In:
The Journal of Agricultural Science, Cambridge University Press (CUP), Vol. 128, No. 4 ( 1997-06), p. 461-468
Abstract:
Water balance components under wheat were assessed by employing two
simple models, differing in their structure and data requirements, namely the
soil-plant–atmosphere–water (SPAW) model of Saxton (1989) and the water balance model (WBM) of Arora et al . (1987).
A few modifications based on the SPAW model procedure for the estimation of green canopy were used in
a modified WBM and its performance was also tested. Soil water loss (the sum of interception
evaporation, soil evaporation, plant transpiration and deep drainage) from sowing to harvest, simulated
with the WBM, modified WBM and the SPAW model, had a close correspondence with the measured sum
of profile water depletion, rainfall and irrigation for values ranging between
18·3 and 42·7 cm. Estimates of drainage with the WBM and modified WBM using empirical coefficients were greater
than those calculated using the SPAW model for situations where the upward flow of water into
the root-zone was negligible. Estimates of soil water evaporation using the WBM and modified
WBM were invariably smaller than those using the SPAW model. A comparison of simulated and
measured soil water storage and a correlation analysis of simulated transpiration with
measured biomass at harvest showed that the performance of the WBM was the most realistic of the
three models. However, it requires the input of leaf area index values to infer green canopy for
each water supply regime. In the absence of this information, the modified WBM and SPAW models are more
useful for assessing water balance components in cropped soils.
Type of Medium:
Online Resource
ISSN:
0021-8596
,
1469-5146
DOI:
10.1017/S0021859697004358
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1997
detail.hit.zdb_id:
1498349-7
