Nutrient planning – it’s time to act

Effective nutrient planning is essential to ensure efficient crop production while minimising environmental risks. 

And with record artificial fertiliser prices, it has never been more important to plan nutrients accurately, as Abbie Allen from Promar International explains.

Is your farm in the right nutrient balance? Is it a leaking nutrient sieve? Is the loss of nutrient impacting your bank balance in a negative way or are you worried that you’re not applying enough nutrients and won’t have a great yield? Do you want to know more about what your manure is worth?

Have you recently had an Environment Agency (EA) inspection and do the words ‘Nutrient management Plan’ (NMP) fill you with dread?  

Whoever asks you to have one; whether your milk processor, the EA, or even as a requirement of some of the options on a government funded scheme such as SFI or Countryside Stewardship, it is worthwhile understanding the benefits that a plan can bring to you.

Lets consider what an NMP is; why is it actually a useful document to have, use and review regularly on your farm. 

© Promar International

Nutrient management is all about balance. Whatever crop is growing in your fields, it has a nutrient requirement to grow, and you need to supply these nutrients. The question are which nutrients to apply, when to apply them, and how much to apply. 

Quite simply, an NMP matches nutrient inputs (fertilisers and organic manures) to crop demand, and the removal of a crop from the field. 

By applying nutrients in the best way, you can increase crop yield and quality, minimise the amount of artificial and organic fertilisers you use and reduce the environmental impact of your system.

There will always be nutrients available in the soil.  How much is available will depend on:

1. previous nutrient applications
2. previous crops (which have used some of the nutrients)
3. soil type (some soils are more prone to quicker nutrient loss)

The starting point to nutrient planning is to soil sample. This allows you to understand how much nutrient is already present in your soils, un-used by the previous crop or slowly accumulated over time. 

This is usually reported as a soil index, which needs to remain as a ‘middle ground’ when it comes to the balance between plant uptake of nutrients, and oversupply of nutrient. 

All plants will always have a nutrient requirement to grow; when the crop is harvested nutrients are removed from the field as the crop exits the field gateway. 

Sometimes, the removal of nutrients with the crop, is greater than what we might have provided to the crop, leading to a negative balance and an erosion of the soil nutrient indices. 

Therefore, understanding what nutrients your crop needs, and supplying the correct amount of nutrients, between manure and artificial fertiliser, is the fundamental aim.

It is vital to avoid oversupply of nutrients. Not only will oversupply increase your growing costs and erode your bank balance, but it also has environmental implications around the pollution of water courses and resulting loss of water quality and aquatic life.

To achieve the right balance of applications you need to understand what your crop needs and manage applications accordingly. A field cut once for silage will not need the same amount of fertiliser, whether manure or bagged, as fields cut three times? 

Then consider fertiliser type. For example, a field with a phosphate index of 4 would not need an application of a 20:10:10. 

What this field actually needs is the phosphate index to be reduced to 3, by not applying phosphate for a few years and allowing the plants to take nutrient from the soil. 

This allows the nutrient ‘store’ in the soil to return to the middle balance. This not only saves cost, but also reduces the risk of phosphate entering local watercourses and impacting aquatic life.

You may think soil erosion and nutrient leaching doesn’t occur on your farm; however you’d be surprised in what direction both soil and nutrients do travel. 

Not only is nutrient leaching (loss) harmful for aquatic life and water quality, but it is also quite simply like an open tap on your bank account. 

With nitrogen fertiliser around £20 per %N, from the days of £14 per %N, NMPs are vital to understanding when you need to apply fertiliser, and as importantly when it’s not needed.

© Promar International

As part of an effective NMP, it is essential to take full account of farmyard manure (FYM) and slurry. These are not waste products but rich sources of plant nutrient. They do come with their own challenges. 

Slurry from cows is rather different to that of pigs, whilst FYM is a different product altogether. FYM should certainly never be applied in the spring to silage ground as you risk the serious consequences of silage contamination.

We also face the challenge of the phosphate content of manures and the requirements of the farming rules for water; manures should not be applied on fields with a phosphate index of 4 or more.

A nutrient management plan simply brings all these points together, into a plan for the year ahead:

• What crops you are planning to grow;
• The nutrient requirements of these crops;
• Your soil samples indicating the current soil reserves, and
• Recommendations of what fertiliser to apply to achieve best yields – whether manure or artificial, or a combination of the two.

A robust plan will focus on what you can supply from your own farm first and so directly impact the efficiency of your farming enterprise.

Because NMPs can refer to the recommended application of artificial fertiliser, they should only be completed by a FACTs qualified advisor. 

Promar International will be at ‘Down to Earth’ in Shropshire on Wednesday 15 June, so why don’t you come along and meet one of our advisors. We’re here to help you navigate what is fundamentally best for your business. 

Contact us today to learn more. 01270 616800 or go to promar-international.com