Egon Zunckel, a fourth-generation farmer from South Africa, has spent a lifetime cultivating the land and advancing agricultural practices. Although he had no tertiary education, he attended Bergville Primary and Estcourt High School, where he excelled in agriculture and earned a trophy for his achievements. With 40 years of hands-on experience, Zunckel now serves as the chairperson of the No-Till Club of KwaZulu-Natal.
He has been practising no-till and minimum-tillage farming for 36 years and incorporating cover crops for the past nine years. He aims to care for God’s creation by copying nature to protect ecosystems through sustainable farming practices.
The mission statement of the Zunckel farm is “Farming to glorify God,” and the farm’s success is not rooted in formal education but in hard work and passion.
The farm experienced several challenges due to conventional farming practices, including soil capping, runoff, wind erosion, water erosion, poor infiltration, poor aeration, and suboptimal crop yields. These issues prompted a search for sustainable solutions. After four years of practising conservation tillage, the farm still faced semi-poor soil quality and produced second-grade maize.
Starting a new chapter
However, upon transitioning to full no-tillage farming, the soil began to improve significantly. Within ten years, the farm doubled the organic carbon content in the soil, leading to enhanced soil health and quality.
Later, they encountered another problem: the lodging of maize plants due to Fusarium root rot. This issue was caused by nematodes eating the plant roots, early planting when temperatures were still low, low nitrogen application, poor control of leaf diseases, and a high level of inoculum in the field due to the history of maize and wheat rotation.
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These problems were addressed by practising no-tillage and cover crops. The results were evident when a field covered with oats produced double the yield (15.8 tons/ha) compared to 7 tons/ha before. The following crop rotation was implemented: white oats were planted first, followed by no-tilled soybeans on top of the oat residues after being grazed by cattle.
Wheat was then planted after the soybeans, resulting in their best wheat crop ever, yielding about 8 tons/ha. Subsequently, maize was no-tilled into the wheat stubble, and in the same field 15.8 tons/ha under irrigation.
The health of the soil improved significantly, with strong root systems and green stubble. Remarkably, a silage-like aroma was still detectable during the dry maize harvest, reflecting the enhanced soil quality and plant health. Two years later, the field with oats yielded 2 tons/ha more than the field without oats.
This convinced Zunckel to incorporate cover crop mixtures into the rotation. For 12 years, the Zunckel farm operated without cattle. However, with the introduction of cover crop mixtures, cattle were reintroduced into the system. The combination of cover crops and the no-till system improved soil health while simultaneously providing feed for the cattle.
Bearing fruit
For 24 years, no fertiliser was applied to soybean crops. Over the past three years, maize crops received only half the recommended fertilizer mix. At planting, they applied 25 kg N/ha, 25 kg P/ha, and 25 kg K/ha. In dryland areas, a total of 150 kg N/season was used for top-dressing, while under irrigation, 200 kg N/season was applied.
Cover crop mixture used at Zunckel Farm
- White oats 10kg
- Stooling rye 7kg
- Black oats 7kg
- Grazing vetch 3kg
- Turnips 1kg
- Radish 1kg
- Forage rape 0.5kg
- Total equals 29.5kg mixture which is recommended per hectare
The benefits of using cover crops and basic soil health principles
Zunckel explains that the cover crop mixtures system provided numerous benefits, including
- Stability in cash crop yields: Improved consistency in crop production.
- Improved soil health: Enhanced structure, organic matter, and nutrient cycling.
- Increased soil biodiversity: A significant presence of earthworms indicates healthier soil.
- Reduced fertiliser usage: Less nitrogen fertiliser application.
- Cost-effective weed control: Controlling weeds with chemicals is more expensive and time-consuming compared to terminating cover crops with herbicides. Additionally, less herbicide is required to terminate cover crops than to control weeds.
- Better water management: Weeds consume more soil water than cover crops, which means they dry out the land more quickly. Terminating cover crops returns additional moisture to the soil, benefiting subsequent crops.
- Supplemental livestock feed: Cover crops fix the soil while providing an additional feed source for livestock, particularly during winter and early spring when feed is scarce or in short supply.
Basic soil health principles
- Cover: Maintain soil cover to protect it from erosion and retain moisture.
- Minimum disturbance: Reduce chemical, mechanical, and biological disturbances to the soil.
- Live roots: Keep live roots in the ground 24/7, 365 days a year, to support soil life.
- Diversity: Promote biodiversity by incorporating a variety of crops into the system.
- Livestock integration: Include livestock in the system to enhance nutrient cycling and soil structure.
Benefits of grazing cover crops
When cover crops regrow after grazing, they push more sugars into the soil through root exudates in exchange for nutrients. This process helps build soil carbon to levels that can even exceed those of virgin soil.
Advice to farmers starting a conservation agriculture system
Be convinced in your mind: Believe in the system and don’t look for excuses why it won’t work—because it can.
If you want to emulate/imitate nature, you need to work with nature.
Start simple: You don’t need the most expensive cover crop mixture seeds. Begin with something simple, like oats and turnips. However, oats are large seeds and may not germinate easily if just spread on top of the soil, whereas finer seeds, such as rape or turnip, are more likely to germinate with late summer or autumn rains.
- Grazing management: Avoid grazing summer cover crops too early; allow them to bulk up, but don’t let them go to seed before grazing. When grazing, do not graze the crop down to the ground or canopy level. Leave at least 30% of the plant intact to ensure enough leaves remain for photosynthesis. Use rotational grazing with camps to manage livestock effectively.
- Timing for termination: Terminate cover crops two months before planting to allow the land to rest, for the cover crops to dry down, and to release moisture back into the soil. This ensures the soil can absorb any spring rain without the cover crops using it again.
- Managing extremely wet conditions: In exceptionally wet years, you can leave the cover crop green and plant your cash crop directly into it. Terminate the cover crop on the same day, one day before, or one day after planting.
- Avoid allelopathy issues: Don’t plant in a field where cover crops were sprayed just a week prior while they are still half-dying, as allelopathy can prevent the next crop from germinating. Instead, spray the cover crops six weeks to two months before planting, or at planting time as needed.
Cover crop systems can address some of the challenges faced by farmers and the agricultural sector, including:
- Global warming
- Low soil fertility
- Poor soil health
- Shortage of livestock feed during winter
- Poor livestock performance
- Low rainfall
By adopting conservation agriculture, farmers can create a sustainable and productive farming system that works harmoniously with nature.
*PN Rakau is a junior researcher at the ARC: Animal production, range and forage sciences
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