A Farmer's Dilemma: To Till or Not To Till

By Science Buddies on March 30, 2015 10:51 AM

As winter turns to spring, farmers are preparing to plant this year's crops. For some, tilling their fields is a thing of the past.

By Kim Mullin

Photo: USDA Natural Resources Conservation Service

When you think of a farmer at work in the fields, do you picture a tractor pulling a plow and turning the soil? In my mind, it is a red tractor, and the soil is rich and dark.

For many people, turning the soil may be an obvious part of growing crops. Of course it is required! Isn't that what farmers do!?! It turns out that the answer to that question isn't easy. Yes, many farmers turn, or till, the soil. But increasing percentages of farmers are opting not to till some or all of their fields, for a variety of reasons.

As farmers prepare to plant new crops this spring, they must weigh the pros and cons of till and no-till farming. On the one hand, tilling a field in preparation for planting aerates and warms the soil, and also buries weeds, animal waste, and leftover crops. However, once the soil is turned, it is much more vulnerable to erosion from wind and water and is likely to have increased run-off of soil and chemicals into local waterways.

On the other hand, leaving a field untilled allows leftover crops to act as mulch and helps protect the soil from erosion and run-off. However, planting seeds through this layer of mulch is more difficult and requires expensive machinery. This method also may require more herbicide to control weeds, and, in some places, crop yields may be lower because the mulch keeps the soil cooler and seeds germinate later in the season.

Can you Dig It? Science and Farming

So what is a farmer to do? With no one right answer, farmers must experiment to learn what works best with their soil and the crops they choose to grow. Do you have an interest in the science behind farming? Try out these Science Buddies Project Ideas:

Dust Busters: How No-Plow Farmers Try to Save Our Soil: Run your own till vs. no-till trials to see how the two farming methods compare when it comes to moisture retention and surface run-off.

Earthworms: Nature's Tiller?: Earthworms do their own tilling and aerating of the soil. With worms, grass clippings, and a few pots of soil, you can see for yourself how effective they are at this job.

May the Best Plant Win! Experiment with Genetically Modified Seeds: What type of seed to use—conventional or genetically modified—is another choice that many farmers face. Put yourself in their shoes, and explore the benefits and drawbacks of RoundUp®-resistant plants.

Run-off and Fertilizer Use*: When fertilizers are applied to farm crops or gardens, how much of it is absorbed by plants and soil, and how much makes its way into local waterways? Create a run-off simulator to find out!

Bacteria Can Fix It! A Comparison of Nitrogen-Fixing Bacteria and Nitrogen Fertilizers: Plants need nitrogen to grow, but what is the best way for a farmer or gardener to deliver it? Grow clover with nitrogen fertilizer and nitrogen-fixing bacteria and compare your results.

Getting Dirty in the Name of Science

Spring is a great time to talk with kids about plant life cycles. Dig in the dirt, plant a few seeds, or just head outside and observe how plant life is changing as the weather changes where you live.