26 April 2015 | Online since 2003



26 February 2013|Arable,Cereal,Crops,News

Bad weather prompts nitrogen soil fears


High levels of rainfall and the continued bad weather in the first months of 2013 have left many farmers concerned about the level of nitrogen losses that may have occurred.

Some advisers are recommending that more nitrogen be applied, as a matter of course, but with ammonium nitrate at around £300/t the cost of applying extra nitrogen cannot be ignored.

Targeting additional nitrogen applications to those fields which actually need it makes good economic sense.

Nitrogen losses will mainly come from leaching but where soils have been waterlogged or even underwater for long periods denitrification may also occur.

According to Sean Stevenson from analytical services specialists, NRM, "The exact extent of nitrogen losses through leaching and/or denitrification following heavy or sustained rainfall can be hard to quantify."

"It is the nitrate form of nitrogen that is susceptible to loss though leaching and denitrification so the extent of any loss is governed by the amount of the crop nitrogen supply that was in the nitrate form when the rainfall occurred."

Other factors also influence the extent of nitrate losses, application timing, soil characteristics the type of nitrogen fertiliser and so on.

In general leaching losses are more likely on sandy soils and denitrification more apparent on medium and fine textured soils that have poor drainage.

However the only way to be sure of how much nitrogen is in the soil is to conduct a soil mineral nitrogen test.

Stevenson explains further: "Soil Mineral Nitrogen is the nitrate-N plus ammonium-N content of the soil within the potential rooting depth of the crop."

"When estimating the total amount of N that will come from the soil – that's the Soil Nitrogen Supply (SNS) – you also need to include an estimate of the N already in the crop and an estimate of the mineralisable soil N. A test is also available from NRM to determine this mineralisable value.

"Once you have your SNS index you can use The Fertiliser Manual (RB209) to determine the correct fertiliser nitrogen recommendation."

Download




Comments


No comments posted yet. Be the first to post a comment

To post comment without approval login or register

Display name

Please enter your name

Email (optional)
Comment

Please enter your comment

Post Comment

Your comment submitted successfully.Please wait for admin approval.

Some error on your process.Please try one more time.



Jobs


8 April 2015
Network Engineer
Experience to troubleshoot network related issues on Linux server farm is preferred. We tackle a range of complex software an...

14 April 2015
Graduate Scheme : Marketing and Communications - Stoneleigh Park
Graduate, Trainee, Apprenticeship, Policy, Agriculture, Horticulture, Government, Farming, Food Chain, Rural, Public Sector, ...

10 April 2015
Wash Crew
This role involves the cleaning out and sanitising of sheds and equipment in both my clients farms in Norfolk and a number of...

16 April 2015
Head Gardener
Some farm and woodland management. Dunsborough Park, Ripley, Surrey (near Wisley Gardens)....

21 April 2015
Renewables Developer (m/f)
These will range from site identification and acquisition, through environmental assessment, wind farm design and financial a...



Top stories you may have missed
10 April 2015 | Agri Safety

The permanent eradication of Bovine Viral Diarrhoea [BVD] in Scottish cattl...


10 April 2015 | Dairy

The abolition of milk quotas in Europe on 1st April has resulted in a numbe...


10 April 2015 | Cattle

The top 14 milk producing countries in Europe will increase their productio...


10 April 2015 | News

Matt Ware is the NFU's head of government and parliamentary affairs, based ...


10 April 2015 | Arable

There is a 'desperate need' to improve farmgate returns given low incomes a...


9 April 2015 | Arable

Rapid stem extension, after a slow start to spring, is likely to create spl...


9 April 2015 | Finance

The time has come for landlords to expect to see reductions in farm rents, ...


8 April 2015 | Cattle

Cogent’s reputation as a source of the highest calibre sires has been enhan...


8 April 2015 | Arable

The spread of exotic and aggressive strains of a plant fungus is presenting...


7 April 2015 | Animal Health

The FSA’s new Food Crime Unit wants the industry to share information, some...