Nitrogen accumulation by pea as affected by topography
van Kessel, C.
Field peas grown under normal field conditions are exposed to variable soil and environmental conditions that will affect both crop yield and nitrogen (N) uptake. Topography and slope position may play an important role in governing soil and environmental factors that influence N accumulation. In 1991, a field experiment was initiated to examine the effects of landscape position on the yield and N accumulation by field pea (var. Marofat). A two-hectare site was located in the Black Soil Zone on land with gently sloping to roughly undulating slopes (2-5 %). Six landform elements were identified at the site location. The site was managed at a farm scale using typical cultural practices. Spring levels of inorganic nitrogen (NO3 + NH4) ranged from 19.0 to 57.4 kg/ha (0-60 cm depth). Differences in levels of inorganic nitrogen between landform elements were observed (p = 0.03). Volumetric moisture content of the soil (0-120 cm) was consistently highest in footslopes throughout the growing season. Water stress was not a limiting factor to plant growth in any landform until 50-55 days after planting. Total yield (seed + straw) of the pea crop ranged from 2310 to 8100 kg/ha while seed yield varied from 960 to 3940 kg/ha. Significant differences between landforms were detected for total yield (p = 0.02) but not seed yield. Seed nitrogen content ranged from 31-133 kg/ha but no differences were observed between landforms.
Soils and Crops Workshop