As the wet spring sees grass growth stagnant it is important to look to other crops to fill the forage shortage, Hannah Noble finds out more
Following the poor spring weather it is possible many farmers will face forage shortages over the summer, autumn and into winter. Using brassicas as a catch crop could be a cost-effective way to extend the grazing period and fill the forage deficit.
Helen Mathieu from Germinal says: “As the forecast gets better and things start to pick up, animals will be turned out, but many places still have a shortage of grass and this will probably have a knock-on effect into the rest of the year.”
“Brassica crops are a versatile feeding solution to fill summer grazing gaps, extend autumn grazing and support out-wintering systems. They can increase output per acre, are an excellent break crop in grassland renewal and help soil nutrient retention and improvement.”
Mrs Mathieu’s advice is to match the crop to fill the gap in forage, look at the area available, stock numbers and energy requirement.
Mrs Mathieu says it is important to identify areas where the use of a brassica crop would be beneficial as a forage and not detrimental to existing leys or rotations.
The growing costs of catch crops are typically £200/ha (£81/acre), with a yield of three to five tonnes of dry matter (DM) per ha, which means they can cost as little as 4-6p/kg DM to grow.
Mrs Mathieu explains: “When identifying the options, farmers need to ask themselves when the extra grazing needs to be available.
Catch crops are crops which are grown in the interim between two other crops, their advantages are they are short-term, fast growing they have a wide sowing window which makes them very versatile
“If the extra grazing is needed throughout summer, Sowing in May and grazing in July would cover grass shortages during the summer months. A fast growing crop is required, this could include forage rape, stubble turnips or a rape/kale hybrid. These crops would be ready to graze eight to ten weeks after establishment, allowing grazing to commence from the end of June.”
Brassicas can be surprisingly drought resistant during times of moisture deficit, therefore they act as an insurance policy when grass starts to burn off. Brassicas will sit in situ until required, regrowth may not be as vigorous if there was a water shortage but they would provide a good initial grazing.
For extended grazing required when grass growth slows in the autumn, rape/kale hybrids planted in June or July will be the most suitable brassica crop. They will fill the requirements of young stock and lambs which are still outside between September and November.
Hybrids allow for utilisation of the whole plant as opposed to crops with bulbs, they benefit from the winter-hardiness of kale, along with the fast-growing characteristics of rape.
Possible areas suitable for growing a brassica crop:
“If farmers require extra grazing over the winter months and are considering out-wintering either catch crops, for example rape/kale hybrids which, sown in July onwards, would be suitable to graze by September. Rape and stubble turnips are not very winter-hardy. Main crops to be considered would be kale and swede. They take five to six months to mature so sowing by the end of June would allow grazing from November onwards. They could be grazed earlier if needed but yield would be sacrificed significantly,” says Mrs Mathieu.
“Although not a brassica, fodder beet is worth mentioning as an alternative. Sown in the spring and used for out-wintering eight to nine months later would bring a much higher yield especially suitable for heifers and dry cows.”
Mrs Mathieu explains attention to detail at establishment is crucial for better rewards, soil should be tested ahead of time, and fertiliser and lime applied to achieve a pH of 5.8-6.5 and P and K values of two.
“When feeding brassicas, animals should be introduced gradually, over a period of seven to ten days, a source of fibre for example straw, should always be available. Plan ahead in dry weather and place bales where needed in the field to avoid excess poaching. Strip graze the crop and allow a run back area,” says Mrs Mathieu.
Top tips for successful brassica establishment: