Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Action: Soil: Plant buffer strips Mediterranean Farmland

Key messages

Read our guidance on Key messages before continuing

Organic matter (1 study): One replicated, randomized, controlled study from Italy found more organic matter in plots with buffers.

Nutrients (1 study): One replicated, randomized, controlled study from Italy found more nitrogen in plots with buffers.

Soil organisms (1 study): One replicated, randomized, controlled study from Italy found more microbial biomass in plots with buffers.

Soil erosion and aggregation (0 studies)

Greenhouse gases (0 studies)

Implementation options (1 study): One study from Italy found some differences between buffers of different widths, and other differences between buffers with different numbers of trees.

Supporting evidence from individual studies

1 

A replicated, randomized, controlled study in (1997–2010) in a maize field in the Po Valley, Italy, found more organic matter, nitrogen, and microbial biomass in buffered plots, compared to unbuffered plots. Organic matter: More organic matter was found in buffered plots, in seven of eight comparisons (0.25–0.35% vs 0.22%). Nutrients: More nitrogen was found in buffered plots, in seven of eight comparisons (0.13–0.14% vs 0.1%). Soil organisms: More microbial biomass (measured as carbon) was found in buffered plots, in six of eight comparisons (316–566 vs 257 mg/kg dry soil), and more microbial biomass (measured as nitrogen) was found in two of eight comparisons (40–47 vs 27 mg/kg dry soil). Implementation options: More organic matter was found in plots with 3 m buffers, compared to 6 m buffers (0.30–0.34% vs 0.25–0.27%). Similar soil nitrogen was found in plots with 3 m buffers and 6 m buffers (1%). Less microbial biomass (measured as carbon) was found in plots with 3 m buffers, compared to 6 m buffers, in one of two comparisons (450 vs 541 mg/kg dry soil), but more was found in one of two comparisons (391 vs 327 mg). Less microbial biomass (measured as nitrogen) was found in plots with 3 m buffers, in one of two comparisons (33 vs 40 mg/kg dry soil). Similar amounts of organic matter were found in plots that had buffers with one or two tree rows (0.20–0.28%). More nitrogen was found in plots that had buffers with one tree row, compared to two, in one of two comparisons (0.14% vs 0.12%). Similar amounts of microbial biomass (measured as carbon) were found in plots that had buffers with one or two tree rows (316–565 mg/kg dry soil). More microbial biomass (measured as nitrogen) was found in plots that had buffers with one tree row, compared to two, in one of two comparisons (40 vs 34 mg/kg dry soil). Methods: Maize plots had grass buffers (3 m grass: tall fescue Festuca arudinacea), grass and woody buffers (3 m grass with one tree row; 6 m grass with one tree row; 6 m grass with two tree rows), or no buffers (two replicates of each plot). Trees included guelder-rose Viburnum opulus and London sycamore Platanus hybrida. Plots were ploughed (35–40 cm depth) and harrowed before sowing crops. Fertilizers were applied (April: 400 kg/ha of NPK; May: 450 kg/ha of urea). Grass buffers were mown twice a year in growing season (residues were not removed) and tree offshoots were removed. Trees were coppiced in 2003 and 2010. Soil samples were taken (0–15 cm) in April and October 2010.

 

Referenced papers

Please cite as:

Shackelford, G. E., Kelsey, R., Robertson, R. J., Williams, D. R. & Dicks, L. V. (2017) Sustainable Agriculture in California and Mediterranean Climates: Evidence for the effects of selected interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.