Soil ammonium: Schizachyrium scoparium Nutrient Uptake Profiles

The objective of this experiment is to determine the distances over which Schizachyrium scoparium can reduce available soil N. This experiment is being conducted in field B, outside the fenced area of the microplots. Each experimental unit consists of a circular plot of 3 meters diameter, at the center of which there is a Schizachyrium scoparium plant. Two treatments are being tested: 1 (=A). All the vegetation around the central S. scoparium was killed with roundup at a rate of 2.04 g/m2 (1g of Isopropylamine salt of N (phosphonomethyl ) Glycine ). Spraying was repeated at the same rate as needed (Yearly folder). A plastic barrier, 80 cm high, was placed around each Schizachyrium scoparium plant to protect it from any drift that might occur. The area sprayed is the circle with 2 m radius around the central plant. 2 (=B). The vegetation around S. scoparium is left intact. Each treatment is replicated 5 times. The two treatments were randomly assigned to the 10 plots of the experiment. The plot layout is: Plot # Treatment 1 2 2 1 3 2 4 2 5 1 6 1 7 1 8 2 9 2 10 1 Soil samples were taken several times and the amount of ammonium and nitrate were determined at the lab. Soil samples were also taken once for mineralization rate, microbial biomass and total carbon determination. When plants reached maturity, they were harvested and dried for dry matter determination, then ground for tissue nitrogen determination. For an additional list of treatments see the treatment layouts in file trmte38.本实验旨在测定小须芒草（Schizachyrium scoparium）抑制土壤有效氮的作用距离。实验于微型样地围栏外的B样地中开展。每个实验单元为直径3米的圆形样地，中心种植一株小须芒草。本实验设置两种处理方案： 1（=A）：以2.04克/平方米的农达（Roundup，有效成分为1克N-(膦酰甲基)甘氨酸异丙胺盐）喷施，杀灭中心小须芒草周围的所有植被；按实际需求以相同施药剂量重复喷施（详见年度记录文件夹）。在每株小须芒草周围布设80厘米高的塑料屏障，以避免喷施药液发生漂移对植株造成影响。喷施区域为以中心植株为圆心、半径2米的圆形范围。 2（=B）：保留小须芒草周围的原生植被。 每种处理设置5次重复，10个实验样地随机分配两种处理方案。 实验样地布局如下： 样地编号 处理编号 1 2 2 1 3 2 4 2 5 1 6 1 7 1 8 2 9 2 10 1 多次采集土壤样品，在实验室测定其中铵态氮与硝态氮的含量；另外单次采集土壤样品，用于测定土壤矿化速率、微生物生物量及总碳含量。待植株成熟后，收获植株并烘干以测定干物质质量，随后研磨样品用于测定植株组织氮含量。如需获取更多处理方案列表，请参阅trmte38文件中的处理布局表。