Cropping

Grain growers warned over nutrient loss

By Country News

Grain growers in Victoria and South Australia who have cut crops due to moisture stress and frost are advised to be mindful of the amount of nutrients being removed from their paddocks.

Cutting crops for hay and silage removes significantly more nitrogen, potassium and sulphur than if the crop was left standing for grain production.

Crop nutrition experts say hay can remove up to two times more nitrogen and up to 10 times more potassium than if the crop was harvested for grain.

Up to five times more sulphur can be lost in canola.

Agriculture Victoria research scientist Roger Armstrong said one-off hay cutting could prompt changes in crop nutrition programs and paddock management into the next season.

He said repeated removal of hay was considered to be one of the most acidifying of agricultural practices, and on acid soils could exacerbate the issue in the longer term.

Growers are, therefore, advised to reduce grazing and traffic across these paddocks to minimise the risk of wind and water erosion which also contribute to soil nutrient loss.

■For more information, go to the Grains Research and Development Corporation’s communities websites at: 

http://bit.ly/2qyUCre and

http://bit.ly/2DByOnz