November 2017

Nitrogen and the sources thereof

A lawyer friend of mine asking a question in all innocence said, “If a cow’s urine is so full of nitrogen that it is causing environmental problems, why is that not enough to boost the grass”? This is a very good question indeed because we are now in a vicious cycle of huge proportions. More bagged nitrogen is going on the pastures making the uptake by the cows many times more than it would otherwise be, and therefore the cows are excreting ever more nitrogen and we are losing it to our streams and rivers. The big words here are ‘excreting’ and ‘losing’. If nitrogen is being wasted to the streams and rivers, it is lost money and lost profit. I am not against nitrogen, far from it. From time to time in critical periods it is a hugely important tool to get grass growth, but to apply it at the levels that some are doing does not make any sense at all and it is quite literally money down the drain.

Nutrient programmes from Fertilizer New Zealand take account of the bottom line at all times and I have to say we are even more concerned about our environment than my lawyer friend. There must be a balance in all soil science and an understanding of what our pasture plants are able to take up and use. If we are applying too much of one nutrient over another there will be waste and that is lost money.

Clover produces most of the nitrogen in our pastures so we nurture that. Effluent distribution certainly puts some back in also. Some comes from the atmosphere (believe it or not) and, yes, some comes out of a bag. But the last option is by a country mile the most expensive so we at Fertilizer New Zealand like to keep that one to a minimum.

Call us, we are here to help.

John Barnes, Managing Director

Typically, fertilisers used in New Zealand can be put into two categories.

Anion is a negatively charged ion. Anions are phosphate and sulphur. This is what we know as Superphosphate. There are many other anions, but these are not the subject of this article.

The other group is cations. Cations are positively charged ions. This group has four major elements for farming. Potassium is one of these elements and is typically added to Superphosphate. Many farmers will be aware of “Potassic Super”. It is prefaced often as a percentage, for example 30% Potassic Super.

Potassium is a cation, which is in a different category than phosphate and sulphur. Potassium belongs to the group of elements which includes calcium, magnesium and sodium. All four of these elements are important for stock health. Potassium usually dominates the other three, and because of this the plant will take up more potash than the others. That is why there needs to be more calcium and magnesium in the system so that the animals will have a correct diet. I frequently say that calcium is King. Farmers are aware that calcium is bone and calcium is milk. Magnesium is also very important; without magnesium stock will suffer and often die.

A lack of calcium in cows is called Milk Fever (Hypocalcaemia). Milk fever is a disorder mainly of dairy cows close to calving. It is a metabolic disease caused by a low blood calcium level (hypocalcaemia).

A lack of magnesium is called grass tetany or hypomagnesemic tetany, also known as grass staggers and winter tetany. It is a metabolic disease involving magnesium deficiency which can occur in such ruminant livestock as beef cattle, dairy cattle and sheep.

A lack of sodium will deliver the farmer with problems of bloat.

The problem will be compounded when potassium is applied with little consideration for calcium, magnesium or sodium.

Potassium tends to dominate the other three elements which means that more of these three elements need to be added to compensate for the first one. In other words, if you add one, the prudent thing to do is to add the other three. The pasture needs more potassium to grow than the animals need to produce so there will always need to be a compromise. When I started to work out the ratios for stock health I had to do this by calculation. Today we can have this given to us through a commercial herbage test. It saves me time. Basically, this can start with having the cations in the soil put into a ratio which is:

Calcium 65% +

Magnesium 10%+

Potassium 3%+

Sodium 1%+

The rule is when applying an element to the soil, ask ‘how will this affect the soil?’. Potassium is just one such element.

I have added a chart I often refer to as a guide to how a variety of commonly used agricultural elements have a beneficial or detrimental effect on each other.

mulders chart


1 x 1000L Pod of Actavize
1 x 200L Verteblack (humate)
1 x 20L MPower

Price would normally be $5539 + GST.  However this Combo deal will be $4995 + GST.  That’s right.. for these three products all together.  

So the benefit to the farmer is over a $500 saving not to mention all the benefits of using these products together to enhance the soil life further.  The rate I would suggest would typically be 20L of Activize, 8-9L of Humate and 1-2L of M-Power to put the real cream on top of this Combo deal making typically 30L p/ha with a dilution rate of 1:10 for pasture depending on application method.

Call us today at 0800 337 869 for more information.