Tuesday, 28 June 2016
How to generate feed fast, post drought
When dry conditions wreak havoc on pasture growth, and there seems like there is little you can do, it is time to turn your thoughts to how feed can be quickly generated once the drought eventually breaks.
Nitrogen key weapon in drought recovery
After the first significant rain, a quick option to increase pasture production is to apply nitrogen fertiliser. While it is preferable to wait for some regrowth, in drought conditions this is unlikely to be practical.
You should apply fertiliser as soon as possible after significant rain (i.e. enough moisture to keep pastures growing for at least 4-8 weeks after application). If you are unsure if there has been enough rain, you should defer any N decisions until further rain has fallen.
Leaf grows leaf
Renewed pastures as well as paddocks with high fertility soils and modern cultivars, have the capacity to recover fastest from drought conditions, producing the greatest dry
Research indicates that older pastures will still give cost-effective responses to N fertiliser. Ideally, it is best to apply it to those paddocks with some cover (i.e. 1,500kg DM/ha or better).
It is preferable to spell paddocks for 4-6 weeks before grazing as this gives the pasture time to express the maximum response possible, although set-stocked paddocks will also give N responses.
As the rate of N applied increases, the efficiency of response decreases. Individual applications of fertiliser N should ideally not exceed 60kg N/ha in high potential growth rate conditions, and 40kg N/ha under poorer conditions.
In general, it is best to use lower rates on larger areas, and you should budget on an 8 to 10:1 response to N in autumn, late winter, and early spring at these rates.
Provided the fertiliser history has been good in the past, and soil fertility status is reasonable, then foregoing the spring maintenance fertiliser in favour of just N is an option which should be considered. It might be possible to catch-up with maintenance fertiliser in the autumn.
Remember that N fertiliser is a growth multiplier - the faster the pasture is growing, both during and following N application, the better the response.
Steps you can take to prepare for future droughts
Ensure you have a soil-testing programme in place to monitor soil fertility. Good P and S levels improve the water use efficiency of plants and produce more, and better quality, feed.
High soil fertility extends the pasture growth supply by bringing it forward in spring. This will delay the onset of drought effects and hasten recovery from drought.
Regrassing might be required. Newer cultivars require high soil fertility, an NPS fertiliser such as Cropmaster 20 is likely to be a good option.
Direct drilling could be a good option because it will conserve moisture and reduce potential wind erosion. Remember - specialist drought tolerant plants they might have higher fertiliser requirements.
Make decisions early. When the drought finally eases, there will be a high demand for fertiliser and spreaders. Taking the early application approach, for fertiliser nutrients other than N, gets you ahead of the queue. Better that the fertiliser is spread and ready on the paddock rather than waiting for trucks or planes to become available.
Talk to your Agri Manager for advice specific to your farming operation.