Case Study - Farm 2 - Jim Collins, Ashlyns Organic Farm
Potatoes (22 ha) and onions (14 ha) on a large scale. Wide range of mixed vegetables grown on a smaller scale (11 ha) including: Brassicas (Calabrese, Cabbage, Brussels sprouts, Kale), Cucurbits (Courgettes, Squash, Pumpkin), Carrots, Parsnips, Lettuce (Cos, Batavia, Red salad bowl), Sweetcorn, Leeks.
Two separate rotations are carried out, one for the large scale onion and potato production and one within the small scale vegetable plots.
Within the large scale onion and potato production the rotation is:
Two year grass/clover ley => Potatoes / onions => Wheat (spring or winter)=> Winter beans => Wheat under sown with clover
The mixed vegetable field is kept in production for 2 years before moving on. Within the field there is no formal rotation but a high degree of diversity is maintained in a strip cropping arrangement.
Crops and Varieties
Potatoes: Romano is the favoured red variety and shows the best resistance to slugs. Sante is also grown on a wider scale. Although very susceptible to blight, Nicola is grown as it is popular with the supermarkets for its quality and flavour. Other varieties such as Cosmos and Colleen have also been tried.
Potatoes planted in April, harvested August-September.
Onions: Sturon is the standard variety grown.
Planted in March and harvested in August.
Mixed vegetables: Carrots: Napoli and Nerac; Leeks: Roxton, Lancelot, Hannibal; Sweetcorn: Concorde, Earlybird, Mainstay; Courgette: Defender, Patriot; Brussels sprouts: Diablo, Revenge.
Slugs (up to 30% loss). Romano the most resistant variety to slugs
Blight losses minimised though timely defoliation
Weeds by far the most difficult factor to control. Where not controlled adequately, crops suffers a 50% reduction in yield and up to 5 fold increase in harvesting time.
Also some signs of nitrogen deficiency
Brassicas: Some quality crops of cabbage grown. Weeds managed effectively using steerage hoe. Some problems with bird damage and flea beetle.
Cucurbits: One of the most successful crops. A range are grown including butternut, yellow scallop, Turks turban and Hasta la pasta. Few problems with weeds arise.
Leeks: Weeds are difficult to control and are often sold as baby leeks have failed to make full size.
Sweetcorn: Strong improvement in yield since began growing as transplants. Tall weeds within crops may have interfered with pollination leading to poor cob sets.