Environmental impacts of outdoor pig production: effects on P sorption

conferenceObject

Monteiro, M.C.H.

MESAEP

MONTEIRO, M.C.H.(2009) - Environmental impacts of outdoor pig production: effects on P sorption. In International Symposium in Environmental Pollution and it's Impact on Life in the Mediterranean Region, 15, Bari, 7-11 October. Bari : MESAEP.

Environmental impacts of outdoor pig production: effects on P sorption

Produção de suínos
Impacte ambiental

2010-03-13T11:49:53Z
2010-03-13T11:49:53Z
2009

Outdoor pig production, nowadays, is increasing consumer’s acceptation, as comparing with intensive indoor systems, because it offers better conditions to animal’s welfare and is considered as “more environmental friendly”. Mediterranean region offers good weather conditions for this type of pig production. This work was developed on an experimental area of outdoor pig production, localized at a farm belong to the Polytechnic School of Agriculture at Castelo Branco – Portugal. This area have 2.8 ha, animal charge is of 1136 m2 / animal adult, on average 9 adults / ha and the soil is a dystric Cambisoil. Earlier work shows an increase in soil P content of all the area, as well as an increase in soil P with time. In this work we evaluate (i) P sorption capacity of this soil, (ii) spatial changes on P sorption capacity and (iii) evolution with time of the P sorption capacity of this soil. Results shows that this soil had a low P sorption capacity (Qmax = 142 mg P kg-1 soil), evaluate from Langmuir isotherm. The evaluation of the effect of pig production, on spatial P sorption capacity shows in some sampled points an increase in P sorption capacity due to the creation of additional sorption sites with similar bonding energy and on other sampled points a decrease in soil P sorption capacity due mainly to a decrease in the affinity of existing P sorption sites or permanent blocking of sorption sites. With time the soil exhibits a decrease of its P sorption capacity. Feeding and excretions of pigs, modifying soil organic matter composition and levels, and erosion of superficial soil may justify changes on P sorption properties in this area. The lost of P sorption capacity in this area is one of the main factors to the increase of P transfer from soil to runoff or drainage waters. The effect of outdoor pig production on the decrease of soil P sorption capacity have an important environmental effect as it increases the risk of superficial waters eutrophication.

openAccess

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