Soil attributes and microbial diversity on 28 years of continuous and interrupted for 12 months of pig slurry application

Abstract

The pig slurry (PS) application as an organic fertilizer in Brazilian soils occurs for many years and the effects of this application are known, but in this study our objective was to evaluate the microbiological attributes and microbial diversity of the soil after the interruption of the PS application. The PS rates were 0, 30 and 60 m 3 ha-1 yr-1 and in 2016 the plots were divided and the PS application was stopped in half of the plot, generating the factorial scheme 2 × 2, being two PS rates (30 and 60 m 3 ha-1 yr-1) and two application conditions (continuous or interrupted). Two soil samples were taken at 5 and 12 mo after interruption. The PS interruption reduced the microbial biomass C (MBC) by 5% and 14% after 5 and 12 mo, respectively. Microbial biomass N (MBN) was reduced too by 32% and 29% due to the PS interruption. The soil basal respiration (SBR) decreased when PS application was interrupted. The metabolic quotient (qCO2) did not change with the PS interruption but was high in the 60 m 3 ha-1 yr-1. The bacteria and archaea genetic profiles showed similarity above 69% between continuous and interrupted applications. The bacterial diversity and richness index were higher than those found for fungal and archaeal communities. In contrast, the interruption had a strong effect on the soil fungi, which had diversity reduced due to the increase of the species dominance. The PS interruption up to 12 mo has an effect on the biomass, diversity, and activity of the microorganisms.

Changes in Dry Matter and Carbon, Nitrogen, and Sulfur Stocks after Applications of Increasing Doses of Pig Slurry to Soils with Tifton-85 for Six Years in Southern Brazil

“…Wastes from pig production are usually stored in anaerobic ponds and used as an alternative soil fertilizer for agricultural crops and pastures [6][7][8][9][10], with similar results to commercial soluble chemical fertilizers [11,12]. Studies have shown increases in biomass production and quality, lower environmental impacts and production costs, and improvements in soil physical, chemical, and biological attributes [13][14][15][16][17].…”

Aggregation Index and Carbon and Nitrogen Contents in Aggregates of Pasture Soils under Successive Applications of Pig Slurry in Southern Brazil

“…Changes in soil chemical [24,25], physical [16,26,27], and biological [28][29][30] attributes have been found with application of PS, with positive effects on soil quality, and crop yields [10,31,32]. These benefits are mainly due to increases in organic matter contents, which favor soil aggregation and availability of nutrients to plants.…”

Influence of Pig Slurry Application Techniques on Soil CO2, N2O, and NH3 Emissions

“…Worldwide, pig manure is not the most common source of nitrogen; it contributes around 10% to total manure production, compared to cattle slurry which is around 44% [20]. Pig slurry enriches soils with nutrients (nitrogen and carbon supply) and promotes microbiological processes [21][22][23][24], consequently influencing CO 2 , N 2 O, and NH 3 emissions [25,26]. The nitrogen content of pig slurry not only ensures balanced crop production and yields but also is a danger for nitrogen losses such as NH 3 emissions and nitrate (NO 3 − ) leaching to the surface and groundwater reservoirs [27,28].…”