Tissue test results, and Kikuyu loves summer rain.
We are now in 2021. What a year 2020 was! 784mm of rain in total (about average). As you can see in the photos below, from a distance our paddocks look brown, but up close, we have plenty of green kikuyu that we are not able to graze down quickly enough. And we are having to sell lambs as they are getting too big and some are 12 months old, so getting close to not being a lamb anymore. So that is only going to add pressure to not being able to graze down the pastures enough. The rams are doing their thing with the ewes trying to produce us more ewes to keep and get our numbers up. Our target is 30 ewes/ha, or ~5,500 on our 185ha, to produce ~9,000 lambs/year. For the new readers of this blog, we do not lamb once a year. We try to have the ewes producing lambs every 7-8 months.
I mentioned in the previous blog that I took the opportunity to tissue test our kikuyu while it was so green in December, and combined with blood tests from different lines of lambs to see if we are too high or still too low in a nutrient or two.
At the time of writing, I only have the kikuyu leaf test results which show most nutrients are at good to high levels, except for manganese and magnesium, which were both marginal. I was pleased because we have come from such a low level of nutrition on the paddocks to now having almost all nutrients at good levels, for the pastures. Manganese will be addressed this year, and magnesium is provided to the sheep via lick blocks at the moment. Our soils are high in magnesium at depth, but the marginal levels in the plants is always when the plants are growing fast, too fast for the sheep's health - which is what the kikuyu is doing at the moment. I have trials I would like to do when we are at a larger scale operation, and will reveal those to you when we are in that position.
However, one nutrient is about 20 times too high. Molybdenum. I have added it at the right and safe ratio to copper, but what I have done with lime has changed the ratio more in the plants than expected. And I expect when the blood tests from the lambs are available, I will see there is a problem in some lambs because of that.
For those who don't know, molybdenum and copper are involved in many of the same enzymes and processes in plants and animals. If one is too high, the other becomes deficient. When you increase the soil pH with lime, molybdenum becomes more available, however, zinc, manganese and copper become less available. For copper, the higher pH does not reduce its availability to plants as much as occurs with zinc and manganese, however, it is the greatly increased availability of molybdenum than can cause problems by inducing copper deficiency.
The plant tissue test results show I have the copper levels at a good level for the plants, but probably not high enough for the sheep to counteract the abundant molybdenum availability. I will see what the blood tests reveal, but I might have to do a little more attention to increasing the copper levels in the plants, and sheep. But the blood tests might also reveal I have a problem with cobalt and selenium levels. I have been adding plenty of both to the pastures. Selenium in particular can become toxic if too much is added.
I am not concerned about the problems that can be caused by adding all the lime that I have done. It is pastures first, sheep second. The soil here was extremely acidic and that was priority one to fix. I could not grow the pastures that we are unless I had fixed the number one problem, then the second etc. As the lime keeps moving down the soil profile, the availability of zinc, manganese and copper will increase and the pastures will keep improving. That bit is easy for me. The harder bit is keeping track of the interactions with the sheep's requirements, which will continue to be a work in progress and I will keep monitoring their blood to see where I need to keep improving.
As for the plans for 2021, it is to keep increasing our ewe numbers as fast as possible. If you would like to be a part of Caluka's growth plans, please come and visit and have a chat.