Potato Review

www.potatoreview.com POTATO REVIEW JULY/AUGUST 2021 23 FERTILISERS produced for all markets. The business also operates a 70-acre commercial seed potato enterprise in Yorkshire where seed crops are produced using new production regimes. “We produce seed from our varieties developed in Holland, some of which are in the top 10 varieties grown in the UK and include Sagitta, Taurus and Innovator,” John said. “High grade seed is grown in Scotland or imported from Holland for multiplication in Yorkshire and other areas of England. “We use a contractor to grow our crop on the 70 acres in Yorkshire, where we are currently testing the benefits of using liquid fertiliser as opposed to granular fertiliser. The 2021 crop will be the fourth one to have benefitted from OMEX suspension fertilisers. “I have already had four years’ experience of suspension fertiliser having been production manager for Edge Potatoes based near Lincoln,” he said. “I introduced HZPC to the benefits of OMEX suspensions and comparisons with granular equivalents are on- going. From my experience, they are trouble free, bespoke, applied by contractor and have an excellent environmental profile. We always used to struggle with the prill fertilisers. “We use some organic fertilisers but achieving a consistent nutritional supply across the field when applying them is challenging. This is a real issue when our fields can have up to 15 varieties with different growth habits.” Another issue when using prills is achieving an even spread pattern and poor ballistics can compromise spreading accuracy, John said. They can also get blocked in the spout, which compromises accuracy further, and an uneven canopy creates a real issue when it comes producing an even crop. John says organic fertilisers are a valuable commodity when used effectively in the rotation, but any additional fertiliser must be consistent quality and nutritionally balanced. Later application Land for potatoes is selected after the previous cereal harvest. All fields are soil tested and organic manure regimes are discussed and agreed. Potato varieties are selected and then appropriate bespoke nutritional packages are put in place having agreed with OMEX’s Sales Manager Dean Waddingham and Agronomist Scott Baker. Suspension fertiliser is applied in April, which is slightly later than some might consider ideal. But, John said his business uses up surplus input seed from the UK operation so his own planting is often delayed until the end of the planting season. The crop is harvested in September, producing up to 1,000 tonnes of crop from the 70 acres. It is then stored at B T Beale and Sons’ dedicated potato storage near Driffield. It is graded out of store between December and April. “Phil Clappison is our contractor in charge of planting, spraying and harvesting in Yorkshire and we place our fertiliser order directly with OMEX in Bardney,” says John. “Suspension fertiliser is then delivered to edge of the field in tankers before being applied by dedicated local application contractors. “The liquid fertiliser can be applied to stubbles or ploughed land, but either way it’s incorporated straight after application. The potatoes are then planted within two weeks ideally.” With much larger fertiliser spinners on the market – often applying product to 36m and above – the biggest challenge is achieving accuracy. However, by applying OMEX liquid fertiliser through a farm sprayer or dedicated suspension fertiliser applicator, John said the accuracy concern is not an issue. “Poor accuracy manifests itself as an uneven canopy,” he said. “But, spreading OMEX liquids at 36m and wider does not compromise canopy integrity. We have found that when applying prills, the headland yields tail off by up to 15%. We have found that when comparing the two systems in a field a key indicator is the dry matter, which is always more consistent where suspensions have been applied.” John’s aim is to minimise uneven emergence as this can make it very difficult to manage a commercial crop that is sold based on size grade and quality. For a seed crop, he aims for 30-35t/ha of 35-55mm seed. “Any seed that falls either below or above the size specification required can’t be sold for human consumption because of the pesticide regimes often employed on the crop,” he points out. “There are also restrictions on sending crop for animal feed if certain insecticides have been applied. Crop then has to go to AD plants or landfill. OMEX suspensions can definitely increase the saleable fraction of the seed crop by at least 15%.” “The plant’s first line of defence is its cuticle and leaf wax and the strength of this outer defence layer is dependant on the correct balance of available nutrients.” Peter Saunders, Agronomist, Cambridge Natural Solutions Peter Saunders, Agronomist, Cambridge Natural Solutions Helping the potato plant defend itself naturally from evolving strains of blight is one of the aims of organic solutions coming to market.