Aglime and Lupins
Long Term Average
Our extensive trial program has shown that, on average, Aglime has no effect on lupin yields in the long term (over 12 years).
This is the conclusion from Aglime of Australia’s long term field trial program which is designed to identify benefits and problems associated with our product, Aglime limesand, under commercial farming conditions and different rotations in the central and northern wheatbelt.
Since the trial program commenced in 1985, we have measured a total of 405 plots from 38 trials at 17 locations where lupins were sown by farmers over limed plots. When yields of control plots (which are not limed) are compared with the yields of limed plots, the average increase or decrease in yield is 0%. These results are summarised in the figure below. It clearly can be seen that lupins tend to be variable in yields regardless of the soil pH. (Most of the plots with pH levels over 5.0 in this graph were limed and below 5.0 were not limed.)
Effect of location and season
When the results are examined for each of the 17 locations there is also no effect of Aglime on lupin yields on average. However, in any one year at some locations there have been occasions when either significant increases or decreases in lupin yields have occurred. For example, at one location, lupins showed no effect from liming in the 2nd season, then responded negatively in the 6th season and positively in the 8th season after liming. However, the average effect of Aglime on lupins at that location was 0%.
Negative responses in lupins to lime may arise from reduced uptake of certain nutrients including potassium, copper, zinc and manganese and farmers should ensure that these nutrients are not limiting when liming in a wheat/lupin rotation.
Chris Gazey (DAFWA) in 1997 has shown clearly that a depression in lupin yields after liming was prevented by applying potassium after sowing and spraying manganese at podding on a soil deficient in these nutrients.
Low manganese levels may also lead to split and shriveled seed. In Chris’s trial, the seed problem was made worse where potassium was applied without manganese. Overcoming the potassium deficiency increased the yield potential and diluted the low manganese reserves even further.
It also appears that sulfonyl urea herbicides may carry over under certain conditions and affect early lupin growth.
However, liming can also increase lupin yields possibly through increased nitrogen availability early in the season before the lupin plant has nodulated or through improved soil wetting and water infiltration. As lupins are more tolerant of aluminium toxicity than wheat, liming is likely to have less effect on lupins than wheat.
To get the best results from liming, especially if lupins are in the rotation, it is essential to ensure:
1. nutrients are at good levels (particularly potassium, manganese, zinc and copper) and
2. sulfonyl urea herbicides are applied according to the label.
Aglime of Australia encourages clients to tissue test regularly to ensure nutrients, particularly trace elements, are not limiting yield.
A tissue sampling service backed by GPS site location and soil sampling can be provided by Precision Soiltech.
Chris Gazey (DAFWA), Gilbert Ackland - Wongan Hills, Grains Research and Development Corporation, Neil Scotney - Kondut, Robert Jenzen - Cunderdin, Ian Bowman - Carnamah, David Antonio- Northam, Gordon Pearse - Mingenew, Mark Brockhurst- Jennacubbine Trevor Ryan - Yorkrakine, Geoff & Lindsay White - Goomalling