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General Comments – Newsletter April 2017

The phenomenon of costs rising to meet expected or actual income is being observed at present, partly due to an increasing emphasis on the use of inputs both in cropping and grazing, rather than on tailoring the production system to the natural resources, based on first principles of crop and livestock production.

Crop seed costs in particular have increased on many farms. However, experience suggests that genetics of the crop is rarely the limiting factor. There is generally a greater difference between crop yields due to the production system and management employed, than there is between relevant varieties under the same management. Likewise there has been a significant increase in the total cost per hectare of the annual chemical bill in cropping. This results from trying to “buy the solution” to weed control in a drum, rather than focusing on crop sequence and selection, inter-row competition etc.

Livestock producers also are not immune to the trend towards higher input use.  Higher wool and meat prices have attracted the attention of suppliers of feed supplements, who have very clever marketing tactics backed by dubious data.

Recent experience indicates that significant areas of cropland are over-fertilised annually, while lime is generally under-applied, but sometimes applied in excess.  This disconnect between application and requirement, is being addressed by soil pH and Phosphorous mapping, which allows better allocation of inputs such as lime, gypsum and MAP, based on more extensive soil testing.  This mapping is often showing higher than desirable soil pH on significant parts of paddocks, which don’t require additional lime, while other areas of paddocks are much more acidic than envisaged, to the extent that crop growth is likely to be compromised.

Phosphorous maps are showing significant areas of paddocks with luxurious levels of soil Phosphorous, where no yield response would be expected to applied Phosphorous.  These maps in conjunction with yield maps plus EM38 survey maps, often reveal that high Phosphorous levels are associated with lower crop yield and subsequent nutrient removal.  Further investigation can reveal that crop yield is limited by soil acidity or lack of water holding capacity of certain soil types, allowing soil amelioration treatments to be better targeted.