Production of High-Value Cash Crops on Mixtures of Sand Tailings and Waste Phosphatic Clays

摘要

Mixing of sand tailings with waste phosphatic clay is an alternative disposal technology to the more common practice in the phosphate industry in Florida of separate disposal. Phosphatic clays are highly fertile compared to sandy Florida soils and are being considered as soils for crop production, but their physical properties can be difficult to manage. In the research, the effects of mixing sand tailings with phosphatic clay in several ratios on the production of several vegetable crops were examined in field and greenhouse studies. Yields of turnip, cabbage and mustard were higher at the lower sand:clay ratios, while squash and pepper yields were higher at the higher sand:clay ratios. Alfalfa was grown on the 2:1 sand-clay mixture amended with sawdust, humate, composted garbage, peat, sewage sludge or composted sewage sludge. Only the sewage sludge increased yield, which appeared to be due to micronutrient contributions, especially Mn.