Long-term tillage and nitrogen fertilization effects on organic nitrogen and carbon in a semiarid soil

Journal Article · · Soil Sci. Soc. Am. J.; (United States)

DOI:https://doi.org/10.2136/sssaj1988.03615995005200040041x· OSTI ID:5987046

Rasmussen, P E; Rohde, C R

Maintaining or improving soil organic matter has high priority in agriculture because of its beneficial effect on soil physical, chemical, and biological properties. Soil organic N and C were measured 44 yr after establishment of a long-term experiment to evaluate tillage and fertilizer effects in a winter wheat (Triticum aestivum L.)-fallow rotation on a coarse-silty mixed mesic Typic Haploxeroll. Main treatments consisted on three primary tillage systems, one conventional and two stubble mulch. Subplots consisted of six N treatments, 493, 728, 986, 1221, 1714, and 2207 kg N ha/sup -1/ applied over 44 yr. Organic N and C in the top 75 mm of soil were 26 and 32% higher, respectively, in the two stubble mulch systems than in conventional tillage, and equal below 75 mm. Stubble mulch plots contained 245 kg more N ha/sup -1/ than conventionally tilled plots, representing the conservation of 5.7 kg N ha/sup -1/ yr/sup -1/. Nitrogen fertilization increased soil N linearly in all tillage treatments, with 18% of the applied N incorporated into the soil organic fraction. Applied N also increased soil C linearly on plots with previous S application. Soil C was higher on plots with no previous S than on comparable plots with previous S, however, which suggests an S deficiency that altered S, but not N, transformations in soil. Identical N fertilization effects on soil organic N and C in both stubble mulch and conventional tillage suggests that N transformations were the same in both systems.

• Research Organization: Columbia Plateau Conservative Research Center, Pendleton, OR (USA)
• OSTI ID: 5987046
• Journal Information: Soil Sci. Soc. Am. J.; (United States), Journal Name: Soil Sci. Soc. Am. J.; (United States) Vol. 52:4; ISSN SSSJD
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ARID LANDS
BIOLOGICAL EFFECTS
CEREALS
CHEMICAL PROPERTIES
CULTIVATION TECHNIQUES
ECOLOGICAL CONCENTRATION
FERTILIZERS
GRASS
LILIOPSIDA
MAGNOLIOPHYTA
ORGANIC COMPOUNDS
ORGANIC MATTER
ORGANIC NITROGEN COMPOUNDS
PLANTS
PRODUCTIVITY
SOILS
WHEAT