Catch Crop Case Study

Peter Hinze farms just South of Hamburg and has developed the use of multi resistant oil radish in his rotation to maximise the contribution of potatoes and sugar beet to his business. “Over the last ten years, growing sugar beet after oil radish has yielded 8-10mt/ha more per year than without,” said Peter, “against which the seed costs are hardly worth mentioning,” he concluded.

  • Peter Hinze and Andreas Henze

    Peter Hinze and Andreas Henze

The farm is completely focussed on maximising root crop yields.  “Everything else is more or less a sideline,” commented Peter. The rotation of winter barley, sugar beet, potatoes combines a high gross margin potential with substantial phytosanitary risk.  Multi resisant oil radish varieties such as CONTRA have been successfully used over a ten year period as a catch crop between winter barley and sugar beet in the rotation.

The success of using CONTRA results from its holistic impact on the cereal rotation rather than just its impact on Beet Cyst Nematode (BCN) “Apart from the phytosanitary effect, the sugar beets find it much easier to root, and the roots penetrate much deeper.  That way they can use existing water better. Overall the water balance appears to be better regulated after catch crops. In heavy rain the water drains more easily and the crops are better equipped to withstand dry spells”, said Peter. The effect was particularly noticeable when following a year with an extremely dry early summer, sugar beet following oil radish endured for 1-2 weeks longer than those crops without the benefit of an oil radish “starter”.

In such a high risk rotation nothing can be left to chance. In the UK catch crops often fulfil a role of little more than cheap and early short term ground cover, however for Peter the opposite is the case. “I cultivate oilseed radish as a main crop – that way I can be sure to make the best of its advantages: nematode control and promoting tilth and water balance," said Peter. "That means, above all, timely sowing with a seed drill at relatively high seed rates as well as sufficient nitrogen fertilisation. For me, oil radish is not merely an in-between crop” concluded Peter.

Peter’s approach to his rotation is focussed on protecting and developing the health and structure of his soil at all times “To avoid overworking the soil beforehand, I only plough in spring just before the sugar beets go in. "It is quite obvious that the oil radish develops better in ploughed soil both above and below ground,” remarked Peter. The better developed a multi resistant oil radish root system is the more enhanced it's effect will be on nematodes such as BCN and trichodorous (carriers of tobacco rattle virus – TRV – in potatoes). Despite oil radish’s vigorous rooting habit, like all crops, the better seed bed it is put into the better it's root structure will be. In the case of oil radish the greater positive impact it will have on the following crop.  Peter, and his advisor Andreas Henze, have become firm advocates of this over the years “I need to give the roots of the oil radish the chance to grow right down to the nematodes, for the nematodes will not come to the root.  A high seed density (23-25kg/ha) supports that growth. The greater the competition between individual plants in the crop stand, the higher the proportion of live roots in the soil, and the more successful the control measure!” commented Peter. As well as driving a good root structure, using a high seed rate also produces good ground cover which performs a good role in suppressing autumn weeds.

Drilling time for Peter is a balancing act between allowing the crop a good 6 weeks to establish before the onset of winter stops growth, whilst avoiding the plant maturing, flowering and setting seed. “You should choose varieties that don’t tend to form a crop and that don’t bloom too early,” Peter advises. Having achieved good results with the variety Defender, Peter has now switched to CONTRA. Both varieties have been specifically developed by Saaten Union to combine multi resistance to soil borne insects and diseases with quick establishment and crucially later flowering and long vegetative growth habit. Typically Peter sows CONTRA after 15th August, with the crop ceasing growing in late October to early November and then once the first hard frost has frozen the ground he then rolls the crop. In the UK, with milder winters, incorporating or spraying of the crop in late autumn is a more preferred approach.

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