viewpoint
June 2016
with John Barnes – Managing Director
Independent Agricultural Science is important
According to a recent news article staff morale at Invermay has hit rock bottom since the announcement that jobs there would be slashed as people were moved to Lincoln.
Although I have sympathy for the poor scientists and research staff, my real fear on reading this latest bit of news is for New Zealand pastoral agriculture. It seems that there is no end to the upheavals and changes taking place in Ag Research and I wonder if they know what they are doing.
In today’s fast changing world we need our scientists to be on top of their game keeping our farmers up with all of the latest methods for gaining every single advantage that we can possibly get out of our pastures and animals.
With this sort of revelation it is no wonder that my concerns about a monoculture focused on pouring more and more superphosphate and nitrogen onto our land continue unabated. These unfortunate souls obviously have more pressing concerns trying to keep up with internal changes rather than being encouraged to look at new and exciting developments in nutrient application.
Our customers are more and more concerned with chemicals in their food and in this wonderful little country of ours we should be at the absolute cutting edge of good environmental practice and gaining the huge financial rewards that this brings.
We need every single scientist and researcher concentrating on this for all our benefits and I get hopping mad when I hear that instead of that they are worried about their futures and not fully on the case. As an industry we simply cannot afford to have our attention diverted from the cause for one minute. Ag Research management need to get their act together.
Keeping the Nutrient tank full but not overflowing
During the next few weeks those who till the land will be planning on the next season. This will include what fertiliser to use and how much.
I have always considered that it is important to keep the nutrient tank full, while making sure that it doesn’t overflow into the environment. I realise that some have said that putting extra on is like money in the bank. I will let the environmentalists tell you what they think of that philosophy. Or take a look at what the media are saying about our environment.
So it is important to have the correct amount of nutrients in our soil for the plants to grow at optimum levels. The question is how much is enough and to that question I would say it depends on the type of soil you have. It is much like saying how much fuel does your car need. That will depend on the size of the tank. Sure, it might take more than one tank of fuel to get your vehicle to its destination so it will need to be topped up along the way. The same will be with some soils which just cannot hold the fertiliser needed to grow the pasture or crop for the season.
Over the years scientists have produced charts and documents to show how all this works. But as is always the case there will be exceptions; not all soils are the same and the way farmers have managed their land will be different. That is why we create a plan for each individual farm.
One such chart is the Mulder’s Chart. Mulder’s Chart shows some of the interactions between plant nutrients. High levels of a particular nutrient in the soil can interfere with the availability and uptake by the plant of other nutrients. Those nutrients which interfere with one another are said to be antagonistic. For example, high nitrogen levels can reduce the availability of boron, potash and copper; high phosphate levels can influence the uptake of iron, calcium, potash, copper and zinc; high potash levels can reduce the availability of magnesium.
Thus, unless care is taken to ensure an adequate balanced supply of all the nutrients – by the use of analysis – the application of ever higher levels of nitrogen, phosphorus and potassium in compound fertilisers can induce plant deficiencies of other essential nutrients.
Stimulation occurs when the high level of a particular nutrient increases the demand by the plant for another nutrient. Increased nitrogen levels create a demand for more magnesium. If more potassium is used, more manganese is required and so on. Although the cause of stimulation is different from that of antagonism, the result is the same – induced deficiencies of the crop if not supplied with a balanced diet.
Grass Grub has been on the move again this autumn with all the problems associated with their activity.
While there are several species of Grass Grub, all cause the same problem. Some have a one year cycle; others have a two year cycle. I don’t want to get into a debate on species or cycles in this article but rather concentrate on the main cause and effect of this problem and, even more importantly, how to control the grub. Why do we have them? What do they do? Why do they multiply so fast? What do they feed on?
The Grass Grub Cycle
To understand how to control this pest there needs to be an understanding of their life cycle.
Eggs of the New Zealand grass grub are laid in the soil during summer; normally hatching after about 2 weeks. The small larvae then feed on the roots of grasses until spring, growing to 20-25mm long.
In October, November and December when the adults emerge from their pupae, massed flights of soft buzzing slow flying beetles often occur on still warm nights. Later these bronze beetles congregate in huge numbers.
Control of Grass Grub in established pasture with insecticide has mixed results, as soil dwelling insects are relatively difficult to kill with chemicals. Grass Grub has been with us for a very long time, but in the past has run in cycles. More recently they have become an ever increasing problem.
What do they do? In nature they feed on dead or dying root systems. That is why their population explodes after a dry spell; the root systems of the pasture are weaker than normal. The greater the feed source the bigger the population. The secret is to create and keep a vigorous root feeding system with good biological activity.
Conventional farming methods look for a chemical fix, but this is almost impossible from what I have experienced. I believe the answer is in a biological fix. To stop the spread of this pest the life cycle needs to be broken, and this can only happen at the egg, larvae or flight stages.
Chemically speaking it is difficult to break the cycle in the ground as it requires an insecticide to kill off the larvae [grub]. But in nature it has been controlled, and this is how. Grass Grub eggs and larvae have predators. The eggs and grubs are a food source for other beneficial soil microbes and fungi. It is festival time for them.
What can we do to control them – Chemical or Biological? The choice is simply add in to the soil the microbes which control Grass Grub. We have had them in the soil in the past but for whatever reason the good ones haven’t survived in great enough numbers to keep these nasties under control.
Fertilizer New Zealand has bred up the beneficial microbes and fungi which live on Grass Grub eggs and larvae. This means when the adult lays eggs, there are the predators waiting to live on them.
The product Fertilizer New Zealand developed is called Vitalife. Contact us today to learn more. 