When Gabe started down the path of cover cropping his organic matter levels were 1.7-1.9% so he could hold approximately 35-40,000 gallons of water per acre. Now the organic matter levels are from 6.1-6.9%. and the soil can hold nearly140,000 gallons of water. That’s how you build your own resiliency.
If you’re in a drier part of your country think of how important that is. You need to capture every raindrop where it falls and then via organic matter store it. You have to increase your organic matter in your soil if you want to advance soil health.
Says Gabe, farming is all about a healthy ecosystem, because if you can improve the diversity, the health of your soils, diversity of the biology, the diversity of the plants above ground, then you’re going to provide the nutrient needs for your livestock. Gabe’s livestock receive zero vaccinations, zero pour-ons, zero de-wormers, anthelmintics, anything, and they’re extremely healthy. Healthy soil makes healthy plants, healthy animals, healthy people. That’s what it’s about.
TALK THE WALK FOLLOW UP
Done watching the video?
Listen to the Follow up “Talk the Walk” Q&A Call Session
with Hugo Disler and Gabe Brown
“Combining Perennial Native Grasslands, Multispecies Cover Cropping & Planned Grazing” Part 2
Join Us!
Details for you to join:
Title: Farming Secrets Round Table with Graeme Hand: Planning For Profit
Time: Tuesday, March 28th at 1:15 PM Australia Eastern Daylight Saving
Listening method: Online Web Simulcast
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Weaning off N & P – are your soils addicted?
Christine Jones, PhD
www.amazingcarbon.com
Cost-effective fertiliser management is the key to profitable and productive farming.
The Chinese government recently announced a policy to reduce fertiliser use by 40% by 2020 – only 3 years from now – due to links between inorganic fertilisers and severe soil acidification. In New Zealand, excessive nitrogen use has polluted many lowland rivers to the point where they are no longer wadeable, let alone swimmable or drinkable. In an attempt to restore water quality, regulations are being introduced to formally limit the amount of nitrogen fertiliser NZ farmers can apply.
It is unlikely that similar restrictions will be introduced in Australia. However, it is proving increasingly difficult for Australian producers to maintain crop and pasture yields under current farming systems. High input costs are driving down profits while the application of nitrogen (N) and phosphorus (P) compromise soil, plant, animal and human health.
Nitrogen
Nitrogen is a component of protein and DNA and as such, is essential to all living things. But not all nitrogen is the same. It is important to make a distinction between organic forms, such as amino acids – and inorganic forms, such as nitrate and ammonia.
Prior to the Industrial Revolution, around 97% of the nitrogen supporting life on earth was fixed biologically, the other 3% being fixed catalytically by lightning. In more recent times, intensification of farming, coupled with a lack of understanding of soil microbial communities, has resulted in increased application of inorganic nitrogen in agriculture.
Australian farmers expend over $3 billion on nitrogen fertilisers every year. Between 10% and 40% of the applied N is taken up by plants. The other 60-90% is leached into water, volatilised into the air or immobilised in soil.
In addition to wastage, the application of high rates of inorganic nitrogen has many unintended negative consequences both on and off the farm. These include the decomposition of the small aggregates that give soil its ‘tilth’. Reduced aggregation results in loss of porosity, lower soil water-holding capacity, compaction, low rates of infiltration in dry times and the propensity for water-logging in wet times. Poor structure also impedes root extension reducing mineral and trace element acquisition by plants.
Fortunately, the news is not all bad. The atmosphere is around 78% nitrogen, which equates to roughly 78,000 tonnes of nitrogen gas sitting above every hectare of land. Thanks to some ‘enzymatic magic’ atmospheric nitrogen can be rapidly fixed – then transformed to stable forms of organic N – by a wide variety of nitrogen-fixing bacteria and archaea – for free.
Chlorophyll is part of a protein complex that contains nitrogen, hence wherever you see green plants (not just legumes), biological nitrogen fixation is taking place.
The reason most nitrogen-fixing microbes have gone unrecognised is that they are not able to be cultured in the laboratory. However, recent bio-molecular methods for determining the presence of the nif genes that code for nitrogenase reductase, have revealed a dizzying array of free-living and associative nitrogen-fixing bacteria and archaea across a wide range of environments.
Ideally, land management – and any amendments used in agriculture – should increase the flow of carbon that supports the microbes involved in the sequestration of organic carbon, organic nitrogen and the formation of soil aggregates.
Phosphorus
The application of large quantities of water-soluble P, such as found in MAP, DAP and superphosphate inhibits the production of a plant hormone called strigolactone. Strigolactone increases root growth, root hair development and colonisation by mycorrhizal fungi, enabling plants to better access soil P. The long-term consequences of the inhibition of strigolactone are destabilisation of soil aggregates, increased soil compaction and mineral-deficient (eg low selenium) plants and animals.
In addition to having adverse effects on soil structure and the nutrient density of food, the application of inorganic water-soluble phosphorus is highly inefficient. At least 80% of applied P rapidly adsorbs to aluminium and iron oxides and/or forms calcium, aluminium or iron phosphates. In the absence of microbial activity, these forms of P are not plant available.
It is widely recognised that only 10-15% of fertiliser P is taken up by crops and pastures in the year of application. If fertiliser P has been applied for the previous 10 years, there will be sufficient for the next 100 years, irrespective of how much was in the soil to begin. Rather than apply more P, it is far better to activate soil microbes in order to access the P already there.
Unfortunately, many biological functions, including natural nitrogen fixation and the solubilisation of phosphorus, are compromised by commonly used agricultural practices – including the application of high rates of inorganic N and/or P – and the use of fungicides and pesticides. Inevitably, the loss of soil function results in more chemicals being used to overcome the loss of natural resilience associated with healthy soils.
There is increasing recognition of the fundamental importance of soil microbial communities to plant productivity. Highest profit in any industry, not just in agriculture, occurs at the point of optimum production rather than maximum production.
The soil, plant and animal health benefits associated with improved nitrogen and phosphorus management are being observed by an increasing number of innovative farmers moving towards a biological farming systems approach.
By understanding – and enhancing – the biological processes by which levels of organic nitrogen and organic phosphorus can be increased in soils, farmers can significantly reduce the need for synthetic fertilisers in food production systems, restoring levels of stable soil carbon, reducing the incidence of pests and diseases and improving farm profits.
