Vegetated Buffer Strips Can Lead to Increased Release of Phosphorus to Waters: A Biogeochemical Assessment of the Mechanisms

Abstract

Establishing vegetated buffer strips (VBS) between cropland and watercourses is currently promoted as a principal control of diffuse pollution transport. However, we lackthe mechanistic understanding to evaluate P retention in VBS and predict risks of P transport to aquatic ecosystems. We observed that VBS establishment led to enhanced rates of soil P cycling, increasing soil P solubility and the potential amount leached to watercourses. Soil in VBS, relative to adjacentfields, had increased inorganic P solubility indices, dissolved organic P, phosphatase enzyme activity, microbial diversity, and biomass P. Small relative increases in the pool of soil P rendered labile had disproportionate effects on the P available for leaching. We propose a mechanism whereby the establishment of VBS on previous agricultural land causes a diversifying plant-microbial system which can access previous immobilized soil P from past fertilization or trapped sediment P. Laboratory experiments suggested that sediment-P inputs to VBS were insufficient alone to increase P solubility without biological cycling. Results showthat VBS management may require strategies, for example, harvesting vegetation, to offset biochemical processes that can increase the susceptibility of VBS soil P to move to adjoining streams.

PERSiST: a flexible rainfall-runoff modelling toolkit for use with the INCA family of models

“…For example, riparian and upland areas can be simulated. Because of the lateral connectivity between upland and riparian areas, representing watershed hydrology using a series of vertically stacked buckets may not be appropriate for simulating the hydrochemistry of headwater forest (Löfgren et al, 2011) or agricultural (Stutter et al, 2009) watersheds. When simulating laterally connected bucket systems used to represent riparian and upland areas, some additional parameters must be specified for the different buckets so as to ensure that hydrology is represented correctly.…”

Phosphorus distribution and sorption-release characteristics of the soil from newly submerged areas in the Danjiangkou reservoir, China

“…According to the results, the arable land was main zone contributed significantly to P release during a water storage period, and 51.7% of the total newly submerged area in the Danjiangkou Reservoir was designated as arable land, thus it was important to explore the distribution characteristics of P in the arable land. Besides, it unwise to establish grass buffer strips in the newly submerged area, because grass buffer strips may be increasing the susceptibility P move to adjoining water (Stutter et al, 2009). …”

A new model of dynamic of plant biodiversity in changing farmlands: Implications for the management of plant biodiversity along differential environmental gradient in the Yellow River of Henan Province in the spring

“…diversity dynamics, species composition, food web structure, diversifying plant-microbial system, ecosystem stability/functioning, organic agriculture, biodiversity law, watershed ecosystem management, assessment of ecosystems and biodiversity, scale dependence) (Stutter et al, 2009;Shennan, 2008;Menalled et al, 2001, Bartels andChen, 2010;Crowder et al, 2010;Bai et al, 2004;Davis et al, 2007;Bernez et al, 2002;Marris, 2010;Crawley and Harral, 2001). For instance, Menalled et al (2001) suggested that agricultural management systems can have both immediate and long-term effects on weed species density, abundance and diversity.…”

“…Shennan (2008) proposed that important elements for understanding biotic interactions include consideration of the effects of diversity, species composition and food web structure on ecosystem processes; the impacts of timing, frequency and intensity of disturbance; and the importance of multitrophic interactions in agroecosystem. Stutter et al (2009) proposed a mechanism whereby the establishment of vegetated buffer strips between cropland and watercourses on previous agricultural land causes a diversifying plant-microbial system. Bartels and Chen (2010) explained that whether resource quantity or resource heterogeneity is the determinant of under-story plant diversity in individual studies was dependent on stand succession stage(s), presence or absence of intermediate disturbance, and forest biome within which the studies were conducted.…”