The exchange of water and carbon by crops in a mediterranean climate

Autor: J. L. Monteith
Rok vydání: 1993
Předmět:
Zdroj: Irrigation Science. 14
ISSN: 1432-1319
0342-7188
DOI: 10.1007/bf00208401
Popis: The amount of biomass accumulated by a crop stand per unit of water transpired is referred to as a Biomass Water Ratio (BWR). The paper is mainly concerned with the dependence of BWR on climatic factors, in particular, saturation vapour pressure deficit (D) and precipitation (P) with which D is highly correlated in a mediterranean climate. A method is outlined for estimating the amount of water evaporated from bare soil during the establishment phase of a crop as a fraction of total seasonal water use. A simple model is derived for the BWR as a function of climate and of two stomatal parameters derived from a relation between stomatal conductance and transpiration. Values of BWR are presented for three contrasting stations in Israel and are shown to be strongly correlated with D and therefore with P. The model is combined with an empirical relation between the Priestley-Taylor coefficient and surface resistance in order to establish a new relation between BWR and resistance and to demonstrate that BWR × D is almost independent of resistance above 100 sm−1.
Databáze: OpenAIRE
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