timing for Row Crops – Especially in a Strip-Till System

For the number of decades (4 and some months) I have worked and dug in fields across the globe, I have observed growers apply commercial or natural fertilizers too early or for convenience-sake for the grower but not the target crop they are growing.  There was old ideas that put it in the soil and it will be there for the plant later on.  Too often we see the application of products laid out on the surface during the winter months and losses are substantial.  Other losses come from leaching the mobile products like nitrogen (N) and sulfur (S).  Losses from volatilization out into the atmosphere can and does occur.   The real need for those mobile nutrients may be 75 to 100+ days later.  In parts of the United States for instance, that far in advance there can be 50 to 75% loss – out the field from rain runoff, snowmelt and into a stream or river.  When applied either by deep tillage, banding or Strip-till too early N and S can leach out of the upper reach of the sol profile and move deeper than what the early root system can intercept, losses do occur.  If we just count the cost in nutrients as well as the dislodged soil particles and organic matter – oh my the dollars are flying away.  Some of those numbers can go over $100/acre.  Enough of the gloom and doom words.

All of the images below are tools for growers to aid them in adding micro’s and Nitrogen near the seed for better use and setting of the stage for early vigorous growth and plant health.

Yetter attachments for 2×2 placement
Courtesy Yetter Mfg.

Bandit 2×2 placement – Courtesy 360 Yield Center

Conceal 2×2 placing nutrients         Courtesy Precision Planting

May I start with the crop we grow extremely well in North America – maize or corn.  Corn has what I have studied seven critical physiological periods in its life span that are nutrient demanding.  With today’s blog I will cover up to the 45th day after emergence and in a subsequent blog finish the corn seasons demands/critical periods for nutrient usage/uptake.  Some folks say that the corn plant is like a hungry teenager, from 13 to 20 years of age for a boy as an example.  My gosh there are not many of his waking moments he is not wanting sustenance.  The bottomless pit Mom may say.  I know when I was a teenager my metabolism ran full steam all of my waking moments even there were some midnight ‘fridge’ raids.  And I am still not a man of weight on my frame.  My studies of soybeans depict four critical times the plant has high nutritional demands as does dry edible beans.  Sorghum for grain or forage – five times.  Cotton which is a perennial plant that we attempt to fool into being an annual crop is a little harder to say but I see – five times.  My experience with peanuts (groundnuts) is so limited I cannot say.  Other crops that are grown in rows; safflower, sunflowers, canola, lentils, potatoes, yams and sweet potatoes, sugar beets, sugarcane and even hemp; all these crops do have specific critical periods of requiring nutrients.  Not all nutrients are being demanded equally across their life span.  Let us look specifically at corn; within the first minutes to hours after the seed imbibes water and the emerging plantlet erupts from the seed shell and the root radicle extends out and downward it will take in P, K, Zn, Fe, Mn a touch of N as ammonium.  Now a portion of this is pulled from the endosperm (starches and proteins) of the seed to send the plant upwards to pierce the soil surface and the seedling root to grow.  When the infantile seedling root does access nutrients right away in the seed trench it will not have to exhaust the supply of food source in the seed.  That being said the first critical period is very early.  The next period is 10-12 days after emergence, mainly uptake is P, Zn, Mn, and Fe.  The amounts are low but critical to starting the developing leaf systems.  Then, at 20-25 days after emergence the corn plant undergoes a change in how it absorbs N.  Nitrogen has been consumed in the ammonium form from root eruption till now.  Now the plant can absorb N as proteins directly, Nitrate, ammonium to a lesser degree.  At 40-45 days after emergence, the corn plant is developing the ear size in circumference, rows of kernels.  P, K, N, Ca, Mg, Zn and small, small amounts of other micro’s are called up.

The Orthman 1tRIPr point and shank system can deliver products in 2 locations – this can be liquid and dry or liquid in 2 spots, very versatile for pre-plant fertilization

By the time the plant is genetically requiring nutrients as of the critical times, yes we need products to be in the root rhizospere, that immediate area where the roots are growing and active ready and absorbing.  Where can those nutrients come from?  A certain portion comes from the soil complex and the soil organic matter that can be from 20 to 50% of the total needs depending upon the exchange capacity, amount of organic matter and what is in the soluble fraction then the rest usually is what we tend to add via commercial or natural manures.  There are a number of schools of thoughts that offer [from University testing and USDA-Agricultural Research Service] what are the plant nutrient needs.  You have trust or faith in a reliable source, do keep tract of their recommendations.  It is also a wise approach to do your own testing to  have a baseline as to what, how much of N,P,K,S and so on your soils, fields and crop selections require.  Climate has a great deal to dictate how your 2020 crop will respond, what I know and have observed filling up the tank weeks ahead of the crop even being planted will lead to losses of the mobile ions.  Spreading on wet, frozen ground due to the convenience of having the local big fertilizer company apply – not so good folks.  Having a better concept of when a crop requires N for instance is so extremely valuable for the plant, your soils and water resources can lose big time, the environment, down river neighbors in their water quality issues. Do not get me wrong our neighbors in the cities have a responsibility too, maybe even more than we in Agriculture.  I am suggesting let us be wise to feed our crops for the first 45 days, not all 125 days.

In the coming weeks we will go into the days after the first 45 to describe those critical physiological time markers that can drive nutrient application.  I am watching that spring is right around the corner this week and the bit is chafing some and the calendar calls, but folks the crop cannot go into the soil until the soils dry enough and the temperatures warm.  The days will come, I know.

What’s all the Hubbaloo with Cover Crops as a Magic Elixer?

Early March 2020, we returned from a high powered, well attended Commodity Classic held in San Antonio, we returned with tired voices from talking and interacting with so many good folks at the Trade Show.  In fact we were informed that the crowd was a record number, made for many conversations going on with two to three sets of growers per Orthman representative and others wanting to ask questions.  Good position to be in.

There were some Win-win sessions going on each morning of the Trade Show and audiences crowded around tables and chairs to hear speakers that spoke to issues marketing, Soil Health, High Yields and Cover Crops.  The latter subject just mentioned was very prevalent with the exhibitors, Soil Microbial mixes were also a topic from many of the exhibitors and then Cover Crop seed sales and mixes they sell.

As a soil scientist I shake my head at the lather that has been rubbed up into suds regarding cover crops, their inevitable roots living longer if planting properly.  In that mantra that is spoken of over and over  (living green matter year around) there seems to be a lack of sense about what

Soil Scientist for Orthman Manufacturing, Mike Petersen [guy in the dark green shirt] explains physical characteristics of Soil Health to Idaho growers.

is happening in the active biological realm of the soil profiles on a growers farms.  There is also a itty-smidgen of material that comes out about the physical characteristics of soil.  I sat in on a breakout session that was to be on Soil Characteristics sponsored by Winfield Ag and the three men on the panel may have talked about characteristics of soils 3 minutes and allowed the Cover Crop person sway the topic to cover crops – not soil characteristics.  As a soil scientist for over 44 years now and would have liked to hear that the audience would get “the rest of the story” promoted.  Remember Paul Harvey on his daily radio broadcast about noon every day when he said with his dramatic pauses, “And now you know the rest of the story.”

Folks living roots, exuding and secreting have a  great effect on the biology and chemistry and yes even the physical.  But with my emphasis for growers is to understand physical characteristics play a very serious part in the orchestra of soil health.  I know No-Tillers bray and proclaim pretty loud that they have the answer for Soil Health, the vertical tillers say they too are strong advocates of Soil Health. Be cautious folks what you read, hear – do investigate the major three components equally when you look into Soil Heath and the selling of the emphasis of Cover Crops being the “Next Best Thing”  I think that was sung by a Country –Western singer.  Weigh the facts with Cover Crops, there are places here in the U.S. and across the planet where Cover Crops may just not have all the bi Wow effects.

I will in the near future, write blogs to go more into each of the three parts to Soil Health.  We here at Orthman Manufacturing want you to have a greater awareness and knowledge level to weigh the cover crops additions to benefit your crop rotations and soil resources where and when they can fit.

How to Look at Nitrogen More Carefully

A pound of nitrogen is not a pound of nitrogen in how a crop responds to what we apply throughout the season whether pre-plant all the way to post pollination.  One particular form of N will give a different response completely different than another form, ammonia vs nitrate nitrogen.  I have been reading up on nitrogen consumption by the  way organic growers like to apply and then the commercial applications of urea or ammonium nitrate as 32 percent.  Plant physiologists are describing that there is the most premium way and what is the least effective methodology as to what portion of photosynthetic energy is used to convert the N source.

Well all of this peaked my interest to dive in deeper.  The best of all worlds for the plant is for the plant root system to absorb amino acids and proteins directly from what the soil microbial population leave as they interact and then die on the surface of the root or directly adjacent to the root epidermis.  Not only the nitrogen but the metabolites in the microbial one-celled bodies furnish antibiotics to help the root fight off disease and maybe even insect predators.

Two important bacteria in soils that aid in N becoming available to plant roots  Courtesy Quora

As I continued in my quest; I read what John Kempf wrote in one of his latest blogs some amazing information; “Increasing Nitrogen Use Efficiency” February 8, 2020.  For me an eye-opening experience for which I am grateful of.  His studies and findings have come to a hierarchy of what form(s) N is absorbed best, second, third and so on. I thought after all these years I had a fair handle on nitrogen sources.  So in the previpous paragraph I described the premium pathway for N to be absorbed and utilized.  Think for a minute on what would be the next best?  Do not just throw something out there right away, give it some thought.  Please do not think this is a dollar for dollar issue or organic versus commercial products discussion.  Far too often growers drive on the wrong country road to say I need pounds of N, just get me the cheapest method or least costing material and I will go further down the yield path. Uffda!  Please that is not what this is about.  A troubling thought there, being cheap with the major nutrient has limited so many folks over the last 65 years of agriculture.  Many scientists have described the 4-R’s of nutrient management, starting with the Right Product…. man oh man if we just would use the right products I have a wild dream of what might happen to American crop production.  Several research papers I read (>36) and studied within the last 6 years have time in and time out stated that urea forms of N, especially controlled release urea (CRU) products are very efficiently absorbed by crops with adequate soil moisture during the last 50 days of the crops life before senescence.  This is in agreement with what John Kempf suggested in his blog.

Microbiology up close – swarm of Bacillis subtillis

Is it so that the least efficient form of N for crops is nitrate?  I said hmmmmmm!  For years and years throughout my agronomic career NO3-N has been touted as the form of nitrogen that a corn plant does best on.  So why is that not so?  Kempf states, plants use a significant amount of the photosynthetic energy to convert nitrate to amino acids and proteins.  For the conversion in the plant root it appears there is more energy required to convert NO3 into the root cells because of transport pumps and needed water.  But then I ask, is not maize (corn) preferential to nitrate as the form of N?  Maybe this can help; Marschner in “Mineral Nutrition of Higher Plants” (1995) wrote that the higher carbon demand for ammonium uptake in roots, compared with nitrate-fed plants is associated with higher oxygen consumption in roots. Accordingly, plant growth, particularly root growth, is poor in ammonium-fed plants when both root zone temperature and ammonium concentration are high. Ammonium is taken up better in cooler soil temperatures.  The suitability of ammonium for achieving high growth rates and yield therefore depends on root zone temperature plus other factors which determine carbohydrate supply to the roots (e.g. light intensity). Nitrate is a storage form in plants with no necessity to be assimilated in the roots, although it has to be reduced before assimilation which is an energy demanding process.

Let us keep going… Marschner offers that it takes right at 3X more water to convert nitrate to amino acids as compared to ammonium conversion to amino acids. Interesting?  Because hundreds of millions of bacteria can live on the root surfaces existing off of the secretions and excretions to eat carbon and use N to convert the rich carbon sources in the soil organic matter and the exudates.  In turn the microbes die and release amino acids, peptides and proteins directly to the roots – their life cycle does very quickly in the manner of minutes to hours.  It is becoming better known that microbial forms of N are not leachable therefore more available even when water is in low quantity in the soil.

I will keep seeking this subject for you to be informed.  So as of now applying nitrogen is more readily availabe in liquid 32-0-0, liquid 28-0-0 or liquid urea 21-0-0.  In lower organic matter level soils it is very wise to add stimulants for the microbiology to rapidly consume and aid the conversion process along.

An Ontario Canada Discussion, Strip Till and Placing Fertilizer – Is it Shanks or Coulters ?

Grower using a 1tRIPr and combination of liquid and dry products

Snow returned to Northern Colorado, a reminder that the groundhog that Bill Murray stole in the SuperBowl commercial with an orange Jeep went to play in the snow irregardless of sunshine or overcast and was having fun, for me it was scooping snow and blowing snow – all of it is not my idea of fun.  But riding a fat tire bicycle with a little buddy groundhog might be a riot.

The conversation regarding coulter strip till rigs versus shank rigs has risen again as to which may offer a better approach to placing nutrients in the soil for furnishing a young row crop to thrive and obtain successful yields.  An article in Farmtario, a journal from Ontario, Canada explored some facets of both sides of the strip till nutrient management program. If you have not read it; I suggest you can just zip over to look at the link: https://farmtario.com/machinery/strip-till-styles/  As a soil scientist I would like to add to what was written in what we do and see with the shank machine from Orthman Manufacturing, our 1tRIPr.

Always part of the reasoning and purpose of the shank unit we employ with the 1tRIPr is to prepare a seedbed, take care of possible soil compaction in the upper 12 inches, place nutrients and offer an optimal seedbed and rootzone for a newly planted row crop.  As a grower does such and wants to strategically place a portion of his/her nutrient program in the roots pathway our shank and with following wavy coulters first mix soil material and then pinch/press soil into the shank slot so we should not have a massive deposit of products plopped at 6 to 9 inches.  Our wavy coulter system which is right immediately behind the shanks on either side of the shank, these coulters are cambered and cast to do just that pinch and close effect.  [See the image to the lower left]  As they turn at the operating ground speed the wavy coulters are mixing the soil in a wave pattern if you will between the two of the them since they ride parallel to one another.  This action distributes dry, anhydrous or liquid products quite well.  I know we have followed behind both Montag and Salford dry fertilizer carts that are blowing dry products right behind the shank and individuals have applied from 40 pounds per acre of dry granular material up to 600 pounds.  The mix effect we have seen distributes dry for instance in a softball sized zone to large grapefruit sized area in the strip.  One can actually count the individual particles and they are not in a concentrated band like some have come to believe.  I say it pays to dig a lot and look so you can make sure.  When applying anhydrous product, the expansion of the gas and liquid turns out to be about a zone the size of a softball also.  With liquid the zone of where the liquid material gets distributed is somewhat dependent upon soil moisture conditions when strip tilled.  But know this folks it is not a hot zone about the size of a tennis ball right where the roots will get a burn.  Sure if the soil conditions are too moist to being wet – trouble can occur.  We at Orthman will be quick to tell you – wait until conditions allow some drying so the  banding of products do not create a hazard.

Red circle aids in telling the 1tRIPr’s proper distribution of pre-plant nutrients; dry and liquid in this case. Notice the wavy coulters position behind the shank to mix the soil.

Strip Till farming in Ontario, CA – applying dry products alone

We have evaluated what our tool provides growers in sandy soils to those with clay contents of near 65% and applying of N-P-K products, we believe a shank and coulter system is the best combination.  With that in mind, applying your years worth of nutrients pre-plant is clearly not the wisest choice in a season long nutrient management program.  So rates of 350 to 700lbs/acre of products is a move for what some thinks is efficient; in reality it is a case for potential losses of 50% or more or, expensive and as questioned – root burn waiting to happen.  Clearly folks from an agronomic point of view – do not do that.  Nobody feeds their pre-teen son or daughter a weeks worth of food in one sitting at the table and tell them survive until you turn 16.  Now that maybe a drastic case, but think about this – roots grow downward and out from the placement of the seed.  The root system continues to feed the above ground portion of the plant, as the roots grow and are pulled downward with gravity.  Yet soils with high CEC’s (>20-24meq/L) or those with substantial amounts of calcium carbonate can grasp onto positively charged ions in the soil solution and either not release them or allow N and S to leach deeper than the biologically active root zone and be out of reach.  With Nitrogen being such a mobile nutrient, it can essentially fly south (deep) and the root system not run into the N material, leaving you with little to none.  Now the fertilizer supplier did okay, you – well not so good.  In better rainfall zones of North America and conditions of a wet spring like 2019 turned out to be, losses to leaching, denitrification were awful.

So where am I going with this line of thought?  Folks the tillage method of Strip Till whether shank of only coulters is very smart.  Applying the seasons worth of N-P-K up front is not efficient, it is not cost-wise, most likely it is environmentally not the best option either.  The row crops we plant do not consume all their nutrients within the first 40 days of growth after seeding, when in reality certain nutrients do not get taken up and used in the plants photosynthetic span until 80-90 days into growth and some after pollination.  In that meantime the mobile nutrients could be off towards the Mississippi Delta.  It is really an education/understanding for you to gain, to “feed the plant, not the soil”.  We feed our kiddos for nearly 20 years do we not?  I suppose that is different for some, they keep showing up asking for Mom’s cooking.  Please I take this seriously to offer you all to look to a full term system methodology of feeding your corn, soybeans, dry edibles, vegetable crops and small grains.  Strip Tillage starts it off with precision placement, we believe the shank machine like the 1tRIPr does it extremely well.

In future articles I will discuss with you more thoughts on the crop life cycle has demands of specific nutrients which we can supply via the root system, yes foliarly and yes sprayed on the ground near the strip till zone and moisture will help in getting it to the roots.  The world of what goes on in the soil ladies and gentlemen is complex but a puzzle we are figuring out.  Stay tuned.

Spring is around a cold corner – But be thinking about all the features of Strip Till

I know I am visiting with a select number of growers and others who are interested in things of Strip Till.  You growers that use strip-till for your pre-plant tillage/field preparation are considered by some as a niche group of farmers.  For one (me) who has been in the group that have found the Strip-Till method as one of the smartest ways to minimize tillage and place a portion of the seasons nutrient package, offer a malleable soil environment for the young root system to expand and get fed, lets move forward.  There are those who believe Direct Seeding is the epitome of “right” farming and Strip-Till is boorish

[This 16 row Orthman 1tRIPr with tool bar mounted tanks are placing nutrients behind the shank and planter directly attached. Courtesy: Orthman Mfg.]

and not politically correct for the environment and soil health.

That is somewhat inflammatory and not founded. Why can I say such?  After field researching the strip-till method since the late 80’s until today I can without reservation in most row crop farming on slopes of less than 7%, the Strip-Till method carried out with care stands right up near the very tippy top in yield potentials with very low erosion rates and preserving over 70% of the carbon in the soil profile.  A large segment of why this conservation practice really works is the tying in of placing nutrients in the till zone down below the seed.With most of the strip-till implements on the market, dry and liquid nutrients can be inserted into the tillage operation.    Growers that have combined dry products with liquid during their strip-till pass are putting products in two locations below the seed placement in a follow-up operation.  Placing phosphates, potassium and nitrogen and maybe some micronutrients brings efficiency, minimizing trips, locating nutrients in the root pathway for early to mid-season growth potentials not normally seen.  Why?  A plant root system does not seek out nutrition because they neither have eyes, tongues, noses to smell or hands to feel, the roots must come in direct contact of compounds to better feed the crop.  Scattering across the soil surface may be fast, easy and workable for the local Coop, yet those products that are not all mobile and subject to volatility, surface runoff, tie up with the organic materials, we have a problem.  Why not put all of those materials in the soil where the roots are growing downward naturally to be in line to intercept?   So both with a planter or drill and the strip-till unit a grower can make great advancements by placing nutrients to start the crop, take it into early season and on into mid-season well fed and making target goals on efficiency and production.  Field research that I have been part of previously and presently has shown liquid nutrients placed with the seed, off to the side and below has many bonus effects.  A couple-three or five of those are:
1.  A larger initial root system, 2.  many more lateral roots to absorb water and nutrients, 3.  ability to overcome the normal mid-May stall-out period, 4. due to placement, significant less sign of the phosphorus deficiency between emergence and third leaf stage, and 5.  biological activity ramps up significantly on and around the root system.  It is absolutely imperative to start a crop off with fewer obstacles to overcome to reach the yield a grower is looking forward to when he/she sticks the snouts of the combine header into the field this coming fall.

Putting together a Strip-Till System that incorporates fertility placed below the seed is well founded and has many benefits I have written about here and others I did not speak of.  Do not hesitate to call or write me or chat with our Territory Rep’s in regards to the placement of nutrients, products that will spark your crop to reaching your goals or anything else with this years crop.  Along with what we are trying to inform you about compaction and its detrimental effects until we show and depict how strip till will add to your understanding pof good soil management; nutrients, placement both with the Strip Till implement and your planter are major steps in becoming proficient and profitable.