Challenging times for grasslands

by Mariecia Fraser

Most farmers are aware of the Recommended Lists of grasses, legumes and other crops – there’s usually plenty of publicity as they’re launched every couple of years.  But fewer farmers and land managers are familiar with how the testing is done. 

A standard trial format is carefully imposed across all six sites that are involved in generating the data used to create the rankings for England and Wales.  This makes sure that all the varieties being tested are treated in the same way.  However, the format used has a number of crucial limitations.  Firstly, the testing is all done at sites with excellent growing conditions in terms of soil and climate.  Secondly, rather than using real animals, grazing is ‘simulated’ by cutting with mowers every three weeks.  This means that all the material is removed at a standard height, which doesn’t represent the impact of real grazing since animals are always removing material selectively. Thirdly, the test plots all receive high application rates of nitrogen fertiliser. 

The format of the testing means that the varieties demonstrate the maximum yields they are capable of, which is the main measure they are subsequently ranked on in the Recommended Lists.  But what happens once the same grasses are expected to perform in less than optimal growing conditions, i.e. those more typical of those found on upland farms? 

To use an analogy; how well is a Ferrari going to do on a rough old farm track?  Will it still be performing well in all conditions, or is a Landrover a safer bet long-term?

And of course, ‘grass seed’ as sown on farm is almost always made up of a combination of different varieties (e.g. a mix of different ryegrasses), and usually a combination of different plant species (e.g. a mix of different grasses and clovers).  So in real swards we have a situation where competition between plants for nutrients, light and water will mean some will thrive while others struggle.  Added to this are the effects of selective grazing, particularly by sheep – some plant species will be heavily targeted while others are largely avoided. 

Given the jump from testing to the on-farm world it’s not surprising that sward stability is almost inevitably poor, with key species being lost after only a few growing seasons.

Plus, these days productivity is just one factor that grassland is judged on.  We also need pastures to support above- and below-ground biodiversity, store as much carbon as possible, cope with dry conditions if there’s a drought, and reduce rainfall run-off when the storms come.  If subsidy schemes shift to a greater emphasis on delivery of ‘public goods’, these measures could have a much greater influence on support payments.

This is the background to a major new project on grassland mixtures that we began the experimental work for last year.  The project is part of a multi-million pound research programme at IBERS, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), aimed at improving the economic, productive and environmental sustainability of crops in the face of climatic and political change.   

Plots being sown at the site 70 m above sea level at Trawscoed. This site represents very good growing conditions.

Our grassland research is testing the effects of multiple stresses on grass and legume mixtures over seasons and years, and is taking place across four sites along a ’challenge gradient’.  We have sites at altitudes of 70 m and 150 m above sea level at the university’s Trawscoed Dairy Research Centre, and sites at 230 m and 340 m above sea level at Pwllpeiran.  Detailed surveys have shown the underlying soil chemistry of the different sites are broadly similar, but that nutrient levels decline with altitude.  Weather stations are providing detailed information on the extent to which temperatures, rainfall, wind speed and other meteorological parameters also change across the gradient.

The top site, at 340 m above sea level, under snow in March this year.

At each location replicate plots of two alternative seed mixtures have been sown; both very similar to mixtures available commercially.  The first is mostly ryegrass with a modest clover component and is typical of a mix aimed at delivering consistent production of high digestibility forage across the growing season (species mix: different ryegrasses, timothy, white clover and red clover).  The second is a more diverse mixture targeted at lower input systems (species mix: different ryegrasses, timothy, meadow fescue, red fescue, meadow grass, crested dogstail, white clover, red clover and lotus).

Each plot has been split into four sub-plots which receive different management regimes; 1) continuous grazing by sheep, 2) rotational grazing by sheep, 3) 3-week cutting (i.e. ‘simulated grazing’), and 4) conservation (silage) cutting (at 6 week intervals).  All the plots were established according to best practice industry guidelines, and the managements imposed also reflect best practice.  This means that the rates of fertiliser nitrogen applied are representative of those on farm.

Plot harvesting underway.
Managements were first imposed in April and this photo was taken in July. It shows a clear difference in clover content between the ‘simulated grazing’ cut and real grazing.

Detailed measurements of the impacts of site and management regime on herbage biomass, sward height and botanical and nutritional composition are being made across seasons and years. To understand the interactions between environmental conditions, the different combinations of plant species and the management regimes imposed, the very latest DNA and molecular techniques are being used to monitor genetic shifts within plant populations as well as the impact of the grazing preferences of the stock.  This will enable us to track the way different sward components respond to varying degrees and frequencies of biomass removal.  The related impact on the nutritional value of the forage is being explored using a variety of metabolomic techniques.  All this lab work is also being complemented by the use of cutting-edge imaging technologies using multi-spectral cameras to map three-dimensional changes in the sward over time. 

Ultimately all the findings will form the basis of new approaches to developing and testing mixtures that deliver stable and persist multi-functional swards.  Results from the project will feed directly into plant breeding programmes at IBERS.

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Energy to burn

by Amanda Holder (a PhD student at Aberystwyth University working on the multi-centre MAGLUE research programme)

As I have spent a lot of time over the past two years crawling around a field not far from the offices at Pwllpeiran I thought it would be a good idea to explain that there was a purpose to it!  It was all in an effort to record soil emissions of the greenhouse gas nitrous oxide emitted during the period of land preparation and planting of a new crop of Miscanthus (of course, why else!).

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Field work selfie!

In order to combat climate change there is a need to reduce emissions of greenhouse gasses such as carbon dioxide, nitrous oxide and methane into the atmosphere. Producing energy from plants to reduce the use of traditional fuels such as coal and gas can help to do this.  Miscanthus is a tall perennial grass, similar in appearance to bamboo, which can grow up to 3 metres in one growing season. Harvested annually its rapid growth makes it good for use as a biofuel (being burned to produce electricity).

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Miscanthus growing in plots at Pwllpeiran

As with all plants Miscanthus absorbs carbon dioxide from the air during growth.  However, it is important that the full greenhouse gas implications of converting land to Miscanthus are understood. This is where I come in.

The period of land use change can be considered a ‘hotspot’ for release of greenhouse gasses from the soil due to the  disturbance involved.  To investigate the extent of soil nitrous oxide fluxes during the establishment of Miscanthus a set of 12 trial plots were set up at Pwllpeiran.  Two types of Miscanthus (the commercially available variety and a new hybrid) were planted using different reduced tillage methods, with some plots retained as sheep grazed pasture for comparison. Minimum tillage (soil cultivated to a shallow plough depth before planting) and no tillage (Miscanthus planted in slots cut into the ground) methods were used for the commercial variety, and the new hybrid was planted with minimum tillage under a film mulch layer.

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The new Miscanthus hybrid being planted.

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The plots set up and testing soil emissions when grazed grassland is converted to Miscanthus.

To record the soil nitrous oxide emissions the hard work started before planting began, with samples taken before any intervention, and then continuing until the plants were 18 months old. To do this, in each plot, a circular plastic ‘collar’ was inserted into ground and then every two weeks a lid was clamped to the collar creating an air tight chamber.

A few spare chamber lids were stored in the field and proved to be popular with local wildlife …

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Field vole nest, latrine, and escape hole made underneath a spare chamber lid that was stored in the field.

…but don’t worry the vole kept his home for the year as the spares lids weren’t needed!

Samples of air were taken from inside the chamber through a rubber seal using a syringe. These were taken at 15 minute intervals over the period of one hour. The samples were then taken to the Centre for Ecology & Hydrology at Lancaster (a partner in the project) where they were analysed for levels of nitrous oxide.

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Gas chromatography machine used to analyse the samples of air taken from inside the sealed chambers.

In the end the study was more than worth burning up some of my own energy!  The results obtained can be used to help balance the pros and cons of land use change to Miscanthus.  It was found that soil nitrous oxide emissions from the cultivated plots were higher than the uncultivated sheep pasture, but levels were similar to those for when a grass ley is reseeded. There was no difference between the cultivation methods tested, or the type of Miscanthus. Work with mature crops of Miscanthus had already shown that their fluxes are very similar to pasture.  When specific emissions related to the cultivation ‘hotspot’ are put into the context of the 15-20 year crop life time the impact is small and overall greenhouse gas balances for using Miscanthus are less than for coal or natural gas.

If you’d like to know more you can read the full paper on the study here.

Deer, oh deer

By Mariecia Fraser

I grew up in the Highlands of Scotland where there are deer everywhere; on hillsides, in woods, on warning signs along roads, in bits on walls, and on menus in most pubs and restaurants.  The monarch of the glen is an icon after all.  And deservedly so.  Red deer in particular seem to embody the free spirit of those that are at one with wild places.  They move swiftly and effortlessly over the toughest of terrain, disappearing into the landscape within moments when disturbed, while a well crowned stag personifies elegant violence.

So it was a bit of a shock to move to a part of upland Britain where there are no deer.  I have lived on the edge of the Cambrian Mountains for over twenty years now, and have never seen a single cervid anywhere in this area.  Apparently there are reasonable numbers in some other parts of Wales, but there are none on the high ground of Ceredigion.  Or if there are they are very, very shy.  In fact you can go for miles and miles without seeing any grazers at all on many of the high plateaux.  Declining stock numbers have meant that farmers have focussed their attention on better pastures down the hill, and without any wild herbivores many of these hill areas are shifting away from the grazed ecosystems that we know.  There are many who hold strong and conflicting views on whether this is a good thing.  To me there is something desolate and depressing about these areas; we have done too much and gone too far to turn back the clock to some Bronze Age idyll without some creative management (but more on that another day).

deer-signOf course there are also some up advantages to a lack of deer.  Wildlife such as deer can be a reservoir for pests and diseases such as ticks and liver fluke.  In addition, fencing of woodland and gardens is simpler and cheaper without them, and there are none of the debates and disagreements over how best to manage population numbers.  In Scotland the majority of deer are free-ranging, passing from one estate to another,and are simultaneously considered pests and commercial commodities.  Originally forest dwellers, they are seasonally and regionally adaptable, taking browse and grasses in various amounts according to season and area.  However, this adaptability has taken its toll; red deer in Eastern Europe have 2 to 2.5 times the body weight and around 3 to 4 times the antler weight of those on Scottish hill-land.

Perhaps the afforestation planned, together with the destocking we’ve already seen, will mean deer naturally spread into favourable habitat within areas such as Ceredigion. Despite the challenges they might bring, I hope so.

Doe-in-meadow-MSHRTIFF-300x195

 

 

A new season, a new blog

20th January 2016 02

Ben’s note;

Hello, and welcome to our blog!

As you may have seen from our other pages, this blog has been set up to provide a little bit of information on the general activities that occur at the the Pwllpeiran upland research platform. Why a blog though?  Well, for the ‘communicating research’ module of my undergraduate degree at Aberystwyth University the main aim of the module was to…  well…  communicate research.  One of the ways covered was establishing a blog.  During that wet lunchtime mentioned on the ‘Why blog?’ page, I thought this would be a perfect chance to put in to practice, what I’d learnt in that module.  The only problem being.. as the blog was my idea, I’ve been tasked with writing the first post.  So here it goes; hope you enjoy! 


A general update from Pwllpeiran

So what’s been going on?  Well, the daffodils are growing! The wet are unseasonably warm weather in December meant that the daffodils were growing even in the heart of the winter months. However by February, the temperature had dropped significantly and all growth – both daffodils and grass seemed to cease. Some days we had glorious sunshine, and using the excuse of checking the daffodil plots – meant I could enjoy the terrain and go running. Though I hadn’t quite considered how bad the wind chill on the top fields would be – needless to say, running shorts in future probably isn’t enough alone! This aside, as we approach the end of February, the weather has warmed considerably and the daffodils are slowly moving their way up again.

Finding a biscuit within a hay stack- Keeping a track on the temperature

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Planting a data-logger. See you in six months!

Having had mild weather in December, and with many reporting this winter as the warmest on record, this had us wondering; ‘Will this affect the daffodil growth?’. Probably, So we decided that collecting data from our weather stations on site wasn’t enough- we need to know what was happening in the soil. So on a cold Mid January day, six digestive-biscuit sized data loggers were placed into the soil, taking great care to mark exactly where we had put them. None of us are enthusiastic about spending a day in the future searching the ground  for.. well.. maybe not a needle, but certainly a biscuit in a haystack!

The hope is, that when the data loggers are full in a few months time we’ll be able to gauge if/ how much the daffodils were affected by this unusual warm start to winter. Presuming we actually find the data-loggers that is!

 

New people

It should also be mentioned that the few first months of 2016 has also seen the arrival of some new faces. Dan; having finished his undergraduate degree in Bangor last summer arrived at the end of January and has begun his PhD on the Brignant extensification plots. Mike, recently returned from working in Australia for the past 5 years – has begun working at Pwllpeiran looking into utilising genetic analysis in upland systems. These arrivals have brought a welcome increase in ideas and knowledge to the research hub – though have likely been a contributing factor to the shortage of biscuits in the kitchen cupboard recently!


 

The first of many

Hopefully you’ve enjoyed looking around our blog! If so, feel free to follow us here, or on our twitter page (@uplandresources). We hope to update the blog regularly with updates, fun facts, and discussion from different member of the Pwllpeiran team.. Which hopefully will make you (and us!) more aware of what goes on in our uplands.

Until next time!

Ben