Fert Options with Robin Boom Agronomic Advisory Services

 On May 11-12, the NZ Grassland Association ran a special Resilient Pastures Symposium at the Don Rowlands Centre at Karapiro which 230 people attended.

The NZGA was formed 90 years ago, and currently has around 800 members nationwide, who are a mixture of scientists, consultants, agribusiness and farmers.

The Grassland website is a wealth of information of historical research related to pastoral farming over nine decades, and accepted papers are put through the peer review process to ensure the science is robust and credible. A motto for the Association is: ‘Fuelled by science and tempered by experience’.

Almost any topic to do with soils, agronomy, fodder crops, fertility, weeds, pests, and the environment has been investigated and reported to some degree, and annual conferences are a forum where new science, ideas and systems are presented and debated.

At this years’ symposium, I presented the results of a lime trial I ran on a western Waikato hill country property, where summer droughts have a huge impact on annual pasture production, and this combined with the effect of low pH and aluminium toxicity, resulted in significant pasture species changes and almost a doubling of dry matter grown from the highest limed treatment compared to the control where no lime had been applied. When the economics were considered, the lower rates of lime gave greater return at four cents/kg DM, compared to the highest rate of lime at around eight cents/kg DM, but this too is still relatively cheap dry matter.

Ryegrass survival

One of the major points of discussion at the symposium was the experience of some Northland dairy farmers who found that ryegrass plants were no longer surviving in their environment, and they had found success in using new cocksfoot cultivars which do not have the palatability and clumpiness challenges which the old cockfoot cultivars had.

If increased droughts and global warming were to continue, they believed in the next two or three decades the problems of ryegrass persistence would creep south into the Waikato and elsewhere, and that looking at alternative species like cocksfoot was a viable solution.

For areas such as the Hauraki Plains which seems to be hit with summer droughts more often than not, planting cocksfoot based pastures may well pay back good dividends.

The Northland farmers cautioned that cocksfoot pastures need quite different grazing management, with much more frequent grazings required to keep the pasture quality compared to ryegrass.

Gobbledegook pseudo-science

Science based organisations like the NZGA, the NZ Animal Production Society, the NZ Institute of Agricultural and Horticultural Science, NZ Agronomy Society and the NZ Society of Soil Science are no place for snake oil salesmen to spout nonsense.

From my experience of more than 30 years, these sorts of people never darken the doorway of any such society’s conferences.

While writing this article, I have had two of my understudies from different parts of the country ask me about supposed soil/plant treatments, one a liquid product that is sprayed onto pastures and orchards, and the other a powdered blend of various quarried mediums which is claimed to help assist plants to take up nutrients locked up in the soil. According to the website of the liquid product, two litres of this product sprayed onto pastures or orchards will result in unbelievable increases in production.

As with many snake oil and muck and mystery type products, the mode of action is usually shrouded in secrecy, and there is a lot of gobbledegook pseudo-science rhetoric that the uneducated can easily get sucked in by.

I have also, over the years, listened to some very charismatic and entertaining characters wax eloquent about their particular product or system and why mainstream science has got it all so wrong, and only they have discovered some new game-changer. Snake oil products are normally very expensive sources of nutrients compared to conventional fertiliser products, and if there is some marvellous new breakthrough which has been discovered, it should be independently analysed with fully replicated trials which are put through statistical analysis to determine its efficacy.

Shot-gun approach

One fad at the moment being promoted by ‘regenerative’ agriculture is multi-species plantings of up to 30 or more different species.

It’s a shot-gun approach of waiting and seeing what germinates, competes and lasts.

The problem is these seed mixes are often very expensive, and although annual fodder species like sorghum and sunflowers can provide quality feed over the dry summer periods, many of the other species just will not handle the competition, and the money spent on these is wasted.

A rep from a reputable seed company I spoke to recently said that usually of the 30 odd species purchased, only about half a dozen will give any financial return and the farmer is much better to purchase those individual plant species rather than wasting a whole lot of money on seeds of species that provide no benefit.

Robin Boom is a Member of the Institute of Professional Soil Scientists.