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Nutrient management on grassland

Last updated: 27 Nov 2015

Name: Andy and Sue Guy_32038

Region: Southwell, Nottinghamshire

Farm: Dairy herd

Size: 79 ha

Background

We hold a 15-year farm business tenancy at Thorney Abbey Farm near Southwell. We have a Lottabottle pedigree Holstein herd numbering 110 with 40 followers. Our average yield is 7,800 litres with stocking at 2 livestock units/hectare. Two thirds of the farm is made up of permanent and temporary grass and 10ha of wholecrop winter wheat is grown.

What does your nutrient management plan consist of?

We analyse the slurry from our 2.25 million litre store and manure from straw yards as part of the Integrated Farm Management (IFM) approach to nutrient planning for LEAF farmers. Analysis shows that manures supplied 3.55kg/tonne of the applied nitrogen (N) whereas from slurry, N measured 1.47 kg/t. Similarly, phosphorous levels are much higher on manure than slurry, at 2.35kgN/t and 0.4kgN/t respectively. We consider the cost of analysis to be a good investment. Our results varied considerably from Defra's RB209 guidance. Relying on these standard figures alone would have lowered productivity.

What other factors affect your nutrient decisions?

We farm in a Nitrate Vulnerable Zone (NVZ) where total organic N loading is limited to 250kgN/ha. I use RB209 to provide a Soil Nitrogen Supply (SNS) figure on which to base my N application. I also monitor soil indices through soil samples taken every 5 years. Most of the fields have indices above 2 so only maintenance applications of phosphorous (P) and potash (K) are applied.

What are some of the benefits?

The available N in organic manures combined with the N fixation ability of red clover has reduced ammonium nitrate purchases by over 16 tonnes. We have also cut back on P and K which have all combined to reduce application costs and produced overall savings of around £60/ha. What's more, matching crop requirements with the availability of nutrients in manures and soil has minimised the risk of leaching and run-off. Application method and timing are also crucial in getting nutrients to plants at the right time.

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What forage crops do you use?

The choice of clover and wholecrop wheat is partly dictated by Thorney Abbey's soil type - heavy clay loam soil over a clay subsoil - and an annual rainfall of 600mm. Nottinghamshire clay doesn't support high grass yields and during most years we can't bank on moisture being available during the summer. A third silage cut is a luxury so we take a first cut in early May and plan from then on.

To overcome this, we find clover is a very reliable crop and usually the timing of the whole crop and second cut clover coincide so they can be clamped together and provide a high protein winter feed. This has reduced the amount of bought-in protein feed required.

How are your nutrient and cropping decisions affected by climate change?

I have seen figures that suggest about a third of energy used in global agriculture goes into making fertiliser. Small savings across each farm will undoubtedly result in a large reduction in agriculture's energy use. By relying on home-grown forage crops we can reduce purchased soya from Brazil and this reduces our carbon footprint hugely. If I want consumers to buy local, I have to adopt the same approach. The measures we've taken already have been quick and simple with minimal outlay but have yielded tremendous savings to our costs and we believe the environment.