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Recent Studies of Phosphorus in Soybeans – Taking You Deeper

Both Mick Goedeken and I are looking deeper into the clues of why soybeans are reluctant can we say to top 100 bushels per acre in a corn soybean rotation on a regular basis..  Microbiology is a big part of the reasoning, labile vs non-labile pools of both inorganic (source from mineral/rock phosphorus sources) and organic pools of P, mycorrhizae fungi activity and  we are speaking of the correct species to best convert P and bring it (P) into the plant root, amount of calcium carbonate (free lime) and soil organic matter.  With all of that said let me attempt to break it down to making some sense from what I have read recently, accumulated over 4.5 decades so it gives you all pause to say hmmm-mm and consider this for a strategy to your fertility management programs in corn and soybeans.  Soybeans having a shallow rooting system compared to alfalfa, sunflowers or safflower – all tap rooted crops but their root systems are quite different in depth and extraction capabilities.  Over 90% of the crops we grow have a requirement for fungi, a relationship with these mycorrhizal fungi such as; Glomus intraradices, Bradyrhizobium japonicum, Rhizophagus irregularis, and Funneliformis mosseae.  

Figure 1: Glomus intraradicies Courtesy Western Sydney Univ.

Indeed, many, many growers discount the needed P and micronutrients Zn and Cu that are needed to develop more pods and beans in soybean production. More often than not, growers cut back dramatically in the soybeans with their fertility program.  Reasons are often – well they only produce up to 65 bushels per acre in a “rainfall dominated” system which is much of the Midwest and Mid-South, so why push the expenses?   Del-Saz et al. (2017), in some recent research studied that P-pulse fertilization (smaller quantities of P fertilizers interspersed strategically in the season of growth and early reproductive stages) in the root zone spurred citrate exudation in arbuscular mycorrhizal actively infested roots by 395% compared to plant-soil conditions that were P sufficient.  P-uptake can be improved by 28 to 44% into the pod and beans themselves with mycorrhizal soybeans. After a P-pulse of P and Zn fertilization the amount of lactate and malate (carboxylates – important plant acids for movement of ions from leaf to root and root to the leaves) changed by an increase of 400% over non-mycorrhizal plants.  These carboxylates along with acetic acid and citric acid (just mentioned) will be exuded around the root tips help the release of P ions, attract microbes, and P is then absorbed.  The pathways are much more complex, I define that further in the “red” paragraphs below.

Figure 2:  University of Illinois Dry Matter and Phosphorus

Now just below the  pictures of this article/blog I am doing a fast submarine dive to 1500 feet with a more complete physiological explanation, it has a great deal of biochemistry and $64 words but nails down what actually happens.  For us science geeks we love the story behind door #3, which is what these paragraphs in red are.

So why over 466 words Mike to tell us phosphorus can be or is a super important factor in raising triple digit soybeans?  Because – too many growers have this misnomer that believe applying nutrients via broadcast spreader methods will get ‘er done. Yep, but how much is tied up? How much is washed away in higher rainfall areas? How efficient is broadcast for a plant that roots downward and phosphorus rarely moves much in the soil?  How much volatilizes?  All of those things are removals of that expensive phosphate fertilizer.  In a Kansas State study [Coelho et al., 2019] they utilized strip till as part of a corn-soybean study for comparison to place P at strategic times.  One very important concept they determined, was that deep, precision placed a portion of the P fertility minimized the potential for P to become fixed due to the smaller volume of soil in contact with the placed nutrient.  That is supported by Anghinoni and Barber, 1980; Sleigth et al, 1984, Khatiwada et al, 2012, Mallarino et al, 2012, Adee et al, 2016, and Hansel et al, 2017 in phosphorus fertility studies.  I reference all those scientists who are proving placement is incredibly important to efficiency and effectiveness of P uptake for crops.

For those of you that would like the more full expression of what happens physiologically the following two paragraphs are for you.

Let me first inform you all that there are a couple of different pathways the plant absorbs P for growth and reproduction; the direct pathway of the cytochrome oxidase (COX), total oxygen uptake pathway (TOU) and then the alternative oxidase pathway [via mycorrhizae most likely].    Let me get a couple words broken down for all; cytochrome oxidase – an iron-porphyrin enzyme adept at absorbing light and using that energy to convert oxygen molecules in the air to a reactive form known as singlet oxygen. We commonly generalize this as chlorophyll; very important in cellular respiration/growth and photosynthesis due to its ability to promote more oxidation of photo-enhanced enzymes functioning in electron transport as carriers of many positive electrons such as P, K, Ca, Mg in the presence of oxygen to move ions through the leaf or up from the roots.  Two specific gene transcriptors LePT1 and LePT2, DNA molecules then signal P movement and to be of use in ATP (Adenosine triphosphate) the major component of plant energy, growth, cellular multiplication for plant growth and eventually grain production. Before I go on – Transcriptors in plant cells copy a segment of DNA into RNA. These segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA) to transport the phosphorus.

Some of us really get this [Mike Petersen does] and well, not so much for others.  Condense it a bit, in plant leaves where photosynthesis is converting radiant solar energy with carbon sources (sugars and such), H2O, carbon dioxide, proteins (that contain N,P,K,S etc), and yes, oxygen for the plant to replicate cells for more leaves, stems, flower parts and then the fruiting bodies.  The second most important nutrient in all of that process is P – PHOSPHORUS.  In the above paragraph I mentioned a transcriptor LePT2 – super important in the rooting part of the plant which instructs the roots at and right behind each growing tip to exude citrate[C6H5O7 -3 ] so the rhizosphere is properly acidified and in the correct form for P to be absorbed.  This also attracts specific microbes that produce organic acids (lactic, itaconic, and malic acids) distinguished between those derived from a main metabolic pathway of aerobic microorganisms that live near and on the root surface to multiply and biochemically then pull the P ion away from the soil organic complex, clay micelles and what maybe in solution right into the plant root epidermis and keep the plant engine buzzing along at 3000 rpm.  In soybeans the uptake of P is incredibly dependent that these acids and fungi are present in the soil so as to obtain P to feed the plant supplying the photosynthesis process to seed fill.  Okay with all of the so called technical stuff, what about why soybeans being difficult in performing to break the 100 bushel acre barrier?  Because if we load up the soil system too early or not at all – 100 bushel soybeans are a fantasy.

Why did I not say that right away?  As scientists, we study processes – all of these complex processes mentioned so far develop in the plant to associate with fungi, bacteria and specific inter-cellular chemistry to feed the plant and it is important to know a little bit of these processes.  What phosphorus is in the soil whether it is labile, moderately labile or non-labile [stubbornly held] on the soil clay complex or tied up with calcium carbonates, or stable organic residues – P rarely seems to be in ample supply at the right times for soybean plant to uptake physiologically.  A 10 year soil fertility study at Kansas State University, (Coelho et al, 2019) in a corn-soy rotation determined that 55 to 65% of all of the phosphorus in the P fraction of the soil they tested was non-labile with only 10-16% readily available in the labile pool. Not readily available – if ever!  They also described in their paper that plants take up only 10-20% of P that is applied as fertilizer during the year it was applied which is corroborated in another study by Vu et al, (2008).  So much of the P added via an annual fertilizer program then is reactive with calcium to form much less soluble compounds to insoluble compounds in stabilized soil organic matter complexes and becomes mostly unavailable.  Soil tests can show there could be 16 to 40ppm P, those values describe P as adequate, no big need at all for additional fertility.  I say better think again, especially in Western United States soils.

We at Orthman Manufacturing truly desire you as readers and growers of the commodity crop Soybeans or corn to gain a science based set of reasons that explain why P can be in short supply to produce top yields, how it gets into the plant, how it accentuates the photosynthesis cycle to help you reach those 100 bushel plus goals in soybeans – then the timing. Observe in Fig. 2 the Univ. of Illinois P uptake curve indicates from V9 of 45 days after planting when soybeans really request P from the soil-root interface.  Look close at 75 days after when the plant needs P to fill beans until 100-105 days after which is all depicted in blue.  All the pre-plant P or residual in the soil from year(s) past could very well be tied up and unattainable from the soil unless we supplement P.  Beans do not have to be the runt or second rate crop in today’s marketplace.  We at Orthman realize with the 1tRIPr you can place nutrients effectively for a good portion of your fertility needs.  Talk to us, visit with other growers that use the 1tRIPr, avoid the losses and see what those soybeans can do.

References Cited:

Adee, E.,Hansel, F.D., Ruiz Diaz, D.A., Jannssen, K. 1980, Corn response as affected by planting distance from the center of strip-till fertilized rows., Frontiers Plant Science.7:1232-41
Anghinoni, L., Barber, S.A., 2014. Phosphorus influx and growth characteristics of corn roots as influenced by phosphorus supply. Agronomy Journal 72: 685-688
Coelho, M.J.A., Ruiz-Diaz, D., Hettiarachchi, Hansel, F.D., Pavinato, P.S. 2019. Soil Phosphorus fractions and legacy in a corn-soybean rotation on Mollisols in Kansas, USA Geoderma Regional 18: 1-11
Del-Saz, N.F., Romero-Munar, A., Cawthray, G.R., Palma, F., Aroca, R., Baraza, E., Florez-Sarasa, I., Lamber, H., Ribas-Carbo, M., 2018, Phosphorus concentration coordinates a respiratory bypass, synthesis and exudation of citrate, and the expression of high-affinity phosphorus transporters in Solanum lycopersicum. Plant Cell Environment 41: 865-875
Hansel, F.D., Amado, T.J.C., Ruiz-Diaz, D.A., Rosso, L.H.M., Nicoloso, F.T., Schorr, M., 2017. Phosphorus fertilizer placement and tillage affect soybean root growth and drought tolerance. Agronomy Journal 109: 1-9
Khatiwada, R., Hettiarachchi, G.M., Mengel, M.B., Frei, M. 2012. Speciation of phosphorus in a fertilized reduced till soil system treatment incubation study. Soil Science Society America Journal 76: 2006-2018
Mallarino, A.P., Schwarte, K., Havlovic, B.J., 2012. Broadcast and band phosphorus and potassium placement for corn and soybean managed with till and no-till Iowas State Res. Farm Report Rep.3, http://lib.dr.iastate.edu/farms_reports/3/
Sleight, D.M., Sander, D.H., Peterson, G.A. 1984. Affect of fertilizer phosphorus placement on the availability of phosphorus. Soil Science Society America Journal 48. 2: 336-340
Vu, D.T., Tang, C., Armstrong, R.D.,2008 Cahnges and availability of P fractions following 65 years of P application to a calcareous soil in a Mediterranean climate. Plant Soil 304: 21-33

Smart Fertility — Speaking About N&P

Happy June to all who visits and reads our blog!  Mike Petersen here for just a brief bit of Introduction of our new Agronomist Mick Goedeken.  Mick is jumping in where angels fear to tread these days; that is right alongside of me the  Soils Guy for Orthman.  He is learning real quick that soil jammed under the fingernails is a common occurrence around here and digging to look at plant root systems as deep as need be is the modus operandii.  I have asked Mick if being down on his hands and knees is a bad thing for his posture and back, he has not complained yet.  Mick hails originally from up near Columbus, Nebraska and has a rich background in the Ag World which both of us find extremely helpful and aids our speaking with growers all across the globe for Orthman Manufacturing.  Before Orthman (he started in April 2021) he worked as the research agronomist for Central Valley Ag out of the Waco, Nebraska site.  His contact information is under the Contact Us tab or right here:  Mick Goedeken, 402-860-2489, or email: mgoedeken@orthman.com.

So please welcome Mick and read his first sashay into the Precision Tillage blog realm of writing and offering up-to-date material that fits the scope of Orthman Manufacturing, how we address fertility and important concepts of fertility management in today’s Agriculture.  I am pleased that he is working with me as we communicate how Agronomics affect the Top company of Strip Tillage, very likely Worldwide.
Mick Goedeken, Precision Tillage Agronomist – Out Standing in His Field

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Many outside the Ag industry complain about nitrogen use efficiency(NUE) for corn being poor and not good enough.  They also point fingers and blame the American farmer for Phosphate pollution.  This blog article will examine smart soil fertility and how we can improve NUE and phosphorus use efficiency (PUE).  Is it possible to improve NUE and PUE on American farms?  Is it possible to improve efficiencies and maintain yield and profitability?

Let’s look at NUE first.  Throughout time the NUE of corn production has seen continual improvement.  Figure 1 from the USDA compares average N rates to average US corn yield.  From this graph we can calculate NUE by dividing the average N rate by the average yield.  If we look at 1970 and 1980 both years averaged 1.35 lbs N/bu of corn.  When we look at 1990 the US average was 1.15 lbs N/bu then improved to 1.0 in 2000 and by 2010 had improved to 0.89 lbs N/bu of corn.  Over the 40 year period we have seen an improvement of 0.46 lbs N per bu or about 0.11 improvements every ten years.  I would say that improvements in genetics, farming practices, a better understanding of soil microbiology, and N management have helped us improve NUE.  Corn grain removes 0.67 lbs N per bushel of corn therefore, it is the opinion of this agronomist that NUE cannot dip below 0.67 lbs N/bu without robbing N from soil organic matter.  Realistically I feel that an NUE between 0.70 and 0.75 is both attainable and sustainable.

Figure 1: USDA Data Comparing Nitrogen Use from 1965-2010

How can we improve NUE? Understandably every operation is different and each individual field within an operation can be managed differently.  When N is applied quite simply there are four things that can happen it can go up, down, in the plant or into organic matter.  N goes up through gaseous losses to the atmosphere and can be volatized ammonia, N2, NO or N2O from denitrification or plant loss as NH3 due to excessive uptake.  Figure 2 has a Nitrogen cycle from Oklahoma State University where yellow indicates N losses and green indicates N additions. When nitrogen goes down it is in the form of leaching or moving below the rooting profile in the form of NO3-N.   Nitrogen can move into the plant as ammonium NH4-N or nitrate NO3-N.  Most N moves into the plant in the nitrate form through mass flow.  Finally N can be immobilized into the organic matter pool.  Some agronomists and scientists consider the immobilization to organic matter as a loss but others such as myself consider it as a storage that can be used later.  Many have tried to manipulate the nitrogen cycle over the years but Mother Nature will only allow attempts to be short lived.  For example, nitrogen stabilizers can help prevent volatilization for a short time (usually 7- 10 days) by preventing the urease enzyme from interacting with urea containing fertilizers.  Likewise, nitrification inhibitors can slow or stop nitrification for a short term (usually 10 days to 2 weeks) by slowing or stopping the nitrification pathway typically by disturbing the bacteria nitrosomonas and nitrobactor that are responsible for converting ammonium to nitrate in the soil.  Utilization of urease inhibitors and nitrification inhibitors are one step to improving NUE.  The most dramatic changes to NUE can be gained by gaining an understanding of when the corn crop needs or uses N.

 

Figure 3 is adapted from How a Corn Plant Develops (see graphic to your left) and will help us better understand when N is needed for corn production.  If we look at the corn crop over 120 days then split that into 40 day increments it helps us understand when N is used.  During the first 40 days corn only uses 15% of its N needs while during the 2nd 40 days it uses 65% of its needs leaving the final 20% being used in the last 40 days.  This is why I find front loading N baffling and especially 100% fall anhydrous programs that can lead to yield loss, financial loss and cause pollution of ground and surface waters.  For example NH3 applied November 15th for corn planted April 15th must be available 5.5 months after application. This is a lot to ask of any product but even more by a product that is vulnerable to loss.  Loss of N is minimized in systems where N is spoon-fed through irrigation applications where 45 to 75% of the N is applied through fertigation.   Understandably, this is not always an option but split applications can still be utilized. For example 25% of N with Strip Till followed by 25% with the planter and 50% sidedress would spread the N loss risk out a lot and insure that N was available during the peak need during the plants second 40 days. Decreasing risk leads to less loss and more available N and can lead to more yield therefore increasing NUE.  Take a look at your NUE and think about spreading your risk is there any option to add another N application to your system that could help you improve NUE on your farm.  Is there room in your system for 1 more application with 20% of the uptake occurring in the last 40 days if we can find a way to apply N later our NUE will improve.

Figure 2: Nitrogen Cycle  Courtesy of Oklahoma State Univ.

 

 

 

Phosphorus use efficiency (PUE) is more difficult to calculate and evaluate than NUE.  The reason for the difficulty is because of the multitude of forms in the soil along with the number of reactions that can occur to each form.   There are differing opinions on how to measure and calculate PUE.  Crop recovery efficiency is calculated by knowing uptake from where P was added and where no P was added calculating the difference and dividing by the amount of P applied.  This always requires a check and can’t be calculated after the fact if a check was not left for comparison.  Another method known as the partial nutrient balance (PNB) is calculated as P uptake by the plant divided by P fertilizer applied.  PNB can be expressed as P removal-to-input ratio or as a percent.  If the PNB is greater than 100% then the plants are removing more P than is being applied resulting in mining of P from the soil.  Conversely if PNB values are extremely low then the P is being used inefficiently.  Typically values for PNB range from 50-70% but can also be higher.  I prefer PNB because I can calculate this post-harvest just by knowing the yield and the P application rate.

Because there is legitimate concern for rock phosphate reserves and how long they will last we must utilize our P as efficiently as possible.  Agronomists, growers and researchers need to explore other P sources that are available, look into new technologies; recycle waste products and most of all utilize P with good agronomics.  In order to improve P efficiency we need to make sure we are managing P in a good agronomic fashion by applying the P with the four R’s (Source, Time, Rate, Place), also make sure that we lime acid soils to help keep P available while managing P with some form of site specific technology at a density that can be managed on your farm. In either liquid or dry forms banding P is more efficient than broadcasting either no-till or incorporated because there is less soil and fertilizer interaction therefore limiting the amount of P tied up by the soil.  In short we can calculate a PUE and from that look at our own operations to find ways to improve PUE and make adjustments to our farms to improve our stewardship and demonstrate to the general public that we are doing a great job with what tools we have.

 

In a world where food production is so vital and yet so ridiculed we have to promote ourselves.  Share with a stranger today how you are improving NUE or PUE on your farm.  Let them know that you are trying hard to be a good steward every day.  Show everyone that by improving nutrient use efficiencies the American farmer is producing more with less in order to feed the growing population. At the Orthman research farm and trials with partners across the globe we are studying different forms of fertilizers and comparing placement of fertilizers to improve both NUE and PUE.  Our Orthman team is committed to demonstrating and recommending the most efficient practices for crop production.

New information regarding placement of Phosphorus with Strip Tillage

I know I have brought before you all information stating that Phosphorus (P) placement can be maximized with Strip Till. This time I am going to touch upon that argument again because some more information has come to light with researchers in the U.K. and Germany just within the last couple of years, as well I want to share with some of our work at Orthman in root improvements with placement.

As a soil scientist working for USDA-NRCS before coming into the private world, I had 25 years of looking at over 420 root systems via post-harvest root digs in both rainfed and irrigated crops; now near 11 more years with Orthman Manufacturing I have more than doubled that number. That said, I have not had the privilege to see roots of corn, soybeans, dry edibles, sunflowers, small grains, canola and other crops with the X-ray computer tomography technologies.  All my efforts have been more hands-on and crop destructive by digging a 3 dimensional pits and teasing out the living roots then sketch a diagram of said roots.  I say this to allow you to compare my information, data compared to what the researchers I typed about in the first paragraph.

The researchers; Morris et al. from the United Kingdom, University of Nottingham in Current Biology wrote that there are several variations of why roots develop and form a specific architecture or shape early in its growth to maturity due to environmental signals, what are called biotic and abiotic.

  • Gravity is the first; roots have the ability to sense direction of gravity very early on. Within 8 hrs after the seed planted imbibes water which is 10-12 hrs prior to root emergence.  This is called positive gravitropism.

  • Light – sunlight that is. Plant roots are negatively phototropic, they grow away from light.

  • Each plant species have differing angles of roots depending upon different classes of roots; primary, seminal, adventitious and so on.

  • Biotic stresses – insects, soil organic matter, microbial and fungal (mycorrhizae) help or hindrances

  • Abiotic stresses – nutrient gradients in the soil, N,P,K, S etc, compaction, and dried out zones

  • Soil water content and replenishing of soil water

  • Soil structure: blocky vs prismatic vs granular vs massive

  • Soil pores; continuous and non-continuous from the soil surface

  • Neighboring plant roots

In this segment of the Precision Tillage agronomic blog I want to expand upon the fifth bullet point, stress or address the advantage from phosphate nutrients placed or absent.  I will attempt to go through the other bullet points in future blogs.

We at Orthman have said and have observed in numerous fields’ better root structure, root numbers, size of roots, even measured root length density when P products are positively and precision placed.  We have stated clearly that there is a “sweet spot” where to place P in the soil with strip till (the Orthman 1tRIPr tool predominantly) and the research papers I have read bear that to be true. We have stated it is between 6 and 8 inches deep.  We have ascertained from reading and our own research that placement depth is when the plants root system is in full force extracting nutrients from 6 to 10 inches depth.  In a fashion folks we have not been telling you all a far-fetched story of fairy dust and the planet Mars having water to drink or irrigate crops with in the year 2155.  Soybean research carried out by scientists [F.D. Hansel et al., 2017] in southern Brazil noted that soybeans using triple superphosphate placed with a strip till method compared to No-Till broadcast and No-Till banded.  These data depict that root length density (RLD) at the 6 to 8 inch zone below the surface in the deep banded strip till P was 58% greater than the No-Till broadcast P approach and 46% improved than No-Till banded P at planting time. Their yield results had little penalty under the strip till compared to No-Till.  At depths of 8 to 12 inches, I saw from their graphs at one site 72% more RLD in strip till compared to No-Till P being broadcast on the surface and at the second site, 38-62% more RLD.  All of this and more is in the paper published in Agronomy Journal referenced at the end of this agronomic blog.

I am including some diagrams to illustrate the point of increased RLD in a specific zone due to placed phosphorus fertility as the scientists from Brazil share from soybeans and of Orthman’s work [soybeans, cotton & corn] and research in barley.

Cotton – Orthman Field research 2013 -Conventional Tillage with surface banded P in Texas

Orthman Field research 2013 – Texas Strip Till Cotton with deep banded P prior to plant

 

From the images to your left you can observe that the surface banded P&K cotton plants show shallow roots in the first set of laterals of the cotton plant in the conventionally tilled portion of the field, then in the remainder of the field the grower strip tilled with an Orthman 1tRIPr and placed a portion of his P&K nutrients with the strip till pass at 6 inches depth.  The plants exerted effort to send laterals at 6-7 in, then 9 to 10 inches and a set of laterals at 18 inches deep.

The total depth of the strip tilled cotton was 29 inches deep and the volume of roots was near 45-50% more in total volume of the soil explored compared to the conventionally tilled cotton and surface banded P&K at planting time.

Cotton yields in bales per acre.  Conventionally tilled cotton yielded 2.9 bales or 1595lbs lint per acre and the strip till yields were 3.4 bales or 1870lbs lint per acre.
(These cotton plots were in the Sunray, Texas area.)

 

 

 

Irrigated soybeans – Orthman Research Farm 2010 Conv Till vs Strip Till with P&K placement (Near Lexington, NE)

In these images to your left and below, soybeans that were strip tilled and conventionally disk-spring field cultivator depict differences from our root excavations.  All delineations are in inches both depth and laterally.

The soybeans that were strip tilled and P&K placed at 6 1/2 inches deep show more total root numbers and soil volume explored in the first 24 inches as well as in final depth at 53 inches ST vs 44-45 inches deep under the conventionally tilled scenario.

Yield in bushels per acre (bpa).  The conventionally tilled soybeans were 62bpa and the soybeans under the strip till yielded 73bpa.

 

 

 

 

 

 

The image down and to your left depicts barley (Hordeum vulgare).  Deep banding of varying nutrient loads are shown between the two dark lines.  The authors of this work in their illustrations depict a larger mass when plants are deep banded with phosphorus and nitrate nitrogen.  This was not strip till research, but work from Hodge shown below, but it depicts what does happen with banded nutrients in a small grain.

Barley root systems enhanced by deep banding various nutrients at the 5 to 7 inch depth with the use of a coulter injection tool.

 

Below are two root systems from irrigated corn research from eastern Colorado at the Irrigation Research Foundation Research Centre near Yuma, CO, 2009. Research funded by Colorado Corn Growers Association and Monsanto.

The root system (see below) of corn which was strip tilled with the Orthman 1tRIPr and liquid N-P-K was applied compared to plots of No-Till corn, same variety and relative maturity day length on the right.  The precision placed nutrient load was the same equivalent of what was used via the 1tRIPr, was band sprayed (15inches wide) one day after the pass of the planter over the row area.  Both areas of the field were planted at 32K plants per acre.

The root system is deeper is 28% deeper, the root mass is 34% more in volume of soil-to-root density with the strip tilled corn compared to the Direct Seeded corn.   The roots in the No Till corn have a wider lateral spread away from the trunk of the plant in the upper 5-6 inches of the soil profile.  In a drought scenario the NoTill corn could suffer.  What we did notice that the No Till called for 2.5 inches more irrigation to be applied under overhead sprinkler irrigation.

The end result was fewer bushels per acre with the No Till or Direct Seed method at harvest time.  Yields; NT – 209 bpa vs ST – 216 bpa.  Water saved was 2.5-3 inches of applied water with the Strip Till and a 7 bpa improved yield.

To Summarize:

From the research efforts of others across the pond and here what we have observed at Orthman; we can offer you these points….

  1. Precision placed P&K has contributed to better P & K uptake

  2. Positive placed nutrients increases biomass of the roots and above ground plants

  3. The illustrations of soybeans, cotton, barley and corn offer strong evidence of more roots which in-turn can obtain more nutrients and water

There can be yield improvements, depending upon climatic concerns; rain, drought, hail and winds.  Our trials in cotton, soybeans and corn all provided some positive results in final grain and lint yield.

Mid-season 50 old corn plants (irr.) on left, Strip Till  w/Deep placed P&K at 6in. a proliferation of roots in orange circled areas.
On right, No-Till surface applied P&K which are mostly immobile in  calcareous soils such as these in Eastern Colorado, orange
outlined area shows where majority of roots are

There is still much more research that is being carried out regarding placement, the right products, the correct timing of application of nutrients beyond nitrogen, phosphorus and potassium the major three of the macro-elements.

Referenced Material I used and read for this blog article:

Morris, E.C., 2017, Shaping 3D root system architecture. Current Biology 27, pg 919-930
McNear, et al., 2013, The rhizosphere – Roots, soil and everything in between. Soil, Agriculture and Agricultural Biotechnical Engineering, 4(3) 1-
Hodge, A., 2004,  The plastic plant: Root responses to heterogeneous supplies of nutrients., New Phytologist 162:9-24
Meurier, F., et al., 2020.  Hydraulic conductivity of soil grown lupine and maize unbranched roots and maize root-shoot junctions. Journal of Plant Physiology  In Press
Peng, Y. et al., 2012,  Temporal and spatial profiling of root growth revealed novel response of maize roots under various nitrogen supplies in the field.  PLoS ONE 7(5) e37726

 

 

 

 

 

 

 

 

 

 

 

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Orthman Corn Research – Yield per Cubic Inch of soil that had roots .. A Different Way to Consider Efficiency

Just this last week (10/26/2020 – 10/30/2020) some of us Orthman were back doing some final work in the field to identify and quantify the root zone that provided us the yields we obtained even with 30-35% GreenSnap problems that plagued us from mid-July until harvest.  Insurance soothed some of that issue that is for sure.

So Pat and I got a small John Deere TracHoe from AKRS in Osceola, NE and dug some pits that we had to go deep to find the total extension of the roots down in the soil profile.  Our discovery was a pleasant outcome, not a surprise to me the “Soil Badger” at all.  Along with that we did some calculations to further express what the yields were in regard to number of bushels per square inch of the soil profile that had roots which we exposed.  Look in the small table below.

 As you look at this table we are determining did the soil profile both efficiently and effectively grow a crop that says it was a top producing hybrid plus – a corn crop that performed very well with the water available.

Now consider the rainfall and water that came via irrigation in the next table below as to efficiency and effectively putting kernels on the cob.

 

A bit more of a standard method to consider what each inch of moisture accomplished in the manner of efficiency and use of water.  Do remember a larger root system and rootzone to attain that moisture has a lot to do with what is the outcome in the way of yield.
So at Orthman we are going to look at what the tillage  tool does, how can we influence and create a better root zone for your crop to meet your expectations.  Another feature we can mention here; the first hybrid we planted and nutured was 1082, the roots went to 72 inches deep (that is down there folks).  The 1108 hybrid is what we planted for the majority of the farm and across the large 23 acre starter trial plot; the corn to use a phrase – drilled down 59 inches and the 1185 a new hybrid in the Pioneer hybrid trial plots went 70 inches deep.  Those extra inches of depth and how much of the root system we observed below 42 inches has a great deal with how they eventually yielded from those extra 30 inches of soil profile.

With Strip-Till providing a medium that grows bigger and better root systems and better placement of the pre-plant fertility – folks those items are part of the entire equation to make your corn yield as would like it to.  Having very deep soils (>60inches) helps a great deal and we know not everyone has that going for them in their fields.  Soils with high water holding capacity are also incredibly important, which the soils on the McNaught Farm do offer – 2.2 inches available per foot of soil root zone.  Everything considered in this idea of soil management and efficiency of water to a bushel of grain going into the bin today can make a grower scratch his/her head.  We like you to break it down to what your fields offer for you.  Todays growers, you folks understand that per pound of Nitrogen you want yield, per inch of water applied and what comes from rainfall all has to be part of what makes a crop and what makes sense in the way of profitability.

Here at Orthman our Territory Reps are very open to discussing this with you as am I the Agronomist for Orthman because we know as the leader in Strip Till we cannot sit back.  Offering different ways to consider what goes on with you at the Farmgate and when you go over your results of the 2020 yield picture – we are open to talking about the system and how it all works for YOU!

 

CORRECTED — Orthman and High Plains Vo-Ag Harvest is Just Completed!

Our first of several results to you is on paper and ready to re-report. Just recently (10-5 to 10-9) we with AKRS Equipment providing us a S770 combine (leased) harvested the Vo-Ag study of placing pre-plant nutrients with two offsets to provide growers an up close and personal look at what corn does and the importance of being right on the money with fertility placement and where the seed sits above the nutrient package.  So two weeks prior to planting back in April we strip tilled in a package of N-P-K & S at a depth of 6.5 inches.  then Pat bumped the GPS to offset by 4 inches and then 8 inches where the plant would grow and develop it’s root system.  We did 48 rows of each approach of a Dekalb 110 RMD variety.

In the corrected table to your left; the O inches details that we planted the seed directly above the nutrients we placed with the Orthman 1tRIPr in early April; the 4 inches offset tells us what it is when we miss the mark and seed is four inches to the right or the left of the nutrients and what kind of results are. Then the 8 inch offset is when seed is 8 inches off from being directly over the top of the nutrition below by 6.5 inches.  I had to correct the table because I had the offset plot data sets west to east with the 8 inch offset numbers as the O inch offset, as well a planting blank spot which needed to be accounted for, and then I had not corrected for the moisture percentage, oh my faux paux!!  I apologize.

What do you see in these numbers?  Yield is down by 5 bu/acre in the 4 inches and 8 bushel/acre down from where the seed and nutrition line up perfectly.  Okay that is fine and dandy.  What can a person have as a Take Away from this field study?  Accuracy pays for itself first off.  A $3.60/bu corn that is an improvement of $28.80/acre when 8 inches off.  If a grower is not using GPS guidance by now and wandering around the row and where you placed a band of nutrition, RTK guidance can and will be a good investment, for the long run.  Placing nutrition is valuable by offering you accuracy and food for the plant to run into since a corn root system does not go hunting for that expensive fertilizer, it has to run into it.  A good RTK system is around $25,000 give or take.  In order to pay for a system connected and ready to roll when you go to the field in one year it would take 5 – 128 acre pivot fields of corn to make it work the first year.  Or 3 pivots over a two year period.  Corn prices step up, it could be fewer acres.  Take the wear and tear off the planter driver, how this can translate to your other tools you pull through the field and this takes fewer acres even more.  This year the plots we had were 48 rows wide by 650 to 679 feet in length due to the shape of the field.  Next year (2021) will be soybeans and a different set of studies.

All season long we watched the corn in the three plots exhibit growth differences, population and time to get to Black Layer.  The 4 inch and 8 inch offset was always further behind where we planted right over the top of the placed nutrients.  The young people under the lead of Mr. Tom Hofmann at the Polk High School watched and measured what was going on and came out to be part of the harvest since they get a portion of the proceeds to fund many of their Vo-Ag/FFA projects in the classroom and shop.  The relationship Orthman Manufacturing has with these young folks in the FFA program is super and we thoroughly enjoy working with them all growing season and teaching agronomic and economic principles.

Orthman-McNaught Farm Update

With soybean harvest into full swing in Nebraska and states all across the Corn Belt we are very pleased with the results of this years soybeans.  They were strip tilled 10 days prior to planting and then planted on April 29th, 2020.  With the abundant amount of sunshine this years, our soybeans that Pat McNaught nurtured with four irrigation events, the month of August continued to bless east Central Nebraska with sunlight and not scorching heat – the beans did well.  This year we followed our own advice as well as our advisor John from Nutrien to spray as a foliar application of a slow release nitrogen, fungicide and a ‘secret sauce’ that spurred at R3 pod set like few have seen before. Thousands of the plants put on 5 to 7 pods per node on the last couple of nodes high up in the plants architecture.  We were pleasantly surprised and pleased.

The good folks from AKRS John Deere helped with the Orthman Soybean harvest this year

Our lowest yield was 77.7bu/ac. and it went up from there. Highest was 93.5bu/acre with an overall average of the field where the plots were was  83.3bu/acre.  Moisture averaged 12.1%.  The root system under these beans was nothing short of superb with laterals going out to 9-12 inches on either side of the main taproot.  The taproot sank itself over 38 inches deep which for beans in this part of the world that is exceptional.  We planted 2.3 to 2.8 soybeans for you that are asking with the 2.8’s tipping the mark at 93.5bu/acre.  All accomplished September 23rd.

I attribute the beans doing so well as we had employed the Orthman 1tRIPr to set the stage for a big root system, good water management with Pat getting to the first water earlier than so many folks surrounding his farm and monitoring the soil moisture conditions.  Treating soybeans like the buck-toothed, redhead stepchild of a wild person was not our plans.  They responded well to good management and the late foliar application.  Next year weather permitting Pat says look out 100 bu/acre ceiling, we will shatter you.

So now it is a game of patience for all of us at Orthman and the McNaught family to stick the snout of the 8row Deere combine head in the field and get after our plots and bulk corn.  We will keep you informed of the results here on PrecisionTillage.com and also the Orthman FaceBook page.

May you all have a happy and bountiful harvest this October.

R2 to R3 Corn in East Central Nebraska – Orthman Research Farm

Tis the season to be grateful and thankful we have got to this point.  Our corn is right in the stage of R2-R3, kernels are turning yellow and getting juicy.  WE have kept Pat busy irrigating via gated pipe twice with a couple of nicely timed rains to keep the corn in real fine moisture conditions. The two hybrids we planted are coming along nicely. Below and to the right is a similar image of what our corn is as of the week of July 26-31, 2020.

A typical ear at R3 stage of reproduction – Orthman Research Farm much like this Courtesy: Purdue Univ.

We want to show you a couple of points from the data we collected in our Pre-plant/Starter/2X Sidedress fertilization program; the chart below depicts 15 of the 18 plots we have in this study and the varying treatments of how we fertilized the crop with differing amounts of N-P-K-Zn etc.  We varied the pre-plant total quantity of nutrients supplied to us by Nutrien™ and the amount sidedressed with the cultivator at ditching time.  Our corn near Polk, Nebraska is furrow irrigated via pipe, thus the ditching operation.  It is our intent in this study we are carrying out to look at how we can use less fertility partly because of accurate placement under the seed early then come alongside and get more nutrients up close to the plant stalk and root system.  With that we are aiming to keep the Nitrogen to each bushel we produce under 1 lb./bushel of yield – preferrably 0.7-0.8lb/bushel.

In the graphic below as we are taking account of crop growth above and below ground, we looked at all plots for height of the plant from the ear to tassle and total leaf number as well as several other characteristics.  The first three plots #1, #2, #3 all took a hit from a severe wind at a rapid growth period and received 25-35% greensnap and leaning corn.  Lucky us!  That which did not snap and leaned over is now back upright but still has something of a lean to the SW.  So we stayed out of those three plots to measure, the going would have been worse than a corn maze at sundown.  The hybrid is all the same a Pioneer 110-111 RMD product.

With this graphic we have 900ft length of plots divided into two 450 ft increments to study a rate change of the last sidedress pass by the westerly plots having 10 gal more per acre than the eastern 450 ft plots.  The plots are 24 rows wide except for the two controls within the study, which are designated as such.

In plots 5 thru 8 we applied less sidedress total by 12 gpa at time of the spring strip till
operation across both the east and west 450 lengths.  Then at sidedress and ditching the corn we applied 10 more gallons/acre of the nutrient mix which are identified in the graphic with black and red checkered fill.  In general we see a small difference in plots 9-13 and then 15-18 compared to 5-8 and 14-15.  From casual walk through we see more two eared plants in 9-12 and 16-18.  Our plans are to actually take 1/1000th of an acre counts of plants across those plots to identify the number of 2 eared stalks.  In nearly all cases that means more yield of grain for folks.

Another detail we have observed in the plots,the late N with S, B and a carbon product, we observed just over 17 total leaves in plots 6, 10 & 14.  Those plots are predominantly with ProZinc-10 in the starter mix.  Interesting to all of us. In the first check #4 the late Nitrogen added shot the plant height from the ear to the tassle but it did not put on any more leaves, it did show us a 5% increase in greensnap over those with an improved starter program.

Stay with us as we continue to measure plant characteristics in the coming weeks.  That is an update as of July 31.

Some of the Latest Field Research on Soil Compaction – 10 Years No-Till to 11 Years Strip Till

It comes to you hot from the fields with growing corn at the V4 stage.  In East Central Nebraska my cohort Pat McNaught and I have been digging up in between corn rows and right in the row where the present crop is growing and taking soil resistance measurements to follow up with the 2019 project and learn even more of what is happening below ground.  This year we were able to get to a long term No-Till field and then same vintage of Strip-Till duration.

In the chart below you can observe in the soft row what the soil condition is like.  Pat and I dug this five days after the 4+ inch rain in late May.  The corn in both fields was V4 to V5 stage and not under any stress, the soil moisture condition was 75-80% of field capacity at 6 inches and 85% at 12 inches.  The lateral (side-to-side) soil resistance values in the soft row is significantly less in the Strip Till ground.  In the upper 5 inches of the soil profile the vertical soil resistance is less dense than the No-Till.  As we observed these two fields within 7 miles of one another, two very dedicated farmers to their systems and very good corn production 250-295 bushels per acre yields (irrigated), we observed the root systems, both were starting the second set of nodal roots. The big difference was the Strip Tilled corn was 23 inches deep and the No-Till was 16 inches.

We are not casting stones here, but you get to look at some differences in how a No-Till field stacks up to a long term Orthman 1tRIPr Strip-Till field.

We will be monitoring these fields as the season progresses.  As of this early part of June all systems are go to hit a top notch yield.

 

A thought regarding last years Prevent Plant acres

As we saw in the middle-few days of April, we saw a dump of snow from the Rockies eastward into Iowa dump 6 to 12 inches here and there of the Christmas Joy, many said Bah-Humbug, tho a reminder came to some of us who are weather watchers – another wet spring.  What does that conger up?  Oh we hope not, more Prevent Planting. Then nice days came the last two weeks for a good cross section of the Midwest –  time to get after the 2020 crop year.

It is being brought up here on Precision Tillage to offer some thoughts and comments what happened last year and what ideas may be important for you all that dealt with 2019’s Prevent Planting ground, especially in fertility management.  A question that comes up; I had lots of weed growth – how does that effect my fertility program for 2020?  Great question for our discussion. I am a student of soil testing but not just any ole go out with a bucket, 10 inch probe and poke a few holes 35 ft into the field and co-mingle the samples and send them off and call it good.  Consider what species of weeds were dominant.  Were these weeds in patches such as huge areas of pigweed or Palmer Amaranth?  Did Russian thistle mix or take over the sandier spots?  In the low lying areas, did Johnsongrass, Quackgrass, Crabgrass, Nutsedge, Yellow and Green foxtail become overwhelming?  I am asking because those weedy species all consumed a tidy amount of nutrition some are nitrogen consumers others the full spectrum of nutrients and not only in the upper 12 inches but deep (>24 inches).

Prevent Planting field in the Platte River Valley – Nebraska

 

There is also the issue of an enormous seed bank now in your field that will become very problematic on into the future which can offer challenges.  Another question; were you able to get into that field or fields and manage the weed growth before they went to seed?  I ask this because those fields will suffer from what is called the “Fallow Syndrome”.  No doubt before the weeds canopied the soil surface the surface baked hard and there was oxidation of organic matter, soil biological activity was reduced, mycorrhizal fungal spores did not germinate and do their job with corn or whatever crop we normally plant.  Some of those spores desiccated and others sat and will wait for a symbiotic host’s root to arrive.  All of this is part of the “Fallow Syndrome”.  Sure the soil may have seemed to have rested but, when weeds went wild and grew prolifically – a real detriment was against  you the grower.

A third issue with Prevent Planting and fallowing ground are losses of residual fertility due to certain percolation and losses out the bottom of the profile.  True phosphates do not move very far downward unless they are in the soluble form in soil solution which was the conditions you sustained with wet, wet soils.  Also sulfur components and maybe some micronutrients leached and reached a water course or water table and gone.  Deep soil testing can be a tool to determine how much is gone.

Why is the agronomist with a tillage implement manufacturer visiting this issue?  I assume by now many have done some form of tillage to deal with the impact of those pesky weeds, with a so called cleanup operations.  What to do?  Do not think you have solved the weed bank, changed the surface 4 to 6 inches, root balls from the big broadleaf weeds and un-oxygenated soil conditions?  Please I am not trying to say all is awry, but if soil conditions are amenable the strip till tool with precision placement of this year’s nutrition program can be very wise choice in preparation for the 2020 year.  Yes last year was unfortunately a stinker and a loss of income.  Using a smart and conservation minded system that can go through all the leftovers, minimize disturbance before you plant and broad-acre tillage only encourages more weed species.  So to minimize unnecessary soil compaction which wetter soils are prone to so often Strip tillage can work.  With the benefits also of less fuel consumption with strip till unless you have already disked the field twice and a surface leveling tool after already, strip till can be effective.  That potential weed seed bank does not need to fed again with high priced nutrients, strip till and placing a portion of your total program in the pathway of the crop you are planting has loads of potential you desire after a year of nothing.

We at Orthman empathize problems that occurred with last year’s flooding and wetness just obliterating the farming potential.  Today we would like to team up and help you see this Strip Till System one that hold potential and financial gains.

By:  Mike Petersen, Agronomist/Soil Scientist

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/