Nutrient Leaching and Management
North Carolina has had record breaking precipitation during the past 12 months, and Sampson County has definitely seen its fair share of the rainfall. This precipitation has prevented some crops from being managed in a timely manner because growers can’t get equipment in the field, and every time they get started more rainfall shows up in the forecast. Not only is this precipitation causing issues from an agronomic standpoint now, it can potentially cause issues in the future as we move closer toward planting time.
Most growers pull soil samples from their fields during late fall to get accurate nutrient information so they know what to expect when they come back in the spring to plant. However, many of these nutrients are prone to leaching over time. This leaching occurs at a much higher level when we receive the amount of precipitation we have so far this winter. Therefore, growers should take this into consideration and monitor their nutrient levels closely this season. The nutrients that were in the field 4 months ago may be very diminished now.
Nitrogen is one of the most highly leachable nutrients that is very important for foliage growth and green color. A good indicator of nitrogen deficiency is reduced growth as well as lighter green/yellow leaf tissue that can be purple and red in some plants. Winter wheat that is currently in the field shows symptoms of nitrogen deficiency very well. Saturating rainfall is preventing nutrient uptake and has leached many nutrients away from the root zone. This has caused much of the wheat in Sampson County to display a “rainbow” of red, purple, yellow and green because it is not receiving the nutrients it needs. Wheat growers will need to adjust their nitrogen topdress applications accordingly at growth stage 30.
Potassium is also a leachable nutrient that is important for plant growth. Potassium deficiency symptoms include reduced growth, shortened internodes, chlorotic margins of older leaf tissue, etc.
Other leachable macronutrients include magnesium, calcium, and sulfur.
Nutrient Management is critical to crop success, especially in years when continuous precipitation causes exponential leaching events. For more information on nutrient management, please contact your local Extension office at 910-592-7161.