For any successful business owner, planning for the long term requires time, resources and (most importantly) a strategy designed to achieve prospective goals. The same can be said for a successful farm. Outlining a strategy to help build soil fertility over time is a smart investment that will result in yield dividends in future years. A long-term soil fertility plan is one that actively tracks the available nutrients in the soil, uses critical data to determine correct fertility needs, and applies fertilizer in a science-based and responsible, yet consistent, way.
“Long-term soil strategies are imperative for increasing yields year after year,” says Ron Olson, senior agronomist at The Mosaic Company. “Up to 60 percent of yield is dependent on soil fertility, and applying needed nutrients annually helps sustain soil fertility. When you invest in a soil strategy like this, not only do you improve your yields, but you build the value of your soil, too.”
Before investing in a long-term soil fertility strategy, there are several things to take into consideration. For instance, is the ground in question under a long-term contract? Is it a cash lease? Building a long-term strategy on ground that may be up for renegotiation soon could have a negative outcome. It’s not necessary to immediately implement a long-term fertility strategy on every acre farmed. Instead, farmers should consider a tiered approach: If there are fields or sections of fields that would benefit most from building up nutrients over time, focus on those areas first.
The most accurate way to determine which acres would benefit most from a long-term fertility strategy is to invest in grid soil samples. The importance of knowing the inventory of available nutrients in every field and mapping each of them accordingly is critical. Once your soil data is available, an agronomist can help determine what optimal nutrient levels should be, and can prescribe a fertilizer plan to build to those levels over several years.
“There are different equations to determine what nutrient levels could and should be, and an agronomist knows which equation to use based on the goals of each farmer,” Olson explains. “So many variables go into creating a long-term fertility strategy — current nutrient levels, what crops will be planted, how much a farmer will invest in fertilizers, and more. An agronomist or certified crop advisor [CCA] is the best resource to put all of that information to work for the farmer.”
Farmers should also be extremely cognizant of soil type when considering a long-term strategy. Most sandy soils allow nutrients to leach lower into the soil profile. While annual fertilizer applications can be impactful, sandy soils simply can’t hold onto nutrients for a long period of time, making a buildup plan ineffective and even wasteful. A long-term fertility plan should take into consideration the 4R Nutrient Stewardship program for all soil types: applying the Right Fertilizer at the Right Rate at the Right Time and in the Right Place. This ensures that the fertilizer applied is being used in the most effective manner. For more information about the 4Rs, visit nutrientstewardship.com.
Another key consideration is geography. While minimal, there are differences in regional recommendations to apply needed nutrients to the soil, such as the amount of potassium or phosphorus. For instance, Iowa State University recommends that if phosphorus soil tests in Iowa show 20 parts per million (ppm), an application of 67.5 pounds/acre of P2O5 should be applied to achieve 180-bushel-per-acre corn. However, to achieve those same yields in Michigan, Indiana and Ohio, the Tri-State fertilizer recommendations include applying 98.8 pounds/acre of P2O5 if the soil tests show 20 ppm of phosphorus. Because of geographic nuances, it is important to consult with an agronomist, CCA or university extension agent to best understand what is recommended for your area.
Those considering an impactful long-term fertility strategy should also consider pH levels of the soil. As Curt Woolfolk, senior agronomist at The Mosaic Company, explains, “No amount of phosphorus or potassium can fix a pH problem. The best return on any investment is to correct the pH levels in your soils. Poor pH levels can limit the impact of added nutrients, making them an investment that doesn’t really offer good returns. Correcting the pH levels should be a priority for every farmer.”
The most important consideration is cost. As with any investment, it’s important to weigh the potential risks against the expected benefits. The current low commodity prices may make it difficult for some farmers to invest in a full-spectrum fertility plan, let alone add nutrients to increase long-term levels in their soils. However, in seasons like 2014, with record yields occurring in much of the country, record levels of nutrients were also removed from the ground. While it might seem fertilizer applications in 2015 may not be manageable with tight margins, eliminating a year of fertilization can result in long-term challenges in soil fertility. Soil samples can be taken and analyses to gauge nutrient inventories can be conducted right away this spring, and applying a maintenance level of fertilizer ensures that nutrient levels won’t drop further.
For many farmers, improvement is a constant goal. While it may be hard to top the yields of 2014, managing soil fertility proactively is a controlled effort that very well could raise the yield bar for specific pieces of ground; plus, the investment can be spread out over a number of years.
“We are big believers in investing in our soil,” says Matt Lantz, a farmer from Lake Crystal, Minnesota. “It’s the foundation of every crop we grow, and a strong foundation is the key to strong yields. I’m always looking at ways to improve what we do — from limiting fertilizer runoff to increasing efficiencies using mapping and precision tools. A long-term fertility strategy lets me invest in our soils over time, improving a little each year, but making huge leaps in nutrient availability in the long run.”
“Proactive management is the best way to keep yields on an upward trend line,” adds Woolfolk. “No matter how innovative the seed traits are, the pest management options, or even what the weather is, all plants still need the right kind of nutrition to grow to their maximum potential. A long-term fertility strategy is a great way to build balanced crop nutrition for future success.”