Impact of Long-term Phosphate Application and Level of Fertilizer Cd on Crops and Soils

Assess the rate of P application from various P sources having different inherent cadmium levels, on Cd uptake and Cd concentration of harvested grain from crops in western Canada.

IPNI-2002-CAN-MB16

18 Feb 2003

2002 Annual Interpretive Summary


Impact of Long-term Phosphate Application and Level of Fertilizer Cadmium on Crops and Soils, 2002

Public concern regarding the transfer of cadmium (Cd) from fertilizer phosphorus (P) products to soils and uptake by crops has increased interest in evaluating the true impact of fertilization practices on food nutrient content. Field studies were initiated at seven sites across the western Canadian Prairie provinces to evaluate the effect of long-term applications of monoammonium phosphate fertilizer containing varying concentrations of Cd. Rates of P application were 0, 45, 90 and 180 lb P2O5/A and the three concentrations of Cd in the fertilizer ranged from trace to approximately 150 parts per million (ppm).

The objectives of the study are: 1) To determine the cumulative impact of applications of P fertilizer varying in Cd concentration on grain yield and micronutrient concentration, total soil Cd, phytoavailable Cd, and grain Cd concentration, on a range of soil types. 2) To determine the impact of soil characteristics on availability of native soil Cd and Cd added with P fertilizer. 3) To determine the effectiveness of several soil testing methods in predicting availability of native and applied Cd across a range of soil types and environmental conditions. The study will continue through a 4-year crop rotation. MB-16