Nitrogen transformations in an aerobic soil as determined by a 15NH4+ dilution technique

Effect of cellulose and glucose on the proliferation of PCP (pentachlorophenol)-degrading microorganisms in soil suspension

“…The soil used was collected from the topsoil (0-5 cm) which had no history of PCP exposure of an upland soil (Andosol Brown) at the National Hokkaido Agricultural Experiment Station (Memuro, Hokkaido, Japan). Some of the soil properties were as follows: pH(HzO) 5.80, pH(KC1) 5.00, %C 1.72, %N 0.19, and CEC 1.29 cmol( +) kg-1 (Nishio et al 1985).…”

Changes in gross rates of nitrogen transformations in soil caused by conversion of paddy fields to upland fields

“…Nishio et al (1990) demonstrated that the gross immobilization rate in an upland soil decreased with the decrease in the amount of ammonium added, and that the gross mineralization rate did not decrease. Our preliminary experiment also showed that the rates of mineralization and immobilization in a submerged soil did not significantly change by the amount of ammonium added.…”

“…The gross rates of N transformations were calculated by using the 15N-ammonium isotope dilution method (Blackburn 1979;Nishio et al 1985). This method is used for calculating the gross rates of N transformations by following the temporal dilution process of 15N in the ammonium pool after the addition of 15N-ammonium to soil.…”

Effects of Irrigation and Fertilizer N on N Accumulation and Partitioning in White Bean and Soybean

“…This was apparent in this study of white bean and soybean (reported in Smith (--) and Maple Arrow soybean (---) Hume (1985)). Irrigation is reported to increase rates of N2 fixation (Nathanson et al 1984;Smith and Hume 1985), photosynthesis (Fisher et al 1981) and soil N mineralization (Nishio et al 1985 (Fig. 1), indicate that white bean is not more N-limited in its growth than soybean.…”

“…Key words: Bean (white), soybean, irrigation, N fertilizer, N yield, N partitioning (Graham 1981 (Hunt et al 1983;Matheny and Hunt 1983 (Nishio et al 1985). Irrigation has been found to increase the concentration of N in soybean tissues (Hunt et al 1983;Hobbs et Muendel 1983), but to decrease it in nonlegumes (Bennet et al 1964;Martin and Dewitt 1982).…”