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The essential nutrients needed to increase photosynthesis

Most commercial crops are photosynthesizing at only a fraction of their inherent capacity. The limiting factors that keep them from reaching their potential are most commonly inadequate water, carbon dioxide, not enough manganese, not enough chlorophyll, and too high leaf temperature. 

Water is obvious. The solutions to infiltrating and retaining large volumes of water in our soil profiles to produce drought proofed soils are known and will be described more in the future.

Carbon dioxide as a limiting factor is often not considered as it should be. The most important reason to have high organic matter content soil is so we can lose the organic matter as CO2 while we have a green plant to capture it. In crops that are efficient photosynthesizers such as a perennial polyculture of well managed grazed forages, corn, sugarcane, and many others, carbon dioxide levels can be depleted in the local air to less than 100 ppm by mid-morning on a warm day. For the rest of that day, photosynthesis is limited by CO2 supply. 

Manganese is needed for water hydrolysis. When water is absorbed from the soil and moves up into the leaf, the first step before water can participate in photosynthesis is that the H2O molecule is split to H and OH ions, hydrogen and hydroxyl. This water splitting process is called water hydrolysis and is completely dependent on manganese. Even when you have perfect environmental growing conditions, perfect water, temperature, sunlight, and carbon dioxide, if the plant does not have abundant manganese, photosynthesis will be slowed.

Chlorophyll levels can often be increased by making sure that plants have adequate levels of magnesium, iron, and nitrogen. Nitrogen is seldom low because it is one of the nutrients much used to cover up other imbalances, and is frequently over-applied. Magnesium is easy to correct with a foliar application, and also frequently low. Iron is almost universally low in plants, contrary to most soil and plant tissue analysis reports, because the (oxidized) form of iron reported on these assays is not physiologically active in plants. Any of these three nutrients can be used to quickly give plants a dark green color by increasing chlorophyll. Since nitrogen is generally abundant, magnesium and iron usually produce the biggest economic crop response. Leaf sap analysis can identify precisely what is needed.

When leaf temperatures are too high, photorespiration becomes dominant instead of photosynthesis, and plant energy levels begin dropping, ammonium is produced in leaf tissue as a result of protein catabolism, and plant immunity is quickly reduced. There is not a direct correlation between leaf temperature and air temperature. Healthier plants remain cooler for much longer at higher leaf temperatures, through a variety of mechanisms.

Look for more detail on each of these in future posts. 

 

2020-03-16T13:54:54-05:00January 15th, 2020|Tags: , , |

Impacts of glyphosate residue on seed germination

Some new research1 describes the impact of pre-emerge glyphosate applications on seedling development and yields, and the impact of prior year appplications. The conclusion: you certainly want to avoid any application until well after seedling emergence, and prior year applications are probably impacting your current yields. It seems we need to begin using alternatives immediately.

The article itself is a great read, here are a few excerpted highlights:

  • The seed germination of faba bean, oat and turnip rape, and sprouting of potato tubers was delayed in the greenhouse experiments in soils treated with GBH (glyphosate based herbicide) or with pure glyphosate.
  • The total shoot biomass of faba bean was 28%, oat 29% and turnip rape 58% higher in control compared to GBH soils four weeks after sowing.
  • Grazing by barnacle geese was three times higher in oats growing in the GBH soils compared to control oats in the field. 
  • Our results indicate that the use of GBH, as well as surfactants and other ingredients of commercial herbicide products, have different effects on the seedling establishment of seed- and vegetative-propagated crops.
  • In all the studied seed-propagated crops, germination was faster, and in turnip rape and oats the total germination percentage was higher in the C soils compared to the pure G- or GBH (Roundup)-treated soils.
  • seed-propagated crops with limited endosperms as an energy source are likely to be exposed to GBH residues in soils following water imbibition at the beginning of the seed germination.
  • Our results suggest that the use of GPH may have unintended and undesirable consequences for farmers. The speed of germination and early growth may be crucial for the plants, depending on the abiotic and biotic environmental factors. Especially in spring, earlier individuals may benefit from moisture and a lack of competition. Thus, delayed germination and weakened growth of seed-propagated crops in GBH-contaminated soils may invalidate the intended crop protection if targeted weeds get a head start in early spring.
  • The use of GBH may increase the yield loss caused by flea beetles and further challenge spring-planted oilseed rape and turnip rape cultivation
  • Glyphosate can enhance the attractiveness of plants to vertebrate herbivores. In the field experiment, the oat plants growing in GBH-treated experimental plots experienced heavy barnacle geese grazing while the adjacent plants in C plots were only mildly grazed. 
  • Glyphosate is known to inhibit the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate acid pathway, thereby interfering with the production of tryptophan, phenylalanine or tyrosine, which are precursors of proteins and other molecules, including growth promoters (e.g., indoleacetic acid, IAA) or secondary compounds with known importance for plant defense against herbivores (e.g., tannins, anthocyanins, flavonoids, and lignin.
  • Overall, the effect of pure glyphosate was weaker compared to that of the commercial formulation (Roundup Gold) containing the same amount of glyphosate. This supports other studies suggesting that other ingredients in GBH, such as surfactants, solvents, and preservatives, could also cause adverse effects on non-target organisms.
  • Our results clearly demonstrate that the use of GBH has detectable effects on crop plant germination and growth, and their quality to herbivores, even though we used field-realistic concentrations of GBH and the experimental plants were introduced into the soil after a two-week withholding period.
  • In contrast to seed-propagated crops, GBH treatment boosted the growth of vegetatively propagated potatoes, and glyphosate appeared to accumulate in the potato tubers. This leads to the critical question of whether the residues in potatoes have consequences for the subsequent year’s yield.
  • These results emphasize the importance of a more comprehensive understanding of the effects of GBH on the productivity of crop plants and their chemical ecology, affecting their pest and pathogen resistance and thus the need for crop protection.
  1. Helander, M., Pauna, A., Saikkonen, K. & Saloniemi, I. Glyphosate residues in soil affect crop plant germination and growth. Sci. Rep. 9, 19653 (2019).

 

2020-03-16T13:54:09-05:00January 14th, 2020|Tags: , , , , |

Effective Seed Treatments

For direct-seeded crops, seed treatments are the least expensive and highest return application a grower can apply. 

Seed treatments can contain bacterial inoculants, fungal inoculants, microbial biostimulants, plant biostimulants, and trace minerals. The most effective treatments usually are a synergistic stack that contains ingredients from several or all of these categories. 

Trace mineral seed treatments are most important with poor quality seed that is small in size and light in weight (most commercial corn seed). High-quality seed often contains enough of the more common trace minerals. 

Many seeds, at least those grown on healthy parent plants, vector their own symbiotic endophytic microbes, both bacteria and fungi. In addition to those microbes vectored on the seed, seedlings also recruit symbiotic fungi and bacteria from the soil, particularly mycorrhizal fungi, as well as others, even some of the same species they carry along on the outside of the seed. 

Applying mycorrhizal fungi and other bacterial inoculants as a seed treatment is generally an effective delivery method to achieve early root colonization, particularly for monocots, where the seed remains in the ground. 

For dicotyledon plants, I have always wondered how effective it is to treat the seed when the seed is soon pushed up and out of the ground. Many growers have used seed treatments on these crops effectively, but I suspect we may get better responses from applying them in-furrow right with the seed when the option exists.

One other thought, applying a fungal inoculant on fungicide treated seed doesn’t seem like the brightest idea under the sun. We know the crop does benefit because this is a (surprisingly) common combination. How much bigger might the benefits be if the fungicide was removed and the beneficial fungi permitted to flourish.

2020-03-16T13:53:28-05:00January 13th, 2020|Tags: , |

Foliar Feeding with pesticides in the tank

Why would you add toxins to your food? ~ Michael McNeill

(When asked whether it is appropriate to add foliar fertilizers to a spray mix which contained fungicides or insecticides.) 

It is fairly common to combine nutrients and biostimulants with toxic compounds in the same tank mix, but is this really what is best for plants?

Sometimes a combination is the only application logistically possible, but field experience suggests that separating foliar fed nutrients and pesticide applications will produce a bigger crop response to the foliar fed nutrients.

Foliar feeding in a combination with pesticides is better than not applying the needed nutrients at all. Applying nutrients and biostimulants without the toxins is best. 

 

2020-03-16T13:52:31-05:00January 11th, 2020|Tags: , |

Why we don’t use Horiba meters to measure nutrients in plant sap

Laboratory leaf sap analysis has given us remarkable insights into plant nutrition. We have learned a great deal about nutrient interactions and plant nutrient absorption of different products and in different environments, and have become champions of sap analysis. 

Occasionally I am asked how we might use the Horiba meters to measure sap contained nutrients in the field, rather than submitting them to a lab.  

I don’t consider Horiba meters to be a viable option if we really want to manage plant nutrition properly. Here are a few reasons why: 

  1. We need to know the levels of many more than four or five nutrients. Knowing the levels of only nitrate, potassium, calcium, sodium, pH, EC, and Brix doesn’t begin to approach the thoroughness of data needed to make informed decisions about nutrient management. For example, manganese influences potassium absorption, and boron influences calcium absorption, to a significant degree. Trying to manage the macronutrients without knowing the levels of the trace minerals promises to be an exercise in frustration and mismanagement.
  2. Nitrate is only one of many possible forms of nitrogen contained within a plant. In a healthy plant with proper protein synthesis, upwards of 80% of the nitrogen will be in the form of enzymes – complete proteins, which don’t register at all on a nitrate meter. It is possible to have a crop with abundant levels of total nitrogen and record a non-detect nitrate on a Horiba nitrate meter. With lab-based sap analysis, nitrate, ammonium, and total nitrogen are all measured separately. Our goal is to have abundant total N, with nondetectable levels of ammonium and nitrate. A goal that we achieve quite regularly.
  3. In many cases, (not always) in-field analysis with the Horiba meters is conducted on the sap contained within the petiole, rather than in the leaf. Yet, we know the petiole is a nutrient and water transport pipeline, and nutrient levels in the petiole sap can fluctuate by as much as 30-40% at different periods during each 24-hour photocycle. With what other analytical methods would we accept a possible 30+% error margin? None, of course. We can reduce this margin of error by collecting samples at the same period of each day, but this doesn’t resolve the challenge that the nutrients contained within the petiole don’t always reflect what is present in the leaf.

In –  lab analysis of leaf sap overcomes all of these challenges. This is why we only use the sap analysis from Crop Health Labs.

 

2020-03-16T13:52:03-05:00January 10th, 2020|Tags: , |

Yield: six thousand pounds of beef per acre

What is the genetic yield potential of forages and vegetative crops, rather than reproductive crops such as corn and tomatoes?

These vegetative crops do not have the same genetic constraints as reproductive crops. For these crops, the limit to growth and yield is the photosynthetic capacity. When optimal CO2, water, sunlight, and nutrients are provided grasses and forages can be extraordinarily productive, as described in this cover article of Acres USA in early 1977.

Original Acres article:

Moving cows from pasture to pasture has a long and respected history, notably in Australia and arid territory where overgrazing is a capital sin. Its application to irrigated and rain belt pasture has seldom been tested on a controlled basis.

Last summer, C.J. Fenzau of Boise, Idaho divided a 31-acre field into single acre plots. He put 272 cattle into the first single acre plot when the grass was knee-high on April 5, 1976. By the next morning the first plot had been mowed down much like a city lawn. During that single day the cattle had eaten the whole plant-the rich upper part, the leafy mid-part, and the fibrous stem. This gave the animals a total ration, a well-balanced ration at that. 

“If you put cattle on fresh young pasture,” Fenzau told Acres U.S.A., they eat the high protein buds the first day. The next day they get a little less value, and so on. In four or five days of milking, you see a cow on pasture give more milk than any grain would ever produce. As pastures go down, farmers put in grain. This animal is fighting her own droppings in the pasture. She is compacting the ground. When you’re stripping a plant, you’re putting it under stress each day, and you have less leaf capacity for photosynthesis. But in 30 days a plant has a chance to grow back all the leaves in their full working power for more productivity.”

On the second day, the cattle were moved to acre No. 2. The first acre was then given a shot of irrigation water. This melted away the still-soft droppings and set the stage for at least 30 days of growth. There was a second irrigation during the 30 to 35 day growth period. 

The growth period was stretched to 35 days as cattle were shifted from acre No.2 to Acre No. 3, 4, 15, 20, whatever. During May, June, and July only 20 of the 31 acres were used. Cattle couldn’t mow down the grass fast enough. 

“We’re looking at having 400 head of 500 to 600 pounders there next year to utilize the grazing potential of those 31 acres to the optimum,” Fenzau summarized.

What does this amount to in terms of beef production? Over the scales, Fenzau logged in 2.4 to 2.5 pounds of grain per head per day. A total of 2.25 or so on 400 head means 1,000 pounds of beef per day. This multiplied by 200 days comes to 200,000 pounds of beef off 31 acres, or in excess of 6,000 pounds of beef per acre.

Needless to say, the best fertility management has to underscore such heads-up farming. This management has only one name—scientific eco-farming.

~~

These results were achieved in 1976. Today is 2020. 44 years. Who will follow through and test what new forage genetics are capable of when provided optimal water, CO2, sunlight and nutrients?

This is without question the most efficient protein production per acre.

 

2020-03-16T13:51:42-05:00January 9th, 2020|Tags: , , |

Electromagnetic Weed Control

Would you have guessed that it is possible to prevent weed seed germination by exposing them to a specific electromagnetic signal?

In 1991, Phillip Callahan1 first published his experiences with a uniquely designed cultivator tine that produced a frequency which inhibited weed seed germination. I am not aware that anyone has picked up this research, which seems like such a golden opportunity. Now is the time! If you know of anyone who has done work in the area, I would love to learn more about it. 

Enter Phillip:

Not so very long ago I was dining with my editor, Charles Walters. I was at the 1991 Acres USA convention and Mr. Walters introduced me to an Australian gentleman seated at the same table. Our Australian friend, John McCabe, was attempting to explain how a cultivator he had modified completely eliminated weeds from his crop fields. Both Mr. Walters and I had a difficult time understanding the modification until Mr. McCabe showed us a photo of the tines on the cultivator.

Each rake like tine had a full loop along its length (see photo). In other words, each tine was a one-loop spring. It was quite obvious that each spring-loaded tine would vibrate at some low frequency made as it was dragged across the soil. The tractor vibrations would also vibrate each tine. The vibrations would enter the soil as sound since the spring would beat against the soil particles. Sound waves are pressure waves, but such a system would also have a low frequency electric radio wave associated with the sound wave. The sound wave would not penetrate the soil for any great distance since it would be muffled by soil. Low-frequency radio waves, however, penetrate to great depths in both water and soil. This is why the Navy utilizes low-frequency ELF radio waves to communicate with the atomic subs underwater.

We may understand now that common sense tells us that low-frequency, radio, especially below 1000 Hz must be significant to seeds and roots. These frequencies, even the atmospheric Shumann frequencies, easily penetrate the soil to both seeds and roots – light does not! Why study the effect of light below the soil when it is not light, but ELF radio that bathes the seeds and roots?

As far as I can determine from the literature, not a single scientist other than myself is concerned with ELF radio waves in the soil. If my thesis is correct, then a simple spring-loaded soil experiment should prove whether or not the spring-loaded tie imparts ELF radio waves into the soil. I, therefore, buried my PICRAM antenna – detector under 4 in of soil (seed depth). 

Whenever I plucked a rubber band, mounted between two nails, the radio electric field penetrated the soil to my buried PICRAM detector. I could hear the sound of a rubber band in the air above the soil, but the weak sound would not penetrate the soil to a microphone below. 

The sound is blocked by a few inches of soil, but the low frequency radio wave from the rubber band is not. From directly on the soil surface, to as far away as one foot above the soil, the PICRAM underground resonated to the fundamental frequency of the snapped rubberband. The frequency range for rubber bands occurs at 140 Hz for larger strong bands to a slightly higher frequency of 150 Hz for small weak bands – a range of about 10 Hz depending on rubber band size and strength. 

The top Figure (1) shows the waveform at a fast sweep 5 ms (5/1000 of a second). Waves are calculated, of course, by how many occur in 1 second (One wave per second equals one Hz). Since wavelength, the distance from crest to crest is the number of waves (frequency) divided into the speed of light which is 186,000 miles per second, then the wavelength of a 140 Hz wave is:

In other words, the fundamental ELF radio frequency of a rubber band at 140 Hz equals a wave from crest to crest, 1328.5 miles long. Every time you snap a rubber band a radio wave of from 140 to 150 Hertz not only passes through the soil but also passes through your body – a mighty long wave!

The bottom sweep at a slower speed 50 Ms (50/1000 of a second) shows how the 140 Hz slowly dies out as the vibrations get weaker and weaker. 

The tines on Mr. McCabe’s cultivator may or may not resonate in the same region (being a metal spring probably not) but what is certain is that they resonate somewhere in the ELF radio range between 1 and 1000 Hertz, and wherever it is, that particular tine frequency is bad for weeds and good for crops in the same way garlic can be good for digestion and bad for love.

Nothing is certain in this world, but if the peculiar Australian cultivator is doing what Mr. McCabe claims it to be doing, what is certain that with a trip to Australia, and a couple of days in those weed-free fields, it would take less than half an hour to determine the fundamental frequencies of those spring-loaded tines. That makes control of weeds as simple as generating that frequency.

(Since I wrote this in 1991 I traveled to Mr. McCabe’s farm and measured his cultivator with my PICRAM. It resonated at 720 Hz so I did not miss it by far. It is an ELF frequency!)

It is obvious that the weed seeds must store the wavelength information that causes them to go into dormancy, for the cultivator passes over any one seed in seconds.

An electronic ELF generator could be designed to transmit those ELF waves into the soil. Attached to any cultivator it would most certainly not poison the soil, for no frequency has ever been known to hang around after it has been switched off. Furthermore, the costs would be thousands of times cheaper than chemical weed killers for you buy it only once. I need hardly mention that not only do chemical weed killers kill weeds, they kill people also – Agent Orange!

From this simple weed – radio experiment my readers, I hope, will be left with a feeling for the importance of understanding the electromagnetic portion of the spectrum. By eliminating chemical poisons, fertilizers and such sick techniques of agriculture, we may not only eventually control diseases, but also increase agricultural output without destroying our spaceship earth. 

  1. Callahan, P. S. Exploring the Spectrum: Wavelengths of Agriculture and Life. (Acres USA, 1994).

 

2020-03-16T13:51:11-05:00January 8th, 2020|Tags: |

Managing the Point of Deliquescence

Managing the point of deliquescence (POD) of a foliar spray solution can tremendously increase the performance of the products applied, particularly in drier climates with low humidity, and when the products applied are ionic salts.1 

It is also possible for plants to absorb insoluble non-ionic nutrients through the leaf surface through endocytosis. For non-ionic products, the point of deliquescence is less critical but still important and useful to manage. 

The point of deliquescence is described as the humidity threshold at which an ionic salt material dries into a crystal on the leaf surface. When humidity is above the point of deliquescence, the salt residue on leaf cuticle dissolves and can be absorbed. When the humidity is below this point, a solid residue remains on the leaf surface and penetration into the leaf stops.

Because of this effect, foliar sprays should be applied in the evening to take advantage of the higher humidity at night.

In addition to the ingredients mentioned in the article, a useful tool to increase the point of deliquescence when applying non-ionic materials are ocean mineral solutions with a low sodium content, which are generally quite hydroscopic and keep the foliar solution liquid on the leaf surface for a longer period.  Urea is also a useful material in this regard.

The reference below describes the POD and speed of foliar nutrient absorption across the cuticle for various ionic nutrient compounds.

  1. Schönherr, J. Foliar nutriton using inorganic salts: laws of cuticular penetration. in International Symposium on Foliar Nutrition of Perennial Fruit Plants 594 77–84 (actahort.org, 2001).

 

2020-03-16T13:50:52-05:00January 7th, 2020|Tags: |

Disease suppression of wheat take-all disease

The presence of soil-borne disease infection is not correlated to the presence of an infectious organism, but to the absence of suppressive microbes.

Here is an example from Paul Syltie1 on wheat take-all disease: 

It is well documented that the fungus responsible for the take all of wheat Gaeumannomyces graminis var. tritici is attacked by soil bacteria, in particular by the bacteria in what are called take-all suppressive soils. These soils are unique in that the severity of the disease becomes progressively less as the cropping season continues. In some cases the disease may not even express itself whatsoever despite being present.

It is concluded by soil microbiologists that most soils express some degree of natural pathogen suppression. This occurs generally in soils by the mass of beneficial organisms overwhelming the pathogens at a critical time in their life cycle, robbing critical nutrients from them. Specific suppression occurs when select species or groups of beneficial organisms antagonize the pathogen at some stage of its life cycle.

Take-all in wheat or barley becomes less and less of a problem if the crop is grown in consecutive years. Both fungi and bacteria, such as friendly saprophytic Fusarium species, reduce pathogen numbers by competing for food supplies, and at the same time specific antagonistic microbes like fluorescent pseudomonads attack the G. graminis. The pseudomonads are especially effective when ammonium rather than nitrate fertilizer is used, resulting in a lower rhizosphere pH. This suppression likely occurs mostly in the rhizosphere, but also throughout the soil mass.

1. Syltie, P. W. How Soils Work. (Xulon Press, 2002). Page 111

2020-03-16T13:50:36-05:00January 6th, 2020|Tags: , , , , , |

Foliars as a tool of soil regeneration

Without the contribution of plants, ‘soil’ is only decomposed rock particles.  

Plants contribute sugars, organic matter, carbon, the energy that sustains microbial populations. 

Plants, through photosynthesis, are the only way we have of bringing new energy into the system.

The photosynthetic engine of most crops is only running at 15%-20% efficiency. (Charles Tsai, et al.) It makes sense to increase the efficiency of this engine as much as we are able.

The first priority of a successful foliar application is to increase photosynthetic efficiency. A foliar application that only addresses nutrient deficiencies and does not increase photosynthesis will not be nearly as effective as a foliar which does both. In fact, a foliar which does not increase photosynthesis can facilitate more efficient extraction of soil nutrients and increase soil degradation. Foliar design matters.

The nutrients which need to be present in adequate supply to increase photosynthesis are nitrogen, manganese, iron, magnesium and phosphorus. Obviously, many others are also important, but these are key.

We can use foliars as a tool for soil regeneration when we use them to increase photosynthetic efficiency and transfer a larger portion of plant photosynthates to the roots to feed soil biology. 

When a well designed foliar is applied, the spike in photosynthesis can be observed in sap sugar content and dissolved solids, or brix. (Measured actual sugars on a plant sap analysis is best by far. Brix can be highly variable because of environmental conditions.)

After a successful foliar application, the photosynthetic rate will gradually drop back down, but not quite down to the previous baseline. With each successive application spike, and return to baseline, the baseline level increases. When photosynthetic efficiency baseline improves to a high enough plateau plants contribute more carbon energy to the soil than they withdraw mineral energy and the entire ecosystem becomes self-sustaining.

The drop back to the new baseline can occur quickly or slowly, depending on the level of ecosystem health. In a compromised and degraded ecosystem, the spike may last for as little as 3-5 days before it drops back down. In a healthy soil, with good biology, the elevated spike may last for as long as 5-6 weeks or even longer. 

The healthier soils and plants become the fewer foliars are needed until the point is reached where they are completely unnecessary to sustain a level of health where plants are completely resistant to diseases and insects.

While on the pathway to this point, we can still use the photosynthetic efficiency spikes to produce interesting and valuable effects. If we have the presence of larval or sucking insects,  a spike in photosynthesis is often successful in giving them a dose of sugar they can’t tolerate.

A slide from an academy presentation. Academy.regen.ag

2020-03-16T13:49:53-05:00January 4th, 2020|Tags: , , , |
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