Polysulphate gives boost to autumn establishment
15th July 2021
Effective autumn establishment is the foundation on which yield and quality of autumn-sown crops are built. Scott Garnett, ICL’s agronomist considers best practice to minimise risk and maximise returns.
Every seed sown has a theoretical yield potential which can be reduced over the growing season by a host of factors including poor seedbeds, adverse weather, pest and disease, and inadequate nutrition. Strong and healthy crop establishment is the key to more yield and improved quality at harvest.
Over several years of trials across the UK and Europe, it has become clear that a good supply of key nutrients in autumn can play a large part in increasing the early formation of root mass and strong plant growth. This, in turn, ensures the plant can grow away strongly in spring.
In ICL Fertilizers trials, an autumn application of phosphate, potassium and sulphur with calcium and magnesium has been proved to boost early root mass, leading to increased biomass in the spring to ensure the crop grows away strongly.
Root mass is key. Just one extra centimetre of root on each plant will touch an extra 130 tonnes of soil over a hectare. This larger root mass increases the plant’s ability to access more soil-bound nutrients and water leading to a stronger, healthier plant going into the winter.
The more contact with soil moisture, the better protection crops will have against drought stress. Larger root structures also help reduce soil compaction and increase organic matter.
From ICL trials and user feedback over the past three years of commercial use, farmers can expect to see an estimated 30-40 per cent increase in root mass following an autumn application of ICL’s FertilzerpluS products.
With the value of crop outputs increasing over the past year, farmers who use autumn-applied products will be insuring themselves against the possibility of poor crops or even crop failure. It is simply not worth the risk.
Essential nutrients for autumn-sown crops
Phosphate is essential for crop establishment. A deficiency leads to reduced movement of all nutrients around the plant. Many arable areas in England now show that more Phosphate is being removed at harvest than is applied which may lead to a potential deficiency. Both Phosphate and Potassium levels need to be at Index 2 to insure against stress and to give crops the best chance against unpredictable weather conditions.
Potassium is required with sulphur for the plant to take advantage of available nitrogen in the soil, resulting in improved nutrient efficiency. Potassium is involved in every single process within the plant, including health, water management etc.
Calcium and magnesium are critical for root development and seed establishment.
Sulphur applied in autumn improves retention of other nutrients as well as helping to capture and retain soil nitrogen reserves. In oilseed rape, an application of sulphur will reduce senescence of lower leaves over winter. The UK and Irish soils are deficient in sulphur due to low atmospheric deposition.
For plants to utilise residual and mineralised nitrogen in the soil, small amounts of both potassium and sulphur are necessary.
Using Polysulphate in autumn provides a prolonged release of plant soluble sulphur over 50 days plus essential potash, magnesium and calcium. As plants can only take up so much sulphur at a time, this prolonged release enables roots to take up nutrients as and when they need it.
In ICL 2020/21 trials an application of 100 kg/ha Polysulphate, applied with – or separately from – phosphate gave up to 41 per cent increase in phosphate uptake and a 28 per cent increase in nitrogen uptake.
ICL recommends 100kg/ha of Polysulphate (or ICL PKpluS or PotashpluS) in the autumn to improve establishment.
You will still need to include your spring application of sulphur.
Please contact your local merchant and ask about ICL Polysulphate and other FertilizerpluS products.