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Managing Potassium in Potato Production Systems of Idaho

Westermann, D.T. and Tindall, T.A. (1995) Managing Potassium in Potato Production Systems of Idaho. Proceedings of the Winter Commodity Schools. 27:201-207.

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Historical soil test information for southern Idaho surface soils (0-12") shows that
extractable K concentrations declined from 400-plus ppm in the late 1960's to 100-200
ppm today. Potatoes, silage corn, and alfalfa can remove nearly 400 lbs K/A-yr when
high yields are achieved. Many irrigation waters contain 28-56 lbs/A-ft soluble K which
is not sufficient to maintain soil test K concentrations with high K removal rates.
Recent data on the K fertilizer requirements of alfalfa, dry beans, Russet Burbank
potatoes and soft white winter wheat supported the use of soil K concentrations
recommended in University of Idaho fertilizer guides (Gaviak et al.,1989). For potatoes,
K fertilization is not recommended when NaHCO 3 extractable K concentrations are
greater than 158 ppm (McDole et al., 1987; Jones et al., 1970; Painter and Ohms,
1967; Iritani and Painter, 1963).
Relatively high potato yields (over 500 cwt/A) are being achieved by many of Idaho's
potato growers. This production level typically removes over 200 lbs K/A in the tubers.
In addition, petiole K concentrations below suggested critical concentrations during mid- and
late-season tuber growth are being reported. As a preventive or corrective
measure, some growers are applying K solutions during tuber growth with their
irrigation systems. Data from Wisconsin indicates that in-season K applications do not
enhance yields or quality, or improve fertilizer-use-efficiency over preplant or side-dressing
applications (Kelling et al., 1994). Plant tissue diagnostic norms for petioles
are generally not available to determine when to recommend this practice. In addition,
it is not known how late during tuber growth K solutions could or should be applied
without affecting tuber quality. The objectives of this study were to a) evaluate the K
fertilizer requirements of Russet Burbank potatoes, b) the efficacy of K-solutions
applied during tuber growth, c) the relative effectiveness of K-sources, and d) the K
dynamics in the potato plant as related to petiole K concentrations. This paper reports
the tuber yield and quality responses obtained with potassium fertilization.

Item Type: Article
NWISRL Publication Number: 0869
Subjects: Irrigated crops > Potato
Mass Import - autoclassified (may be erroneous)
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:54
Last Modified: 14 Nov 2016 17:15
Item ID: 644