Nutrient losses to soil from field storage of solid poultry manure

The study was done to quantify the effect of uncovered field storage of solid poultry manure in south coastal British Columbia on a site where solid turkey manure was stored uncovered each fall and winter for approximately 6 yr. The soil was sampled to 370 cm depth in a transect with six sampling locations: two in the manure storage area, and two on either side of the manure storage area. The soil was analyzed for the concentrations of total organic C, total Kjeldahl N, ammonium, nitrate, K, P, Mg, and Na in addition to soil pH and electrical conductivity. The mass of nutrients to 370 cm depth was 39 700 and 330 kg NH4+-N ha(-1), 500 and 480 kg NO3--N ha(-1), 36 400 and 1440 kg K ha(-1), 12 100 and 2190 kg P ha(-1), 3150 and 1140 kg Mg ha(-1) and 9850 and 975 kg Na ha(-1) for the manure storage and non-storage sampling locations, respectively. The depth weighted average soil pH was 8.4 and 4.7 and average soil electrical conductivity was 3.3 and 0.3 dS m(-1) for the manure storage and non-storage sampling locations, respectively. The lack of an increase in soil nitrate concentration in the manure storage area was attributed to concentrations of free ammonia in soil solution toxic to nitrifying bacteria. The results highlight the high potential for nutrient loss from uncovered fall and winter field storage of poultry manure in south coastal British Columbia.