Beware dry conditions when planning soil sterilisation

Growers planning soil sterilisation treatments are urged to ensure that conditions are optimised before beginning applications, in the light of recent warm dry weather conditions.

"Attention to detail and thorough preparation is critical to the success of soil sterilisation practice in order to maximise the benefit," comments Certis’ technical officer, Alan Horgan.

"Given the recent summer-like weather conditions and dry soils, anyone considering using Basamid (dazomet) must take these conditions into account before commencing and plan ahead accordingly.

"Adequate soil moisture is essential for effective treatment and is required to prime weed seeds, encouraging dormancy break, before the operation commences," he advises.

"It take time for soils to wet up and growers should ensure steps are taken to optimise soil conditions for the duration of the treatment process to get the most from Basamid this season," urges Alan.

He explains that if applications occur without sufficient soil moisture, below 50% water holding capacity, the breakdown of Basamid prills and subsequent release of sterilising gas will be adversely affected, with the concentration not reaching levels high enough to be effective.

Alan advises that soils which are too dry should be wetted-up at least seven days before application "sufficient to achieve 60-70% of field capacity which may require up to 22 litres per square metre."

"And it’s not just the surface soil condition which must be optimal. Sufficient moisture throughout the soil profile to the depth of incorporation is required to aid the release pattern of the gas. Achieving an even moisture distribution to depth will take time.

"The recent warm weather has, however, delivered sterilisation advantages, with soil temperatures often well above the minimum of 10oC for at least 48 hours," adds Alan.