Atributos físicos e carbono orgânico de um cambissolo háplico alumínico submetido a diferentes métodos de incorporação e doses de calcário.

Abstract

Soil acidity is a limiting factor for agricultural production. In association, intensive methods of limestone incorporation can cause negative changes in soil attributes. The research aimed to evaluate the effect of the application and doses of limestone combined with different methods of incorporation of soil amendment on physical-hydric attributes and organic carbon of a Haplic Cambisol (Cambissolo Háplico alumínico), in the southeastern region of the State of Paraná. The treatments consisted of three forms of limestone application to the soil (CSI: without incorporation, CIAG: incorporated with disc plough + disc harrow, and CIEG: incorporated with chisel plough + disc harrow), and four doses of limestone (0, 10, 15 and 20 Mg ha-1 ). Samples were collected in the 0-0.1 and 0.1-0.2 m layers in May 2019, seven months after the limestone replication, with the experiment started in 2012. Increased soil mobilization resulted in higher bulk density in the surface layer and lower in the subsurface. In CSI, the increased in limestone dose resulted in higher macroporosity (Macro) and bioporosity (Bio), while in CIEG and CIAG, the highest dose decreased Macro and Bio. Soil water retention increased with limestone application and was higher in CIAG and CIEG compared to CSI. Liquid limit and plasticity index of soil were higher in CIAG and CIEG compared to CSI. The contents of total organic carbon in the soil were higher in CSI and CIEG, while labile carbon decreased in the following order: CIAG>CIEG>CSI. The stocks of total organic carbon increased up to the dose of 15 Mg ha-1 of limestone, and the CIAG reduced stocks compared to the others treatments.