LINDLEY, FREE STATE — For Junior Ferreira, a farmer in the Lindley area, successful dryland agriculture revolves around one core principle: moisture conservation. After five years of extensive, hands-on experience using the Bok.I high-speed disc, Ferreira shares valuable insights into how the right implement choice and a long-term vision for soil health play a decisive role in sustainable, profitable farming.
Ferreira’s farming system in the diverse soil environment of the Free State—ranging from sandy soils to heavy black clay—consists of an equal split of maize and soybeans, supplemented by a cattle component. In 2019, he transitioned to full strip-till using Orthman combination planters and completely ceased conventional tillage practices.
Moisture Conservation as the Absolute Priority
According to Ferreira, the ability to carry moisture over to the following season is the most critical factor in dryland farming. “If the answer to the question ‘will this conserve my moisture?’ is no, you must find an alternative. End of story,” he explains.
His system begins immediately after harvest: cattle are placed in the fields for seven days to graze the stalks. Following this, a compact disc is used to cut in the residue, adhering to a strict 70/30 rule: 70% of the material must remain above ground to provide shade and retain moisture, while 30% is incorporated to manage winter weeds. Before planting, a burndown spray is applied, followed by the strip-tillers and planters.
Carbon Building and a 20-Year Vision
Ferreira emphasizes the critical role of soil carbon. He points to a specific field acquired in 2015 that consistently outperforms all others, regardless of whether the season is wet or dry. Soil tests revealed that this field contains double the carbon and organic matter of his other lands.
“Farmers have approximately 35 harvests in their careers to achieve their goals,” Ferreira notes. “The question is always: what can I do to hand over better soil to my son than what I received from my father and grandfather?” This 20-year vision drives every decision regarding implement selection and tillage practices.
The Trial: Chopper Disc vs. Compact Disc
To determine the ideal implement for residue management, Ferreira recently conducted a field trial. He alternated contours, working one with a chopper disc, the next with a compact disc, and leaving a third contour untreated to observe the effects.
The results were highly insightful:
- The compact disc provided the best weed control and left a light protective blanket of residue.
- The chopper disc successfully flattened 80% of the stalks and chopped approximately 50% to 60% of the material.
- Visually, there was no significant difference in moisture conservation between the chopper and compact disc methods, though the compact disc’s superior weed control offered indirect moisture benefits.
Ferreira notes that the chopper disc has a specific and valuable role in minimum-tillage systems. It is ideal when there are too many upright stalks hindering planters, but the farmer wants to avoid the soil compaction caused by the repeated use of a compact disc. Furthermore, because the chopper disc flattens the material without grinding it too finely, wind erosion remained minimal, even during a wetter-than-average year.
Practical Wisdom: Cattle and Equipment Longevity
An interesting observation from Ferreira is the benefit of leaving stalks upright initially for livestock. He prefers to let the cattle graze the residue first. “If you throw sand and grit onto the leaves, it doesn’t just grind down the cattle’s teeth; it also rapidly wears down the discs of your implements,” he explains.
Five Years with the BOK.I High-Speed Disc
Ferreira purchased his Bok.I high-speed disc in 2021. Over the past five years, this 8-meter implement—among the first of its size built by Bok.I Implemente—has successfully worked approximately 1,200 hectares per year, totaling around 6,000 hectares.
He notes that he regularly discusses continuous improvements to the machine with Henry from Bok.I Implemente. “The disc has handled my conditions well, and I cannot speak negatively of it,” Ferreira says. However, he offers a practical warning: when the ground becomes too hard, farmers should stop cutting to avoid unnecessary wear on the discs. Because the implement is heavy, it does not need to be forced, but respecting soil conditions is key to preserving the equipment.
For farmers grappling with wind erosion or residue management without inducing soil compaction, the chopper disc and the Bok.I high-speed disc present a balanced, sustainable solution that keeps moisture in the ground where it belongs.
For more information on BOK.I Implemente and their tillage solutions, visit www.boki.co.za.
