Performance of enhanced efficiency nitrogen fertilizers in green-harvesting sugarcane

Abstract

Enhanced efficiency fertilizers (EEF) are of interest for sugarcane (Saccharum spp.) production due to the potential to reduce N losses, and improve crop yield and environmental conditions. This study was conducted to determine the effect of urea with N-(n-butyl) thiophosphoric triamide (NBPT) or dicyandiamide (DCD) on NH3 volatilization and sugarcane yield. The NH3 volatilization, the foliar concentration of N and S, and yield of stalk and pol were monitored in two field trials testing six N sources (urea; urea + NBPT; urea + DCD; ammonium sulfate [AS]; ammonium nitrate [AN]; ammonium sulfate nitrate), and three N rates (50, 100, and 150 kg ha−1). The N losses from urea totaled 22 and 18% in Sites 1 and 2, respectively. Treating urea with NBPT reduced NH3 volatilization by 60%. Sugarcane yield increased 8.8; 11.6; and 16.0 Mg ha−1 (Site 1), and 4.5, 9.3, and 14.2 Mg ha−1 (Site 2) with the application of 50, 100, and 150 kg ha−1 N as compared to control, respectively. All N sources increased yields, demonstrating similar efficiency for sugarcane production. Green harvesting sugarcane cultivated in sandy soils with low organic matter concentration is highly responsive to N, showing similar efficiency between EEF and conventional N fertilizers.