April 2026

Q: Why is liquid foliar fertiliser especially important as we head into colder months? As soil temperatures drop, pasture growth slows. At around 5 to 6 degrees, grass can stop growing. The primary reason is reduced microbial activity. In warmer conditions, soil microbes convert nutrients into plant-available forms. In the cold, this slows significantly. Foliar fertiliser works differently. It delivers nutrients directly into the plant through the leaf, bypassing the soil. When applied, nutrients can enter the plant and roots within an hour, keeping growth systems active when soils are not. Q: How does foliar feeding work? Foliar fertiliser is applied to the leaf and absorbed directly into plant tissue. This allows rapid uptake and immediate use and growth. Farmers understand this. Herbicides such as Roundup are applied as foliar sprays to kill weeds quickly, the same principle applies here. Just as it’s possible to get herbicide into a plant rapidly using foliar to kill and eradicate plants quickly, you can just as effectively deliver nutrition for plant growth. Foliar is a more efficient pathway, especially in challenging conditions. Q: What have trials shown about its effectiveness? Trials in New Zealand, including Canterbury, show clear increases in pasture growth when foliar fertiliser is used in cooler conditions. International research supports this finding. Studies show yield increases of 15 to 19 percent under stress conditions, particularly when soil performance is limited. This has been demonstrated in the field with farmers seeing a response within days and maximised within 3 to 4 weeks. In addition, foliar application is more uniform and provides nutrition to plants evenly. Q: How does New Zealand’s foliar fertiliser use compare internationally? Overseas, foliar fertiliser is no longer niche. It is standard practice across many farming systems, from broadacre crops like wheat and maize to intensive production. In high-performing systems, multiple foliar applications are used through the season to maximise results. In comparison, New Zealand systems still rely heavily on soil-applied fertiliser, often around 70 kilograms of urea (36 kg N) per hectare in a single application, with less focus on foliar strategies. Q: Why is foliar more widely adopted overseas? The main driver is nutrient use efficiency (NUE). Overseas farmers focus on maximising return from every unit of nutrient. Foliar fertiliser allows faster response to plant demand, quicker correction of deficiencies, and better performance when soil conditions are limiting. In many cases, farmers use half to a quarter of the usual fertiliser and still achieve the same response. Q: Is foliar fertiliser a replacement for traditional fertiliser? No. The most effective systems use both. Soil fertiliser builds soil foundation, while foliar fertiliser fine-tunes performance by filling in the gaps. It is about using the right tool at the right time. Q: What is the key takeaway for farmers? As soils cool and biology slows, relying on soil fertiliser alone limits potential. Foliar fertiliser provides a direct line into the plant when other conditions are not favourable. Consequently, for growth maintenance and improved efficiency, foliar feeding can be a game-changer. Contact Dr Gordon Rajendram 021 466 077 | rajendram@xtra.co.nz www.gordonrajendramsoilscientist.co.nz Contact MediaPA Phillip Quay MediaPA 027 458 7724 phillip@mediapa.co.nz

An escalation in global fertiliser prices due to the Iran war will force New Zealand farmers to rethink traditional input-heavy systems, according to one of New Zealand’s leading soil scientists, Dr Gordon Rajendram of Hamilton (pictured) “The solution is a combination of using less fertiliser and also using better science to apply only what is truly needed,” Dr Rajendram said today. A crucial starting point is soil and pasture testing. Dr Rajendram consistently emphasises that without accurate data, fertiliser programmes become guesswork. “Comprehensive testing identifies nutrient deficiencies, soil pH, and retention capacity, allowing farmers to apply inputs precisely rather than broadly,” he says. “This avoids over-application, which not only wastes money but can also lead to nutrient losses through leaching. In fact, testing is considered one of the most cost-effective steps in nutrient management, often representing a very small proportion of overall fertiliser spend while delivering significant savings,” Dr Rajendram said. Beyond testing, there is growing evidence that many farms are applying more nutrients than required, particularly phosphate. Dr Rajendram notes that some New Zealand soils can retain phosphate for several years, meaning annual applications are not always necessary. Shifting away from routine fertiliser programmes to a needs-based approach can significantly cut costs without impacting production. “Nitrogen use is another area where efficiency gains can be substantial” he says. “Rather than relying heavily on granular applications, more farmers are adopting targeted methods such as foliar spraying. This approach delivers nutrients directly to the plant, improving uptake and reducing the total amount required. Trials have shown that significantly lower nitrogen rates can achieve comparable pasture growth when applied in this way, highlighting a clear opportunity to reduce input costs.” Soil condition itself also plays a major role. Maintaining optimal pH through liming improves nutrient availability and root development, meaning plants can access more of the nutrients already in the soil. Poor pH, on the other hand, limits growth and reduces fertiliser efficiency, effectively increasing the cost per unit of production. While reducing synthetic inputs is important, Dr Rajendram also advocates for strengthening biological systems within the pasture. Clover remains a critical component, naturally fixing nitrogen from the atmosphere and reducing reliance on purchased fertiliser. However, he stresses that clover should be part of a broader, balanced system that includes diverse pasture species and well-managed soils. Excessive nitrogen use can actually suppress clover’s ability to fix nitrogen, reinforcing the need for moderation and balance. “Ultimately, the shift is about moving from a fertiliser-driven system to a soil-driven one,” Dr Rajendram said. As Dr Rajendram states: “Farmers are increasingly recognising that they may not need as much fertiliser as once thought. By combining accurate testing, targeted application, improved soil management, and biological inputs like clover, farmers can reduce costs, maintain productivity, and build more resilient farming systems in the face of ongoing global price pressures.” About Dr Gordon Rajendram: With more than three decades of experience in soil fertility, Dr Rajendram’s approach centres on improving efficiency, reducing waste, and unlocking the natural potential already present in the soil. For more information, please contact: Contact Dr Gordon Rajendram 021 466077 rajendram@xtra.co.nz www.gordonrajendramsoilscientist.co.nz Contact Media PA phillip@mediapa.co.nz 027 458 7724