Seasonal Corn Nutrient Concentration and Uptake in the Mid-Atlantic USA.

Periodic assessment of corn (Zea mays L.) nutrient uptake and utilization is necessary to ensure high yields and efficient fertilizer use.  This study was undertaken to assess the range in nutrient concentration and uptake for corn grown in Virginia at various stages of development and link this to grain or silage yield.  Fields from throughout the Commonwealth of Virginia were selected for study.  Samples were collected at V4, V8, V12, VT, 1-week, and 3-weeks post silking from 10 representative plants at each site.  All aboveground plant material was dried to a constant weight and dry matter biomass calculated as a product of this factor and measured plant population.   Aboveground tissue was analyzed for nitrogen content by dry combustion and for P, K, Ca, Mg, Zn, Mn, Cu, Fe, B, and Al via ICP analysis.  Nutrient contents of on-farm silage samples will be compared to commercial silage samples for the various growth stages.