Continuous potassium (K) removal without replenishment is progressively mining Argentinean soils. Our goals were to evaluate the sensitivity of soil-K to K budgets, quantify soil-K changes over time along the soil profile, and identify soil variables that regulate soil-K depletion. Four on-farm trials under two crop rotations including maize, wheat and soybean were evaluated. Three treatments were compared: (1) control (no fertilizer applied); (2) application of nitrogen, phosphorus, and sulfur fertilizers -NPS-; and (3) pristine condition. After nine years, crops removed from 258 to 556 kg K ha−1. Only two sites showed a decline in the exchangeable-K levels at 0–20 cm but unrelated to K budget. Topsoil exchangeable-K levels under agriculture resulted 48% lower than their pristine conditions, although still above response levels. Both soil exchangeable-K and slowly‑exchangeable K vertical distribution patterns (0–100 cm) displayed substantial depletion relative to pristine conditions, mainly concentrated at subsoil (20–100 cm), with 55–83% for exchangeable-K, and 74–95% for slowly- exchangeable-K. Higher pristine levels of exchangeable-K and slowly-exchangeable-K and lower clay and silt contents resulted in higher soil-K depletion. Soil K management guidelines should consider both topsoil and subsoil nutrient status and variables related to soil K buffer capacity.
Correndo, A. A.; Rubio, G.; García, F. O. & Ciampitti, I. A. (2021). Subsoil-potassium depletion accounts for the nutrient budget in high-potassium agricultural soils. Scientific Reports,11,art. 11597,10 p.
10.1038/s41598-021-90297-1
Correndo, Adrián Alejandro, Rubio, Gerardo, García, Fernando Oscar, Ciampitti, Ignacio Antonio. 2021. "Subsoil-potassium depletion accounts for the nutrient budget in high-potassium agricultural soils". Scientific Reports 11:art. 11597,10p..
Recuperado de http://ri.agro.uba.ar/greenstone3/library/collection/arti/document/2021correndo