Atmospheric nitrogen(N) deposition has been increasing in recent decades. N addition and mowing could influence micronutrient cycling in grassland ecosystems. It remains largely unknown about how different N forms affect micronutrient status in plant-soil systems. 

Recently, Prof. Yong Jiang’s Lab from the Institute of Applied Ecology of Chinese Academy of Sciences, examined the effects of different N compounds of (NH₄)₂SO₄, NH₄NO₃, and urea with and without mowing on micronutrient Fe, Mn, Cu, and Zn in soil-plant systems in a meadow steppe.  

They found that (NH₄)₂SO₄ addition had a stronger negative effect on soil pH compared with NH₄NO₃ and urea, resulting in higher increases in soil available Fe and Mn herein. N addition decreased plant community-level Fe concentration but increased Mn concentration, with a greater effect under (NH₄)₂SO₄ addition. Community-level Cu concentration increased with (NH₄)₂SO₄ and NH₄NO₃ addition only under mowing treatment. Mowing synergistically interacted with urea addition to increase community-level Mn and Zn concentrations even with decreased soil organic matter.  

The study highlights the importance of various N compounds in biogeochemical models when projecting the effects of N enrichment on grassland ecosystems. 

The study entitled “Effects of nitrogen addition on plant-soil micronutrients vary with nitrogen form and mowing management in a meadow steppe” has been published online in Environmental Pollution. 

This study was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, National Natural Science Foundation of China, and National Key Research and Development Program of China. 

YUE Qian 

Institute of Applied Ecology, Chinese Academy of Sciences 

Tel: 86-24-83970324 

E-mail: yueqian@iae.ac.cn 

Web: http://english.iae.cas.cn