Soil solution and plant nitrogen on irrigated rice under controlled release nitrogen fertilizers

Nitrogênio na solução do solo e em plantas de arroz irrigado sob adubação com fertilizantes nitrogenados de liberação controlada

ABSTRACT:

A study was conducted to evaluate the solubilization and nitrogen (N) use efficiency (NUE) of controlled release nitrogen fertilizers in irrigated rice, compared to urea. It was developed under semi-controlled conditions, including five treatments: Control, Splitted Urea (pre-sowing and topdressing), Pre-sowing urea, and Polymer Coated Urea (PCU) with 60-day and 90-day release. PCUs did not maintain high NH₄ ⁺ and NO₃ ^- levels in solution over a longer period than urea. NUE of PCUs was similar to uncoated urea, not increasing nutrient release in irrigated rice field.

Key words:
nitrogen fertilization; polymer coated urea; efficiency; flooded soil