Just the facts. From the experts.


It is apparent to us at Best Food Facts, that consumers are concerned about pesticide and fertilizer use, based on the comments from our recent Food Fight Poll. Not only that, we received the question, “What are farmers and ranchers doing today to reduce their usage of pesticides and fertilizers?” from www.fooddialogues.com. To address the topic, and as a follow up to our recent post on The Dirty Dozen, we asked experts Dr. Matt Helmers, Dr. Gerald Miller and Dr. Roy Parker to answer a few questions about fertilizers and pesticides.

  • Dr. Matt Helmers is Associate Professor, Agricultural & Biosystems Engineering, Iowa State University.
  • Dr. Gerald Miller is Professor and Associate Dean Emeritus, Iowa State University. 
  • Dr. Roy Parker is Professor and Extension Entomologist, Texas AgriLife Research and Extension Center at Corpus Christi.


What is a pesticide?

Dr. Parker: “The term pesticide is often misunderstood. A pesticide is the overall encompassing term, meaning to kill a pest. There are many different kinds of pesticides – herbicides, fungicides, insecticides, miticides, rodenticides, bactericides, among other things.”


Why do farmers and ranchers want to reduce the amount of pesticides and fertilizers?

Dr. Miller: “The farmers I know and work with are concerned about the environment the same as I am. Through research and through technology, they are doing the best that they can do, and still make a profit for themselves and their families. Farmers are aware of the impact of their management practices on the environment, and by and large, they’ve adapted to the technology that’s available. And they are looking at new practices that will reduce the impact on soil and water resources.”

Dr. Parker: “They want to use these materials in an environmentally-friendly way and are looking for the most economical way to do it, all while reducing input costs. For example, a grower that has 1,000 acres or even 30,000 acres might be looking at spending $8 per acre on a certain product. That grower needs to know for absolute sure if that is going to result in a dollar return. Farmers and ranchers attend schools and short courses and field tours in order to gain knowledge and competence in using these inputs. They’ve developed Best Management Practices.”


What are farmers and ranchers doing to reduce fertilizer and pesticide use?

Dr. Helmers:

  • “New technologies such as variable rates of fertilizer applications can allow producers to put on fertilizer (specifically phosphorous and potassium) in areas where it’s most needed for the crop. In areas where the soil is testing high in phosphorous and potassium, farmers apply less, and as a result, we can reduce the risk of loss to the environment.
  • “From a nitrogen standpoint, producers are looking at ways to use sensors to sense the status of the corn crop in particular and applying nitrogen based on the needs of the crops.
  • “There’s also new things like the nitrogen rate calculator, which is a tool that’s being used throughout the Midwest, to help producers understand appropriate amounts of nitrogen to put on to get the maximum return on that nitrogen, to minimize the risk of downstream nitrate loss. Nitrate loss is a concern for local waters as well as to the Gulf of Mexico, and we want to do all we can to reduce the risk of loss of nitrate to downstream water bodies.”


Dr. Miller:

  • “The invention Roundup Ready seeds was a major step forward in reduction of use of herbicides for weed control. We have noticed a resistance in some weed species is becoming more common, but producers recognize that. They’re looking at different herbicides as well as a mix of methods for applying herbicides. Utilization of Bt corn has also been a step forward in major reduction of insecticides when it comes to corn rootworm.
  • “Farmers using GPS when applying pesticides and fertilizer has also allowed them to use less. GPS reduces spray overlap in pesticides. Many fields have contours and terraces, making less than square fields; therefore, farmers can turn off a spray path along a row of two or more when the terrain changes, reducing spray overlap. It has also has allowed producers to apply their pesticides while taking into account the solubility component, using variable rates. GPS technology is really a promising area for additional reduction of pesticides as well as fertilizer.
  • “We’ve seen a major increase in soil sampling over the last 20-25 years. Because of the soil sampling, producers can be much more tactical in terms of fertilizer application, applying only what’s needed and where needed.
  • “Looking at nitrogen use efficiency, as a general statement, corn hybrids today are more efficient in their use of nitrogen than previous generations. We’ve seen many changes in hybrids with standability, tolerance to moisture and nitrogen efficiency. So as yields have increased, we’ve seen some decrease in the amount of nitrogen required to get those increased yields.
  • “Finally, with fertilizer prices increasing over the last several years, we’ve seen increased use of farmers who have livestock or their neighbors have livestock, using manure as a nutrient resource.“


Dr. Parker:

  • “Farmers have hired crop consultants. Years ago, there were very few crop consultants, but now, they hire crop consultants to scout fields for insects and weeds and make recommendations based on established economic thresholds, taking into account the natural enemies that are present.
  • “They are testing their soil on a regular basis. This allows farmers to determine the actual fertilizers need before application.
  • “They are incorporating fertilizer into the soil instead of placing it on the surface, which allows them to use less and protect from runoff.
  • “They are using Integrated Pest Management systems that incorporate multiple suppression tactics to manage pests, and they do not rely on automatic or scheduled pesticide applications. This helps conserve natural enemies in the field (beneficial organisms).
  • “They are selecting certain varieties or hybrids or genetically engineered varieties, which reduces both insecticide and herbicide use.
  • “They are selecting planting dates to avoid heavy pest populations. Sometimes, you can plant earlier to avoid pests.”


What about technology of pesticides?

Dr. Parker: “Technology of pesticides has been changing over the years to what EPA and others view as safer materials. In fact, you can see that even in the homeowner market. Nearly all the products have changed in the last 20-30 years, and we’ve moved away from certain types of products. Years ago, we stopped using the very long-lasting materials that tended to stay in the environment a long time. We’ve come up with some safer products in the last 30 years.”


What about tillage and herbicides?

Dr. Parker: “There’s a balance between tilling too much and pesticide use. Tilling too much can be a big issue - you do not want to lose top soil. We farm in an area that has a lot of wind, for example, and the protection of that soil and methods to do that by leaving debris on the soil surface is critically important. And that will require increase in herbicide use. I feel like we could do more in our part of the country to move more toward limited tillage to protect the soil, but there has to be a balance with herbicide use. Protection of land is critically important to all of us in agriculture.”


What else could farmers and ranchers do?

Dr. Helmers: “Even if producers are using the best management practices possible, specifically from a nitrogen-phosphorus standpoint, because the timing of our rains may be when the crop does not need as much water, we still see some loss of nitrogen and phosphorus to downstream water bodies. This happens even when farmers are using the best in-field management practices possible. We need to practice a systems approach and look at the implementation of edge of field practices, as well, to further provide environmental benefits, through things like grass water ways or buffer strips at the field edge to reduce loss of surface runoff contaminants such as phosphorus and sediment. In addition, end-of-drainage pipe technologies such as bioreactors and nitrate removal wetlands have been shown to be effective in removing nitrate in the drainage water. We still need to do more to meet goals for water quality improvement.

“In general, the farmers are implementing a lot of practices that can help improve environmental quality, but I think there’s probably a need to do a bit more. I think the more practices we can implement, not only would we see benefits on water quality, but also other environmental factors like increasing habitat for water fowl or other wildlife. There would be added benefits of increasing our implementation of conservation practices.”



Click here to listen to Dr. Matt Helmers discuss protecting the land.

Click here to listen to Dr. Gerald Miller discuss how corn hybrids play a role in fertilizer efficiency.

Click here to listen to Dr. Roy Parker discuss how crop consultants help reduce pesticide usage.


Add a Comment

Craving more food facts? Read on!

Will Reducing Meat Consumption Help the Environment?
Farm Size: Environmental Impacts
Are Fruits and Vegetables Sprayed with Pesticides Less Safe than Organic Produce?