关键词: 中国东北, 受威胁植物, 优先保护值, 优先保护区域

Abstract: By the methods of adsorption and soil column leaching, a laboratory simulation test was conducted to study the effects of palygorskite application on the volatilization and leaching losses of urea nitrogen in loess soil. Comparing with applying urea fertilizer alone, the addition of palygorskite could decrease the volatilization rate of soil urea N at peak time, with the ammonia volatilization loss decreased by 136%〖KG-*2〗-〖KG-*7〗150%. When the palygorskite application rate was 03 and 06 g·kg-1, the leaching rate of soil NH4+-N and NO3--N decreased, with the leaching loss of soil mineral N decreased by 137% and 136%, respectively. Applying 09 g·kg-1 of palygorskite application increased the leaching rate of soil NH4+-N and NO3--N, with the leaching loss of soil mineral N increased by 61%. Applying 03 g·kg-1 of palygorskite increased soil NH4+-N content by 020 mg·kg-1, while applying 09 g·kg-1 of palygorskite decreased soil NH4+-N content by 042 mg·kg-1. Palygorskite application increased soil NO3--N content by 124〖KG-*2〗-〖KG-*7〗252 mg·kg-1. It was concluded that the application of palygorskite could decrease the volatilization rate of urea N, and applying appropriate amounts of palygorskite could decrease the leaching loss of soil mineral N and increase the contents of soil NH4+-N and NO3--N.

Key words: Northeast China, threatened plant, priority conservation value, priority conservation region.