An Inside Look at Mid-Season Management of GMO and Organic Crops

By Jennie Schmidt

Jennie is a Maryland farmer. She is also a registered dietitian who speaks about food and farming systems, sustainability and family farms.

When I tell people I’m a farmer, they often think I work hard at planting and harvest, but assume I have summers “off.” As nice as that sounds, if I went and hung out at a beach all summer, I’d likely come home and have no crops left. For organic and GMO crops alike, summer is a time to monitor for and respond to a variety of potential issues, from drought to diseases.

Earlier this season, I posted a few differences between planting GMO and organic corn. Now that the corn is growing, allow me to paint a picture of summer on my farm.

Growing like weeds

My husband, Hans, brother-in-law Alan, and I run a diversified operation. This means we plant a variety of crops, which allows us to spread risk – if one crop is having a bad year, chances are others may be having a good year. Because we grow many crops, it seems like we’re always harvesting something. In June, we harvest barley and wheat. In July, we harvest tomatoes and green beans. We also grow corn and soybeans. As I shared this spring, over the years we’ve planted conventional corn (not biotech but not organic), GMO corn (genetically modified to better withstand insects and diseases) and organic corn (certified organic).

This time of year, the biggest difference between growing organic and GMO corn lies in how we control weeds. Weeds rob nutrients, water and sunlight from our cash crops and can create a haven for insects or diseases, so it’s important to manage them early, just like your garden at home.

Did you know that corn is a type of grass? This means that we can spray both our conventional and our biotech corn with herbicides that target broadleaf weeds but do not harm the corn, similar to you spraying your grass at home with a product that kills dandelions but preserves your plush lawn.

Organic crops cannot be sprayed except with an organic herbicide before the seedlings emerge from the ground, but it’s nevertheless important to kill weeds. We do so by using a rotary hoe to turn the top few inches of soil to bury the weeds. This is necessary until the corn canopies, or grows tall enough to shade the ground, preventing weeds from growing. It’s a lot more work, which is why farmers receive a premium for the time and effort entailed to produce an organic crop. In a season, we will do approximately six passes across a field of biotech corn to perform all operations from planting to weed control to fertilizer to harvest. For a field of organic corn, it takes a total of about 13 passes including rotary hoe and cultivation passes to bury the weeds into the ground – which translates to a lot of man hours in the tractor when you are talking about hundreds – or thousands – of acres.

Other than controlling weeds, growing an organic crop is really not very different from growing a GMO crop, but it is one more step. Becoming a certified-organic farm requires lots of paperwork and record-keeping. Organic farmers can be audited at any time and have to be ready to produce documentation proving that practices used were approved by the certifying agency.

Monitoring and Mother Nature

No matter the crop or how it’s produced, during the summer we scout our fields for signs of insects or disease. This entails walking acre after acre to physically see what’s out there and to establish a threshold for insect control. If I see a Japanese beetle, for instance, is it a fluke, or is it a big enough threat to my crop that I need to spray?

I walk hundreds of acres pulling leaves and assessing plant health and looking for damage. I’ll send some for a plant-tissue test, which is similar to a blood test but determines the nutrient profile of a plant which tells me if I need to apply any nutrients. While walking the fields, I’m also checking my irrigation pivots to make sure they are running properly. Later this summer, we’ll begin inspecting and repairing equipment to prepare for harvest.

Mother Nature is the most universal summertime threat to crops. GMO corn might better withstand insects, but there’s not yet a corn variety that can survive a severe drought, massive hail storm or bad flood. These are weather events I cannot control, but I will spend my summer addressing any elements I can in an effort to provide a healthy and plentiful corn crop.

One Comment

Lawrence Caird

Those man hours in a tractor on the hundreds or thousands of acres of “organic,” corn, increase the fossil fuels used in growing this crop. It increases the carbon footprint in ways that many people do not consider. If we are to take global warming seriously, we must all accept responsibility for the life-style choices we make that increase greenhouse gasses. In this example, organic corn contributes to global warming, more than GMO corn.


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