Effects of N, P, and K Fertilization on Barley Grown in a Newly Cleared Subarctic Soil 1

• Published in: Agronomy Journal
• Main Authors: Michaelson, G. J., Loynachan, T. E., Wooding, F. J., Mitchell, G. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1982
• Subjects: Agronomy and Crop Science; Subarctic; Alaska
• Online Access: http://dx.doi.org/10.2134/agronj1982.00021962007400040024x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2134%2Fagronj1982.00021962007400040024x; https://onlinelibrary.wiley.com/doi/pdf/10.2134/agronj1982.00021962007400040024x

Abstract Alaska has vast areas of undeveloped land with the potential for agricultural expansion. To develop renewable resources from oil royalty monies, the state has initiated a 24,000 ha agricultural demonstration project near Delta Junction, Alaska. Little is currently known, however, concerning the natural fertility of these virgin soils. A 4 3 factorial experiment was established, with barley ( Hordeum vulgare L. var. ‘Otra’) as the test crop, to determine responses to fertilization the first 2 years after clearing on a Typic Cryopsamment soil. Fertilizer was applied before seeding each year at 0, 45, 90, and 135 kg N/ha; 0, 34, 68, and 102 kg P/ha; and 0, 34, 68, and 102 kg K/ha. Grain yields, protein contents, and subsequent soil‐test levels were measured. Nitrogen increased grain yields from 2 quintal/ha with no applied N in 1979 to 25 quintal/ha with 135 kg N/ha and from 4 quintal/ha with no applied N in 1980 to 31 quintal/ha with 135 kg N/ha. The yield response to N was linear throughout the 0 to 135 kg N/ha range in 1979, and both the linear and quadratic regression terms were significant in 1980. Cooler initial soil temperatures, lack of native residual nutrients, or N immobilization may have contributed to lower overall yields in 1979. Grain protein increased linearly with added N both years. Phosphorus increased yield up to 34 kg P/ha, with little response beyond that in either year. In 1979, both P and K were significant in increasing the yield response to N. In 1980, only K increased the yield response to N. Neither P nor K fertilization significantly increased grain protein contents. Multiple‐regression equations were developed to predict grain yields and protein contents with rates of fertilizer applied. When considering only N, P, and K fertilizer additions, equations with relatively high coefficients of determination were obtained for the first 2 years of production (Yield: R 2 = 0.929,0.937 for 1979 and 1980; and protein: R 2 = 0.684, 0.842 for 1979 and 1980, respectively). Thus, the ...