David and Kim Hunt grow limes near Maryborough in Queensland. They are relative newcomers to this industry so they attended the four-day NTS Certificate in Sustainable Agriculture course to bring themselves up to speed with the most productive strategies for high-production, sustainable horticulture. They also decided to enlist the help of accomplished biological orchard consultant, Heinz Gugger, who farms stone fruit and persimmons, biologically, near Amamoor in South-East Queensland.
This package of empowerment through education and informed guidance has proven very productive. The orchard of 2100 trees was producing just 30 tonnes of limes when they purchased the property two years ago. The yield this past year had increased to 100 tonnes and the focus is now on improving quality rather than yield.
The Changes that Made the Difference
David and Kim inherited a standard nutrition program, which involved monthly fertigations of high rates of calcium nitrate, urea, potassium sulphate and magnesium sulphate, along with some sulphate-based trace minerals. There was no precision in the program. The plants were simply provided with these soluble salts whether they needed them or not. Heinz introduced the Hunts to our Soil Therapy™ and Plant Therapy™ testing services, to help them gain an insight into exactly what minerals the soil needed and what nutrition the trees required. This enabled a reduction of 90% in the salt fertilisers, which were replaced by an emphasis on correcting the mineral balance in the soil and plant, and firing up the soil biology. Compost and core minerals were applied to the soil and appropriate NTS foliar fertilisers were used to address tree nutrition. Crumb structure returned quite rapidly to the soil with the help of humates and compost, and the crop became noticeably more drought resistant in the face of the recent long dry period. Soil bacteria produce an exudate that acts just like water crystals in the soil and this can make a real difference during dry spells.
This avoidance of blind fertilising (uninformed nutrition), combined with successful efforts to build biology, has seen a good increase in the resilience and visual health of the trees. They are a darker green than previously due to the fact that a greater percentage of their nitrogen comes through nitrogen fixation.
The decision to stop using fungicides was based upon both a desire to reduce damage to soil life and a recognition that these chemicals were no longer required, due to the marked increase in tree health. Interestingly, we are seeing increasing research that suggests a link to fungicides and reduced plant performance and resilience. You might have stopped the disease at the time, but there is a price to be paid for that chemical intervention in the bigger picture.
Similarly, Heinz suggested that they should also reduce herbicide use under the trees, as these chemicals are really hard on beneficial soil life. Heinz Gugger is a talented orchardist, who has moved away from the use of herbicides on his own orchards in favour of under-tree mowing and grass control with mini cattle.
Meters to Monitor Progress
Aside from the obvious changes to soil health and tree health and the trebling of yield, David and Kim use in-field monitoring tools to monitor their progress. Their favourites are the refractometer and the sap pH meter. They have seen a 50% increase in the brix of the fruit and a 40% increase in the brix of the leaf since they began the Nutrition Farming® approach. However, there is still some way to go with their brix-building efforts to ensure fruit with forgotten flavours and greatly extended shelf life (two of the key benefits of high brix levels). The Hunts have no doubt that they are on the right path and are passionately pursuing their goals.
The goal with sap pH is to achieve a sap brix of 6.4. At this point it becomes very difficult to contract a fungal disease. In fact, in the last 15 years of international consulting, I am yet to see a plant with a sap pH of 6.4 that had a disease. The concept of using sap pH as a guideline to crop health was a tremendous breakthrough finding by renowned American scientist, Bruce Tainio. The Hunts have achieved a sap pH of 6.3 and hence the reduced need for fungicides.
We would like to congratulate David and Kim on becoming the first Nutrition Farmers of The Month in our new competition. We would also like to thank consultant, Heinz Gugger, for helping them achieve this victory. We hope that the Hunts use their $500 prize to move further along the Nutrition Farming® path.