Pasture rest, is it time or timing?
The people who achieve the most in land regeneration are not the ones who lock up country for the longest time. Instead, it is the ones who act when something can be achieved.
Everybody knows pastures have to be rested, but ask a collection of people what rest is and surprisingly there is no consensus. Those who prefer to use the term recovery, in preference to the term rest, appear to have a better understanding. They appreciate the issue is actually allowing plants to grow and become healthy, rather than the removal of animals from pastures for a given length of time.
Pasture rest is really timing, not time.
A trip to South Africa clarified the importance of timing as the real issue to me, when I was shown a grazing trial at the Grootfontein Research Institute at Middleburg.
The message from the inspection was that grazing plants while they are trying to grow is what does the damage, and rest at the wrong time is of little value, unless it prevents the landscape from becoming too bare.
This last statement is not profound or new, but unfortunately this principle is not promoted by all who enter the pasture management debate.
In the early 1950's rural producers were getting good advice on how to manage pastures, even if the science behind it was not explained. I quote from the "Handbook For Woolgrowers" issued by The Australian Wool Board in 1954.
"The perennial grasses are adapted to withstand long periods of drought and this also enables the grasses to withstand continued grazing provided they are dormant. No such adaptation protects them during periods of active growth, so that these pastures should not be heavily grazed immediately after heavy summer rains, nor should they be continuously grazed during a long period when conditions are generally dry with an occasional light fall of rain which produces a slight growth from the grasses. During dry periods, heavy grazing will not harm the perennial grasses provided, of course, that it is not so heavy that sheep paw at the tussocks and expose the roots."
The key word in the above quote is "dormant". If the plant is dormant, then it is not depleting it's root reserves (energy reserves). As soon as a perennial grass starts to grow after dormancy it has to call on root reserves until there is enough green leaf for photosynthesis to supply energy. If animals are allowed to maintain green leaf surface area at a low level, and hence stop photosynthesis, then plants are forced to call on root reserves as there is moisture to promote growth. This is why the 1954 advice was to not heavily graze perennial grasses immediately after heavy summer rains.
Personal experiences have confirmed that above average seasons are not needed to regenerate the landscape. Taking this position shifts the emphasis from relying on good seasons for pasture repair to concentrating more on every useful rainfall event as a possible repair agent.
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