2020 journal article
Soil slope and texture as factors of phosphorus exportation from pasture areas receiving pig slurry
SCIENCE OF THE TOTAL ENVIRONMENT, 761.
author keywords: Slope; Phosphorus losses; Erosion; Soil texture
TL;DR:
The soil clay content and slope are aggravating factors to the P transfer process, thus must be considered in suitable models to predict the P losses risk and a P-threshold model for Mehlich-1 extractable P levels for Brazilian subtropical soils is proposed.
(via Semantic Scholar)
UN Sustainable Development Goal Categories
2. Zero Hunger
(Web of Science)
Source: Web Of Science
Added: February 15, 2021
Phosphorus (P) loss from agricultural areas to waterbodies is a worldwide concern. However, the effect of soil source and transport factors, such as clay (C) content and slope (S), on the magnitude of the P transport in Brazilian subtropical soils is still understudied. The objectives of this study were i) to quantify the loss of P fractions by runoff in areas receiving pig slurry application and with variations in S and C content; ii) propose an environmental critical limit model of P (P-threshold) for Brazilian subtropical soils. Thus, two series of experiments were conducted from 2016 to 2018, one under a Nitisol with 642 g kg -1 of C and another under a Cambisol with 225 g kg -1 of C. The treatments were four P rates (0, 56, 112 and 224 kg P ha -1 year -1 ) superficially applied as pig slurry, on Tifton (Cynodon sp) pasture, and three S (10, 20 and 30% in the Nitisol and 15, 25 and 35% in Cambisol). P losses increased in both soils as the S and P rates rose. The Nitisol showed P losses three times higher than the Cambisol. Soil S above 25% promotes P losses at a rate three times higher than in soil below this limit. Therefore, we propose a P-threshold model for Mehlich-1 extractable P levels for Brazilian subtropical soils as: "P-threshold = (42.287 + C) - (0.230 S + 0.0123 C S)" in soils with a S ≤ 25% and "P-threshold = (42.287 + C) - (-0.437 S + 0.039 C S)" in soils with a S >25%, where both C and S are shown in percentage. The soil clay content and slope are aggravating factors to the P transfer process, thus must be considered in suitable models to predict the P losses risk.