New silicon and iron technologies
Fertiliser International Magazine March-April 2023
British crop nutrition company Levity Crop Science has recently developed two new products designed to help growers better manage silicon and iron and prevent deficiencies across a variety of crop types:
Its new Zeme product features Si-X silicon technology, while Elona-Fe employs the company’s well-proven LimiN system – a chemically stabilised amine nitrogen formulated with Levity’s nutrient uptake stimulant.
Silicon – vital for plant structure and metabolism
“Although silicon often doesn’t register on the ‘essential nutrient scale.” says. Levity’s founder Dr David Marks, “It plays a vital role in plant metabolism and structure.
“Metabolically, it confers stress tolerance on plants to help them counter both abiotic and biotic factors, and it’s instrumental in the transport of phosphate, zinc, manganese and copper through the plant. Plants also use it to build up a hard layer of opal, a type of silica, in the cuticle. This opaline layer has a dual-purpose:
- First, it slows the speed at which fungal pathogens can colonise the plant
- Second, it improves structural robustness by increasing stem thickness and reducing the plant’s susceptibility to lodging – this being especially evident in cereals.
Dr Marks says that, while awareness of its role is growing, silicon is a difficult nutrient to tackle. “Those opals are great for physical protection. But once they’re formed, the silicon’s no longer bioavailable for metabolic needs. “Silicon constitutes around half the content of any typical soil, although most of it’s not bioavailable. Also, what little there is – usually in the form of silicic acid (H,Si0,) – is subject to fierce competition between plants and soil bacteria. There have been attempts to make foliar applications of silicon, says Dr Marks.
“But there’s another obstacle: silicon isn’t phloem mobile. Levity responded to this challenge by developing SiX technology (patent-pending) to stimulate the plant’s naturally occurring silicon transporters. This overcomes the problems associated with the ‘lock-up’ of conventional foliar silicon, says Dr Marks.
SiX underwent its first major field trials in 2020 as part of Levity’s Zeme formulation. Its application to spring wheat at T1 and T2 timings in tank-mix with conventional fungicides delivered a yield response of 1.2 t/ha.
The iron deficiency challenge
Elona-Fe, meanwhile, has been developed mainly to help growers address the long-standing problem of iron deficiency on high pH, calcareous soils.
“Traditionally, iron chelates such as EDDHA have been pushed as a solution, says Dr Marks. “But once you understand the reasons for the iron deficiency, it’s easy to see that EDDHA is only a sticking-plaster.” That’s because there’s a strong link between nitrogen uptake and iron demand and deficiency, he explains. “The more nitrogen plants receive, the more iron they require. Iron’s used as an essential enzyme co-factor when plants process nitrates into proteins.
“But when plants take up non-nitrate forms of nitrogen, such as ammonium and amine, the roots release protons during the exchange process. These protons then go on to dislodge soil-bound nutrients such as iron, allowing their absorption by the roots.
“Research shows that plants can use as much as 70 percent of their available iron for processing nitrates. Most of the nitrogen we apply to crops around the world is picked up by the plant in the form of nitrates, so we’re feeding plants in a way that increases their need for iron, while decreasing its supply.
Once armed with this information, priorities for reducing iron deficiency can then be identified and acted on. These should include reducing the overall need for iron, improving harvesting of soil-bound iron, and only then supplying any additional requirement. “Yet the traditional approach – EDDH – simply ignores these first two points, suggests Dr Marks. “Repeated applications of synthetic chelates are not resource-efficient in our view.”
Levity’s R&D team turned to one of its earlier technologies, LimiN, when develop- ing Elona-Fe. This chemically stabilised amine nitrogen (SAN) allows the plant to access a non-nitrate form of nitrogen, thereby reducing the plant’s iron demand and helping to unlock natural iron sources in the soil. Furthermore, by linking iron to the stabilised amine, the plant absorbs iron alongside the nitrogen.
Levity has enhanced this process by formulating Elona-Fe with its proprietary nutrient uptake stimulant, Catalyst. After application, this helps eliminate short-term deficiencies immediately by increasing the speed of uptake and iron utilisation by the crop. “Iron’s another vital element needed by the plant. The reason iron deficiency shows up as chlorosis [yellowing of the leaves] is because it’s directly involved in chlorophyll synthesis – if there’s no iron, there’s no chlorophyll and therefore no photosynthesis!”
Both new products demonstrate Levity’s problem-solving approach to crop nutrition, comments Dr Marks. “We identify ways in which we can work with, or enhance, the plant’s own metabolic pathways. It’s about helping the crop to help itself, effectively by supercharging its own systems – in a way that maximises resource-use efficiency, something we should all be committed to.
A growing portfolio
Both new products, Elona-Fe and Zeme, are available from Levity’s UK and international distributors. They join a growing range of ‘smart’ products from this R&D focused company, such as LoCal and Damu. LoCal is a calcium transport stimulant that improves quality and shelf-life in fruit crops. The boron-based Damu, in contrast, helps regulate carbohydrate transport in plants – a property that can optimise yield and yield distribution by manipulating plant growth stages and the way nutrients partition within the plants.
