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Nitrogen and Carbon Mineralization of Potential Manure Components
Author(s) -
Van Kessel J. S.,
Reeves J. B.,
Meisinger J. J.
Publication year - 2000
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2000.00472425002900050039x
Subject(s) - mineralization (soil science) , manure , chemistry , nitrogen , zoology , nitrogen cycle , urea , nutrient , agronomy , biochemistry , biology , organic chemistry
Current estimates of plant availability of manure N are highly variable. A study was conducted to examine C and N mineralization characteristics of manure components from feeds (immature and mature alfalfa and orchardgrass, soybean meal, roasted soybean meal), forage cell walls (acid detergent fiber [ADF] and neutral detergent fiber [NDFI), simple N compounds (urea, amino acids and peptides), and nondietary metabolic components (ruminal bacteria and colonic cells). Nitrogen and C mineralization were determined by aerobic incubation of sample‐amended soil. Changes in NH + 4 and NO − 3 concentration and CO 2 production were monitored over 112 d. At C to N ratios below 15, there was a declining exponential relationship between the initial potential rate of C mineralization and the sample C to N ratio. However, at C to N ratios above 15, the initial potential rate of C mineralization was low and insensitive to C to N ratio. Percent of added N mineralized ranged from 92% for urea and 13% for mature orchardgrass to a net N immobilization for ADF‐ and NDF‐amended soils. When the C to N ratio was below 42, there was a linear relationship between readily mineralizable N and the C to N ratio. There were also positive relationships between readily mineralizable C and N and the components' total N concentration. Manure contains a range of compounds that have rapid or intermediate N mineralization characteristics, or that are strong immobilizers of N. These results suggest that improved estimates of manure N mineralization may be obtained by considering both the readily available N components and components that strongly immobilize N.