Tilling: time old trick, or outdated agricultural method? The practice of tilling has existed for generations, and it is beneficial in many instances. However, the No-Till movement of recent decades has exposed the failures of tilling practices and offered practical and sustainable alternatives to tilling. Though tilling remains one of many efficient organic farming techniques, nature provides natural alternatives that render it unnecessary in many instances.
What is Tilling?
Among organic farming techniques, tilling is not a new contender. Tilling is a centuries-old practice that emerged alongside the development of settled agriculture. Traditionally, farmers and their slaves tilled by hand using wooden or iron tools. Farmers also used their animals for pulling large plows to till larger tracts of land.
The emergence of the wooden plow, followed by the steel plow, simplified and rendered more efficient the tilling process. The introduction of the tractor in the 20thcentury is part of what made possible the advent of large-scale agriculture the United States.
Though tilling large tracts of land efficiently requires a tractor, small scale farming operations still typically till by hand. The objective of tilling is to penetrate and overturn the soil to create better growing conditions for plants. Using a rake, pick axe, hoe, or shovel, farmers penetrate and churn garden bends to create porous, aerated, and weed-free soil.
There are two types of tilling: primary and secondary. Primary tilling requires penetrating and turning the soil at a depth of 8-10 inches, and is more necessary in climates with dense, clay-rich soil. Secondary tilling is relatively shallow, penetrating only to a level of 4-8 inches.
The Benefits of Tilling
The primary objective of tilling is to aerate and render more porous the soil, either in preparation for planting or to improve growing conditions for a current crop. Aeration of the soil permits water, air, and roots to penetrate deep into, and thus improve the quality of, the soil. Aeration also stimulates the activity of beneficial microbes in the soil and maintains even moisture levels throughout its layers.
Tilling incorporates nutrients and organic matter deep into the soil. Organic matter can include compost, remnants of an old crop, weeds, or wood chips. It is also an excellent way to ensure that soil amendments, like fertilizer and compost, reach the deepest levels of the soil where the roots of plants can access them effectively. Thus, though tilling is used in large-scale growing operations, it is also one of many effective organic farming techniques.
Farmers often till to break up and bury weeds, preventing photosynthesis and thus killing them off. It also disrupts the germination of weed seeds. In so doing, farmers are able to reduce competition for nutrients in the soil, which produces healthier crops. Turning the soil also allows farmers to remove foreign matter, like large rocks and sticks, which can impede plant growth.
The Drawbacks of Tilling
Tilling is actually a process that, to some extent, occurs naturally thanks to the activity of earthworms. Earthworms will turn over the top six inches of soil in a bed in 20 years. These earthworms also excrete organic material that nourishes and promotes the healthy development of plant life. Tilling can interrupt the activity of, and even kill off, these friendly and beneficial earthworms, decreasing the quality of soil over time. Thus, another one of the best organic farming techniques is to just let nature do the work!
Though aeration is beneficial, excessive aeration due to deep and fervent tilling can kill off humus. Humus, which is a combination of decomposed organic material and beneficial microorganisms, nourishes and sustains healthy plant life. The destruction of humus can therefore damage plant life and degrade soil quality.
Further, humus itself aerates the soil and improves water retention. Thus, when tilling destroys humus, it by extension downgrades the soil in ways that make future tilling even more necessary, fueling a vicious cycle of soil degradation.
Over time, regular tilling can actually exacerbate the problems that made tilling a necessity in the first place. Regular tilling leads to gradual soil compaction. It can also lead to drying, impairing the ability of the soil to retain moisture and thus sustain plant life. Tilling also increases erosion, which strips the soil of essential nutrients and fertilizers.
Though tilling destroys existing weeds, it can also stir up weed seeds from the deepest layers of the soil. Brought to the surface, these seeds thrive, only exacerbating an existing weed problem.
To Till or Not To Till?
Do the benefits of tilling outweigh the drawbacks, or vice versa? Advocates of the No-Till movement, which has emerged over the course of the last 50 years, argue the latter, and do not include tilling in their organic farming techniques.
Indeed, no-till farming reduces both soil erosion and the need for environmentally damaging, fuel guzzling machinery. However, many no-till methods of farming employ herbicides or require limiting crops to varieties that can tolerate compacted soil. In so doing, no-till farming can harm the environment and impede biodiversity—quite contrary to other organic farming techniques.
Tilling is necessary and beneficial in certain environments. Severely compacted, dry, weed-ridden, or clay-dense soil may require repeated tilling to be useful at all.
Shallow tilling, which occurs in the top 4-8 inches, or cultivation, which entails overturning the top 1 or 2 inches of soil, can effectively disperse nutrients, incorporate organic material, and promote aeration without killing off humus and earthworms or drying the soil. Tilling at a shallow level actually makes nutrients more available to earthworms, which then disperse nutrients in the soil’s deeper levels.
Tilling may also be beneficial when preparing a plant bed, again provided that it doesn’t disturb the deepest levels of the soil. It is also necessary for incorporating large amounts of organic matter into the soil. (However, leaving organic material on the surface of soil allows nutrients to gradually penetrate and nourish the soil).
Tilling in Hawaii
Hawaii’s rich volcanic soils benefit from consistent rainfall and cloud cover. They are therefore naturally nutrient-rich, moist, and porous. To till at Gingerhill would thus be far more likely to strip the soil of moisture, nutrients, and beneficial life forms than it would be to enhance soil quality.
Earthworms naturally perform the work of aeration and overturning at Gingerhill. We occasionally perform shallow tilling or cultivation to mix amendments and organic material into the soil, but we prefer to allow Mother Nature to function beautifully and intuitively in her characteristic manner.
There are several steps we take to prevent the need for tilling. By creating designated walkways for foot and wheelbarrow travel, we reduce soil compaction. Lighter, occasional tilling allows us to prevent the need for deep tilling in the future. Regularly cultivating plants with deeply penetrating roots also permits natural aeration.