Seasonal,annual, and treatment-induced variation in available nitrogen pools and nitrogen-cycling processes in soils of two Douglas-fir stands |
| |
Authors: | C S White J R Gosz J D Horner D I Moore |
| |
Institution: | (1) Biology Department, University of New Mexico, 87131 Albuquerque, NM, USA |
| |
Abstract: | Summary Forest-floor and 0–10 cm depth mineral soil horizons in two stands of Douglas fir were sampled for available NH4
+-N and NO3
–-N, N-mineralization potentials, and nitrification potentials for 2 years. The plots in each stand were sampled for 1 year, treated with either ammonium sulfate, carbohydrate (sawdust-sucrose), irrigation, carbohydrate plus irrigation, or no treatment (control), and then sampled for 1 year following treatment. In general, the direction of change following the treatments was the same for both the forest-floor and the mineral soils. Fertilization increased the NH4
+-N and NO3
–-N pools, nitrification potential, and N-mineralization potential, while treatment with carbohydrate decreased all of these characteristics. Irrigation generally increased NH4
+-N pools, nitrification potential, and N-mineralization potential, but decreased these characteristics in the soil at one site. Irrigation plus carbohydrate gave similar results to those of carbohydrate alone. Treatments altered pool sizes and/or potentials, but did not reduce within-year variance in any of these characteristics. Distinct seasonal patterns occurred in all measurements, suggesting that control of short-term variation in N-transformation processes is by factors which are dynamic in nature. |
| |
Keywords: | Ammonium Nitrate N-mineralization Nitrification Fertilization Irrigation Forest ecosystems |
本文献已被 SpringerLink 等数据库收录! |
|