No-Till Urban Farming
more GROWERS are using no-till to improve soil health, and urban farmers can too
How healthy can dirt be?
No-till farming has an answer.
How healthy can dirt be? There is a huge difference in what we can grow in soil that has the right balance of nutrients. Unfortunately for farmers, obtaining and retaining soil health is a time consuming challenge, particularly in industrialized areas. Soil at urban farms can often be unusable because of the contaminates, making it impossible to grow healthy crops outside of raised beds. Although building up and bringing in organic soil works great for sensitive crops like root vegetables and greens, there is an effective way to bring balance to even polluted city soil. The answer? No-till urban farming.
No-till farming is a method that allows farmers to grow crops without disturbing the natural efficiency of the soil they grow in. In turn, soil health and crop efficiency improve. Unfortunately, it's not as simple as it seems. There are a few reasons for that.
Despite the proven benefits of no-till farming, only 35% of farmers have some land dedicated to no-till, and just 10% of farms are nearly or entirely no-till. There can be a learning curve for farmers used to tilling. There are several steps that need to be taken to ensure your yield doesn't reduce when switching to no-till, such as planting cover crops, rotating crops more frequently, and introducing organic matter such as compost and fertilizers.
Even among organic farmers who already use these practices, no-till is still debated who fear the practice could encourage weed growth or crop infections that will require chemical to eradicate, putting their crops at risk. Now with scientific advancements, however, herbicide tolerant (HT) crops are becoming increasingly common. A study in the Journal of Agrobiotechnology Management & Economics found farms that combine the no till method and plant HT crops have a significant reduction in chemical herbicide use. There is also evidence that practices like crop rotation and crop residue itself can actually reduce weed germination from year to year.
Studies like this have led agencies like the NRCS to advocate for farms to "mimic nature" and go no-till. "Conventional thought suggests this fluffing action allows for better seed placement, but no-till systems, especially when combined with cover crops, are better – and lead to healthier, more drought-resistant soil." says Ray Archuleta, conservation agronomist with NRCS.
Despite the proven benefits, the biggest pushback against no till from big ag. comes down to costs. Using rototillers has been the standard practice on large acreage farms for preparing crop beds. Despite the time or labor it might save, the cost comes from erosion, nutrient loss, lower yields, and often, more work. Even if rototilling was ultimately more efficient, the machinery isn't compatible with the spaces available for farms in populated cities. No till is a low cost and organic solution to improve your soil and produce on any type of farm land, and fundamental for restoring the soil quality on urban farms.
Reduce erosion, Improve soil structure, and retain nutrients
Mechanical tilling is a fast way to turn a lot of soil, and a very fast way to lose it, too. Each turn of the till breaks up more soil aggregates, causing the soil to dry out and erode. Archuleta compares soil aggregates to lungs and the circulatory system. Aggregates provide oxygen for roots, increase pore space for water infiltration and reduce erosion.
No-till farming leaves the soil mostly undisturbed, allowing aggregates to form under crop residue and nearly eliminating soil erosion. Between 1982 and 2003 there was a 43 percent reduction in soil erosion that the USDA’s National Resources Inventory credits to the increase in conservation tillage.
Increase organic matter and microbes
As the undisturbed soil begins a natural flow of oxygen and water, the first signs of an ecosystem will follow. Because the soil is not being frequently agitated, biodiversity in and around the soil has the opportunity to thrive. Commensal organisms like mycorrhizal fungi form mutually beneficial bonds with crop roots. The plants support the fungal growth while the fungus colonization increases the plants water and nutrient intake. Best of all, nature's helpers are allowed to do their work. Earthworms, whose porous tunnels increase soil's water retention, are allowed to flourish through no-till farming.
Since the majority of these helpful organisms are housed in a few shallow inches of the soil, their cycles are disrupted by over tilling the land. As more organic matter is allowed to work on the soil, native regenerative plants can be planted to further improve soil health.
Although there are conflicting studies, there are many examples of no-till farming increasing crop yields over time when done consistently. While it's true that no-till crops will generally see a reduction of 5% on average, no-till fields that are established over the course of 3-5 years will see reduced erosion and improved water retention immediately. With those conditions, higher yields follow. And there are plenty of farmers leading by example.
A grain farm in North Dakota was able to double their yields after adopting no-till farming practices in 1996. "Prior to no-till, their wheat yields averaged 20-30 bushel per acre, but after nearly 20 years of no-till, they harvest 70-90 bushels per acre." the Rohrich family says. Although it wasn't an overnight success, the higher yields have allowed the Rohrich's to plant sunflowers, significantly reducing the amount of pests and weeds in their fields. Now they start and end each season with sunflowers to ensure a healthy harvest of corn and wheat.
Recently the NRCS showed support for no-till practices by highlighting Bartt McCormack, a Tennessee grain farmer who dropped the till technique more than 35 years ago. For him, the impact of no-till with cover crops on the soil ecosystem have been easy to measure when he looks at his bottom line. With 95% of his 6,000 acre farm committed to no-till, McCormack would have a hard time employing the labor needed to manage the land traditionally.
Converting the land to no-till didn't happen overnight, but rather acre by acre after the traditionally tilled farm enrolled in NRCS programs. This slow change of the land and farmer require re-tooling and new management practices, as well as an increased knowledge of cover crops, agronomics, and be more mindful of rotations and herbicides. Perhaps most importantly, McCormack says farmers converting to no-till "Need to have an open mind at the possibilities that no-till with cover crops can bring. It’s not like changing a pair of pants,” he said.
While the transition takes time, McCormack has seen a 60-bushel difference in yield. As he continues to experiment with cover crops, and allows them to work with the soil, he now sees how much plowing up the fields was reducing his yields. Now he is eager to plant multiple species of cover crops and let the land work it's magic.
Retain natural moisture of soil and conserve water
As demonstrated by the results above, it makes sense that no-till farming allows water to filter through crops easier. This method also allows farmers to use crop residue to their advantage. With organic matter to retain the increased water infiltration, soil stays moist closer to the surface for longer with less room to evaporate. This keeps the necessary nutrients in the soil around the crops and prevents contaminates from fertilizers or pesticides in runoff.
More water in the soil means less watering will be necessary for a given crop. It's estimated that the crop residue no-till leaves behind provide an additional two inches of water for crops in the arid late summer months. As agricultural land becomes more prone to drought, like in California, farmers will have to incorporate water retaining techniques to keep their crops viable. With the NRCS finding that no-till farm soils have twice the water penetration rate of conventionally tilled land at 5.6 inches per hour on average. This means that if farmers nationwide began the transition to no-till, we would be on track to halve water usage on farm land.
Reduce labor, fuel use,carbon footprint
The farmer also significantly benefits by the adoption of no-till farming, in particular through a reduction in labor. Conventional tillage practices require sometimes as many as five passes over the land with a plow, however, no-till requires just a single pass.
An study by Purdue University calculates that a no-till farmer will save 225 hours of labor per year on a 500 acre farm (or saving about four 60-hour work weeks a year). Some studies estimate that the no-till method could reduce overall farm labor by as much as 50%. Although, it may not feel like half the work when actually digging, as we've learned while establishing our 24 permanent beds this year!
With less time spent tilling, farmers can focus on improving all practices that contribute to farming's global warming immense footprint. The fuel costs saved by ending farmer's dependency on tractors could reduce fuel usage by as much as 80%. It's not just about machinery, though, as tillage can cause disruptions in the carbon cycle and have consequences for the atmosphere.
Any tillage causes organic matter to decompose, resulting in loss of soil carbon. Agriculture has contributed to the loss of 133bn Tonnes of carbon alone. However, no-till farming when paired with crop covering reduces carbon emissions through greater sequestration of carbon dioxide by the soil. Photosynthesis and other biological processes of the organic matter in the soil allow carbon to stay stored in underground reservoirs.
When land is overworked through traditional tillage, these reservoirs are opened and release an excess of CO2 into the atmosphere. Carbon dioxide isn’t the only greenhouse gas reduced by no-till; nitrous oxide is immobilized in the soil, reducing the need for nitrogen rich manures Over half of the carbon sequestration and most nitrogen rich soils are on farmlands following conservation tillage practices, making it a worthwhile way for farmers to help the environment.
improved relationships with the land
When we decided to be a no till urban farm, we knew that double digging 1000’ of beds wouldn't be easy, but we also knew it would ultimately be rewarding. It's one of those things that happens a bit at a time. All you can do is keep going, not looking at how far you've gone or how much is left. Our bodies ache, but our arms, backs, and faith in this process get stronger. The best part? Seeing the progress made when it's time to add amendments, prep beds and transfer the young plants to thrive in the soil full of their favorite things. For that satisfaction, we will always choose no till.