We lose 23 billion tons of fertile soil every year - at this rate, we won't have any left in 150 years, unless farmers convert to practices that restore and build soil organic matter and fertility.
One of the biggest contributors to soil degradation is the common practice of tilling. Fortunately, soil-preserving practices like no-till farming practices are growing in popularity in recent years.
No till farming is the practice of cultivating crops on the land with minimal disturbance to the soil. It is one of the core pillars of regenerative agriculture - a practice of agriculture dedicated to rebuilding soil health and fertility.
In conventional agriculture, it is common practice to overturn, or plow, the topsoil before planting seeds. Plowing serves several purposes, including burying crop residue, manure, and weeds, while aerating and warming the soil. This method of soil preparation and management has been practiced for thousands of years - so much so that it is now seen as a standard and sometimes necessary part of farming by many across the globe.
However, plowing soil over a period of years can eventually lead to degradation and a loss of soil fertility. What this means is that while plowing might serve farmers for a period of time, yields on that land will decrease over time, until the soil is not viable from growing anymore.
In the late 1970s, in parallel with greater general environmental awareness, a new movement emerged in agriculture that looked at soil management through a different lens. No longer was soil seen as mere dirt - it was treated as a living thing in its own right, rich with microbial life and symbiotic root/fungi relationships, among other things.
Soil started being treated as a valuable resource - something that needed maintaining and care to remain healthy and productive - and so no-till practices took off. In 1988, only 5% of farmers practiced no-till methods - by 2008, that figure had jumped to 25% and has been growing since.
In conventional tillage, a plow is used to overturn the topsoil to a depth of 8 to 12 inches. Following this, the plot of land is disked at least twice more before the seedbeds are considered ready for planting. This is usually done to bury crop residues from previous growing cycles, incorporate manure into the soil, or bury outstanding weeds that might have arisen and then remained post-harvest.
However, in no till farming, the soil is not plowed or disked at all. It is left undisturbed, and seeds are instead pushed straight into the ground through all the crop and weed residues. This is usually done with a device known as a coulter, which cuts a slot a few inches wide, followed by equipment that places the seeds and closes the trench.
This allows the soil to remain largely intact. It also means the soil doesn't tend to come loose during episodes of rainfall or high wind, minimising soil erosion compared with conventional soil management techniques. Soil that is not tilled tends to hold more water, is more porous and therefore better aerated (giving plant roots better access to oxygen), and hosts millions of microbes that form beneficial ecosystems that support plants' growth.
One of the most obvious and immediate benefits of no till farming are the financial savings. Skipping the tilling and disking process not only saves money on equipment, but also on fuel and labor costs associated with running that equipment. Over time, no-till can save significant money, simply by cutting the added step of plowing each year.
In no till farming, crop residues remain on the surface of the soil, rather than getting buried underneath. These crop residues are then able to absorb excess water from irrigation or rainfall. Not only does that limit runoff into nearby waterways, which can be devastating for local aquatic ecosystems, but this heightened water retention can be a real asset to farmers and their crops in times of drought.
The increased water retention capacity of no-till soil means that soil is less likely to runoff in times of high precipitation. Runoff of agricultural soil can wreak havoc on local waterways, as the high concentration of chemicals and minerals can be potentially toxic to much wildlife. High levels of nitrogen specifically are directly responsible for algal blooms, which lead to dead zones in local aquatic ecosystems.
Higher water retention in the soil means there is a reduced reliance on irrigation, which can definitely be a bonus in areas like California where water use is closely monitored due to frequent shortages.
Farmers who practice no-till farming can expect higher crop yields, particularly if they are in dry areas, or areas of low moisture. For example, one farmer in Kansas reported a 50% increase in harvested crops since he stopped plowing his soil.
Skipping the tilling allows a biodiverse microbial ecosystem to flourish in the soil. In conventional agriculture where plows are running through the soil on a regular basis, these ecosystems don't have the chance to develop. Therefore, farmers never unlock the potential that comes with root-mycelium interactions, for example.
No-till practices ensure that the soil is viable and fertile for decades to come. It is a core tenant of regenerative agriculture to build soil that is self-sustaining, and eliminating tillage is a core component of that strategy. Building up soil organic matter by sequestering carbon ensures that the same plot of land can continue to reliably produce healthy yields for 30 or 40 years into the future and ad infinitum, if well managed.
Specialized seeding equipment, including a “no-till drill,” can cost more than $100,000. Even if this cost is eventually absorbed into day-to-day operational savings, it’s a significant upfront expense that many farmers simply do not have the capital to invest in.
This is the downside of increased soil water capacity. Elevated moisture levels in the soil can promote fungal diseases that previously weren't an issue.
One of the main reasons farmers plow the soil is for weed management. Since no till farming doesn't allow for this, many farmers turn to herbicides to deal with weeds. In turn, this leads them to using genetically modified crops that are herbicide-resistant. However, it is worth noting many farmers don't turn to herbicides as favor organic no-till farming practices instead. Such weed management techniques include using cover crops, crop rotation, and livestock instead.
It can take years or even decades to start seeing the payoff of switching to no till agriculture. These gains don't happen overnight.
There is a risk that over time, farmers practicing no till farming might find their soil starts to compact. This is no good, as compacted topsoil makes it more difficult for plant roots to penetrate downward in search of water and nutrients, and also makes oxygenation more challenging as the soil is less porous.
Organic no-till farming has the potential to bring up problems that previously weren't problems, such as creative weed management techniques, fungal remedies, and prevention of soil compacting. There is always something new to learn, and farmers can certainly suffer yield losses or overall lower yields if they are unsure of what they're doing. Deeper knowledge of agricultural science is needed, more specifically, a robust understanding of the biological and ecological principles governing what is happening in the field. A good organic no till farmer is also a scientist.
In conclusion, no till farming is an alternative soil management technique that falls under the tenant of regenerative agriculture. It brings with it a plethora of benefits such as increased water retention capacity, increased soil organic matter, higher yields, better soil health, and longer-term fertility when compared with conventional plowing practices.
However, there are some drawbacks to consider, namely alternative weed and disease management techniques, as well as specialist knowledge and machinery.