We are very honored to have Graeme Sait and his Nutri-Tech team’s experience and help with the Orchard health section of our website. In this section, we highlight the secrets of building up your Honeyberry orchard’s bank account – it’s organic matter. After reading this, we believe you will see how important organic matter or humus is to your bottom line and the health of your orchard.
There are no magic bullets in agriculture but if you were aware that a substance in your soil could increase productivity, reduce pest pressure, enhance water use efficiency, reduce fertiliser requirements and spare the planet the chaos of global warming, you might prick up your ears and listen.
This “magic” substance actually exists but it is not some commercial “cure-all”. It is, in fact, an essential component of soil that has been mercilessly mined for twelve decades of extractive agriculture. Organic matter (or humus) is measured in all soil tests but the critical importance of this remarkable substance is rarely recognised. Not only does it offer the most cost-effective and efficient water storage option, but humus is actually the essence of high-production fertility in your orchard.
Your bank needs to be banking on biology
The Australian National Bank discovered this some years ago when they commissioned research to determine the key players in farming profitability. The bank had been using their existing criteria to determine the worthiness of applicants seeking to buy their neighbour’s farms, but the ‘fall over’ rate was proving unacceptable. In a comprehensive study involving 800 properties in the Hilston region of New South Wales, Australia. They set out to determine what makes a new farming venture successful. To the surprise of everyone involved, the one thing that stood out head and shoulders above the next closest contender, was organic matter levels in the soil. In fact, researchers actually put a monetary value on humus to the extent that organic matter gains of just 0.15 % substantially increased the associated land value. The financiers had literally discovered that they could bank on biology. The humus by-product of microbial activity was of more import than all other inputs.
What is humus?
It is the chocolate brown, sweet smelling substance that drives healthy, productive soils.
This material created by the soil’s natural biology and serves as the contemporary ‘Hotel’ for this vital workforce. Humus is the soil glue without dust storms would strip the thin veil of our precious topsoil. It provides the single most efficient storage of water, minerals and carbon in your Honeyberry orchard.
Top ten benefits of building humus in your soil
1. pH buffering – the higher your humus levels, the less the importance of maintaining a perfect soil pH of 6.4
2. Mineral Retention – humus has negatively and positively charged sites so it can store and stabilise all minerals. If you can build your humus levels, it will dramatically improve fertiliser efficiency.
3. Soil Detoxification – humus acts like a carbon filter to neutralise chemical residues and heavy metals in the soil.
4. Root Zone Chelation – humus contains both humic and fulvic acids which are nature’s most powerful chelating agents.
5. Crumb Structure Promotion – this unusual soil structure is not something you can buy in a bag. Bacteria release a sticky exudate that creates small aggregates in the soil. Then, fungi use their hyphae to wrap these particles into larger aggregates to form a highly desirable crumb structure that allows easy access to oxygen and water. Plant roots, earthworms and beneficial nematodes can move smoothly through this soil and everything works as it should naturally!
6. Plant Growth Promotion – the organisms that live in humus produce growth hormones, B group vitamins (now known to promote plant growth) and other growth promoters.
7. Water Retention – humus holds it’s own weight in water and is a far more efficient means of delivering water directly to the roots.
8. Soil Structure Improvement – poor drainage, hard pans, erosion and dust storms are far more likely in low humus soils or dirt. The life that creates a crumbly, friable soil is missing and the glue that holds the soil together is also lacking.
9. Less Chemical Intervention – high humus soils usually feature the full suite of protective organisms which reduces the need for toxic chemicals.
10. Solubilisation of Mineral Fertilisers – the better your humus levels, the faster your response to mineral fertilisers like lime, dolomite, rock phosphate and rock dust. The speed and release of these materials are governed by its biology.
The ultimate in water storage and delivery
Just 3% of the planet’s water is fresh and of that meager total, 90% is used to irrigate crops. Climate change is currently impacting this precious resource by delivering unprecedented droughts and, in some cases, unanticipated rainfall. There is a problem here in that rain is often falling where it has rarely fallen before and there is little infrastructure to capture and store the bounty.
Dams are the most common method of storing water but they are notoriously inefficient. A large carbon footprint is often involved in pumping the water to its destination and then more evaporation and energy is involved in pumping water through centre pivots or flood irrigation ditches.
Organic matter is a vastly superior water storage and delivery medium. It can hold its own weight in water and the plant can access this moisture, right beside the roots, at will. An increase of 1% organic matter means your soil can hold 170,000 L/ha of water that it could not previously hold.
If we bring this down to a home garden comparison, each square meter of your humus-enriched garden can now store and deliver 17 litres more water per square meter. There is an excellent win/win situation here in that carbon is now stored in your soil rather than contributing to the heat-trapping blanket of greenhouse gases that is over warming the planet and changing the climate for better or for worse.
Humus houses trillions of soil bacteria (at least 2.5 tonnes of these organisms per hectare) that release a sticky biofilm in which they congregate to provide protection from the ravages of their fellow soil foodweb inhabitants. This biofilm offers an additional moisture-retaining medium associated with humus. In fact, this slime exudate works very similarly to water crystals in the soil and can retain moisture accordingly.
Many costly fertilisers are wasted
There are two storage systems in the soil and they involve the clay and humus components. Positively charged minerals, called cations, store on the negatively charged clay particles (colloids), while negatively charged anions are attracted to the positively charged humus colloids. If you have depleted the organic matter levels in your soil, you have reduced your capacity to retain and utilise some key minerals and the efficiency of your expensive fertilisers is seriously reduced. Phosphate, for example, is much more likely to become locked-up and unavailable in the absence of humus. Up to two-thirds of applied phosphate can rapidly become part of a massive frozen reserve of this mineral when organic matter is missing.
Sulfur is another important anion that is seriously impacted in low humus soils. Sulfur, which is so critical for nitrogen utilisation and protein formation, is amongst the most leachable of minerals when humus, the ‘sulfur storehouse’ is missing. Boron, the most leachable of trace elements, is also an anion can that can only be stored on the humus colloid. However, it is the most widely used nutrient in agricultural production that is most seriously affected by humus depletion and the loss of this mineral affects more than your bank account.
Nitrate nitrogen is another anion that can only store on the humus colloid and, in the absence of organic matter, nitrates flood our waterways and increase our likelihood of succumbing to a deadly disease. There are multiple published papers linking nitrates in the food chain to the current cancer plague.
The bottom line here is that the humus levels in your soil will directly influence the amount you waste on fertilisers susceptible to lock-up and leaching. However, there is more than leaching and lockups involved here. The delivery of minerals to your crop involves a biological link and the organisms responsible for enhanced nutrient density and resilience survive and thrive in organic matter.
Nurturing the delivery boys
Organic matter levels are directly related to biological activity and reflect the health of your soil life. Microbes serve as the bridge between the soil and the plant and when we bomb that bridge with farm chemicals and poor soil management decisions, there is a price to pay. That price involves compromised mineral delivery and an associated reduction in plant resilience (necessitating more chemical intervention).
Nitrogen fixers are the link to the “free gift” of atmospheric nitrogen, phosphate solubilising organisms allow access to frozen reserves of P and potassium mining organisms deliver the third mineral in the NPK trio. Manganese and iron reducing organisms deliver these two trace minerals to the plant and we have yet to discover which microbes are responsible for solubilizing silica from clays and sand. The creatures involved here have obviously been impacted by modern agriculture, however, as it is extremely rare to find a soil with its full complement (100 ppm) of mono-silicic acid (plant available silica).
Organic sulfur is converted to the plant available, sulfate form by microbes and there is a microbe link to the uptake of all minerals. The higher your organic matter levels, the greater the delivery of minerals to your crop and the lower your need for expensive chemical intervention. Hopefully, it is now becoming more obvious why The National Australia Bank found such a profound link between profitability and organic matter.
Organic matter and pest pressure
Pest pressure is based upon a combination of mineral and microbial imbalances. From a mineral perspective, this might, for example, involve an excess of nitrate nitrogen, which enters the plant with water and dilutes nutrient density as a result. The nitrate-packed plant then becomes a calling card for both insects and disease.
Alternatively, a healthy, active soil food web deactivates pathogens through a variety of mechanisms ranging from competitive exclusion, predatory control and biochemical stimulation of plant immunity. In both cases, humus has a major role to play. Humus buffers imbalances. In fact, the higher the humus levels, the less important the mineral imbalance. Similarly, the more humus, the more beneficial microbes and the lower the opportunity for opportunistic disease organisms. Insect resistance is a function of plant immunity, fueled by micro-nutrients that are more available in a high-humus soil, along with a strengthened cell wall (determined by calcium and silica).
Humus levels also have a direct effect on the level of mycorrhizal fungi in your soil and it is these creatures that play a key role in the delivery of calcium to the plant. These fungi increase root surface area by up to 1000% and this massive maze of root extensions releases biological acids that break the bond between locked up calcium and phosphorus in the soil.