Connecting with the community

One of the biggest benefits of the project for this small rural school has been strengthening ties with the local community. The problem solvers have enlisted the help of more than 30 experts and sponsors who provide their time and expertise for free, including members of the Whangarei Bee Club, local farmers, contractors and merchants. Jocelyn Yeoman, who supplied the school’s alpacas, is also a member of the school’s Board of Trustees.

“When I saw what Bastienne was doing, I was absolutely thrilled that we had a principal who had the vision and determination to get everybody involved. It’s now a huge community project and a great thing for the school,” says Jocelyn. “We have a lot kids at this school, particularly boys, who come from farms and who are not into learning in a sit-down environment. There’s so much learning around this type of education, which gives them more interest. Hopefully it will help us to retain that top end of the school, the older children, instead of them going off to Intermediate.”

Bastienne agrees that the local community’s investment in the school has been one of the most positive outcomes of the project.

“I coached another problem solving team seven years ago at a different school and we focused on healthy eating and activity. We changed the whole school’s perception around eating, which is how I know the programme develops real life learning for everyone. But that was a hard one, because at first it was really difficult to convince the community and the children not to eat pies! This was a great programme because everybody wanted to be involved.” n

a fertiliser, while proprietary biological seaweed fertilisers and biostimulants process the raw seaweed using a range of techniques to concentrate the desired components and/or enhance certain components to create the final product.

Foliar-applied biofertilisers (and mineral fertilisers) can boost nutrient uptake even when soil nutrient levels are at an optimum. In some cases this can increase yield and quality, but in other cases it can also lead to ‘luxury uptake’ which can have negative effects such as lodging, sappy growth, increased pest attack etc. More is not always better.

Soil-applied biofertilisers cannot be taken up by plant roots because the molecules are mostly too big to get across the root epidermis. They have to be decomposed (mineralised) into inorganic salts/minerals to be absorbed. Nutrients supplied by biofertilisers sit in the same queue for plant uptake as the existing soil nutrients, so the potential for a biological form of a nutrient to have a markedly different effect to a mineral form on immediate plant uptake is small.

However, there are important system level effects to take into account. Mineral fertilisers don't contain biological forms of carbon and don't supply energy to soil biology so they can cause a reduction in soil organic matter as microbes use up the soil organic matter to make use of the extra mineral nutrients. By definition, biofertilisers do contain biological carbon so there is a much reduced likelihood that they will cause microbes to consume soil organic matter. Whether they cause a significant increase in soil organic matter depends on how much is applied. For example, compost, manure, biodigestate, wood chips and similar bulky materials, applied at tens of tonnes per hectare on a regular basis, are just about guaranteed to noticeably increase soil organic matter. Highly processed products applied at kilos per hectare are unlikely to result in comparable increases in soil organic matter. Determining whether any particular product works is where things get complex and a bit tricky, so we’ll start with an anecdote.

Back in the 1980s, the first wave of seaweed biostimulants came to market. A vining pea grower in the UK was interested in the claims being made, but thought he would test the products before using them over his whole farm. He sensibly set up a simple experiment in a field, spraying several strips of the seaweed product up his field of peas with unsprayed strips in-between.

It was soon pretty obvious where the peas had been sprayed as the plants were both bigger and greener, a property that lasted until harvest time. To test the effect on yield he drove the harvester across the strips: every time he hit one of the sprayed strips the harvester groaned and he had to put it down a gear and hit the throttle. He assumed that it was the weight of extra peas. Fortunately his farm adviser suggested that he get off the harvester and actually have a close look at the crop itself. It did not take long for the grower to realise that the extra work the harvester was doing on the sprayed strips was nothing to do with peas, because there were hardly any pods on the sprayed vines, let alone peas. The seaweed biostimulant was one that contained plant hormones (phytohormones) which are chemicals that regulate plant growth. In this case the phytohormone was one that encouraged vegetative growth in peas and suppressed reproductive growth. The strain on the harvester was not lots of peas – it was lots of vine.

There are a couple of key lessons to take from this true story. It is simply impossible to predict the effect of complex products (those containing several ingredients, as opposed to one or two) on plants and the rest of the system. The only way to determine the effects is by empirical scientific experiment (spraying strips up the field).

However, you must make a direct measurement of the results such as count the number of pods and peas on the vines and not rely on indirect measurements like the response of the harvester. Bigger vines and less peas was not what the farmer wanted. It is essential that the product has been tested on your specific crop (even specific cultivars) for the effect you want to achieve, at the point in the crop's lifecycle you plan to use it (eg, early growth, post flowering). Just as there are selective herbicides that will kill weeds and not the crop, any one biofertiliser or biostimulant may have quite different results on one crop species than another, and different effects at different growth stages.