There is no shortage of biological products on the market. Claims of improved soil health, better nutrient availability, stronger root growth, increased production, or less reliance on fertiliser are everywhere on product labels. What products contain, how they are supposed to work, and the quality of the evidence of their claims varies widely. While some products may have a place in your operation, the term ‘biological’ is broad. So, rather than accepting or dismissing them as a group, we need to ask the right questions.
The goal
Your first question is simple: what problem are we trying to fix? If there is no clearly identified limitation, then what benefit the product is expected to provide? General claims of ‘improved soil health’ may sound good, but what does that mean in the paddock? How is it measured?
The evidence
Your next question: is there is good evidence to show the product works? Has it been tested in replicated field trials? Are the claims mainly based on testimonials, laboratory work, or a few demonstration paddocks? While overseas results can be useful, they may not directly translate to New Zealand soils, climate, and farming systems.
What was the product compared with? If only compared to an untreated crop when normal fertiliser or farm practice would have produced a much better result, then be cautious. If the claim is
fertiliser inputs can be reduced, then you need to know what happened to production and soil fertility over time.
The details
Then there are the practical questions. What is in the product? How is it meant to work? Is the proposed mechanism reasonable? Are the conditions needed for it to work likely to occur on your farm? How often it needs to be applied? Will the benefit continue once applications stop?
Answers to these simple, practical questions will save you time, effort, and investment.
Biologicals are not bad just because they are new, nor should you accept all the product’s claims without sound evidence and measurable farm value. Rather, asking questions and evaluating evidence is the best basis for the adoption of biologicals into your operation.
TECH TIPS
- Identify potential micronutrients issues, such as molybdenum deficiencies, by herbage testing newly growing lucerne. Soil testing alone does not detect these issues.
- When looking to cultivate land, make sure soil moisture is ideal. Disc and plough plans can be formed in the soil, if too wet.
- When walking paddocks to be put into spring sown crops, dig a hole in the soil 20 to 30 cm deep to look for signs of compaction. If identified, ripping can improve crop yield.
