Pig slurry and mineral fertilization strategies' effects on soil quality: Macroaggregate stability and organic matter fractions

• Published in: The Science of the total environment Vol. 438; pp. 218 - 224
• Main Authors: Yagüe, María R., Bosch-Serra, Àngela D., Antúnez, Montserrat, Boixadera, Jaume
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.11.2012; Elsevier
• Subjects: aggregate stability; Agriculture - methods; Animal, plant and microbial ecology; Animals; application timing; Applied ecology; biogeochemical cycles; Biological and medical sciences; Biological soil fertility; Biomass; Dryland areas; Ecotoxicology, biological effects of pollution; environmental impact; Feces - chemistry; Fertilizers - analysis; field experimentation; Field studies; Fundamental and applied biological sciences. Psychology; General aspects; grains; microbial biomass; nitrogen fertilizers; organic matter; Physical soil fertility; pig manure; silty soils; Soil - analysis; Soil - standards; soil aggregates; Soil organic carbon; soil organic matter; soil quality; soil sampling; Soil structure; Spain; Sus scrofa; tillering; Water - chemistry; Spain; SS; PS; WSA; Field studies; SMB; Soil structure; Physical soil fertility; AN; FS; M; AGBM; SOM; Biological soil fertility; WSAMOD; Soil organic carbon; OM; Dryland areas; Organic carbon; Organic matter; Stability; Soil fertility; Arid environment; Animal slurry; Soil quality; Soils; Mineral fertilization; Strategy; Dryland; Field study
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2012.08.063

Applying pig slurry to the land as fertilizer at appropriate agronomic rates is important to close nutrient cycles and optimize the value of organic matter. However a long-term discussion has taken place about its effects on soil quality. In the north-east of Spain, eight fertilization strategies were evaluated on the soil quality parameters' aggregate stability, soil organic matter (SOM) physical fractions and soil microbial biomass (SMB). Six strategies used different pig slurries (PS) which provided organic matter from 1.7 to 2.6tha−1yr−1, the rest (mineral N fertilization and a control) did not. Pig slurries were applied at sowing and/or at cereal tillering, as sidedressing. Field experiments were maintained for an 8-year period, in a silty loam soil devoted to a rainfed winter cereal. Soil samples were taken once, before the last sidedressing in 2011. Aggregate stability was quantified using the standard water-stable aggregate method but including a modification which meant that pre-wetting was avoided (WSAMOD). When using the WSAMOD method, we found a tendency for the percentage of water-stable aggregates to increase due to PS application (differences of up to 74% in the increment) and it was more marked the nearer they were measured to the application time (3months vs. 12months). The strategies which include PS show a positive effect on the SOM amount, mainly in the 0.05–0.2mm light fraction, which increased by up to 34% with every 10tha−1 organic C applied, and on SMB (up to 53% increment). There is a positive and significant linear relationship (p<0.05, R2=0.75) between the SOM light fraction (%) and the water-stable aggregates soil content (%, WSAMOD). Thus, the introduction of PS in fertilization strategies improves soil quality parameters. However, the soil quality benefits need to be balanced with any other potential environmental impact. ► Pig slurry has a positive effect on the total amount of soil OM and microbial biomass. ► Pig slurry fertilization increases soil water-stable aggregates related to slaking. ► Light SOM fraction is positively correlated with soil water-stable aggregates. ► Pig slurry at agronomic rates improves soil quality parameters in dryland areas. ► WSAMOD test is recommended for soil stability evaluation in dryland areas.