Strategies to Mitigate Frost

Frost damage is an issue all too familiar to farmers across Australia. Frost damage occurs when the ambient temperature drops below zero, causing water within the plant cell to freeze, splintering and damaging the cell wall. A damaged cell wall constricts and inhibits the flow of water and nutrients throughout the plant, often inhibiting further plant growth. Frost burn in plants occurs when the thawing process takes too long, depriving the cells of water, causing cell dehydration. Both frost damage and frost burn can drastically impede crop performance and yield.

Thankfully, there are methods to mitigate the effects of frost, both at seeding and during the growing season – such as seed selection, plant nutrition, timing and soil biology. Selecting seed varieties that are hardier and more tolerant to colder growing conditions will contribute to managing the effects of frost. Storing and re-seeding grain that survive a frost event will slowly pass on local tolerances unique to that farm microclimate.

Plant nutrition, such as the use of silicates (the bio-available form of silicon), have the ability to assist the development of thicker, multi-layered cell wall architecture in plants. A stronger cell wall can withstand longer periods of freezing temperatures and facilitates osmosis after the frost event. Silicate is also known to assist the uptake of zinc and phosphorus. Potassium is also vital to mitigate frost, promoting the growth of large xylem vessels and carbohydrate reserves in the cell. Potassium can be monitored throughout the growing season with a tissue test, like those offered at AMF. Silicates are best applied at seeding or as a spring top up with other trace elements, like offered in the Grow Safe® mineral products.

Another factor to consider is selection and timing of nitrogen fertilisers. Heavy use of soluble nitrogen results in rapid foliar growth – at the cost of cell elongation and thinner cell walls, intensifying plant damage in a frost event. This can be managed with use of slow or controlled release forms of nitrogen, or where possible, smaller quantities at more regular intervals. Overuse of fast-acting nitrogen can be a major contributor to frost damage in plants. 

Lastly, maintaining adequate soil moisture can alleviate the effects of frost by radiating stored heat up from the soil at night, delaying the time for foliage to get to freezing point. The most effective way to retain soil moisture is to build a larger root biomass, giving the plant greater surface area to store water and nutrients. Root biomass can be enhanced through biological means such as the microbial products offered by Grow Safe® that include strains such as Bacillus, Rhizobium and Mycorrhizal fungi. Grow Safe® microbes are available precoated on fertiliser (opt for the Grow Safe® coating) or as a standalone product (Premium Ag Microbes) to inoculate seed (pasture & cropping) prior to seeding.

Grow Safe® mineral and microbial products have been the culmination of consistent performance in over forty-five independent and scientific investigative trials – statistically designed with replications and randomisations both on paddocks and in pots. The majority of the on-field evaluation multi-year trials, conducted by independent agencies like the University of Western Australia (UWA), the Department of Primary Industries and Regional Development (DPIRD), Living Farm Ag- Research, MEAG Soil consultancy, Ferti-Tech, FACEY & RAIN groups, run for assessing the performance of Grow Safe® ‘Mineral + Microbe products’ – resulted in significantly higher root biomass, Nutrient Use Efficiency (NUE) and yielded as well as any of the ‘Conventional Fertiliser Products’ (such as DAP, MAP, Urea and Liquid N), yet with half the applied major nutrients (nitrogen & phosphorus) compared to the conventional programs.