John Kempf

Mitigating heat stress

When leaf temperature becomes too warm, plants switch from photosynthesis dominant to photo-respiration dominant, and begin ‘consuming themselves’.

The threshold for C3 photosynthetic pathway plants is a leaf temperature of 78 degrees Fahrenheit (25.5 C). For C4 plants, the threshold is 86 degrees Fahrenheit (30C) leaf temperature.

Leaf temperature and air temperature are not the same. The healthier plants become, the better they are at cooling themselves. There are several mechanisms in play, topics for future blog posts. It is clear that plants with a waxy sheen on the leaf surface can have a leaf temperature as much as 8-10 degrees cooler than plants that lack nutritional integrity in the same climactic conditions.

When this threshold is crossed and photo-respiration becomes the dominant process, a few important shifts occur:

photosynthesis/sugar production drops or stops completely
plants consume the limited available sugar supply
plants consume any free/available lipids as an energy source (these are abundant in high energy plants, very low in plants getting nutrition from soluble ions instead of from living microbes.)
once the supply of available sugars and lipids has been used as, plants begin consuming their own proteins as an energy source.

80% of the nitrogen (proteins) contained in plants is in the form of enzymes. Breaking these down further weakens the plants ability to recover quickly. Protein catabolism also leads to the formation of ammonium, which is a requirement for spider mite infections.

When plants experience periods of high heat stress, one of the best management strategies is to provide them with a surplus of energy in the form of sugars, oils, and sometimes proteins, to avoid the stress consequences of catabolism.

Foliar applications of sugars and sometimes vegetable oils can produce a tremendous crop response. In the past several weeks heat stress period, growers have reported some remarkable crop responses within 24 hours from foliar applications, both when applied proactively as a preventative, and during and after the heat stress. Rejuvenate inclusion in the foliar mix seems to consistently deliver clear visual results.

John Kempf2021-07-16T07:01:46-05:00July 16th, 2021|Tags: foliar feeding, heat stress, Rejuvenate|

Improving liquid manure

We are recognizing that liquid manure often has a very negative effect on soil biology and soil health. It may deliver nutrients, but it comes with a long list of possible negatives.

It is often in an anoxic state (deeply anaerobic), where the organic residues contained within it are putrified rather than fermented. (which is the source of odor and microbial toxins)

The microbial activity which might be present in the liquid manure has often been suppressed or even shut down completely as a result of this anoxic state, along with the presence of antibiotics.

Liquid dairy manure generally contains quite a high salt content, which has a negative effect when applied to the soil.

In some cases, cleaners and antimicrobial chemicals from milking parlor waste wash-water are also put into the lagoon or pit. (Which is a very, very bad idea, and will increase weed pressure of velvetleaf and other weeds dramatically where this is applied to soil).

Often, when liquid manure is applied, dead earthworms can be found on the soil surface the next day. Might this be a signal that this product is harmful to soil biology?

The odor is also an indicator of fermentation and decomposition gone wrong.

It doesn’t need to be this way.

It is possible to turn liquid manure lagoons into fermentation tanks that turn this valuable nutrient source from something that is harmful to soil biology to a fermentation broth that is very beneficial to soil biology.

When healthy fermentation is taking place in a liquid manure pit there is no odor near the pit, and there is no odor when it is spread. It may still smell slightly like manure when spreading, but there is no ‘stink’ that spreads for hundreds of yards.

When healthy fermentation is taking place, there is no crust on top of the liquid manure, and there is no accumulation of sludge at the bottom. All the solids are consumed, fermented, and the entire lagoon turns into a nice consistent liquid.

Imagine turning all the liquid manure into a fermented product that resembles concentrated compost tea. This is what is possible, and it is a much more valuable nutrient source than anoxic liquid manure that suppresses biology.

A number of manure treatment products are on the market, with varying degrees of effectiveness. Old-time treatments that have been reported over the years include adding yeast, adding molasses, and adding hydrogen peroxide. These can still be effective sometime but seem to be less effective as more GM grains are used as feed, and more antibiotics are present. Here are three AEA products I have worked with for this purpose that I know work very effectively.

The first one is HumaCarb. HumaCarb is not as effective as the other two products in triggering healthy fermentation. It does improve fermentation, but not so actively that it drives the digestion of accumulated sludge. HumaCarb is unmatched in its ability to bind odor-causing compounds, and it does so fast. In one case, a neighboring farm was spreading liquid hog manure on an AEA customers farm, and the odor was drifting to the house a quarter-mile away. The AEA customer asked him to take some HumaCarb back and mix it in before continuing to spread. HumaCarb was added to the liquid pit at a rate of 1 gal/10,000 gallon of liquid manure, lightly mixed in, and then immediately resumed spreading. The very next load, (20 minutes later) the odor was eliminated completely. The following day there were no dead earthworms where the treated manure was applied, where the soil was covered in dead earthworms where the first load had been spread. Obviously, it was binding more toxic compounds than just the odors. Depending on the manure concentration, HumaCarb is commonly added at concentrations ranging from 1/5000 to 1/15,000.

The second product is Rejuvenate. Rejuvenate does not bind odors as rapidly as HumaCarb, and delivers the best results when it is added some time before spreading. Rejuvenate activates and amplifies the existing organisms in the liquid manure and speeds up fermentation. When Rejuvenate is added the crust is quickly dissolved, and some sludge is digested as well. When it is added in advance, as the manure lagoon is filling, it will prevent the development of odor simply by facilitating good fermentation. It is usually added at similar rates as HumaCarb.

When there is accumulated sludge a microbial inoculant called OP8 is the heavy hitter. OP8 can digest accumulated sludge that is feet deep, and it will do so quite rapidly. Usual recommended rates are 1-2 ounces per 100,000 gal, depending on sludge accumulation.

Rejuvenate and HumaCarb are not microbial inoculants, they only speed up the microbes that are already present. OP8 is an actual inoculant.

For the most rapid digestion and highest quality conversion from liquid manure to liquid gold, use a synergistic stack of all three.

Imagine liquid manure that truly smells good, is good for the soil, and has no chance of killing anyone from inhaled gasses? Imagine how much additional value you bring to your soil and crops when you add a product that drives soil health instead of reducing soil health?

John Kempf2020-10-03T08:46:52-05:00September 28th, 2020|Tags: HumaCarb, liquid manure, OP8, Rejuvenate|

Residue digestion and nutrient delivery

When fungal activity looks like this beneath the tree row, how long do you suppose leaf residue will be around to carry over disease to the next season?

How will this fungal activity compete with Armillaria and other potential pathogens in the rhizosphere? How will it influence nutrient availability?

From our observations and experience, soil biology can deliver essentially all of a plant’s macronutrient requirements without any added fertilizer, provided that the nutrients are already present in the soil’s native geological profile. When we farm the biology, we no longer need to import fertilizers that are generally already locked up in our soils.

It may not be wise to simply discontinue fertilizer applications if the soil biology is severely compromised. They need to deliver whatever does not come from imported fertilizers in order to maintain or increase yields and quality, and in challenged soils they are often unable to do so.

John Kempf2020-09-22T16:43:18-05:00September 23rd, 2020|Tags: Rejuvenate|

Rapidly regenerating tired greenhouse soil

Several years ago we worked with a greenhouse grower where crops were being grown in the soil continuously for over a decade. The soil was quite sandy and became quite tired as you can imagine. The large investment in the greenhouse made it worthwhile to invest in regenerating soil health.

The grower green chopped cover crops grown in the field, applied them to the soil surface to a depth of several inches, sprayed Rejuvenate and Spectrum on the residue, and incorporated it into the soil. In 3 weeks the soil had noticeably darkened in color and had developed good aggregation.

The following crops grew better than they ever had in recent memory, and without any disease or insect pressure. Biology can regenerate soil health quickly and provide all the nutrition a crop requires when given a food source.

The soil sample on the right is from an untreated greenhouse bay, taken at the same time.

John Kempf2020-09-04T09:36:18-05:00September 4th, 2020|Tags: Rejuvenate|

Rejuvenate speeding the digestion of corn residue

Rejuvenate was originally developed to speed up residue digestion. Once it was discovered how rapidly the product stimulated soil biology and released nutrients from the soil, growers began using it in-season with some very good crop responses.

The intent was to develop a microbial stimulant that would lead to rapid residue breakdown without added purchased nitrogen. When purchased nitrogen is added, much of the carbon in the crop residue is lost to the atmosphere as CO2. While we do want to cycle large volumes of carbon and have CO2 release to the atmosphere, we only want this to occur when green photosynthesizing plants are present that are capable of capturing it once more.

When Rejuvenate is added, crop residue breaks down very quickly and is captured as organic matter in the soil, and can be released during the following peak photosynthesis period.

This is a set of comparison photos of corn residue treated and untreated with Rejuvenate five days after application. In the treated section, the center pith of the stalks has already turned black, while the untreated side is still white.