40 Years of Organic Green Manure for the Win

A new study finds:

  • Organic Green Manure and Organic Animal Manure treatments increased cumulative water infiltration by about 10 times compared with the conventional farming treatment
  • Soil aggregates increased by 50% with the Organic Green Manure and by 30% with the Organic Animal Manure treatments in the upper 15-cm depth
  • At the same depth, bulk density was 3% lower under organic practices than in the conventional farming treatment, suggesting that organic farming reduces the soil’s susceptibility to compaction.

Organic Farming and Soil Physical Properties: An Assessment after 40 Years

Continuous Monocropping.

A new study using a LARGE dataset has found for corn and soybean:

  • Analysis of 748,374 yield records showed a 4.3% yield penalty for continuous corn.
  • Corn yield penalties were more severe in areas with low moisture and low yields.
  • Continuous soybean showed a 10.3% yield penalty, worse in low-yielding years.
  • Corn yield penalties grew with up to 3 yr of continuous cropping, but not more.
  • Soybean penalties increased monotonically with number of years continuously cropped.

Continuous Corn and Soybean Yield Penalties across Hundreds of Thousands of Fields

 

Cover Crops May Increase Soil Microbial Biomass 3x More Than Compost

Three to six times more microbial biomass carbon and nitrogen depending on soil type.

These results provide evidence that carbon (C) inputs from frequent cover cropping are the primary driver of changes in the soil food web and soil health in high-input, tillage-intensive organic vegetable production systems.

Fresh is best.

Cover cropping frequency is the main driver of soil microbial changes during six years of organic vegetable production

New Slow-release Nitrogen Calcium Phosphate Fertilizer

ureaca

Researchers have used nanoparticles to create a a fertilizer that releases nutrients over a week, giving crops more time to absorb them (ACS Nano 2017, DOI: 10.1021/acsnano.6b07781).

They attached urea molecules to nanoparticles of hydroxyapatite, a naturally occurring form of calcium phosphate found in bone meal. Hydroxyapatite is nontoxic and a good source of phosphorous, which plants also need.

In water, the urea-hydroxyapatite combination released nitrogen for about a week, compared with a few minutes for urea by itself. In field trials on rice in Sri Lanka, crop yields increased by 10%, even though the nanofertilizer delivered only half the amount of urea compared with traditional fertilizer.

Slow-release nitrogen fertilizer could increase crop yields | Chemical & Engineering News http://cen.acs.org/articles/95/web/2017/02/Slow-release-nitrogen-fertilizer-increase.html

They should call it UreaCa! Geddit?

Alternately you could just use fresh plant litter or cover crop residues that leach nitrogen over two weeks and also feed soil microbes carbon. Or faba bean that will release it over three years[1] and build soil carbon so eventually you don’t need to add any.

[1] Carbon and Nitrogen Release from Legume Crop Residues for Three Subsequent Crops
Abstract | Digital Library https://dl.sciencesocieties.org/publications/sssaj/abstracts/79/6/1650

[2] Formation of soil organic matter via biochemical and physical pathways of litter mass loss : Nature Geoscience : Nature Research http://www.nature.com/ngeo/journal/v8/n10/full/ngeo2520.html

Gardening with Organic Mulch [+Rant]

What he’s practising is excellent, however I felt I needed to make a few comments, firstly on the use of the word aggradation and then a few other terms.

I believe the word he wants is aggregation, which is what soil microbes do by aggregating soil particles with mucilage and exudates to build soil aggregates and structure as they move through it. Aggradation however is the formation of soils by geological process, like wind, rain, and the movement of water causing sediment accumulation. It is often caused by soil degradation through poor land management practices such as tillage.

Also, a more appropriate title for his clickbait would probably be Gardening with Organic Mulch, as I’ve titled it here. As decomposing plant residue is considered an organic fertilizer by many. Ramial chipped wood is just one form of mulch, and not always the best form for every application or soil. It is excellent for building soil however for subsoil application material higher in nitrogen will feed microbes more of what they’re made from and build soil faster if the soil moisture and environment are adequate.

I believe the fungi that break down the ramial chipped wood and other organic matter are collectively known as saprophytic fungi, Basidiomycota mentioned are just one division of that family and of the larger that make up the Saprotrophs, which include other microbiology, fauna, plants and animals. Holistic approaches use all of these to build soil for differing plant needs.

Ramial chipped wood tends to be high in potassium and low in phosphorus, why fungi love it. The high carbon content also buffers soil pH and moisture which they like. Just add water.

The fastest ways nature builds soil organic matter is actually in prairies and grasslands with high rainfall, not forests. Protected seagrass bays are even more productive than these and contain the highest amounts of soil organic matter recorded to date. These areas maximise photosynthesis and nutrient runoff from higher elevations and tides, and in native grasslands the long thin root perennials sequester carbon, the building block of all organic matter, deep within the soil profile where it isn’t easily oxidized and will live for centuries to millennia. Fungi also store carbon inside of soil microaggregates preventing their oxidation by other organisms that would release it as atmospheric gases. Releasing these gases isn’t always bad as plants can feed off these higher concentration atmospheric gases created by the soil biology to increase productivity and sequester more, but only if the soil moisture and environment is adequate.

I keep repeating soil moisture because it has been shown to be by far the most important factor in building organic matter in native soils. And ramial chipped wood in moderation is certainly an excellent way of managing soil moisture while also fertilizing. It covers soil, it hold moisture, it fertilizes.

You will however not get Back to the Garden of Eden with just wood chips!

Wood chips reduce photosynthetic land productivity when not planted out!

A more holistic approach is needed to solve for these!

Now I’m tempted to start my own growing movement and calling it Holiculture. 😛

Hieronymus_Bosch_-_The_Garden_of_Earthly_Delights_-_The_Earthly_Paradise_(Garden_of_Eden).jpg

Is Bokashi and Natural Farming good for soil?

Bokashi consists of anaerobic bacteria. Such bacteria is pathogen, isn’t it?

The deeper in the soil profile you go, the less oxygen there is, making soil more of a spectrum from aerobic to anaerobic, however a lot of plant available nutrients including nitrogen are formed in the aerobic top soil where there is most microbial activity, which is part of the reason aerobic microbes tend to get the most attention and results.

This in the permaculture world is the edge effect in action.

The question assumes that anaerobic microbes are all human or plant pathogens. However studies I’ve read suggest otherwise, and that both aerobic and anaerobic brewing will result in human or plant pathogens if the material or environment you start the brew with contains those pathogens and creates an environment they thrive and multiply in over other organisms.

This is why I believe diversity in the soil food web is important in preventing any one organism taking over and overcoming a host. That means an array of aerobic to anaerobic microbes and that means an array of feed material and environment. The reason many superbugs are super is because they work together using techniques such as quorum sensing and overcome a host that may not have a diverse enough line of defence or environment. Monocultures are breeding grounds for these organisms. Broad-spectrum antibiotics and even personal and cleaning sanitization products create these kinds of environments.

I’m no Bokashi expert but it’s likely there is still some oxygen in the upper layer of Bokashi, especially if you keep opening the container to check it or when adding material, however it can be a pathogen to some soil organisms. Bokashi is often used to eradicate plant-based pathogens. The phenols it contains, which are weak acids, and other acids such as lactic acid produced in Bokashi have a sterilizing effect on some microbes. Bokashi can also be quite acidic with a pH of 3.5-4.5 or lower apparently, however soil organic matter works as a great buffer to pH changes.

From soil microbial genetic studies I’ve read, acidic soils actually reduce microbial diversity. However as the study below mentions, the pH of Bokashi may not be a factor in plant growth when used in appropriate concentration. Used appropriately it’s likely that Bokashi or many other Natural Farming anaerobic or fermented formulations could add to microbial diversity long-term so long as those same soils are amened with a diverse range of materials to feed them. That can be as simple as chop, throw, and drop and creation of a diverse Food Forest.

Below is an abstract from a study on Bokashi used to germinate and grow a brassica, with a recommendation of limiting Bokashi to 30% mixtures with soil by volume because of the phenols. Keep in mind the study only trialled one species of plant. It may also be a good idea to dilute any Bokashi water extract. In order to get the dilution rate correct I always like to test any microbial liquid amendments for at least pH and EC (electrical conductivity), which is an indicator of cations and nutrient concentration.

A kind of fermented organic fertilizer known as Bokashi in Japanese has been used by many Japanese farmers for many years. Bokashi is the fermented product of some organic materials such as bran, oilcake etc. mixed with soil under low temperature (below 50 – 60 deg C) during short period (about 10 days). In this study, experiments were carried out to find the influence of application of Bokashi on germination and early growth of komatsuna, [Japanese mustard spinach] (Brassica campestris L.) by using the water extract from Bokashi and different volume percentages of soil and Bokashi mixture. The results obtained were as follows. 1) The germination percentage, stem and root length of komatsuna decreased with increase of concentration of phenolic substances in the water extract from Bokashi, and a close negative correlation was found between the inhibition on komatsuna growth and concentration of phenolic substances. 2) It was found that volume percentages of Bokashi mixed with soil should be limited below 30% because the emergence percentage of komatsuna became lower on increasing volume of Bokashi in the soil, and many plants died, to above 50% of their volume. In addition, the emergence percentage and the concentration of phenolic substances in the soil had negative correlation. From these results, phenolic substances can be used as an indicator to investigate the effects of application of Bokashi on plant growth. 3) Early growth of komatsuna on the soil applied with fermented Bokashi was better than that on the soil applied with unfermented materials of Bokashi. Consequently, it was suggested that fermented Bokashi had an effect of promoting plant growth, but the cause of promotion should be investigated further. 4) pH of the Bokashi fermented under high temperature (above 60 deg C) was higher than those fermented under low temperature (below 50 deg C), but there was no difference on plant growth between them. From this result and 3),it was found that the fermentation was important, but the different temperature ranging from 40 to 60 deg C had few influences on plant growth. 5) The number of lateral root was increased by application of Bokashi and the effects of application of Bokashi on plant growth were more effective at root growth than germination percentage and stem growth. Therefore, it was suggested that detailed investigation of root was very important in order to find the influence by application of Bokashi.

Influence of the application of “bokashi” a kind of fermented organic fertilizer on germination and early growth of komatsuna (Brassica campestris L.) [2001] 

If you want to read more about how different natural farming formulations can impact microbial diversity, the following genetic study compares a number of fermented products and sequences their genomes to see what microbes are in the formulations.

Cultivable bacterial diversity and early plant growth promotion by the traditional organic formulations prepared using organic waste materials


The heat map shows the number of bacterial species isolated from different organic formulations and their ingredients. T1 100 % panchagavya; T2 33 % panchagavya; T3 plant extract with native microorganisms; T4 commercial organic fertilizer extract with 2 % leaf soil extract; T5 commercial organic fertilizer extract with 2 % yogurt; T6 cow urine; T7 cow dung; T8 cow milk

Effect of different organic formulations on dry weight of radish (a) and Chinese cabbage (b) under pot culture condition. T1 100 % panchagavya; T2 33 % panchagavya; T3 plant extract with native microorganisms; T4 commercial organic fertilizer extract with 2 % leaf soil extract; T5 commercial organic fertilizer extract with 2 % yogurt. Control, 0, 50 and 100 times of dilution organic formulations are represented in different shades. Values are mean ± SE of three replications, and same letters in each treatment are not significantly different from each other at P < 0.05 according to DMRT

Natural Farming is an art, unless it’s a science.

Controlling Fruit Flies with Netting or Clay [+Rant]

While many of the suggestions in this big ag monocropping series include sprays and traps with inorganic and organic pesticides, inorganic (that word again) row netting or kaolinite clay may be a good option according to their trials. Careful though, as kaolinite can kill all, including the protective microbes on leaf and fruit surfaces that we eat. It’s also known to be effective on superbugs that form biofilms and quorum sense to work together and overpower a larger host. Powerful stuff.

Personally I’m not a fan of any form of aerosolised compounds, as without protection they are easily inhaled. One study I read even highlighted how many dangerous microbes in a grey watering systems became aerosolised when the winds picked up, and these weren’t even sprayed on!

Weather matters when you spray, fertigate, or simply irrigate! Why it’s a good reason to always subsurface irrigate where possible.