Application of mechanistic model for phosphorus uptake by barley under low temperature conditions

Abstract

Mechanistic single root model that estimates nutrient flow and total uptake of nutrients was applied to phosphorus (P) uptake by barley under different temperature (8 and 20°C) conditions with and without P application treatments. Temperature markedly affected growth. The difference between P treatments was rather negligible. The dry-matter weight and P uptake increased slightly with P application under low temperature conditions, unlike in the case of higher temperature conditions. Root length under low temperature conditions was short, with large radius. P application led to a reduction of the root length. Soil solution P concentration decreased under low temperature conditions. Estimated P uptake with the model was within the confidence limit of experimental values but rather smaller than the observed values for the plants which did not receive P (74 and 94%). Based on sensitivity analysis of the model, lower P concentration in the soil solution was considered to be the reason for the lower P uptake under lower temperature conditions. The effect of P application was estimated to be larger under low temperature conditions than under high temperature conditions (60 and 17% increase, respectively). Diffusion around root along with root length seemed to be the process that dominated P uptake under different temperature conditions. © 2002 Taylor & Francis Group, LLC.