Influence of Long-Time Fertility Management Practices on Chemical and Physical Properties of a Fargo Clay1
- R. A. Young,
- J. C. Zubriski and
- E. B. Norum2
Laboratory phases of a study to evaluate the effectiveness of various long-time management practices in maintaining fertility of Fargo clay are reported. Soil samples which had been taken at the beginning of the trial in 1913 and those taken in 1952 and 1953 were used for chemical analyses. Physical measurements were made on samples taken from 1954 to 1956. Analyses included total N, organic C, pH, cation-exchange capacity, exchangeable cations, extractable and organic P, nitrification capacity, aggregation and aggregate stability by wet-sieving, porosity, density, and hydraulic conductivity. Soil organic C and N declined 27% in check plots and 20% in residue or manure plots. Phosphorus-treated plots suffered slightly greater loss than similar plots without P. Lime had no effect. C/N ratio did not change. Nitrification capacity correlated with total N content. Extractable P declined appreciably in check plots, less in residue and manure plots, and increased in P-treated plots. Organic P losses were similar to those of organic carbon. In all plots, CEC declined slightly. pH increased slightly in nonlimed plots and moderately in limed plots. Physical measurements did not reveal any important differences in structural properties of Fargo clay that could be related to past management practices.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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