Archive: What actions make financial sense when it comes to grassland intervention?

Published 21 November 14

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What actions make financial sense when it comes to grassland intervention?

We’re told grass is cheap but across many fields in Britain, it is costing 10p/kg DM to graze and over 20p/kg DM to ensile, said Chris Duller, independent soil and grassland consultant, at last week’s Pasture to Profit Conference. Key is knowing what you are growing, the reasons for any low yields, and which actions make financial sense when it comes to intervention.

Often, fields don’t hit the basic targets for yield and growth of at least 10t DM/ha, utilisation of 80% of this and quality above 11.5 ME (see below).

Are all fields hitting the following targets?

  • Growth of at least 10t DM/ha
  • Utilisation of at least 8t DM/ha
  • Quality above 11.5 ME throughout the year
  • Good response to nitrogen – an average of 30kg DM grown for every 1kg N applied
  • Cost of less than 8p/kg DM utilised.

With 1t DM worth around £200 in feed value, there is, if you target the right areas, a good return on investment available from increasing production and utilisation.

The best results come from spotting any problems early and stepping in quickly. Inputs don’t have to be huge to have a big impact. Lime, phosphate, nitrogen and small changes in management can all boost the output significantly.

When a cow eats an average of 12kgDM/day for 250 days, this equates to 3,000kg DM a year. If you are able to grow grass £0.03 per kg cheaper, it saves you £90 per cow, over the same period.

The recent Grass Values project shows there can be huge ranges in both grass production and utilisation between different paddocks on the same farm, as well as between the same paddocks from year to year. Measuring and analysing will keep you informed of the true performance of the paddocks.

With improvements to grassland, an increase in DM production isn’t the only gain. A bettering in soil and sward condition also improves utilisation and increases the number of grazing days. Every day the cows are out to graze it saves you at least £1.30 per cow, as you do not have to feed or bed them, and scrape and store slurry.

It’s crucial to get to the real reason behind the lack of grass growth. You can do this by what I call, asking the Five Why’s (see below). The example shows how to identify and treat the cause of the problem, not just the symptoms.  


The Five Whys

1. Why did paddock four grow less grass?

Because it’s short of ryegrass, and it’s open

2. Why is it short of ryegrass?

Soil tests are ok – but it is a bit compacted and there are no worms

3.  Why is the soil compacted and short of worms?

Because the paddock was damaged at turnout. Oh, and it gets lots of slurry.

4. Why did it get poached and why does it get lots of slurry?

Because it was wet and cows had to go somewhere, and the pit was full at Christmas.

5.  Why did the cows and slurry have to go there?

Because it’s one of the few fields with good tracks and it’s close to the slurry store. Which isn’t really big enough.


Given the right conditions, swards and soils can recover from damage over time. If you want to speed up this process you can try to mechanically improve soil conditions, and oversow more ryegrass and clover.

The Grass Values project puts the value of grazed grass at £197/t DM, and, even if only 75% of that is utilised, you can afford to spend £150 to get that extra tonne.

It’s important to know where to spend the money. Do you go for big investments in very poor fields or small investments in fields where problems are just developing?

There are three options for improving poor fields.

Option one is a bit of TLC. This involves making the soils and swards the priority, not the cows or bulk tank. You can employ strategies allowing the soils to recover by themselves, such as avoiding grazing in poor conditions, back fencing, using FYM not slurry or rotating silage and grazing ground. You can also encourage ryegrass and sward density, such as avoiding high covers, pre-mowing, using sheep or applying no slurry.

For some fields, if you get there in time, a bit of TLC will be enough to increase yields by 1 or 2t DM, but it might not be a quick fix.

The second option involves investing in your soils and sward to improve the ryegrass/clover content and improve utilisation. Table 1, demonstrates the average costs of soil intervention.

Table 1: Average cost of soil intervention 

CD table 1

Source: C Duller

Table 2 shows the costs/ha/year of these investments, and the return of investments.

Table 2: Costs/ha/year of soil intervention and return on investment

CD table 2

Source: C Duller

So, as 1t DM is worth £197 and one grazing day saves £1.30/cow/day, is soil serration the answer to poor performing fields? In reality, results may be patchier, and will depend on the severity and depth of the problem. Research results from soil aeration have ranged from small losses in grass production to a boost of 5t DM/ha. Most studies, including a recent DairyCo trial, recorded a reduction in soil bulk density and drying of soils, with aeration. This could compromise summer growth.

Many of you will have fields where the investment will mean one to two extra tonnes of DM, but first of all dig a hole and test if the investment is worth it.

Option three is reseeding and, although there is a significant cost, the cost recovery from a well-established reseed is rapid. Reseeding is an opportunity to stop damage as well as to tap into the latest grass varieties and genetics. Make sure to select a grass variety from the Recommended Grass and Clover List which suits your system.

Manage your reseed well and feed it, and you’ll get payback pretty quickly!

All fields are different and may need a different management approach to keep you on target. Keep monitoring, to see what you grow, and look after what you’ve got – don’t assume the fields will look after themselves.