Silicon accumulation and water uptake by wheat

Mayland, H.F. and Wright, J.L. and Sojka, R.E. (1991) Silicon accumulation and water uptake by wheat. Plant and Soil. 137(2):191-199.

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Abstract

Silicon (Si) content in cereal plants and soil-Si solubility may be used to estimate transpiration,
assuming passive Si uptake. The hypothesis for passive-Si uptake by the transpiration stream was tested
in wheat (Triticum aestivum cv. Stephens) grown on the irrigated Portneuf silt loam soil (Durixerollic
calciorthid) near Twin Falls, Idaho. Treatments consisted of 5 levels of plant-available soil water
ranging from 244 to 776 mm provided primarily by a line-source sprinkler irrigation system. Evapotranspiration
was determined by the water-balance method and water uptake was calculated from
evapotranspiration, shading, and duration of wet-surface soil. Water extraction occurred from the 0 to
150-cm zone in which equilibrium Si solubility (20°C) was 15 mg Si L-1 in the Ap and Bk (0-58 cm
depth) and 23 mg Si L-1 in the Bkq (58-165 cm depth).
At plant maturity, total Si uptake ranged from 10 to 32 g m-2, above-ground dry matter from 1200 to
2100 g m-2 and transpiration from 227 to 546 kg m 2. Silicon uptake was correlated with transpiration
(Siup = –0.7 + .06T, r2 = 0.85) and dry matter yield with evapotranspiration (Y = 119 + 3.3ET, r2 =
0.96). Actual Si uptake was 2.4 to 4.7 times that accounted for by passive uptake, supporting
designation of wheat as a Si accumulator. The ratio of Si uptake to water uptake increased with soil
moisture. The confirmation of active Si uptake precludes using Si uptake to estimate water use by
wheat.

Item Type:	Article
NWISRL Publication Number:	0754
Subjects:	Irrigated crops > Small grain Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	06 Dec 2016 23:50
Item ID:	563
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/563