Biogenic aggregation intensifies soil improvement caused by manures

The use of manures as organic fertilizers commonly improves soil chemical and structural attributes. We investigated the effect of biogenic aggregation on the structural and chemical dynamics of a Rhodic Ferralsol after nine continuous years of chicken manure or swine liquid manure application. The biogenic aggregation increased nutrient availability, neutralized acidity, and increased organic matter content. Additionally, the proportion of pores with a diameter higher than 0.100 mm was increased by biogenic aggregation. The intensity of this improvement depended on the manure nutrient content, and the rate of biogenic aggregation depended on the carbon input provided by the manure. However, aggregates with higher base saturations were more susceptible to dispersion and such aggregates, therefore, need to be protected from mechanical disrupting agents.