Authors: Celso Aita Sylvie Recous Regina Helena Osmari Cargnin Laura Patrícia da Luz Sandro José Giacomini
Publish Date: 2012/01/17
Volume: 48, Issue: 6, Pages: 633-642
Abstract
The joint management of animal manures and plant biomass as straw on agricultural soils may be a viable option for reducing the environmental impacts associated with livestock production and recycling nutrients efficiently To investigate this option an incubation in controlled conditions examined how the simultaneous addition of 15Nlabeled pig slurry and 13Clabeled wheat straw either on the soil surface or incorporated into the soil affected the mineralization of C from the organic materials and the soil N dynamics Samples from a typic hapludalf were incubated for 95 days at 25°C with eight treatments unamended soil S wheat straw left on the soil surface Ws wheat straw incorporated in the soil Wi pig slurry on the soil surface Ps pig slurry incorporated in the soil Pi and three combinations of the two amendments Pi + Ws Pi + Wi and Ws + Ps Carbon dioxide and 13CO2 emissions and soil N content were measured throughout the incubation Pig slurry stimulated the decomposition of straw C only when wheat straw and pig slurry were left together on the soil surface Incorporation of both wheat straw and pig slurry did not modify straw C mineralization when compared to straw incorporation alone but this promoted a higher rate of N immobilization The results suggest that when pig slurry is used in field under notill conditions the best strategy to preserve environmental quality with regard to CO2 emissions would be to apply pig slurry underneath the crop residues
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