Newsletter - November 2010

 

Under long term DoloZest/CalciZest based programmes the use of nitrogen fertiliser in early season appears to shift feed from the key growth times of October and November.  Total seasonal growth appears lessened and, if this is the case, then increasing growth earlier at the expense of growth later is both inefficient and expensive.
 
This does not mean that fertiliser nitrogen is not able to be used to good effect.  As with all intensive systems dependant on sunlight and moisture from rainfall there will be times when a short-term boost in pasture cover may be desirable, however it comes at a cost.
 
The application of fertiliser nitrogen with Zest (BaseMix), containing the ESI unique blend of soft carbon, carbohydrate, and beneficial fungi and bacteria provides an excellent response. 
  
Typically N is applied in the form of sulphate of ammonia at about 60% of the N input rate used in conventional systems i.e. 15kg N per hectare.
 
Air is approx. 78% nitrogen and pastoral soils usually contain in excess of 5,000kg/ha of nitrogen in the top 20cm. Well structured biologically active soils with sufficient other essential nutrients are able to grow 18,000kg of DM/ha/year without dependence on fertiliser nitrogen.
 
It is often stated that we are now producing more kilograms of milk solids per hectare than 20-30 years ago, so fertiliser nitrogen driven pastoral systems must be growing more grass.  Factoring in bought-in feed and grazing off is likely to make sense of this equation.  20–30 years ago many dairy units were self contained, all young stock reared and grown at home.  Annual production of 800 – 900kgMS/ha from grass, hay, and silage from the property alone was common.

Recent Observations

 
Moss, this winter and early spring, was more evident than in the past.  In the last two months this has largely disappeared.  Winter and early spring were particularly wet, conditions that favour moss.  As natural systems are always tending to wellness, following a dry summer where bare patches of soil were evident, moss perhaps is a natural part of the recovery process.
 
Docks are more evident this spring than in recent springs.  Dock usually grows on soils that have been saturated for a period of time over winter.  It seems that it is a result of excess potassium relative to phosphorus that promotes dock growth.
 

Brix levels                  

 

Brix levels alter throughout the day so it is important to take plenty.  There are often marked differences between clover and rye grasses with levels of clovers never less and always higher than rye grasses.

Rapidly growing pasture nearly always provides lower brix levels than mature pasture that has passed the ‘blaze of growth’ and is slowing.
 
Taking a sample of grass that is around 30cm in length and splitting into roughly equal thirds will provide higher brix levels for the top 10cm sample and lesser readings for the 0–10cm sample and the 10–20cm sample.
 
Brix levels tend to build throughout the day with energy being transferred to the root system as sunlight decreases. The energy transferred to the root system is then used by the beneficial mycorrhizal fungi for the harvesting of nutrient, particularly phosphorus.
 
Phosphorus is essential for the formation of sugars and as phosphorus is bound relatively tightly in many soils, the action of mycorrhizal fungi is essential for optimum uptake.
 
All long term pastoral farmers know that the best time to cut hay is during the afternoon on a bright sunny day when sugars are at their highest and the resultant crop is of highest possible quality.
 
Ideally clover stems should be solid.  To achieve this there needs to be high levels of plant available calcium.  Calcium is essential for strong structures and where there is long-stemmed, large-leafed clover with solid stems, the system is functioning at or near optimum.
 

As early as 1978 MAF trial work showed that introduced mycorrhizal fungi on an eroded Kaikoura soil in Canterbury resulted in large and very highly significant growth responses in Marku lotus.
 
Between 1978 and 1981 several field trials were undertaken at Invermay’s Wairoa farm that showed the introduced mycorrhizal species Glomus mosseae gave significant increases in plant growth at all levels of applied phosphorus.  Phosphorus is a major cost in conventional fertiliser programmes and a reduction in required inputs can provide real cost savings.  
 
CalciZest and DoloZest contain a wide range of selected soil friendly fungi and bacteria that include mycorrhizal fungi.  Mycorrhizal fungi grow out from plant roots increasing the area from which particularly phosphorus and moisture can be harvested.
 
Mycorrhizal fungi, rhizobia bacteria, legumes, and non-legume plants can all interact in a four-way mutually beneficial relationship.  Due to the link provided by mycorrhizae, nitrogen fixed by clovers can be taken up by non-legume plants, in exchange for phosphorus provided to the clover plants.
 
Obviously a great deal more research is required to know with certainty the effect that different nutrient programmes have on this process, however soils that are physically well structured and biologically active are capable of providing more total pasture growth over a twelve month period.
 
Animal feet provide a great deal of downward pressure and the only way of ensuring soils do not become increasingly compacted is by providing an environment that favours both earthworms and other beneficial soil dwellers.
 
Both dolomite and lime have a marked beneficial effect on the physical structures and biological activity of pastoral soils.  Calcium provided by lime increases moisture holding capacity as well as earthworm activity, with dolomite used where magnesium is also a requirement.
 
Now into the tenth year of commercial use our monitoring systems have shown that relatively small quantities of calcium applied in the form of CalciZest provide significant lifts in clover growth as well as markedly reducing the damage by clover flea and weevil.
 
The benefits of DoloZest and CalciZest are available to all farmers and growers regardless of other nutrient inputs.  There is an increasing number of farmers applying CalciZest solely to reduce clover flea and weevil damage and reports to date have been positive.