Arroz irrigado no Rio Grande do Sul: um enfoque sobre fertilidade do solo

TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Curso de Agronomia.O estado do Rio Grande do Sul (RS) se destaca na produção de arroz irrigado no Brasil, sendo o maior produtor do grão no país. A adoção de práticas e tecnologias que visam à manutenção ou aumento da fertilidade do solo é fundamental para se obter altos rendimentos, o que proporciona sustentabilidade econômica à cadeia produtiva. Entretanto, o RS apresenta uma grande diversidade de solos, que quando alagados para o cultivo do arroz modificam a solução do solo e disponibilizam nutrientes em diferentes quantidades e intensidades. O trabalho objetivou acompanhar atividades realizadas no Instituto Rio Grandense do Arroz (IRGA), na Estação Experimental do Arroz (EEA), principalmente com relação a fertilidade do solo, e verificar as modificações na solução de diferentes solos do RS após o alagamento, com e sem o cultivo de plantas de arroz. O estágio de conclusão de curso foi realizado no período de 20 de agosto a 10 de novembro de 2012. O presente trabalho foi dividido em dois capítulos. O primeiro trata da descrição de atividades realizadas no IRGA e segundo aborda as atividades em um experimento realizado em casa de vegetação. Durante o período do estágio participou-se de diversas atividades no IRGA, como em trabalhos e experimentos relacionados às áreas de sistemas de cultivo, manejo da adubação, disponibilidade de nutrientes em solos alagados, plantas de cobertura, integração lavoura pecuária, tecnologias mais limpas e rotação de culturas. Além disso, foram acompanhadas as atividades no Laboratório de Análise de Solo, além de vários eventos relacionados à atividade orizícola. No experimento em casa de vegetação observaram-se modificações na solução de diferentes solos do RS, sendo observado o aumento dos valores de pH, condutividade elétrica e diminuição dos valores de potencial de oxirredução, ao longo do período de alagamento. Alguns solos com presença de plantas apresentaram valores menores de pH e condutividade elétrica, a partir de 45 dias de alagamento

Effectiveness of current fertilizer recommendations for irrigated rice in integrated crop-livestock systems

Irrigated rice in the state of Rio Grande do Sul (Brazil) has shown significant growth in yield in recent years due to improved management practices, especially in regard to fertilizer use. However, the response curves that led to the current fertilizer recommendations do not consider integrated systems prevailing in rice-producing regions that have adopted the practice of integrated crop-livestock systems. The aim of the present study was to evaluate the effectiveness of current fertilizer recommendations for irrigated rice in lowland soils in Rio Grande do Sul under integrated crop-livestock systems for different periods of time. The experiments were performed in the 2012/2013 growing season on four farms in the state with different forage species under cattle grazing. In these areas, fertilizer recommendations were made based on previous soil analyses, and treatments consisted of fractions of the currently recommended application rates. At the end of the crop cycle, the percentages of maximum technical efficiency (PMTE) and maximum economic efficiency (PMEE) of NPK fertilizers, and increases in yield and net income provided by PMEE were determined. Rice yield increased and fertilizer response decreased over time in a rice-beef cattle integrated system. The highest incomes with fertilization of irrigated rice occurred at lower application rates than those recommended by soil analysis

Effectiveness of current fertilizer recommendations for irrigated rice in integrated crop-livestock systems

Irrigated rice in the state of Rio Grande do Sul (Brazil) has shown significant growth in yield in recent years due to improved management practices, especially in regard to fertilizer use. However, the response curves that led to the current fertilizer recommendations do not consider integrated systems prevailing in rice-producing regions that have adopted the practice of integrated crop-livestock systems. The aim of the present study was to evaluate the effectiveness of current fertilizer recommendations for irrigated rice in lowland soils in Rio Grande do Sul under integrated crop-livestock systems for different periods of time. The experiments were performed in the 2012/2013 growing season on four farms in the state with different forage species under cattle grazing. In these areas, fertilizer recommendations were made based on previous soil analyses, and treatments consisted of fractions of the currently recommended application rates. At the end of the crop cycle, the percentages of maximum technical efficiency (PMTE) and maximum economic efficiency (PMEE) of NPK fertilizers, and increases in yield and net income provided by PMEE were determined. Rice yield increased and fertilizer response decreased over time in a rice-beef cattle integrated system. The highest incomes with fertilization of irrigated rice occurred at lower application rates than those recommended by soil analysis

Effectiveness of Current Fertilizer Recommendations for Irrigated Rice in Integrated Crop-Livestock Systems

ABSTRACT: Irrigated rice in the state of Rio Grande do Sul (Brazil) has shown significant growth in yield in recent years due to improved management practices, especially in regard to fertilizer use. However, the response curves that led to the current fertilizer recommendations do not consider integrated systems prevailing in rice-producing regions that have adopted the practice of integrated crop-livestock systems. The aim of the present study was to evaluate the effectiveness of current fertilizer recommendations for irrigated rice in lowland soils in Rio Grande do Sul under integrated crop-livestock systems for different periods of time. The experiments were performed in the 2012/2013 growing season on four farms in the state with different forage species under cattle grazing. In these areas, fertilizer recommendations were made based on previous soil analyses, and treatments consisted of fractions of the currently recommended application rates. At the end of the crop cycle, the percentages of maximum technical efficiency (PMTE) and maximum economic efficiency (PMEE) of NPK fertilizers, and increases in yield and net income provided by PMEE were determined. Rice yield increased and fertilizer response decreased over time in a rice-beef cattle integrated system. The highest incomes with fertilization of irrigated rice occurred at lower application rates than those recommended by soil analysis

Changes in soil acidity and organic carbon in a sandy typic hapludalf after medium-term pig-slurry and deep-litter application

Successive applications of liquid swine waste to the soil can increase the contents of total organic carbon and nutrients and change acidity-related soil chemical properties. However, little information is available on the effects of swine waste application in solid form, as of swine deep-litter. The objective of this study was to evaluate alterations of organic carbon and acidity-related properties of a soil after eight years of pig slurry and deep-litter application. In the eighth year of a field experiment established in Braço do Norte, Santa Catarina (SC) on a sandy Typic Hapludalf samples were taken (layers 0-2.5; 2.5-5; 5-10; 10-15; 15-20 and 20-30 cm) from unfertilized plots and plots with pig slurry or deep-litter applications, providing the simple or double rate of N requirement of Zea mays and Avena strigosa in rotation. Soil total organic carbon, water pH, exchangeable Al, Ca and Mg, and cation exchange capacity (CECeffective and CECpH7.0), H+Al, base saturation, and aluminum saturation were measured. The application of pig slurry and deep-litter for eight years increased total organic carbon and CEC in all soil layers. The pig slurry and deep-litter applications reduced active acidity and aluminum saturation and increased base saturation down to a depth of 30 cm. Eight years of pig slurry application did not affect soil acidity