Farmers use a variety of tools each year to help grow an abundant crop. Have you ever wondered just what exactly farmers are putting in the ground and why they are using these substances? I’ll try to shed some light on what actually goes on out in our fields. After reading this, I hope you feel confident and reassured that we do everything we can to take the best care of our most precious resource – our land.
On our farm, we apply nutrients such as manure from our livestock, nitrogen, potassium, lime and phosphorous. We also use chemicals such as herbicides, pesticides and insecticides to control weeds, pests and insects that negatively impact our crop yields. I will talk more about spraying chemicals a little later this spring when I can show you what we do in action. For now, I’ll focus on fertilizers.
Why do we use nitrogen? Nitrogen is essential for a healthy and successful corn crop. Each year’s crop removes a certain amount of key nutrients from the soil and it must be replaced in order to continue raising crops and maintain the overall health of the soil. It is critical to keep the soil in good condition, otherwise, it will be “mined” of its key nutrients and will not be productive. On our farm, we do a variety of things to ensure that we are using the most efficient amount of nutrients. By this I mean the right amount to have a successful crop while at the same time minimizing negative impacts on the environment. One thing we do regularly is take soil samples. Soil sampling helps us to know how much of each key nutrient is currently in the soil. It provides direction to know if we have too little, too much or an optimal amount of any particular nutrient.
In addition to soil samples, we also use soil and yield maps to understand how much was removed by last year’s crop and to determine how much we need to apply to reach our yield goals for the coming year. From these and other factors, we are able to decide how much nitrogen each field should receive. We can even use variable rate prescriptions which means that we load a prescription into our monitors and our equipment will apply varying amounts of the nutrients throughout the field, depending on how much each area of the field actually needs. This way, we’re not overapplying in an area of the field that is already abundant or underapplying in an area that is deficient.
Since we have livestock on our farm, we are able to utilize their manure as a fantastic source of fertilizer for our soils. We use a lab analysis from our hog manure samples to help us understand how much of each key nutrient is in the manure that we apply to our fields. Manure has been identified as a waste product for years. This couldn’t be further from the truth. Manure is full of valuable, key nutrients and is a real asset for our soil health and crops.
In the next month or so, when driving across corn country, you are likely to see farmers pulling white tanks across the field, like the one pictured below. These tanks are filled with anhydrous ammonia, a form of nitrogen. There are many different forms of nitrogen and methods of applying nitrogen. With this particular method, we pull a toolbar with the anhydrous tanks hooked up behind it. The anhydrous is knifed into the ground about four to six inches deep depending on the field conditions and amount of residue left over from previous years’ crops. The trench that the anhydrous is placed in is then covered and sealed with closing discs. The goal is for the nitrogen to be placed where it will be readily available for the corn plants’ roots to take up.
How do we determine how much anhydrous ammonia to put into the ground? There are several variables that play into this decision. On our farm, we utilize a crop model to help manage our nitrogen decisions on several of our fields. This will help us monitor the amount of nitrogen in our soils throughout the growing season to make sure we have enough to reach our yield targets without wastefully overapplying.
For years, there has been extensive research done on nitrogen management as it pertains to crop farming. As an industry, we have learned many things that help us do the best job possible to be good stewards of nutrients and our land. For example, we know that adequate levels of potassium helps the crop to utilize the nitrogen in the soil so we make sure that our soils have adequate levels of potassium as well.
We also know that multiple applications of lower rates of nitrogen is typically better than one larger shot of nitrogen. Whenever possible, we try to “spoon feed” the crop. For example, we may apply a baseline amount of anhydrous ammonia before planting. And then come back and sidedress liquid nitrogen around early June. Later in the season, when the corn plants are very tall, we could use an application such as Y-Drops if (and only if) the crop is needing more nitrogen at that point. The benefit to doing multiple, lower dose applications is that you’re applying the nutrient as the crop needs it and eliminating waste of the nutrient. This benefits us from an economic perspective and it benefits the environment as well. In a perfect world, we could do this with every field. But, we don’t farm in a perfect world. On our farm, we have hills, contours and odd-shaped fields that don’t allow us to make applications once the crop is up out of the ground (because we would run over and damage too much of the crop). Nevertheless, we still try to manage each field as efficiently as possible.
In addition to the technology used to determine how much nitrogen to apply, we also utilize a variety of conservation practices on our farm to help prevent the soil and its nutrients from eroding and leaching into the water. We use things like grass buffer strips, grass waterways, planting on contours, terraces and more to help keep our soil in place and prevent as much run off as possible.
Farmers are investing a tremendous amount of time, energy and money to manage fertilizers better than ever before. And the ag industry as a whole has made incredible advances in understanding how the soil holds these nutrients so that we can all benefit from more efficient application of them. It maximizes the profitability of our operation and helps us take care of our resources like soil and water. This ultimately benefits everyone by growing safe, sustainable food while protecting our environment.