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Aggregate strength in calcareous soil fertilized with pig slurries
Author(s) -
BoschSerra À. D.,
Yagüe M. R.,
Poch R. M.,
Molner M.,
Junyent B.,
Boixadera J.
Publication year - 2017
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/ejss.12438
Subject(s) - slurry , calcareous , soil structure , porosity , environmental science , fertilizer , aggregate (composite) , soil test , soil science , agronomy , soil water , materials science , geotechnical engineering , geology , composite material , environmental engineering , paleontology , biology
Effects of applications of pig slurry on soil aggregate stability are not well understood in dryland agriculture. This research aims to (i) identify aggregate stability tests that give a reliable description of the soil's behaviour when pig slurry ( PS ) is applied to calcareous soil and (ii) interpret them in terms of chemical, biological, morphological and physical soil properties for soil quality assessments. Soil samples from eight fertilizer treatments (mineral fertilizers and PS ), applied over seven growing seasons were analysed. We applied five methodologies to examine different mechanisms of aggregate breakdown. Porosity was characterized by image analyses. There was minimum resistance to the mechanical breakdown of aggregates when slurries had been applied 12 months before analysis. Recent applications of slurry (3 months before the analysis) improved resistance to implosion caused by the penetration of water into dry aggregates (slaking), although the opposite result can occur if the method of evaluation is not chosen properly. Recent applications of PS also enhanced soil respiration and increased soil porosity in the 25–100‐µm size range (packing pores between aggregates) and in the 100–400‐µm size range (interaggregate or faunal pores). In dryland systems and in the winter cereal cropping season, the resistance of dry aggregates to slaking is improved temporarily if PS is applied at N rates equivalent to around 1.7 Mg OM ha −1 year −1 . Highlights How does soil aggregate strength change in response to pig slurry ( PS ) applications? Improve understanding of PS as a fertilizer and its effect on soil quality assessments Changes in aggregate stability are controlled by time since pig slurry application The effects of PS on the increase in packing pores between aggregates are transient