On the back of posting double digit earning leaps for the first half for Target and Kmart, driving the group's profit well above expectations, Wesfarmers also forecast increased demand for its mining chemicals after a rise in first-half earnings.

Wesfarmers finance director Terry Bowen said farmers had begun to react to rising prices by ordering fertilisers earlier than they had been to avoid further price rises, reports The Australian Financial Review.

Last month CSBP increased prices across many of its fertiliser products as a result of higher global prices and a weak Australian dollar.

But weaker domestic fertiliser prices in the first half forced Wesfarmers to make a $25 million write-down on its fertiliser inventory.