JapanFlux2024 JP-NsC National Institute of Livestock and Grassland Science, Nasu Research Station: Chemical Fertilizer Plot

Grasslands provide a globally essential ecosystem service by storing carbon (C). Management practices affect the net C balance in grasslands positively and negatively. In Japan, farmyard manure (FYM) application and grassland renovation are common and essential grassland management practices; however, the long-term effects of these practices on C balance are not known. We conducted a field experiment in a managed grassland for 11 years (2004-2015) to investigate the effects of FYM application and grassland renovation on net ecosystem C balance (NECB), estimated from eddy covariance measurements. Two experimental plots were used: One received only chemical fertilizer (CF plot), and the other received FYM and supplementary chemical fertilizer (CM plot). This site is an observation site where chemical fertilizer is applied.

草地生态系统通过固存碳（C），提供了具有全球关键意义的生态系统服务。草地管理措施对其碳净平衡兼具正负调控效应。在日本，农家肥（farmyard manure, FYM）施用与草地改建是应用广泛且至关重要的草地管理手段，但目前尚未明确这两类措施对草地碳平衡的长期影响。本研究于2004年至2015年间，在一处人工经营草地开展了为期11年的野外试验，依托涡度协方差（eddy covariance）测量法估算生态系统碳净平衡（net ecosystem C balance, NECB），以此探究农家肥施用与草地改建对该平衡的影响。本试验设置两块样地：其中一块仅施加化肥（chemical fertilizer, CF），记为CF样地；另一块则施用农家肥配合补充性化肥，记为CM样地。该站点为化肥施用型草地观测样地。