Opinions are divided
The days of ploughs being pulled by horses and oxen are far behind us. Nowadays, large tractors with plenty of horsepower pull ploughs through the fields with ease. However, it seems that we have reached a turning point. Is it still necessary to remove all of the weeds and dig several centimetres into the ground?
Ploughs have been used for thousands of years. Drawings have been found in Egypt dating back to 1200 BCE that show an ox pulling a kind of plough, led by a farmer. In the early days, farmers mostly used a type of plough called an "ard", which pulled open the soil. A major advance in farming came in the form of the turn plough. Attaching a mouldboard to the plough made it possible not only to pull open the soil but also to turn it over. This meant that the weeds ended up underneath and the nutrient-rich soil came to the top. As time went on, ploughs became increasingly advanced. Metal took the place of wood and various components were added. In the 18th century, developments came thick and fast, and during this period the plough became a commercially viable product to manufacture.
Since then, the plough has become an indispensable tool on many farms, and large manufacturers such as Lemken, Kongskilde and Pöttinger have been successfully producing tillage machinery for years.
Cultivating, not tilling
The preference for reduced tillage is a relatively new one, and varies considerably between countries. In countries with distinct variations in altitude, such as Germany, this form of cultivation has enjoyed considerable popularity for quite some time. Meanwhile, in countries with relatively flat terrain and intensive agriculture, such as the Netherlands, the "old-fashioned" method of ploughing is still by far the most popular. However, reduced tillage is becoming increasingly popular in flatter terrain countries too, particularly with organic farmers.
What is reduced tillage?
With this form of cultivation, the farmer only loosens the soil. This is in contrast to ploughing, which involves cutting the soil to a depth of up to 30 cm and turning it over, which in turn means that the stratification of the soil is damaged. Reduced tillage aims to ensure that the soil maintains a better structure and, as a result, better biodiversity. More water is able to penetrate the soil and important nutrients are better retained. An additional advantage of this approach is that it prevents problems such as erosion.
It is important to point out, however, that converting to reduced tillage involves much more than simply no longer ploughing the soil. It can take years before an optimum result is achieved and it is very important to know what happened to the soil in the past.
Food and Agriculture Organization
Reduced tillage is widely promoted by the Food and Agriculture Organization (FAO) of the United Nations. Incorporated under the umbrella of "conservation agriculture", the UN considers it to be a method of producing crops that requires fewer resources and provides sufficient profits on a sustainable basis, while also preserving the environment. The UN has established three principles for how reduced tillage should be implemented:
- Minimum mechanical soil disturbance (ploughing). This aims to help retain minerals, prevent erosion and maintain water levels in the soil.
- Permanent soil organic cover. This allows the soil to achieve adequate biodiversity. The mulch is broken down, which results in organic matter that can then act as a fertiliser.
- Species diversification. At least three different crop types should be alternated on the land. As a result, crop and soil infections do not have a chance to take hold. Diversification also helps support a better soil structure.
Research has generally shown positive results for reduced tillage. Studies suggest that it allows farmers to save money, produce crops in a less time-consuming manner and protect the environment. So why has not everyone converted to this method of cultivation?
To answer this question, we must first look at the various methods available. There is no single system for reduced tillage — there are various options, and it is still a case of trial and error. Despite its relative success, this new technique is still in its early stages of development. What is more, the choice of crop is very important. What works for grain could be a different story for potatoes, and we haven't even touched upon the type of soil and what kind of cultivation it has already undergone. Another issue is that crop growers have to be able to afford the transition. It is clear that switching to reduced tillage requires some investment in the first few years. It can take several years before the soil is in an optimum condition and the crop yield is at the desired level, and farmers must take this smaller harvest into account. At the same time, the switchover also requires investment in terms of machinery.
Strip-till
Strip-till is popular in the United States. It is a technique that only disturbs the portion of the soil that is to contain the seed row. This leaves the remaining soil effectively "untouched". This principle is already in use in Europe, in sugar beet cultivation. On paper, strip-till is considered the best way to implement reduced tillage. The entire field has a groundcover crop, such as mustard, and only the seed bed is processed. However, strip-till requires the use of special machinery and not all types of soil are suited to it.
Benefits
(According to the UN and studies)
- Increases organic matter in the soil
- Preserves water in the soil thanks to the layer of organic matter (less erosion)
- Improves the soil structure and root zone (more worms)
- Preserves the levels of nutrients and crop protection products
- Provides greater capacity and accessibility
- Allows higher levels of C and CO2 in the soil (organic matter)
- Improves disease prevention
- Saves on fuel
Problems
(According to the UN)
- The process requires a certain amount of time. The initial results may not be as good as expected and it can take years for the soil to reach an optimum condition
- There is a chance that the farmer will need to invest in new machinery
- The history of the soil is important. Not all types of soil are suited to reduced-tillage farming
The verdict?
There is no unequivocal answer to the question of which type of cultivation is the easiest, best, or most ideal. A lot depends on the circumstances. The only thing that can be said with certainty is that reduced tillage has a positive effect on the environment and in preventing erosion. Results also depend considerably on the region. Reduced tillage seems to be a preferred option on hilly terrain as it helps to prevent erosion, but another factor to consider is whether the crop or soil is suited to this type of cultivation.
* This article previously appeared in Kramp Focus Edition 4 2016
