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Nitrogen and potassium fertilization of potatoes: Yield and specific gravity

Westermann, D.T. and Tindall, T.A. and James, D.W. and Hurst, R.L. (1994) Nitrogen and potassium fertilization of potatoes: Yield and specific gravity. American Potato Journal. 71:417-431.

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Potassium and N fertilization is often required for maximum potato
(Solanum tuberosum L.) production. Nitrogen, K, and K-sources (KCl, K2SO4)
are known to affect yield and quality of potatoes but N and K interactions
as affected by K-source have not been defined. This study evaluated the
N*K and K-source interactions on Russet Burbank tuber yields and specific
gravity (SG) in two irrigated field experiments. Nitrogen rates of 0, 112,
224 or 336 kg ha-1 were combined with selected K rates of 0, 112, 224 or 448
kg ha-1 as either KCl or K2SO4 in an incomplete factorial. A multiple linear
regression model was fit to the data and used to predict yield and SG for a
complete factorial for each K-source. Both N and K applications increased
yields independent of K-source. Nitrogen decreased yields at the 336 kg ha-1
rate. Potassium increased yields up to 448 kg K ha-1. Both K-sources decreased
SG a similar amount with N application; without N, KCl decreased
SG but K2SO4 did not. Nitrogen also decreased SG. Petiole NO3-N and K
concentrations were positively related to yields and negatively to specific
gravities. The petiole K concentration 100 days after planting should be
above 4.5 for highest tuber yields. The N*K*K-source interaction was important
for yields at low available N and for SG at adequate N availabilities.
This study showed that N or K fertilizers can be applied according to their
respective soil test concentration and the crop's requirement, generally
without consideration of K-source.

Item Type: Article
NWISRL Publication Number: 0846
Subjects: Irrigated crops > Potato
Mass Import - autoclassified (may be erroneous)
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:54
Last Modified: 28 Nov 2016 18:47
Item ID: 624