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Changes in Soil Carbon and Nitrogen Due to Irrigation Development in Nebraska's Sandhill Soils
Author(s) -
Lueking M. A.,
Schepers J. S.
Publication year - 1985
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1985.03615995004900030020x
Subject(s) - kjeldahl method , soil water , chemistry , zoology , nitrogen , entisol , irrigation , soil carbon , total organic carbon , soil test , soil horizon , agronomy , environmental chemistry , soil science , environmental science , biology , organic chemistry
Carbon and N parameters were compared for nondeveloped and developed soils (predominantly mixed mesic, Typic Ustipsamments, and sandy, mixed mesic Entic Haplustolls). Soil samples were collected from four developed center pivot irrigation sites and from the nondeveloped corners at depth increments of 0‐ to 75‐, 75‐ to 150‐, and 150‐ to 300‐mm. Total C, total Kjeldahl N (TKN), hydrolyzable N, and mineralizable N by autoclave and by a 112‐d incubation study were determined. Changes in TKN were not significant in the 0‐ to 75‐mm depth, but in the second depth increment, TKN increased with development (507 to 569 kg ha −1 ). Total C also increased at this depth (5650 to 6400 kg ha −1 ). The C/N ratio increased with development in the surface 75 mm (11.5 to 12.2). Inorganic N increased in the top 300 mm due to development. Mineralizable N by both techniques increased in the 75‐ to 150‐ and 150‐ to 300‐mm depth increments. Steady state values for ln TKN were calculated to be 6.6, 6.4, and 6.8 kg ha −1 for soil depth increments of 0‐ to 75‐, 75‐ to 150‐, and 150‐ to 300‐mm, respectively. The ln total C steady‐state values were 9.1, 8.8, and 9.1 kg ha −1 . In some cases, undeveloped soil contained more N and C than these steady‐state values, suggesting that development tended to decrease the soil test values. If the undeveloped soil was lower in N or C than the steady‐state value, development tended to increase the test value. Total C, TKN, hydrolyzable N, mineralizable N (both techniques), and inorganic soil N were all highly correlated. Changes in TKN and total C were not correlated to landscape position or time since development.