Potatoes are traditionally one of the most intensive crops to grow on a commercial scale in terms of soil disturbance and chemical input usage. Is there potential for the economically viable production of high-quality seed potato crops using regenerative agriculture practices and minimal to zero synthetic fertilisers and chemical inputs? The team at RegenZ is on a mission to find out.

RegenZ is running a “Crane-Friendly Trial” in honour of protecting these iconic South African birds at a farm in the KZN Midlands owned by Ivanhoe Farming Company, one of the oldest seed potato growers in the country. Ivanhoe is a Crane Custodian working closely with the KZN Crane Foundation. The farm boasts flourishing populations of all three crane species.

This groundbreaking trial, conducted using Zylem and RealIPM agricultural inputs, aims to transform potato farming practices while championing regenerative agriculture and minimising synthetic inputs. As the trial progresses, the team hopes that the insights and results will have the potential to revolutionise farming methodologies while preserving the region’s delicate ecological balance.

Objectives of the Crane-Friendly Trial

Initiated in September 2021, the trial aims to pioneer economically viable high-quality seed potato production through regenerative agricultural practices. With an intended duration of eight years, the primary objective is to explore methods that reduce reliance on synthetic fertilisers and chemicals.

Nick Platt from RegenZ says: “The cranes are essentially the face of the overall agricultural ecosystem at Ivanhoe (and any growing environment/ecosystem more broadly). Essentially, the products in the CF programme are predominantly natural/biological in their formulation and designed to have a minimal and even positive impact on the soil and farming ecosystem.”

As the trial approaches the halfway mark with the recent planting of its third crop, it’s already shown promising signs. Notably, control rows devoid of in-furrow fertilisers surprised observers with unexpected but encouraging yields, supporting the idea that most commercial potato crops can be produced with drastically reduced fertiliser applications.

Trial methodology and products

The trial follows a holistic approach, where products are carefully selected to harmonise with the farm’s ecosystem and benefit the crane population.

Dividing an 8-hectare block into yearly 1-hectare segments, the trial compares Ivanhoe’s ‘Farm Standard’ spray program with the ‘Crane-Friendly’ (CF) regimen. While both receive in-furrow fertilisers, the Crane-Friendly block explores a range of Zylem’s nutritional products and RealIPM’s biopesticides to minimise chemical dependency and enhance soil health. We have reduced the use of chemical pesticide sprays for the trial segments, and have only sprayed chemicals for late blight. However, the applications have been far less frequent than the conventional chemical spray programme would dictate.

Within the CF block are 2-4 control rows in which no in-furrow fertiliser is applied at all; these rows receive the same spray programme as the rest of the CF block. This allows the team to make observations and inferences regarding inorganic fertiliser usage.

The trial includes experimentation with various cover crop mixes and strategies to build overall soil health and address soil pathogens that affect potato crops. Post-harvest, the block will be planted with a cover crop, which will then be periodically grazed by Ivanhoe’s beef herd in accordance with the farm’s existing land management/crop rotation practice.

Zylem’s nutrition product range includes:

Real IPM’s range of seed treatments and biopesticides includes:

  • Real Trichoderma
  • Real Bacillus
  • Bioneem
  • Neudosan

What would success look like?

Soil sampling and analysis is the primary measure of trial assessment. “We are still in the learning phase of the trial. In the second half, we hope to synthesise and apply these learnings into the way we approach and manage the trial,” Platt says.

Success will be evaluated by:

  • Yield and quality: To run a commercial seed potato operation, the programme must produce a high-quality seed crop at the required volumes.
  • Cost: Growers won’t consider these methods if the numbers aren’t commercially viable. A successful result would be a programme/methodology that can achieve the required yields at a comparable or improved cost to existing programmes.

Dealing with the challenge of disease pressure

The trial has encountered some challenges, notably disease pressure during the 2023 harvest. Late blight and Rhizoctonia posed hurdles, underscoring the complexities of sustainable farming. Platt says: “Disease pressure is always going to be a challenge, and for now, we are tweaking the inputs in our spray programme to address these. Several interrelated factors impact the success or failure of each crop. For now, we are primarily trying to refine our programme. Thereafter, we will shift our focus to other areas of planning and management to improve our outcomes.”

Mixed trial results thus far

“Although the trial is building the data, the Crane-Friendly yields have been lower than the Farm Standard at both harvests, but they have certainly not been total failures from a yield perspective,” Platt says, “for our approach to succeed, this will have to be addressed. We are still at the stage of refining our approach to try and bridge this gap in a manageable and cost-effective manner.”

But there have also been promising results: “For both the first and second crops we planted, there were a few control rows in which no in-furrow fertiliser was applied at all. At the harvesting of both crops, we observed a surprisingly high yield in these control rows. Nothing near the yield achieved in the conventionally managed crop, but very encouraging signs on which to build our programme (particularly when some observers and trial participants doubted whether any tubers at all would grow in these rows).”

RegenZ Managing Director Justin Platt adds: “It’s important to note that a lower yield may be acceptable if the return on investment justifies it, and recognising that using fewer pesticide applications has many direct and indirect benefits—both to the ecosystem and those who are handling the pesticides.”

Environmental impact and observations

Beyond productivity metrics, the trial also examines the environmental impact on the different trial groups. Observations post-harvest reveal a significantly improved earthworm population in the Crane-Friendly block, highlighting the positive effects on soil health compared to the Farm Standard. “This is a simple but powerful indicator of soil health,” Platt says.

Redefining agricultural practices

As the Crane-Friendly trial unfolds, it illuminates the potential path toward sustainable farming—the idea that we can respect nature while pioneering progressive farming methodologies.

The RegenZ team looks forward to sharing more results and insights as the trial progresses.