Optimizing your crop fertilization efforts
- Joe Christner: SWCD
- April 29, 2024
- 332
Today is one of those days most of us have been looking forward to after several days of cool, wet weather. The sun is shining, and it is a very comfortable 75 F. I sneak away from my desk occasionally, just to step outside and enjoy a perfect spring day. For farmers and gardeners, it also means planting time is just around the corner. After several months of planning, ready or not, that time is here. There is just something very rewarding about planting seed in the soil and seeing it grow into a plant.
During the busy planting season, one basic task takes center stage — the application of crop nutrients. As seeds are planted in the soil, the timely application of essential elements such as nitrogen, phosphorus and potash become very important, providing the nutrients for healthy crops and great yields. Ideally, the winter planning included a nutrient management plan that answered two basic questions: How much? And when?
It may be too late for a plan, but it is not too late to think about nutrient management and make some adjustments while you plant this year. The spring planting and growing season represents a critical window of opportunity where the correct application of nutrients can make the difference between a poor harvest and a bumper crop. It takes careful planning and strategic management to determine the optimal amount to apply. Whether it’s too little, just enough or an overapplication, the consequences can have a huge impact on yield, profit, and the water quality of our streams, rivers and lakes.
Effective nutrient planning includes knowing the specific needs of the soil and the crops being planted. Simply stated, nutrient planning consists of the following: How much do I have? How much do I need? When and what will I use to balance the difference?
Soil testing plays an important role in this process, offering valuable insights into nutrient levels, pH balance and potential deficiencies. It is recommended to take a soil test every three years. Knowing the nutritional needs of the crop based on a yield goal is the next step. The Tri State Fertility Guide can be used to determine crop nutrient needs based on soil tests. Crop nutrient requirements also can be based on crop nutrient removal rates but could result in overapplication because it does not consider the nutrients that may already be in the soil.
Nutrient planning is managing a balance between the nutritional needs of crops and the resources of the soils. It also is determining the type and amount of fertilizer, manure and/or other sources for those nutrients. Nitrogen, phosphorus and potash, often referred to as the “big three” nutrients, play key roles in plant growth and development. Nitrogen fuels leafy green growth and vibrant foliage, phosphorus promotes root development and flower formation, and potash enhances overall plant health and resilience. Achieving this balance is not merely a matter of quantity but also of timing.
The goal is to apply the nutrients as close to plant demand during the growing season as possible. This is especially important for nitrogen. Because nitrogen is volatile and water soluble, overapplication in the early spring during low plant demand increases the risk of leaching with early spring rains. Side dressing nitrogen later in the spring to a growing crop during peak plant demand can reduce risk of runoff and ensure a steady supply of this vital nutrient to meet the needs of the growing plant. By synchronizing nitrogen application with plant demand and soil conditions, you can optimize nutrient uptake while minimizing environmental impact.
To harness the full potential of phosphorus, pay careful attention to soil conditions and crop requirements. Unlike nitrogen, phosphorus exhibits limited mobility in the soil, necessitating strategic placement near the root zone for maximum benefit. By incorporating phosphorus-rich fertilizers into the planting bed or banding them beneath the seed row, you can ensure efficient nutrient uptake and promote healthy, vigorous growth throughout the season.
Completing the trio of essential nutrients is potash, an important aspect of plant health and resilience. Rich in potassium, potash serves as a multifaceted nutrient, regulating water uptake, improving stress tolerance and enhancing disease resistance. Timing is key when it comes to potash application, with early spring representing an opportune moment to supply this vital nutrient, ensuring optimal growth and productivity throughout the growing season. Additionally, split applications of potash can provide a sustained source of nutrition, replenishing soil reserves as crops progress through their life cycle.
The importance of crop nutrients in spring planting cannot be overstated. From nitrogen’s role in fueling vegetative growth to phosphorus’ contribution to root development and potash’s support of plant health, each nutrient plays a vital part in nurturing crops to their full potential. By carefully balancing the amount and timing of nitrogen, phosphorus and potash application, you can optimize nutrient uptake, maximize yield and safeguard environmental sustainability.
This spring during planting, you may want to consider the benefits of developing a plan or, if you have one, managing and recording this year’s nutrient applications. Whether you are a farmer or plant a garden, Holmes SWCD can help you answer any questions you may have about how much fertilizer to apply and when to apply it.
While talking about nutrient planning, we’d be remiss not to mention H2Ohio has officially rolled out to the entire state. The program for statewide rollout looks different than what is offered in Northwest Ohio. A two-year nutrient management plan development and implementation on cropland are the two practices that are available. We suggest talking to Holmes SWCD to discuss feasibility, details and how to be prepared to sign up. We are taking applications through May 6. Call 330-674-2811 ext. 3 and ask for Darby Sherman or email dsherman@co.holmes.oh.us.
Joe Christner is a program assistant with the Holmes Soil & Water Conservation District.