Agronomic Characteristics of Lettuce Grown with Monoammonium Phosphate in Sandy Soil

ABSTRACT

Information related to phosphate fertilization and coated phosphate fertilizer in lettuce (Lactuca sativa L.) is scarce. Thus, this study was carried out to evaluate the agronomic efficiency, production, and nutritional characteristics of coated monoammonium phosphate (MAP) in two subsequent crops with lettuce cv. Solaris. The experimental design was completely randomized (2 x 5 factorial experiment): two sources of phosphorus (P) (MAP and coated MAP), five applications (0; 75; 150; 300; and 600 mg phosphorus pentoxide (P₂O₅) kg⁻¹) with four replications. In the first crop, there was a greater accumulation of P in plants shoot with the application of coated MAP until 150 mg P₂O₅ kg⁻¹ dose, surpassed by MAP after this dose. On the second crop, fresh mass and the accumulation of P in the leaves were higher than the uncoated MAP. In both crops, the agronomic efficiency of P fertilization decreased with increase in the amount of phosphorus applied in lettuce cultivation.

KEYWORDS:

• Lactuca sativa L
• phosphorus nutrition
• polymers