Right People, Right Machines, Right Results

Land Conversion

In 2005, Sesi personnel oversaw and managed two of the largest and most prominent projects in the land conversion industry. Both of these projects were in New Zealand and involved converting over 70,000 hectares of pine forestry back into dairy and farm land.

We set benchmarks in this industry and developed new systems totally unmatched by any other company. The company approach was to work with our customers or end-users and develop systems, methods and machinery for the entire project, which included developing biological microorganisms to help breakdown the mulch and to change soil regime from fungal (being the predominant regime in forestry) to bacterial (being the predominant regime in pasture).

There are a number of options for removing stumps and slash in conversions but all of these involve the complete removal and/or burning of the bio-mass or proposed organic matter. When utilising excavators to remove stumps, the stump holes remain. When the ground is levelled out, most of what is left of the topsoil is scraped or dragged into the bottom of the stump holes, basically rendering the utilisation of this organic matter useless.

In general, the industry fails to take into consideration the time and cost for burning the huge amounts of stump piles, or take into consideration the share area that these piles consume; on average from 10-30% of the total land mass area.

Our philosophy is to utilise as much as possible of the remaining residue. You will only have one opportunity in a life time to increase the organic matter in your soil in one operation. This is your opportunity.

Once we have incorporated the organic matter into the soil, we then have to convert this to a useable product for plant uptake, as this will maximise pasture growth. The organic matter or mulch acts as a moisture retention barrier and also helps to alleviate the leaching of nutrients and fertilisers.

A series of trials has been performed by a major agricultural company on the amount of dry matter available on their farms throughout the North and South islands of New Zealand. The only major common denominator for the amount of improved pasture growth was directly related to the amount of organic matter available in the soil. We increase the organic matter from 3%-5% to 43% which is 40% more organic matter.

“Organic matter in the soil has a direct effect on pasture production with every 10% increase of OM% (organic matter) being equivalent to 1 tonne of dry matter per ha per annum, and in terms of dairy farming for example, this would represent a potential increase of 1,000 litres of additional milk per ha.

It would take at least five years of conventional dairying to get to this equivalent benefit from the increased OM%, and when you consider that milk is worth 35 cents per litre the increased returns from dairying in this case would be around $1600 per ha per year on average for the first five years from conversion, not counting the savings in labour and cultivation”.

Below are a series of photos showing of our land conversion machinery and techniques that we have employed in the North and South Islands of New Zealand.





Typical forested area showing slash, wind-rows and stumps.


First pass mulching slash



Pulling apart wind-rows



Grinding stumps



Second pass with the Mulcher



Mulching completed



Blending the mulch with the soil using the stabiliser


Completed and ready for seeding



Project completed another job well done!