By Angus Deans
We are coming into winter in a very sad state of affairs as far as pasture production goes. And this is such a turn around from a few months ago when we were enjoying the most amazing early summer season we have experienced in our time as custodians of this land.
In early summer the rainfall was such that our problem was how to manage the growth that was far in excess of what we could hope to manage with grazing. This created a few conundrums for us.
Some schools of thought believe that it is necessary to graze actively growing pasture every 30 days, or thereabouts, in order to maintain maximum vegetative growth. For us even with lambs on the ground our rotation was taking a minimum 63 days – and even achieving this meant that the sheep barely touched the majority of the feed each pass. We do not believe that trying to keep a pasture leafy is necessarily a good thing anyway. We believe that the plant only gets to express its full potential as a member of the farm community when it reaches maturity and preventing this reduces the contributable energy we could have gained. We also gain a benefit from the ripening seed heads in autumn that help to fatten the young stock that should be leaving the farm then in keeping with the natural cycles that demand reduced carrying capacity in winter.
So what to do? We could have bought more sheep but that is not an answer for people who try to manage within the average productive capacity of the land. I am also glad that we did not pursue this avenue as the rain switched off at the end of January and forgot to turn on again until mid-March with a measly half inch followed by the same at the end of March. These falls were effectively useless due to the very high temperatures and constant hot winds we were experiencing. As a strategy in this land of very variable rainfall I think this can often be short-sighted anyway. I would rather use the extra growth as an opportunity to allow the pastures to build bigger reserves both of fodder above ground but also of root mass below ground.
In managing our rotation during January - and the growth was such that our sheep could have been outfitted with flags to see them above the grass – and realising that the sheep were very selectively grazing each paddock with a 24 hour shift I decided to try a 48 hour shift, to try and encourage consumption of less desirable pasture species as well. What transpired has lent weight to what I had believed was most appropriate as far as longevity of a graze period in times of growth. With the 24 hour graze the sheep had cropped the desirable pasture species to a height of about 40mm whilst leaving the majority of the herbage untouched. With a 48 hour graze they came back and cropped the same desirable plants to approximately 10 -15 mm and still left the longer ranker pasture largely untouched! So back to 24 hour graze periods we went.
The reason we decided to stick with the 24 hour graze was that we are largely farming our land with a view to growing soil. For we believe that if we are actively growing soil then we will be, by default, actively growing herbage and biology and thus maximising our productive potential. This happens because as our organic matter level rises so does our ability to store water and thus maximise rainfall use, and we have a more active soil biota all helping this happen at an exponential rate of increase as well as helping recycle wastes and making minerals available. As this happens we automatically grow more feed with deeper roots to hasten the process still further.
The thing that makes this most possible though is the efficient conversion of free sunlight into energy – and this is dependent upon the solar panel – the green leaf. If the most desirable pasture was cropped to a height of 40mm after 24 hours grazing then we had an adequate solar panel remaining to produce energy quickly to replace that lost via the grazing. This promotes a more rapid response of this desirable plant species in order that it might be even stronger and more productive the next time it is grazed.
After 48 hours of grazing and with a negligible solar panel left the plant really struggles to recover and if the environment is not kind for whatever reason it may never. It may lose out to a more hardy less desirable plant beside it. This is partially a factor of the fact that plant roots are usually only as long (as deep) as the leaves are high above the ground. So obviously a plant with roots only 10 – 15mm deep is going to find it harder to access sufficient moisture and nutrients to promote rapid growth and this is compounded by the lack of solar panel (leaf) anyway.
There is another reason for not wanting to graze this short that is equally as important. It is believed that parasitical worm larvae seldom climb higher than 50mm up the leaves of herbage. In order to minimise ingestion of same it is desirable to leave a longer leaf residue. For those whose paddocks resemble a bowling green not only are the sheep ingesting most of the worm larvae but they are also probably ingesting worm eggs from the soil surface. Not helpful!
Another possibility to have managed our surplus pasture production would have been to have turned it into either hay or haylage. On a larger scale this would have been a more possible solution but for me it also raises another possible problem. If it ever becomes necessary to feed out this stored feed then doing so may cause more harm than good. Here is why we believe this to be so.
If you are short on feed and supplementary feeding is necessary then you are effectively overstocked. By this stage pastures will already be degraded and then becoming more so every day. Having supplementary feed on hand may mean that you are able to carry more stock than your natural production would allow and doing so will compromise the ability of your pastures to both respond and flourish when the next growth period occurs. This becomes an ever downward spiral of diminished productivity requiring more supplementary feeding that diminishes productivity and so on it goes.
Another noteworthy thing we observed as a result of this extremely harsh late summer was the amazing ability of native pastures to survive and even thrive. By the time we had completed a rotation after the rain effectively stopped we were left with not a drop of green in our pastures. We still had herbage up to about 18 inches high but it was totally brown – totally burnt. We received 23mm of rain about 10th April that coincided with more moderate temperatures – still about 4 degrees above average – but much more moderate none the less. Amazingly our native grasses changed colour almost overnight! Whilst the whole leaf did not become green most leaves became green from the midrib out and so became about a third green! In the absence of any rain since then we have still achieved growth. I am absolutely astounded at this ability.
We are coming into winter in a very sad state of affairs as far as pasture production goes. And this is such a turn around from a few months ago when we were enjoying the most amazing early summer season we have experienced in our time as custodians of this land.
In early summer the rainfall was such that our problem was how to manage the growth that was far in excess of what we could hope to manage with grazing. This created a few conundrums for us.
Some schools of thought believe that it is necessary to graze actively growing pasture every 30 days, or thereabouts, in order to maintain maximum vegetative growth. For us even with lambs on the ground our rotation was taking a minimum 63 days – and even achieving this meant that the sheep barely touched the majority of the feed each pass. We do not believe that trying to keep a pasture leafy is necessarily a good thing anyway. We believe that the plant only gets to express its full potential as a member of the farm community when it reaches maturity and preventing this reduces the contributable energy we could have gained. We also gain a benefit from the ripening seed heads in autumn that help to fatten the young stock that should be leaving the farm then in keeping with the natural cycles that demand reduced carrying capacity in winter.
So what to do? We could have bought more sheep but that is not an answer for people who try to manage within the average productive capacity of the land. I am also glad that we did not pursue this avenue as the rain switched off at the end of January and forgot to turn on again until mid-March with a measly half inch followed by the same at the end of March. These falls were effectively useless due to the very high temperatures and constant hot winds we were experiencing. As a strategy in this land of very variable rainfall I think this can often be short-sighted anyway. I would rather use the extra growth as an opportunity to allow the pastures to build bigger reserves both of fodder above ground but also of root mass below ground.
In managing our rotation during January - and the growth was such that our sheep could have been outfitted with flags to see them above the grass – and realising that the sheep were very selectively grazing each paddock with a 24 hour shift I decided to try a 48 hour shift, to try and encourage consumption of less desirable pasture species as well. What transpired has lent weight to what I had believed was most appropriate as far as longevity of a graze period in times of growth. With the 24 hour graze the sheep had cropped the desirable pasture species to a height of about 40mm whilst leaving the majority of the herbage untouched. With a 48 hour graze they came back and cropped the same desirable plants to approximately 10 -15 mm and still left the longer ranker pasture largely untouched! So back to 24 hour graze periods we went.
The reason we decided to stick with the 24 hour graze was that we are largely farming our land with a view to growing soil. For we believe that if we are actively growing soil then we will be, by default, actively growing herbage and biology and thus maximising our productive potential. This happens because as our organic matter level rises so does our ability to store water and thus maximise rainfall use, and we have a more active soil biota all helping this happen at an exponential rate of increase as well as helping recycle wastes and making minerals available. As this happens we automatically grow more feed with deeper roots to hasten the process still further.
The thing that makes this most possible though is the efficient conversion of free sunlight into energy – and this is dependent upon the solar panel – the green leaf. If the most desirable pasture was cropped to a height of 40mm after 24 hours grazing then we had an adequate solar panel remaining to produce energy quickly to replace that lost via the grazing. This promotes a more rapid response of this desirable plant species in order that it might be even stronger and more productive the next time it is grazed.
After 48 hours of grazing and with a negligible solar panel left the plant really struggles to recover and if the environment is not kind for whatever reason it may never. It may lose out to a more hardy less desirable plant beside it. This is partially a factor of the fact that plant roots are usually only as long (as deep) as the leaves are high above the ground. So obviously a plant with roots only 10 – 15mm deep is going to find it harder to access sufficient moisture and nutrients to promote rapid growth and this is compounded by the lack of solar panel (leaf) anyway.
There is another reason for not wanting to graze this short that is equally as important. It is believed that parasitical worm larvae seldom climb higher than 50mm up the leaves of herbage. In order to minimise ingestion of same it is desirable to leave a longer leaf residue. For those whose paddocks resemble a bowling green not only are the sheep ingesting most of the worm larvae but they are also probably ingesting worm eggs from the soil surface. Not helpful!
Another possibility to have managed our surplus pasture production would have been to have turned it into either hay or haylage. On a larger scale this would have been a more possible solution but for me it also raises another possible problem. If it ever becomes necessary to feed out this stored feed then doing so may cause more harm than good. Here is why we believe this to be so.
If you are short on feed and supplementary feeding is necessary then you are effectively overstocked. By this stage pastures will already be degraded and then becoming more so every day. Having supplementary feed on hand may mean that you are able to carry more stock than your natural production would allow and doing so will compromise the ability of your pastures to both respond and flourish when the next growth period occurs. This becomes an ever downward spiral of diminished productivity requiring more supplementary feeding that diminishes productivity and so on it goes.
Another noteworthy thing we observed as a result of this extremely harsh late summer was the amazing ability of native pastures to survive and even thrive. By the time we had completed a rotation after the rain effectively stopped we were left with not a drop of green in our pastures. We still had herbage up to about 18 inches high but it was totally brown – totally burnt. We received 23mm of rain about 10th April that coincided with more moderate temperatures – still about 4 degrees above average – but much more moderate none the less. Amazingly our native grasses changed colour almost overnight! Whilst the whole leaf did not become green most leaves became green from the midrib out and so became about a third green! In the absence of any rain since then we have still achieved growth. I am absolutely astounded at this ability.