Tackle the 4 W’s of Fertility Management 

The good news: Fertilizer prices are *headed in the right direction following record highs last year. 

The bad news: Spring nitrogen commitments are lagging at the retail level as farmers play the “wait and see” game to see how far prices may recover.

The added uncertainty of unbooked fertilizer at this time in the season means it’s time to engage farmers in tough conversations about their plans. After all, if they don’t have a plan yet, how can you? Use this guide to build confidence in fertilizer decisions for 2023.

You and your farmers know sufficient fertility is critical to maximizing yield potential. But why? What do macro and micronutrients actually do for the plant? A quick Crop Nutrition 101 conversation with customers can help bridge their educational gaps. Here’s a reminder of the primary plant nutrient functions in a plant.

Macronutrients (N, P, K)
Nitrogen – Nitrogen is one of the most essential nutrients to maximize a crop’s potential. Nitrogen is a crucial component of the amino acids that support plant protein and enzyme production. It’s also necessary for chlorophyll production in the plant, which drives photosynthesis, plant growth and yield.

Phosphorus – Like nitrogen, phosphorus is an essential building block for many plant components. It is required for ATP production and energy transfer within a plant. It’s also part of a plant’s RNA, DNA, and membrane phospholipids. Breaking it down, without phosphorus, plants can’t grow, maturity is delayed and yield is reduced.

Potassium – Think of potassium as the “movement” nutrient. It helps transfer water, nutrient and carbohydrates in plant tissues. Potassium also helps activate enzymes in a plant, which can impact protein, starch and ATP production. Plants need sufficient potassium to regulate water vapor, oxygen and carbon dioxide exchange. If K is deficient, growers can expect stunted plants and lackluster yields.

While macronutrients are the main focus of most fertility programs, adequate micronutrient levels are just as crucial to the plant. Here is an excellent refresher about how they contribute to crop yield.

Now that your farmers understand why crops need nutrients, get a bit more granular about what their particular crop needs. Every field will likely have different fertility requirements depending on the crop planted, yield potential, past fertility schedule, tillage practices and a host of other variables. So, do farmers need to apply every nutrient every season? Not necessarily. 

Encourage soil and plant tissue testing to drive more informed fertility planning. Soil samples done in the fall or early spring can give you an idea of what nutrients are available in the soil. That’s a good place to start for planning fertility needs. If nutrient levels fall below optimal ranges, farmers should plan to add amendments. But, some nutrients, including phosphorus and potassium, are relatively stable in soils and may persist, so applications aren’t needed every season. If farmers do plan to skip a year of potassium or phosphorus, it’s important that they supplement the following year based on what the crop removed.

While soil samples give an idea of what is in the soil, they don’t necessarily provide reliable information about what the plant actually takes up. That’s why in-season tissue sampling is a valuable tool. Timely tissue samples give a real-time snapshot of a plant’s nutrition. Sampling plants can help identify hidden hungers that can be remedied in-season with a crop nutrient application. 

Beyond what nutrients to apply, farmers may also need to consider the fertility source. For example, we’ve seen significant price differentials for UAN, anhydrous ammonia and urea, which may cause some farmers to change their fertility management practices. Have candid conversations about the pros and cons of different fertility sources to ensure your customers make the most profitable decisions.

The closer farmers can time their fertilizer applications to crop needs, the more effective and profitable they will be. Scientists at Pioneer Hybrids explain that modern corn hybrids take up nitrogen later in the season, making in-season applications optimal to maximize yield potential. Split nitrogen applications are also preferred over a one-time application in the fall or spring because nutrient loss is higher in the latter situation. 

However, on-farm logistics can make fall applications more practical for farmers. In those cases, strongly encourage farmers to protect their nitrogen investment with a nitrogen stabilizer that can keep more nutrients in the root zone for plant uptake. Stabilizers are formulated to slow chemical and biological processes that promote nitrogen volatilization and leaching.

Farmers are looking at the days of blanket fertilizer applications through the rearview mirror. With today’s input costs, treating every field the same way is not economical. It’s simply more profitable to apply fertilizers where they offer the highest potential for return on investment. That’s why more farmers are adopting zone management practices and using variable rate technology (VRT).

Put the prescription technology your ag retail has invested in to good use with custom fertility recommendations by field. While most farms haven’t invested fully in VRT equipment, they can easily alter their nutrient applications on a field-by-field basis using the equipment they already have. For example, in more productive fields, ensure growers apply sufficient nitrogen to maximize their crop’s genetic potential. Pull back nitrogen recommendations on less productive fields so growers can use those dollars more profitably. 

Some ag tech modeling tools can help you pinpoint the most profitable amount of nitrogen to apply based on local conditions. These tools can also help you nail down the best time for growers to apply nitrogen.

While fertility prices are expected to come down this season, managing operational costs are still top-of-mind for conscious growers. Services like GROWERS Guide can help farmers easily translate their farm data into management decisions that will directly improve fertilizer cost estimates while keeping up with the dynamic market changes. When there is a favorable marketing opportunity, be sure your growers know about it. Instead of focusing on fertilizer prices, turn the conversation into profitability and value.

The bottom line: Always recommend fertilization when soil test levels fall below the optimal range, help farmers optimize fertility rates by field, time fertility applications to match crop needs and use digital tools to support decision-making.

*DTN Retail Fertilizer Trends