When plants are exposed to too much water, it’s hard to determine whether they are drowning or suffering from nutrient leaching.
Leaching occurs when some nutrients sink below normal rooting depth because of an excess of water percolating through the root zone of deep, sandy soil. If a grower’s soil is composed of clay within 10–12 inches of the surface, leaching generally is not a serious problem, as the clay restricts percolation through the root zone.
Determining how to replace nitrogen lost through leaching can be difficult. North Carolina tobacco experts say that between 50 and 80 pounds of nitrogen per acre may be needed to replace lost nitrogen, but three factors can influence the amount: depth from topsoil to clay, age of crop when leaching occurs and the estimated amount of water that moved through the root zone.
Often, wilting is a symptom of drowning. Wilting also indicates that leaching losses are minimal because water stays in the root zone instead of moving through it.
Recommendations can vary depending on the region, so experts recommend that growers consult their state’s Extension specialists for specific recommendations on correcting drowning and leaching in their area.
To learn more about nutrient management programs, order your copy of the 2013-2014 Tobacco Farm Quarterly Production Guide.