Pasture grass sampling and chemical analysis, field dropping densities and vegetation height

round: sampling round (1=Mar 26 2013, 2=April 10 2013, 3=April 21 2013, 4=May 8 2013, 5=May 21 2013)
transect: transect ID (see stations data file)
field: field ID (see stations data file)
N [ug]: microgram Nitrogen (Thermo Scientific FLASH 2000 elemental analyzer)
C [ug]: microgram Carbon (Thermo Scientific FLASH 2000 elemental analyzer)
sample_weight [ug]: sample weight (for N, C analysis)
perc_grass_ADF [%]: mass percentage acid detergent fibre (ADF) pasture grass on ash-free dry mass basis (Bruker MPA FT-NIR analyser)
perc_mest_ADF [%]: mass percentage acid detergent fibre goose droppings on ash-free dry mass basis (Bruker MPA FT-NIR analyser)
droppings [#/m^2]: dropping density, as an average over 5 dropping stations of 4 m^2 area each
veg_height_out [cm]: vegetation height outside the exclosure, as an average over measurements at the 5 dropping stations of the field
veg_height_in [cm]: vegetation height inside the exclosure (measured before moving it to a new position every 2 weeks)