Relationship of Solid Cattle Manure Placement Method in a Black Chernozem to Phosphorus and Nitrogen Movement in Simulated Snowmelt Water.

In Saskatchewan, the annual spring snowmelt is often the major run-off event of the season.  However, little is known about transport of nitrogen (N) and phosphorus (P) in snowmelt from manured soils in this region. The objective of this experiment was to determine what effect solid cattle manure application method had on run-off/ leachate collected from intact soil monoliths subjected to simulated snowmelt conditions in the laboratory.  Intact soil monoliths were collected in the fall (post-harvest) from a loamy textured black Chernozem soil that had solid cattle manure field applied in the spring at a rate of 60 tonnes ha^-1 using broadcast, broadcast and incorporation, and subsurface band injection placement methods. Soil monoliths were kept frozen, placed into insulated boxes, and field collected snow was applied to the monoliths.  The snow was allowed to melt under simulated spring temperature conditions over a period of 5-7 days. Runoff/leachate was collected and analyzed for orthophosphate (PO₄-P), nitrate-nitrogen (NO₃-N), total nitrogen and total carbon.  Cattle manure addition significantly (p<0.10) increased phosphate concentration in the runoff/leachate collected.  Broadcast, and broadcast & incorporated treatments had about 0.3 kg P ha^-1 removed in snowmelt run-off versus 0.6 kg P ha^-1 in the injected treatments. Nitrate-N removed was ~ 0.6 kg N0₃-N ha^-1 in the broadcast and incorporated and subsurface injected treatments, and was significantly (p<0.10) higher than the 0.1 kg N0₃-N ha^-1 removed by the snowmelt water in the broadcast treatment. Total N, total carbon, NO₃-N and PO₄ in snowmelt runoff/leachate from the monolith slabs tended to be highest in the subsurface injected band treatment, suggesting that movement of these constituents may possibly be accentuated by placement at depth in bands.