Carbon fractions and soil fertility affected by tillage and sugarcane residue management an Xanthic Udult

Abstract

The gradual change in management practices in sugarcane (Saccharum spp.) production from burning straw to a green harvesting system, as well as the use of minimum soil tillage during field renovation, may affect soil fertility and soil organic matter (SOM) contents. The objectives of this work were to investigate the influence of sugar cane production systems on: (1) soil fertility parameters; (2) on physical carbon fractions; (3) and on humic substance fractions, in a long-term experiment, comparing two soil tillage and two residue management systems an Xanthic Udult, in the coastal tableland region of Espírito Santo State, Brazil. The treatments consisted of plots (conventional tillage (CT) or minimum tillage (MT)) and subplots (residue burned or unburned at harvesting), with five replicates The highest values of Ca 2+ + Mg 2+ and total organic carbon (TOC) were observed in the MT system in all soil layers, while high values of K + were observed in the 0.1-0.2 m layer. The CT associated with the burned residue management negatively influenced the TOC values, especially in the 0.1-0.2 and 0.2-0.4 m layers. The carbon in the humin fraction and organic matter associated with minerals were significantly different among the tillage systems; the MT showed higher values than the CT. However, there were no significant differences between the sugarcane residue management treatments. Overall, fractioning the SOM allowed for a better understanding of tillage and residue management systems effects on the soil properties. Key words: Saccharum spp. Soil tillage systems. Residue retention. ResumoA mudança gradual nas práticas de manejo da cana de açúcar (Saccharum spp.) de colheita com queima de palha para o sistema de colheita sem queima, bem como o uso de preparo mínimo do solo durante a renovação do canavial, podem afetar a fertilidade do solo e o conteúdo de matéria orgânica do solo (MOS). Os objetivos específicos foram investigar a influência de sistemas de produção de cana-deaçúcar sobre: (1) os parâmetros de fertilidade do solo; (2) sobre as frações físicas do carbono; (3) e em frações de substâncias húmicas, em um experimento de longa duração, comparando dois tipos de preparo do solo e dois sistemas de manejo da palhada em Argissolo Amarelo, na região tabuleiros costeiros do Espírito Santo, Brasil. Os tratamentos consistiram de parcelas (preparo convencional (PC)

Trade-Offs between Sugarcane Straw Removal and Soil Organic Matter in Brazil

“…It was in accordance with data shown by [50], which a portion of C derived from straw enters into the soil as labile organic C pool. Additionally, a greater protection and increase in C in humic substance fractions in areas where there is a minimum tillage of soil was reported by Lopes [59]. Studies using stable isotopes of C (δ 13 C) have shown that a greater proportion (about 60%) of soil C is derived from the straw in the sugarcane field, which indicates that the humification process was stimulated [54].…”

Materia orgánica particulada y mineralogía de un Andisol bajo labranza y barbecho

“…Los Andisoles se caracterizan por su alto contenido de MO, propio del desarrollo del complejo aluminio-humus (Malagón et al, 1991) sin embargo, esta MO es susceptible al manejo, disminuyendo su contenido de manera significativa por acción de la continua labranza del suelo (arado de discos y arado rotatorio) y el monocultivo (Shoji, et al, 1993;Lopes et al, 2017;Silva et al, 2007). Sin embargo, como muestran nuestros resultados, se logra incrementar la MO con periodos relativamente cortos de barbecho, 5 años, aunque la tasa de incremento posterior a este período disminuye.…”

Stock and indices of carbon management under different soil use systems

“…This negative variation in StockC in the 0-0.05-m layer is more evident in the SC area. This is mainly due to the intense soil management in the SC area, where gradation is used for crop renewal (Lopes et al, 2017). This process breaks the soil aggregates, leaving the SOM exposed to microorganisms that consume this organic matter, releasing CO 2 (Bertollo and Levien, 2019;Gonçalves et al, 2019).…”