Surprised at the lack of published research into the benefits of the system he was gambling the farm's future on, Tim set up a simple experiment with the help of Harper Adams and Oxford universities. A field where strips of land are ploughed and the rest of the field is not. In went a standard crop of wheat and Tim settled back to see what the difference between the ploughed and unploughed soil would be.
The focus of this experiment is the long-term health of the soil. Oxford University is carrying out sophisticated DNA analysis of the many organisms living in the ground. But to the surprise of everyone, the difference between the two approaches showed itself much earlier in the actual crop itself. As Tim showed me, the no-till wheat is stronger and healthier and it's growing in soil with far fewer weeds. In comparison, the wheat in the traditionally ploughed ground is struggling and there are also a lot more weeds.
Such a pronounced difference and a clear benefit to no-till is reassuring for Tim and other farmers who want to make the switch. Running water is the leading cause of soil erosion, because water is abundant and has a lot of power.
Wind is also a leading cause of soil erosion because wind can pick up soil and blow it far away. Activities that remove vegetation, disturb the ground, or allow the ground to dry are activities that increase erosion. What are some human activities that increase the likelihood that soil will be eroded? Agriculture is probably the most significant activity that accelerates soil erosion because of the amount of land that is farmed and how much farming practices disturb the ground Figure 1.
Farmers remove native vegetation and then plow the land to plant new seeds. Because most crops grow only in spring and summer, the land lies fallow during the winter.
Of course, winter is also the stormy season in many locations, so wind and rain are available to wash soil away. Tractor tires make deep grooves, which are natural pathways for water.
Fine soil is blown away by wind. The soil that is most likely to erode is the nutrient-rich topsoil, which degrades the farmland. Figure 1. Grazing animals Figure 2 wander over large areas of pasture or natural grasslands eating grasses and shrubs. That means mechanically preparing seed beds by breaking the ground.
Soil can become dense and compact. Plowing also makes it easier to plant. Plowing breaks up the blocky structure of the soil which can aid in drainage and root growth.
Plowing fields can also turn organic matter into soil to increase decomposition and add nutrients from the organic matter to the soil. Many farmers spread manure from cattle and swine onto their fields. This manure is rich in nitrogen which is essential for plant growth. Turning the soil over not only mixes this organic matter, but it also increases oxygen in the soil which speeds up decomposition of the organic matter and makes more oxygen available for the plant roots.
One problem that farmers face is weeds in their field. Weeds compete with the planted crop for water and essential nutrients. Weeds typically grow fast and can crowd out the desired crop.
One advantage of plowing is that it can mechanically break up weed roots and disrupt weeds from growing. By mechanically controlling weeds farmers may be able to spray fewer herbicides to control the weeds. A bushel of wheat will be worth more if it has fewer weed seeds in it. So, having fewer weeds can lead to increased profit. Planting seeds is always weather dependent. Farmers need to wait until the soil temperature is above 50 degrees Fahrenheit so that the seeds will germinate.
Farmers want to plant as early as possible so that they can maximize a short growing season and give their crops the best chance to be productive. Black soil will absorb more sunlight and increase that soil temperature more quickly than soil that has plant matter on it.
Plant matter reflects some sunlight and might delay how quickly soil temperature warms to 50 degrees Fahrenheit. There are a lot of reasons for farmers to plow or till their fields. But, plowing does present some challenges and costs. Soil-saving practices like contour terracing, cover crops, and forested windbreaks can protect soils and conserve nutrients—but soil losses continue to affect agriculture and the environment.
Conservation-oriented farming sustains soils. Ground covers sown after crop harvest protect land that would be bare in the off-season. The results are healthy soils, profitable to farm.
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