Clovers will help clean up Lake Rotorua

Last month I gave a half-hour presentation to the Bay of Plenty Regional Council’s Plan Change 10 hearing committee relating to Lake Rotorua with support persons Anna Mayne and Rotorua-based vet-consultant Hugh Jellie.

Anna has developed her Ag Monitor model and has surveyed a small number of my dairy farmer clients looking at their financial and production data and compared their performance with the averages from DairyNZ information.

She’s consistently found drops in fertiliser costs per kilogram of milk solids, and in vet and animal health costs, less metabolic and animal welfare issues and better environmental stewardship factors from adopting my balanced approach to soil fertility.

I’m grateful to those clients of mine who’ve opened up their historical financial and production records to Anna to put through her model.

Leaching halved

I only have one dairy farmer client, one drystock client and a lifestyle block client who farm within the Lake Rotorua catchment, but see this PC10 change submission process a forerunner to the much more significant Waikato Regional Council Healthy Rivers submission process.

The previous owner of my client’s dairy farm in the catchment was applying 296kg of artificial nitrogen 15 years ago and according to Overseer modelling was leaching 96kg N/ha back then. Whereas my client is down to applying only 15kg of artificial N/ha and Overseer modelling shows their N leaching figure has more than halved down to 42kg/ha from what the previous owner was leaching.

It was through my client that I got to meet Hugh Jellie, who had used this farm as an example to apply for funding from the BOP Regional Council to prove his ‘Caring Dairying methodology of Good Farming Practice’. If followed, Hugh believes the N leaching figure would drop down to 25kg of N/ha. If all 26 dairy farmers in the Lake Rotorua catchment used his ‘Caring Dairying’ approach, all of the lake’s pollution problems would be sorted in one fell swoop.

‘Caring dairying’

However, to get the hard data for three years using lysimeters on three different dairy farms to qualify his ‘Caring Dairying’ methodology Hugh needed about $500,000 to fund the project but was unfortunately turned down.

Under the ‘Caring Dairying’ approach, farms need not be closed down and planted into trees, but could remain economically viable and environmentally sustainable – and it is our combined desire to see farming continue around Rotorua.

When it comes to the BOP Regional Council’s PC10 change submission process we are but minnows compared to the much bigger voices of DairyNZ, Ravensdown, Ballance and Federated Farmers. However, these organisations do not address the elephant in the room when it comes to the environment – which is artificial nitrogen.

For the two big fertiliser co-operatives nitrogen products make up nearly half of their sales and DairyNZ trumpet artificial Nitrogen as the cheapest form of dry matter and their consultants regularly advocate 150kg-200kg N/ha be applied annually. Federated Farmers remains largely silent on the issue as their membership is composed of both high N users and low and nil users.

Grand-parenting opposed

Consequently, these organisations also accept grand-parenting and the use of nitrogen reference points I am utterly opposed to because it allows bad polluters to continue polluting but restricts development of under-developed farms in achieving their natural biological potential.

The elephant is not going to go away until bagged nitrogen drops away significantly, and farmers return to biologically fixed clover nitrogen.

Before the highly successful release of the parasitic wasp when clover root weevil was at its worst, using artificial nitrogen made sense because clovers were being hammered by the pest and little biological N was being fixed. This is no longer the case, so farmers need to again focus on getting optimal clover performance in their pastures and cut out urea.

Nutritionally balanced pastures where cows need to consume less to achieve the same production, where metabolic problems and animal welfare issues around calving disappear, and correct mineralogy of grass from using important trace elements to assist with cow fertility and animal health pays good dividends according to Anna’s Ag Monitor data.

Biological capacity

And don’t overstock land beyond its biological capability, but rather unleash its biological potential by getting soil fertility to optimum levels for all 16 essential elements.

Money spent here will pay much better dividends than short-term fixes using artificial nitrogen. Also seek qualified independent fertiliser advice as there are some very competitively priced fertiliser options around at the moment from companies that didn’t even exist several years ago.

If you cannot find anyone independent, get quotes from several companies including one of the big two co-operatives – because I come across farmers all the time who’ve been ripped off by salesmen from so called ‘biological fertiliser’ companies when the same nutrients can be purchased from one of these co-operatives significantly cheaper. It’s your hard earned money they are taking.

Robin Boom, CPAg, member of the Institute of Professional Soil Scientists. Ph: 0274448764.


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