Utilization by early harvest sugar cane ratoon of the nitrogen from 15N-aqua ammonia and 15N-urea applied to the soil as vinasse N-complement

• Autor(a) principal: Trivelin, Paulo Cesar Ocheuze
• Data de Publicação: 1996
• Outros Autores: Rodrigues, João Crisóstomo Simões, Victoria, Reynaldo Luiz
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/4457
• topic: nitrogen fertilizer; isotope technique; first ratoon crop; Saccharum spp.; nitrogen accumulation; fresh matter; dry matter; fertilizantes nitrogenados; técnica isotópica; cana-soca; Saccharum spp.; acumulação de nitrogênio; massa verde; massa seca

The utilization of nitrogen from aqua ammonia and urea applied to the soil as vinasse N-complement by early harvest sugar cane ratoon was, evaluated using 15N tracer technique. The experiment was conducted in São Paulo State on a commercial sugar cane field planted with the variety SP 70-1143, first ratoon crop. Two treatments of nitrogen fertilizer (urea and aqua ammonia) were used. Each treatment consisted of 19 neighbouring rows of sugar cane, 10 m long and 1.4 m apart. After vinasse application to the soil surface at a rate of 100 m3/ha, the N-fertilizers; (100 kg/ha of N) were manually applied and buried to 15 cm deep in furrows located 25 cm from both sides of all cane rows. The 15N-fertilizers were applied to subplots of 2 linear meter row segments (4 replicates). The results of fresh and dry matter yield and nitrogen derived from the fertilizer in the shoots (12-13 kg/ha of N-fertilizer recovery) were the same for both treatments (aqua ammonia and urea), 12 months after N fertilization. Six months after fertilization the estimates of nitrogen recovery from the aqua ammonia and urea in the shoot of the ratoon crop were 24 and 19 kg/ha of N, respectively. The total N in the shoot decreased from the 6th to the 9th month, possibly indicating translocation to the roots, or even volatilization losses; by the sugar cane foliage.