TITLE:
Evaluation of Soil Potassium Test to Improve Fertilizer Recommendations for Corn
AUTHORS:
Manbir K. Rakkar, David W. Franzen, Amitava Chatterjee
KEYWORDS:
Potassium, Soil Test Methodology, Fertilizer Recommendations, Grain Yield
JOURNAL NAME:
Open Journal of Soil Science,
Vol.5 No.5,
May
28,
2015
ABSTRACT: The soil potassium (K) test methodology is under
increased evaluation due to the soil sample drying effect, temporal variations of test results and inconsistent crop
response to applied K fertilizers. Ten on-farm trials were conducted in 2014 in
eastern North Dakota to determine the corn response to different K-fertilizer
rates and to assess the variation of soil K test levels between air-dried (KDry) and field moist (KMoist) soil samples
during the corn growing season. Significant differences were observed
between KDry and KMoist soil K test results. The ratio of KDry/KMoist showed
high correlation with cation exchange capacity (r = 0.63, p