So, what's the best way to wean our grassland off fertilizer and cut out the N altogether?The Myth of Fertilizer
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We’re told fertilizers are simple; when a crop grows, it draws nutrients from the soil, these nutrients are then removed when you harvest a crop or sell the milk from your goat or take steers to the sales. At least that’s what has been taught to producers and agronomists since Liebig first did his NPK plant test in the 19th century.
Certainly, there is ample evidence for this in the field. Without fertilizer many hay producers see yields drop, and bare soil increase every year; dairy farmers produce less milk; and ranchers see reduced carrying capacities. It all makes logical sense. Doesn’t it?Clean calculations bring us a sense of security, something we can control and give people peace of mind. And these calculations stand true in conventional agriculture, 40 kg of P is removed by crops, so 40 kg must be replaced. An agronomist can predict yield based on an addition of 200kg of N – that’s as long as being outside doesn’t intervene with drought, hail, insects or disease. Many credit NPK fertilizers for the great leaps forward from the Green Revolution last century. However, that’s not the whole story, yield responses were due to several factors including irrigation, new cultivars, machinery and access to credit. Over 70% of new high yielding varieties of rice and wheat were bred enabling global yields to double.The benefits to producers have been a mixed bag, as these growing methods demand more investment into infrastructure, machinery and land. Over time input prices rose, and the return on products which now flooded markets, dropped. Many food producers are no more profitable per acre than they were 100 years ago. As a result, many producers had to “get big or go home”, and their kids left to the cities. In the US over 73% of smaller rural communities are shrinking as more people leave than arrive, a pattern mirrored across the developed world. Debt and stress are an everyday occurrence for many working on the land.
I recently presented to 30 ‘conventional’ cropping operators. One topic raised was, “who wants to see their kids take over the farm?” The resounding response was…a long silence. Then into the void a farmer spoke up, “I’m sick of this stress, of the debt, and the increasing inputs. Why would I want to hand this over to my kids?” Times like these make me reflect on the profound positive difference regenerative land systems can make in people’s lives. We’re not just talking soil, we’re talking about a revolution that impacts on every aspect of rural life. And its time is now.
If you put all of these pieces together, the Green Revolution has not delivered on its promises to producers. It is however delivering for the banks, supply and chemical companies; they come out laughing whichever way the dice land. The FAO (Food and Agriculture Organisation) is certain that modern farming has increased the risks for food producers, with market volatility and increasing climactic unpredictability. And farming is a risky business. Nature is fickle mistress; as all who work on the land know. How to mitigate risk is the greatest challenge for producers today.
I once had the privilege to hear a powerful presentation by soil scientist Dr Daniel Hillel. In 2012 he received the World Food Prize for developing a method termed “micro-irrigation agriculture” which increases water efficiencies in arid climates. He shared his story of camping with Bedouin in the Arab desert, he overheard an elder asking his students what 1+1 equals. Their answers were more varied than the stock standard “2” that western children are raised to answer. One child replied thoughtfully; “well, if it’s one nanny goat and one billy, then 1 plus 1 could be 3 or 4”.
When working with biological systems, 1+1 rarely equals 2. We often see surprising results as soil systems function again, as they flocculate (open-up), roots penetrate deeper, nutrient cycles turn and the carbon buffer builds.
There are multiple factors involved in building topsoil, one driver happens from the top down, with biological activity, and the other happens bottom-up through chemical and microbial mineralization. These soil building processes can dramatically speed up, making previously unavailable ‘locked-up’, raw mineral materials available to crops. One NZ high country station we’ve worked with saw the equivalent lifts of 1500 kg/Ha (1300 lb/Ac) in calcium in just one year across treated areas on the farm. That’s with no additions of calcium. Dr David Johnson (NMSU), Col Seis, the Haggerty’s, Gabe Brown (and many others) are measuring plant-available nutrient increases from 200 to over 1000% higher, just through stimulating this microbial mineralization process. It is how soils are meant to function; all without the need for external inputs. Consider, did a fertilizer truck follow the bison around?
I’m not saying the natural cycles are closed however, they not. We live in an interconnected world. The global P cycle is driven by organic inputs from animals like birds, bears, buffalo and wind. In 2015 NASA discovered that the Sahara was delivering phosphate dust to the Amazon, at about the same rate it was losing from erosion; around 22,000 T of the stuff every year. In many regions collapses in biodiversity are leading to catastrophic declines in ecosystem health. New Zealand forests for instance, once dependent upon regular seabird guano, are now hungry for P and diseases are running rampant. Bears in North America were significant contributors of nutrients, including N and P from their rich salmon diets, apparently yes, they do poo in the woods.
No man, or woman, is an island. Encouraging biodiversity, brings increased nutrients from outside the farm gate. A recent study in Nature concluded that seabirds are full of crap (at least that’s how I interpreted the papers title), with excrement making a global contribution to over 1.3 billion pounds of N and 218 million pounds of P. With birds and insects in our agricultural lands in rapid decline, their losses are having a broader impact on nutrient cycling. Insects are the “nitrogen thieves” in any ecosystem and when they poop and die they may be contributing as much as 40kg / N/ Ha! In an organic form readily available when plants need it. Unfortunately scientists are estimating we’re in the middle of a catastrophic insect extinction event, how much potential N have you lost or gained by encouraging insect diversity?
Our modern practices which create monocultural deserts are putting the costs back onto farmers, society and the wider environment. It’s not a lack of fertilizer that drives profit and resilience, it’s diversity. Diversity which is enhanced by diverse microbial communities, plant rooting systems, insects, birds, livestock and diverse crops. How can you increase the diversity above and below-ground? It’s well overtime for use to step away from 19th century extractive thinking into the 21st century of regeneration.
Written by: Nicole Masters 14th February 2019
Image by:Kim Deans, Linnburn Station
I suspect going full "cold turkey" will see a large drop in production in year 1, maybe 2 & 3 as well, until the soil biology picks up. Easier for us as we're lightly stocked and have never been big N users.
Definitely don't go "cold turkey"
do not translateI don’t know how good you are at Welsh but it’s absolute gibberish to me. I didn’t realize I had so many Welsh named folks from here until I started having trouble telling them apart because they all just look like random letters
Great minds.. the grazing parameters also make a huge difference.
Yeh, was quite taken with portable water, just didn't realise about the dry break things.The only thing I would watch with the micros is that the float valve tends to weap after a few months. Easy and cheap enough to fix on one above ground but could be quite irritating.
Also in my experience it pays to double, double check the kiwitech water fittings as doing them up tight can be a bit hit and miss. Once they are tight though, they do seem reasonably reliable.
I had one with the heifers when you came here, and a big one with the cows. They are really excellent.
38-40.
my ideas suck so I have sowed the seed and am currently standing back waiting for it to be "our idea" - and then we will get to it
Agreed, they tend to have really uneven impact on those high-traffic areas, in my experience.
so the bulls have an extra cell to run back onto just in case.
