Nitrogen Availability from Poultry Litter and Pelletized Organic Amendments for Organic Rice Production
- Paula L. Wild,
- Chris van Kessel,
- Jessica Lundberg and
- Bruce A. Linquist *
Nitrogen is the most limiting nutrient in irrigated rice (Oryza sativa L.) production, and growers continue to be faced with the challenge of meeting crop N demand, particularly in organic production systems. The main objective of this study was to determine how rice yield was affected by seasonal availability of N from organic sources under continuously and noncontinuously flooded conditions. Laboratory and field experiments were conducted to determine the effectiveness of the commonly used poultry litter, pelletized organic fertilizers (blood, meat, and feather meal 13–0–0, feather meal 12–0–0, poultry litter plus feather meal 6–3–2), and (NH4)2SO4, in synchronizing the supply of mineralized N with the demand of N by rice. The N mineralization of all organic fertilizers occurred primarily during the first 53 d after planting, results which were confirmed subsequently in a laboratory incubation study. In all fields, fertilizers increased grain yield and N uptake relative to a zero N control. Relative to poultry litter, the pelletized fertilizers resulted in higher yields (9980 vs. 9267 kg ha−1), N uptake (140 vs. 114 kg ha−1), and N recovery efficiency (35 vs. 20%) in all fields. It was concluded that pelletized fertilizers were significantly more effective than poultry litter in supplying N to the crop when fields were continuously flooded. In contrast all organic fertilizers were less effective in supplying N when fields were drained for weed control due to lower N recovery efficiency (26%) and N loss through denitrification, indicating that organic fertilizer application may not be economically viable under such circumstances.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2011. . Copyright © 2011 by the American Society of Agronomy, Inc.