Evaluation of laboratory-based measures of soil mineral nitrogen and potentially mineralizable nitrogen as predictors of field-based indices of soil nitrogen supply in potato production

详细信息    查看全文

• 作者：Mehdi Sharifi ; Bernie J. Zebarth ; David L. Burton ; Cynthia A. Grant ; Gregory A. Porter ; Julia M. Cooper ; Yves Leclerc ; Gilles Moreau and Walter J. Arsenault
• 关键词：Field experiment ; Long term aerobic incubation ; Plant N uptake ; Potentially mineralizable N ; Soil mineral N ; Solanum tuberosum
• 刊名：Plant and Soil
• 出版年：2007
• 出版时间：December, 2007
• 年：2007
• 卷：301
• 期：1-2
• 页码：203-214
• 全文大小：424.5 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Plant Sciences
  Soil Science and Conservation
  Plant Physiology
  Ecology
  
• 出版者：Springer Netherlands
• ISSN：1573-5036

文摘

Accurate estimation of soil nitrogen (N) supply in the field is required to optimize fertilizer N management and to minimize environmental N losses in humid environments. Laboratory-based measures of N availability were evaluated as predictors of field-based indices of soil N supply within potato production systems. Pre-plant soil samples (0–15 cm) were collected from a series of forty treatments in established potato trials located in Atlantic Canada and Maine, USA. Total plant N uptake at topkill with no fertilizer N applied (PNU_0N), PNU_0N plus soil mineral N to 30 cm depth at harvest and relative yield were considered as field-based indices of soil N supply. The potentially mineralizable N (N₀) was determined by aerobic incubation at 25°C and periodic leaching for 24 weeks. A series of laboratory-based measures of soil N supply were measured in soil samples. Pre-plant soil nitrate or total mineral N at 0–30 cm depth was the best single predictor of PNU_0N (r?=?0.67 and 0.71, respectively) and relative yield (r?=?0.58 and 0.61). The ultraviolet absorbance of 0.01 M NaHCO₃ extract at 205 nm (NaHCO₃-205) was suitable as a predictor of PNU_0N and relative yield in each growing season, however, the relationship between this parameter and PNU_0N or relative yield varied somewhat among years. A combination of pre-plant mineral N plus N mineralized in the first 2 weeks period of incubation after re-wetting is proposed as a more robust measure of N availability compared with use of mineral N alone.