Estratégias de uso dos dejetos de suínos em plantio direto para mitigar as perdas de nitrogênio por volatilização de amônia

• Ano de defesa: 2019
• Autor(a) principal: Bazzo, Heitor Luís Santin
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Agronomia; UFSM; Programa de Pós-Graduação em Ciência do Solo; Centro de Ciências Rurais
• Palavras-chave em Português: NH3; Método PET; Parcelamento; Aplicação dos dejetos; Injeção; PET method; Split application; Slurry application; Injection; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: http://repositorio.ufsm.br/handle/1/18631

Ammonia volatilization (NH3) is the main process of nitrogen loss (N) from liquid swine manure (PS) after application to the soil. Its quantification and the development of management alternatives to reduce losses are essential, decreasing the environmental liabilities generated by the use of PS. The first objective of this work was to evaluate the application and splitting strategies of PS with organic or mineral complementation, aiming at the reduction of N losses by volatilization of NH3 in corn/wheat succession in no – tillage. The second objective was the calibration of the semi-open collector PET for quantification of volatilized ammonia after application of PS to the soil. In order to reach these objectives, two studies were conducted under field conditions at Soil’s Department of the Federal University of Santa Maria. The first study was conducted in the succession of maize and wheat crops in a randomized complete block design with four replications, consisting of six treatments: Control; Mineral Fertilization (NPK + U); PSs - surface broadcast of PS with 100 % of N applied at sowing; PSi – PS injected with 100 % of N applied at sowing; Psi + PSs - PS injected with 50 % of N applied at sowing and 50 % of N applied in top-dressing through surface broadcast of PS; Psi + U – PS injected with 50 % of the N applied at sowing and 50 % of the N applied in top-dressing through surface broadcast of Urea. The second study consisted of two experiments performed in winter (I) and summer (II). The experiments were arranged in a randomized block design with four replicates, composed of the following treatments: Experiment I: Control; PSs (70 kg of total ammoniacal nitrogen (NAT) ha-1); Experiment II: Control; PSs (140 kg TAN ha-1). In the first study PSi treatment was the most efficient in reducing losses of NH3, with cumulative annual loss of 13.6 % of the TAN applied during the succession of crops. The Psi + PSs strategy did not differ from the traditional application (PSs), with cumulative annual losses of 90 kg N-NH3 ha-1. The treatments NPK + U and PSi + U presented intermediate losses of 42 and 34.5 kg N-NH3 ha-1, representing 22.1 and 20.1 % of the applied TAN respectively. In the second study, the volatilization of NH3 captured by the PET method in experiment I was 2.35 kg of N-NH3 ha-1, corresponding to 22.6 % of that emitted through NH3 detected by the soil balance. In the experiment II the volatilization of NH3 captured was 9.29 kg of N-NH3 ha-1 resulting in an efficiency of 19.1 %. From these two experiments the NH3 emission correction factor of the soil was obtained, based on the average efficiency of the collector in the two evaluated periods, resulting in a factor of 4.8. Thus, the adapted PET method proved to be an adequate alternative to quantify for the evaluation of NH3 volatilization after PS application. Injection of the full dose of PS in the soil at sowing is the best strategy to reduce ammonia volatilization in notillage crops.