Aglime increases wheat yields and profits
Long Term Average
Aglime has increased wheat yields up to 17% in the central and northern wheatbelt over a period of many years. For many years now, Aglime of Australia has measured yields and soil pH down the profile on many trials across Western Australia.
Effect of Soil pH on Wheat Yield
The trial results show that as topsoil pH increases after liming, wheat yield, on average, increases by 8.5% per pH unit increase (figure below). In other words, if liming increases pH by 1 unit (eg 4.5 to 5.5), yields increase on average by 8.5%.
Effect of location on yield response to Aglime
Yield increases varied from site to site in our long-term research programme.
The highest average increase was 17% for 1 pH unit increase following liming and was achieved over 5 wheat crops between 1985 and 1993 on productive tammar country (loamy sand over gravel) north of Goomalling.
Although no reduction in wheat yields was measured from liming, it is evident that sites low in zinc and/or manganese show lower yield increases from liming.
Wheat yield responses tend to increase over time with the best results 3 to 4 years following liming. In the long-term Aglime trials we have been able to demonstrate that aglime lasts for many years.
How does aglime increase yield?
Aglime can increase wheat yield by:
1. increasing nitrogen by improved nodulation of legumes and N fixing by free living bacteria.
2. increasing the availability of most nutrients (eg phosphate)
3. increasing soil moisture levels through improved soil structure and soil wetting.
4. increasing microbe numbers and activity resulting in faster breakdown of organic matter to release nutrients, especially nitrogen.
5. reducing aluminium toxicity
It is most likely a combination of these improvements that lead to yield increases at any site.
Action to increase the yield response to liming
Tissue sample and apply trace elements (particularly zinc and manganese) and other nutrients where marginal or deficient. Reduce take-all through grass control and/or acidifying fertilizers.
Grains Research and Development Corporation, CSBP and Summit Fertilisers.
Robert Jenzen- Cunderdin; David Antonio- Northam; Mark Brockhurst- Goomalling; Charles Chitty- Konnongorring; Geoff and Lindsay White- Konnongorring; Ian Leeson- Goomalling; Barry Morrell- Ejanding; Bill Dickson- Wyalkatchem; Jim Shepherd- Kwolyin; Gilbert Ackland-Wongan Hills; Neil Scotney-Kondut; Graeme Dodd- Kalannie; Ian Bowman- Carnamah; Peter Smith- Carnamah; Gordon Pearse- Mingenew. Trevor Ryan- Yorkrakine