Scotiabank's Agricultural Commodity Index dropped almost 4 and a half per cent from November to December.
The bank says the December index was 13 point 6 per cent lower than it was in December of 2014.
Economist Patricia Mohr says canola, wheat and barley prices all edged down in U-S dollars in December.
But she says the weak Canadian dollar is providing some cushion for Canadian farmers.
Mohr believes overall gross farm cash income from crops across Canada was likely very little changed in 2015.
However, Scotiabank reports cattle prices have lost significant ground from the peak in July of 2014.
Herd rebuilding in the U-S and weaker American exports to Asia are being blamed for lower prices on both sides of the border.
Mohr points out despite lower prices for farmers, the impact on beef prices in Canadian grocery stores to date has been limited.
