Relationships between Soil Physicochemical, Microbiological Properties, and Nutrient Release in Buffer Soils Compared to Field Soils

• Published in: Journal of environmental quality Vol. 41; no. 2; pp. 400 - 409
• Main Authors: Stutter, Marc I., Richards, Samia
• Format: Journal Article
• Language: English
• Published: United States The American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc 01.03.2012; American Society of Agronomy
• Subjects: Carbon - analysis; Carbon - chemistry; Chemical Phenomena; Creeks & streams; dissolved organic carbon; dissolved organic nitrogen; fungal communities; Leaching; Moisture content; Nitrogen - analysis; Nitrogen - chemistry; Nutrient concentrations; Nutrient content; Nutrient release; Nutrient retention; nutrients; Organic matter; phosphorus; Phosphorus - analysis; Phosphorus - chemistry; Porosity; restriction fragment length polymorphism; Retention; riparian buffers; River ecology; Soil - chemistry; Soil density; Soil erosion control; Soil management; Soil Microbiology; Soil moisture; soil organic matter; soil water; Solubility; streams; Studies; Surface water; Vegetation; vegetation types; water content; Water quality; United Kingdom > UK; Scotland
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2010.0456

The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nutrient retention between buffer and field soils were determined using a combined assay for release of dissolved P, N, and C forms and particulate P. We then explored these differences in relation to changes in soil bulk density (BD), moisture, organic matter by loss on ignition (OM), and altered microbial diversity using molecular fingerprinting (terminal restriction fragment length polymorphism [TRFLP]). Buffer soils had significantly greater soil OM (89% of sites), moisture content (95%), and water‐soluble nutrient concentrations for dissolved organic C (80%), dissolved organic N (80%), dissolved organic P (55%), and soluble reactive P (70%). Buffer soils had consistently smaller bulk densities than field soils. Soil fine particle release was generally greater for field than buffer soils. Significantly smaller soil bulk density in buffer soils than in adjacent fields indicated increased porosity and infiltration in buffers. Bacterial, archaeal, and fungal communities showed altered diversity between the buffer and field soils, with significant relationships with soil BD, moisture, OM, and increased solubility of buffer nutrients. Current soil conditions in VBS appear to be leading to potentially enhanced nutrient leaching via increasing solubility of C, N, and P. Manipulating soil microbial conditions (by management of soil moisture, vegetation type, and cover) may provide options for increasing the buffer storage for key nutrients such as P without increasing leaching to adjacent streams.