0800 843 809 info@esi.org.nz

It’s been fascinating talking over Christmas and New Year with smart intelligent people that have no direct farming connection.

They’re keen to embrace a more environmentally focussed future even if that means having the inconvenience and extra cost of less plastic, and more time and effort spent recycling household waste.

However, the ‘all farming is environmentally negative’ message doesn’t resonate with them, and it’s not about losing the cream for their coffee and replacing meat with alternative protein.

It all just sounds a little too simplistic.  Even though a significant proportion of those aged 45 and younger haven’t spent time on farms and don’t have close contact with practical farmers, replacing all farms with trees just doesn’t sound right to them, with good reason.

The ultimate test of whether individual farms are environmentally positive lies with their ability to sequester carbon, and it is under permanently grazed pasture that carbon may be most rapidly sequestered.

Whether it’s a one to one ratio or not, for every kilogram of dry matter produced there’s dead root, dung, and old leaf matter being actively broken down with the carbon content being stored in the soil, and in a healthy situation forming humus.

Humus is a term no longer used by the local scientific fraternity and they will have their reasons which in time will become apparent.

Humus as most understand it is what is left after full biological degradation of organic matter, and as the material from which it is formed naturally varies, it is perhaps not easily defined.

Humus in its true form is extremely stable and not easily lost from the soil, even during droughts and extreme wet.  It is where nutrient and moisture for plant growth is held, and farmers pay a premium for soils with high levels of humus.

In regions dominated by cropping long term pastoral properties are keenly sought when available, as crop yield in the first three years is always superior, often considerably so.

Excellent physical soil structures mean less cultivation is required initially, nutrient inputs are better utilised, and the crops initially require less water and therefore yield, and crop quality is higher.

The question is why is it that pastoral farming is receiving such a hard time?  It may possibly be justified on the fact that in general terms all irrigated land is losing carbon, however that is not the case with every farm.

Ultimately it comes down to the amount and regularity of nitrogen applications.  Years ago, when growing peaches, apples and nectarines for sale it was recommended that a high concentration urea spray was applied as soon as the trees had lost their leaves in autumn.

The reason given was to clean up the trees destroying any old leaf matter lodged in the forks of branches, and it proved highly effective.

It does the same to organic matter in the soil and when the loss of organic matter is greater than the amount gained soils degrade and yield steadily decreases over time.  It may take 20 years for that decline to become obvious but long-term growth figures will show it to be the case.

The answer is to provide plants with all their required nitrogen with that fixed naturally by clover.  And an increasing number of farmers are joining those that have been successfully doing that twenty years or longer.

Some of the characteristics of these operations is they have higher levels of total farm performance with lower costs, as well as enjoying more reliable annual pasture production.

Mating performance and overall animal health is generally better.  Water drains more freely after wet periods, with pastures growing longer into a dry spell and recovery taking place more quickly after rain arrives.

There is a theory, regarded as fact by some, that nitrogen fixed by clover is just as readily leached as that applied in the form of urea.  That is not the reality and there is already enough data to refute that, with more measures to come.

Clover fixes nitrogen in response to declining plant-available levels and therefore the supply and demand equation is far more finely balanced than in a regular urea application situation, and that nugget came from a senior soil scientist running soil fertility courses at Ruakura Research Station in the early 1990’s.

For more information call Peter on 0800 843 809.

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