Plant aboveground biomass data: The Seasonal Effects of Nitrogen Addition in the Spring on Vegetation at Differing Times of the Growing Season

The purpose of this experiment is to measure the effect of addition of NH4NO3 in the spring on vegetation at different times during the growing season. This experiment is located within the fenced area of field C. See E001 about the construction of the fence. There are three NH4NO3 levels labeled E, G, and I as defined in fertilization details in the "microplot" category. There are 4 replicates and the treatments were randomly assigned to the 12 plots. The plots are laid out in a 3 by 4 grid and are 1.5 by 3.9 meters in area. To measure effect at different times during the growing season each plot will be sampled by clipping 0.2 m by 0.5 m quadrats every two weeks during the 1985 growing season. See CALENDAR.DOC for exact sampling times

本实验旨在测定春季施加硝酸铵（NH₄NO₃）对生长季不同时期植被的影响。本实验设于C地块的围栏区域内，围栏搭建详情参见E001文件。实验共设置3个硝酸铵施用量水平，分别标记为E、G、I，具体施肥参数详见“微区样地（microplot）”类别下的施肥说明。实验设置4次生物学重复，处理组被随机分配至12个样地中。样地以3×4的网格形式布局，单块样地面积为1.5米×3.9米。为测定生长季不同时期的处理效应，本实验将于1985年生长季内，每两周通过刈割0.2米×0.5米的样方对每个样地进行采样。具体采样时间详见CALENDAR.DOC文件。