By Clint Thompson
Sandy soils dominate the soil landscape for vegetable production throughout Florida, according to University of Florida (UF)/IFAS. They provide growers distinct advantages, such as an ease of tillage and production of the earliest vegetable crops. However, a key disadvantage is the ability of nutrients to be leached, specifically with nitrogen, potassium and phosphorous.
Leaching refers to nutrients being drained away from the soil by excessive water, either from rain or irrigation. That’s why it is essential that growers manage their fertilizer programs and irrigation scheduling carefully.
“From a grower’s standpoint, every time you have nutrient leaching, you’re losing money. With that respect, all of the nutrients, you don’t want any to be leached,” said Eric Simmone, UF/IFAS Northeast Extension District Director.
While all nutrients are valuable, some are more limited in certain areas of the state than others. This speaks to the added importance of avoiding nutrients being leached after they are applied.
“From an environmental standpoint, you have different types of ecosystems. Some ecosystems are phosphorous limited, and some others are nitrogen limited. In a nitrogen limited watershed, you don’t want nitrate leaching. That’s going to be mostly North Florida,” Simmone said. “In South Florida, the big ecosystem starts from the lake and goes down to the Everglades. It’s all about phosphorous. It’s difficult to paint a blanket situation of what is the important nutrient. It is on an ecosystem-by-ecosystem basis.”
Soil tests are recommended so farmers have an idea of what nutrients are in the soil and what needs to be applied before planting begins. However, since nitrogen can leach rapidly, its application is required every growing season. It is not dependent on soil test results.