Why sunlight and regenerative agricultural practices are the key to this Macadamia Orchard.
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Read the story here - provided by Rex
Since 1998 Piccadilly Park Macadamia Orchard has been the home farm of Rex and Lynette Harris. Together with Sons Carl and Daniel, farm manager Mark Jones, and agronomist Ray O’Grady, they collaborate in a stewardship with nature to care for this 90 ha’s of diverse Macadamia, Rainforest, and inter-row cover crop operation just outside Bangalow on the NSW Far North Coast.
Following purchase in 1998, months were spent clearing the rampant exotic weeds of Camphor Laurel, Privet, and Lantana before proceeding to establish 16,500 Tree Macadamia Orchard and then planted approx. 60,000 rainforest and sedge species along Riparian zones and gullies.
The Orchard was managed under conventional practices until 2011 when it became obvious something was wrong. The orchard was showing signs of tree dieback and production was well below similar farms.
About that same time, it was discovered that corn and potatoes had been grown on the property for many years during the early 1980’s. Standard practices for growing those crops included heavy tillage practices on undulating land. The topsoil loss during the normal rain events let alone “East Coast lows” would have been substantial.
It was obvious that soil health needed to become the number one focus.
In Nov 2011 Ray O’Grady became consultant agronomist and under his guidance a natural approach to nutrition began particularly moving away from chemical fertilisers and using animal manures and compost. Aluminium toxicity was a major problem and a program to balance all soil elements began. As time passed sourcing animal manure became difficult and it was decided to make our own compost. Three full length rows of Macadamia trees were removed to make way for a compost making pad. New compost making equipment was purchased and compost applications became a core practice for tree health instead of applications of chemical fertiliser. Following harvest each year 100 kg of compost is applied per tree. Sweet smother-grass had been established throughout the orchard as a ground cover to help protect the precious topsoil that was being re-formed.
Gradually tree health and production improved but the 7-metre-wide rows of Macadamia trees began to canopy over the inter row space thus blocking sunlight to the orchard floor. This caused smother grass to rapidly disappear and provide little protection to the precious topsoil that we had spent vast expense and time rebuilding.
In Aug 2017 an 8-year program commenced to remove 1,000 trees per annum. Tree removal was full row, every second row. All the removed tree biomass was double ground and used as a component of our compost. Nothing was wasted.
Full row tree removal left 14 metres between tree rows and large areas of uncovered and unprotected soil. Daniel had recently completed a Regen Ag course and started hand sewing Sunflowers, Millet, Sorghum, Clovers, and other species to help stop the erosion.
Hand seeding worked well but soon became impracticable. We purchased a small spreader to broadcast seed and later as we learnt and observed the benefits of the cover crops (CC) a no-till seed drill and roller crimper were purchased to better plant and manage those crops
Transitioning from bare unprotected soil took approx. 2 months for the cover crops to provide soil protection and 9 months for grass & clovers to protect the area from the inter-row CC to the trunk line of the trees. This also started our journey into researching, learning, and implementing Regenerative Agricultural practices. Plenty of mistakes were made but from those mistakes, other ideas and methods evolved.
Learning by observation is important as is getting out with a spade. We discovered between 20 to 25 worms per Sunflower root ball. The rough math was 110,00 Sunflower seeds per Ha = 2.5 million worms per ha working 24/7 and that’s just on Sunflower, let alone the other 8 to 10 species in the planting mix. Deposits of worm castings were abundant providing the perfect natural package of highly active biological mixture of bacteria, enzymes, rich in water-soluble plant nutrients, 50% more humus than topsoil – all provided freely by nature.
Vast amounts of Regenerative Ag information are freely available on-line in audio, video, journals, papers, and podcasts plus learning by doing. Once the tree removal program is complete half the Orchard area will be Macadamia Trees and the other half will grow diverse species of seasonal cover crops. This will convert the Orchard from a monoculture to a polyculture plus the natural Rainforest plantings
The benefits of full row tree removal, cover crops and regenerative practices.
SUNLIGHT is the key
Full row tree removal provides the space to allow sunlight to fully penetrate the remaining trees as they relax branch structure from growing forever upwards like tall Poplar trees. As branch structure relaxes downwards, holes appear in the side architecture of the tree rows and this openness to sunlight energises the trees to produce new fruiting wood in the previous dead zone of the trees. It has taken approx. 4 years for this process to near peak at Piccadilly Park and those trees remaining from the first thinning in 2017 now showing productive fruiting wood through the whole of the tree not just the top canopy.
Sunlight also provides the driving force to introduce diverse and seasonal inter-row cover crops. These crops become an eco system engine using their elevated solar array to collect sunlight and through photosynthetic capacity these plants exudate carbohydrates to vastly increase and feed soil biology. This eco system service builds soil organic matter and soil carbon.
Now nature started showing cumulative benefits which gradually change one’s mindset to think different, to join with mimicking nature and transition away from chemical dependence.
Farming becomes enjoyable and rewarding, regenerative practices enhance an appetite and hunger for learning which is diverse and freely available.
Sunlight and regenerative agricultural practices provided the following benefits in the Macadamia Orchard.
Diverse cover crops (CC)
- they exudate a cocktail of carbohydrates feeding soil biology and sequestering carbon
- roots have a symbiotic relationship with mycorrhizal fungi to extend, connect and share nutrients and water o root hairs farm endophilic bacteria via an incredible process named “The Rhizophagy Cycle”
- roots exudate glomalin to assist with the formation and gluing of aggregates to allow space for water & air o increase organic matter and soil carbon = increased water holding capacity. As the carbon builds Inter-row CC become water reservoirs. Every 1% increase in Carbon is like a sponge that will hold an additional 120,00 L/Ha o Roots gradually break through compaction and increase water penetration, reduce run off and soil erosion o CC mixes with inoculated legumes fix plant available nitrogen freely into the soil with tiny cost of seed. o become a bountiful home for beneficial insects, pollinators, birds, and other animals. The farm has become alive with nature. Bird song in the orchard is a pleasure ~ Brahminy Kites are regular visitors and recently a White-bellied Sea-Eagle has been seen surveying the CC areas.
Sunlight also allows Vetch and Rye to be grown under the dripline of the trees in a window of time between the end of harvest in August and January. The Vetch fixes nitrogen in the root zone of the trees and the Rye roots gradually penetrating deeper each year to reduce compaction.
The above are some of natural system services provided by nature to build healthy soil to produce healthy nutrient dense food for human health.