The response of finely textured and organic soils to lime and phosphorus application: Results from an incubation experiment |
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Authors: | David Corbett Bridget Lynch David P. Wall Patrick Tuohy |
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Affiliation: | 1. Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Cork, Ireland;2. Teagasc, Crops, Environmental and Land-use Programme, Wexford, Ireland |
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Abstract: | A soil's responses to phosphorus (P) input differs based on its chemical composition. Soil acidity and the presence of metallic cations dictate a soil's chemical composition. Currently, soil P application recommendations are universal and do not account for differing soil composition. A targeted soil-specific approach is required to optimize P efficiency and availability. A pot incubation experiment was established to explore the effects of contrasting lime and P application rates across a range of soils (25), characterized by fine particle size and high levels of soil organic matter. Three contrasting rates of P were applied (0, 50, and 150 kg P ha−1) both with and without ground lime (CaCO3) at 5 tonne ha−1 over a 140-day incubation period. The addition of lime buffered the soil, increasing nutrient availability and reducing P fixation. The 50 kg P ha−1 treatment rate was required to achieve sufficient plant available P in both mineral soil textural classes. Current legislative recommendations however do not allow the application of such rates, which has an impact on agronomic performance. Loam soils experienced a greater increase in M3 soil P in comparison to clay and organic soils. Organic soils posed a major threat to water quality due to poor P retention. A re-evaluation of P recommendations is required to account for soil variability as current P allowances are insufficient on these particular soils. |
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Keywords: | metallic ions P fixation soil pH soil phosphorus water quality |
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