How to return pastures with little ground cover quickly to quality feed status will be a dilemma facing many landholders.
But eventually this drought will be over and an action program is worth evaluating.
Jeff Esdaile, a pioneer of zero tillage farming and an ex NSW DPI and Sydney University research agronomist, (now retired and living in the Upper Hunter) has given this considerable thought.
He believes zero-till sowing of summer fodder crops into some of these pastures is more than worth a thought. Even if stock numbers are low and if such feed is not required should the season turn around, fodder crops can also provide a great opportunity to replenish hay or silage reserves.
Mr Esdaile describes a common scenario facing much of the state, especially in his region the Upper Hunter. After a long period of drought there is often no subsoil water, and often little to no ground cover residue in pasture paddocks. Unfortunately, little to no ground cover means it is difficult to capture storm rains or heavy rain downpours should that be the way that significant rain eventually falls.
However, Jeff believes some sort of a no-till rehabilitation system should be feasible, at least in some paddocks following a reasonable rain event that produces some significant soil moisture build-up.
No-till or zero till has a particular advantage he stresses.
Any sort of tillage will slow up the process of recovery and waste water.
Research over many years has shown that cultivation results in far greater loss of soil water than had the paddock been direct drill sown, especially with low soil disturbance planters.
Cultivation can also encourage a new batch of weeds. Mr Esdaile indicates perhaps after useful rain, a herbicide treatment to kill any existing germinating weeds followed by sowing of a summer growing forage crop could be the best option for quick feed.
For direct drilling fodder crop into pastures a low disturbance direct drill planter would be by far preferable to a full disturbance planter. Jeff believes the less disturbance of the soil and preservation of what little residue remains then more moisture remains for the next crop.
Where pastures have been grazed hard for a long time, commonly their recovery, other than from weeds, can be somewhat slow following breaking rains.
We have seen ample evidence of this in areas where partial breaking rains have occurred.
Long hard-grazed perennial pastures, natives, tropicals or temperate species, generally have very low root reserves and it takes a long time for them to pick up and provide adequate feed and competition to annual weeds such as burrs, cathead, melons, mint weed and the like.
Various summer forage crops can be used, depending on soil type, soil fertility, likely weeds and ability to handle possible toxicities (for example prussic acid in stressed sorghums). Note toxicity risk is normally manageable provided one has read up on risks and evasion strategy. Summer forage legumes such as lab lab and cowpeas are other options, as are millets.
The amount of forage produced will largely depend on the amount of rain received, how well it infiltrates into the soil and the success with establishment and post establishment management.
For example, if a rain event of over 50mm occurs there will be the possibility of a good start from the forage crop as compared to the response one might expect from a similar fall on degraded pasture.
In addition, useful groundcover from the fodder crop helps capture future rainfall and lessens erosion risk should storm rains follow.
Mr Esdaile considers that this sort of recovery would be a better strategy than waiting for the denuded pasture to recover naturally.
For future planning retaining useful pasture stubble and grazing management that avoids long overgrazing can also be part of an upgraded drought recovery management plan.
Unfortunately it is not possible to "reset" this strategy until well after the drought breaks, and hence these suggestions may be a useful approach to restart the recovery process.
Next week. Reassess pastures for future establishments
- Bob Freebairn is an agricultural consultant based at Coonabarabran. Email firstname.lastname@example.org or phone 0428 752 149.