In this podcast, Georgia talks with Fernando Avendano a Massey University PhD student from Chile, about “Vegetated Buffer Strips”.
Fernando has a background in edge of field treatments to reduce nutrient losses from cropping systems. He studied the use of vegetated buffer strips to prevent nitrogen losses from maize paddocks, and is now working on a range of N loss mitigation trials in the Horowhenua district of Manawatu.
Vegetated buffer strips can help to prevent nitrogen losses from farming land, thus protecting nearby water resources. The main aim of Fernando’s Chilean study was to assess narrow buffer strips (5 m) wide of different species effectiveness in removing nitrogen forms that flow from cultivated maize fields towards surface water bodies.
During the second year after establishment, variable N loads were estimated from nitrate-N (NO3-N) and ammonia-N (NH4-N) concentrations measured at 1 m depth during the study period. Fernandos’ trial had five treatments: a strip of grass, a strip of grass and a row of native shrubs (Fuchsia magellanica); a strip of grass, a row of shrubs and a row of native trees 1 (Luma chequen); a strip of grass, a row of shrubs and a row of native trees 2 (Drimys winteri); and bare soil as control. The experiment was set in two cultivated maize (Zea mays) fields located in the commune of Pichidegua, Región de O’Higgins. In a clay loam, buffer strip outlet nitrogen measurements from subsurface lateral flow ranged from 10 to 105 kg N ha-1. All treatments were more effective in N removal than the bare soil control treatment and with the grass strip, row of shrubs, and row of native trees treatment performing the highest N removal.
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