Renewing paddocks which have poor growth or high weed content can give high financial returns. In this example, we’ve used top end renewal costs ($985/ha), but this still returns $2284/ha in profit over 5 years. Few other investments can match this.
This return comes from two benefits. First, increased annual and seasonal pasture production allows a higher ewe stocking rate, and produces more lambs, value $2032/ ha. Second, increased feed quality of the new pasture allows faster lamb growth rates and finishing of more lambs, value $1237/ha.
In this example after a crop, glyphosate is sprayed to kill weeds prior to cultivation. Full costs are presented, but these should be partly attributed to the cost of growing the crop.
Typical costs of renewal
Cost benefit example
This example considers a case where new pasture increases growth by 4 t DM/ha, which is often achievable, but depends on the situation. The extra DM yield allows carrying capacity to be increased by 2.8 ewes/ha in year one, while the new pasture is still establishing, and by 4.5 ewes/ha once the new pasture is established.
New pastures typically have a higher feed quality (ME), as you replace weeds in the old pasture with desirable species. This allows lambs to be finished faster (e.g. 200 g/day) than old pasture (e.g. 120 g/day), setting up the opportunity to trade and finish an extra 15 lambs/ha. This would vary year to year depending on rainfall and availability of store lambs.
Gross margin from extra ewes run
Gross margin from faser lamb finishing
Without attributing part of the costs to growing a crop, eliminating soil compaction or levelling a paddock, sowing 10 ha would cost $9850 but return $22840 in profit.