Ask the professor!
When should you add Farmyard manure (FYM)?
In terms of FYM addition, when it is applied is not too critical. You would not want to do it during hay growth & hay making (April-June). It could go on in summer after hay is removed (Aug-Sep) or in the autumn (Oct-Dec) in areas where there is little risk of floodwater washing it away. Applying it in winter (Jan-Mar) would not be a direct problem to the plants, but the soil would be more vulnerable to compaction at this time, and losses to water courses via leaching would be greater too.
How do I measure Phosphate availability and how much does this cost?
Measuring the P-availability at a site is quite straightforward to do and costs perhaps £100 - £200 for the laboratory analysis. Quantifying the deposition of P from sediments is a bit harder. If you know the flood return period and there has been some analysis of sediments in the catchment, then a judgment could be made as to whether excess P deposition was a real threat.
The better thing would be to take a soil sample before and after a flood and look at increase in total P content. Or better still, try to trap sediment using an Astroturf mat.
On another front, analysis of the vegetation itself will indicate how available P is and whether it is likely to be limiting growth. We have studied P budgets across several sites, and hope to expand that in the current work so that we can make more confident generalisations.
How rich in Phosphate is too rich for meadow restoration?
The 5 to 15 mg/kg range is based on the inter-quartile range of values from sites with good examples of MG4. That means 25% of such sites have values > 15 mg/kg. I would say that species richness does fall away above 20 mg/kg, and restoration schemes on soils > 30 mg/kg would not develop species rich communities until hay making had started to strip P out of the soil, which would take a few years. If your soil is > 50 mg/kg, then you either should not have species-rich grassland as a restoration target or you need to think about drastic action such as topsoil stripping, deep ploughing to invert profile or chemical amendment.
25 ppm is not so high that it should preclude you trying to restore species rich grassland. It would be best to try to lower the level first however. Is the site currently under arable management? If funds are available and the current farmer is willing, then he could be asked to grow a barley crop to which he adds nitrogen but no phosphorus at all. This is an effective means of stripping P from the soil. IF the site is already grass, then could a hay crop (or better two) be taken from the site this year to strip P before you add other species?
How effective stripping is depends on the soil type. IF it is heavy clay, then it might be necessary to strip for more than one year before P levels start to fall noticeably. Is your project long enough to do that? If instant returns are needed, then you could try to diversify this year but then take an early hay cut in June followed by a second in September for a few years to wear down the more aggressive species. Grazing can also keep aggressive species in check, but it does little to lower the fertility, so double hay cuts are better.
Is soluble phosphate from surface waters an issue?
Soluble P from surface waters is rarely an issue as it contributes rather less than any sediment deposition. P in ground water is rarely a threat unless it is significantly polluted. Groundwaters having contact with chalk and limestone tend to have very low P content. We do not currently record P in groundwater.
Where can I get a copy of the WETMECS research from?
This research has not yet been published. It is imminent.
Are we looking at an historic assessment of Floodplain Meadow distribution?
No not at the present time, but if local groups have this information it would be very useful to collate.
When is the best time for seed spreading?
Seed spreading is best done in autumn because some species have a cold requirement to trigger germination. Others naturally germinate in autumn and are adapted to survive the winter as a seedling; the same species would be susceptible to drought if sown in spring. You would expect more grass and fewer herbs from a spring sowing. Seed being washed out is a risk, but most of it would probably just be re-deposited within the site, so would not be a total loss.
Does an early cut or double cut of sedges make any difference in controlling them?
We cannot give hard evidence of the effectiveness of double cutting yet, but we are currently trialling early and late cuts at East Cottingwith and Cricklade and will keep the website updated as and when we collect results. A cut in early June with repeat cut in July OR a normal cut in July with a second cut in September are both advocated as means of controlling sedge.
What is the difference between floodplain meadows and water meadows?
Our working definition of "Floodplain Meadows," in terms of the Partnership's scope, covers water meadows. Water meadows are a particular kind of floodplain meadow in that they have more intensively managed hydrology. "Water Meadow" and "Floodplain Meadow" are colloquial terms applied to particular vegetation communities, and so there is scope for the two terms to become confused depending on whether you are describing the physical system or the biological community. For our purposes, we use these names to describe the physical systems and we use the National Vegetation Classification to label the biological communities.
What are the uses of opico harrow and airseeder, and the benefits of slot sowing?
We have no specific knowledge of the opico harrow, but anything that results in > 50% bare ground should be OK. Surface sowing is the norm and is recommended by Emorsgate. Attempts to bury the seed are unnecessary and potentially may be counterproductive.
Late cutting greatly reduces nutrient off-take; what's the evidence for this?
The evidence is based on our own data which has been collected to develop nutrient budgets for individual sites and from some mesocosm work. There is a pattern that the total N (and to lesser extent P) content declines once the seeds are shed - suggesting substantial allocation of resource to seeds. We have not published these data yet as they were not collected systematically, but we are now addressing this. One of our PhD students, Katherine Wotherspoon, is systematically harvesting hay at two-weekly intervals from a replicated block experiment and assessing total nutrient content. She is just entering her second year of study, so hopefully a publication is not too far away.
Several papers show protein yield falls as season progresses (e.g. Mahli et al, 2003, Can J Pl Sci, 83); a recent paper on haylage (Ragnarsson, Livestock Science, 131) suggested protein content almost halved over a period of a month. We have not seen anything quite that marked so far.
Is light harrowing on floodplain meadows beneficial in late February?
Using a spring-time harrow in spring is a fairly normal grassland management procedure and I have known it happen on floodplain grasslands without ill effect. There is no scientific evidence that I am aware of, however, to tell us whether it is beneficial to biodiversity conservation or not. My main concern on floodplain meadows would be whether the soil was firm enough to support the tractor. Any soil compaction due to rutting would offset any good being done by the harrowing. Chain harrows are often used in early April, primarily to knock down molehills. They are used extensively on floodplain meadows and appear to do no harm, whilst facilitating hay making.
My advice would be to say yes to spring-tine harrowing if the grazier is keen to do it and there is a real problem with dead thatch at the base of the sward, but then only if the soil is dry enough.
What can be done about molehills?
Molehills, if bad, can be harrowed. A chain harrow is generally used and is not thought to be damaging to the vegetation. Nesting birds are an issue though. Molehills can be a problem even for modern machinery; particularly if a bar cutter is used and for the baler itself. Raking them by hand is the minimum disturbance option, but unfeasible on a large site.
Moles are not a bad thing for the meadow itself. They generally improve soil structure and aeration, and create regeneration sites for seedlings, so are not damaging per se. It is the hills that need to be dealt with and a chain harrow is the simplest means. Some farmers would use a spike harrow if they have a thatch problem too.
What can be done about nettle and reed control?
In terms of weed control, earlier cutting can help if meadows are cut late. Nettles and reeds are to be expected in meadows that are cut later. See http://www.floodplainmeadows.org.uk/files/floodplain/Cutting%20Article.pdf for more information on cutting times and the impacts on plant species.
What are the effects of liming on hay meadows and on the soil, especially on MG5 vegetation?
We have not looked at meadow communities in this respect and we have rather limited data on MG5, but we do have some. Rodwell gives a fairly full account of MG5's response to surface pH in the relevant section of British Plant Communities. The Rothamsted Park Grass experiment is the best data source for MG5. The team there know that dataset pretty well. Jerry Tallowin has published on the subject.
There is a general trend in European grasslands that the higher the pH the higher the species richness reflecting the fact that calcicoles survived the last ice age in their Mediterranean refuges much better than did calcifuges. Therefore as a rule of thumb addition of lime will assist species diversity. However if there are specific species of interest, their preferences in terms of pH (see Grime or Ellenberg) should be used to inform management.
How do I grow fritillaries from seed?
Keep them in pots for at least a year before planting out, though they can stand outside. Perhaps sink the pots in a larger pot or tray full of sand to help keep the compost cool and moist.
They have been germinated successfully from pots in the past, but have been lost after planting them in to the soil, so best to protect them for as long as feasible. They do make a very small bulb in the first year. The shoot will wither away by late summer, so don't get worried if they have disappeared by August - they should reappear the following March (insert link to fritillary leaflet).
Is there a cheap method for cutting very small sites that will not cause compaction, but also does not require bespoke machinery?
A number of organisations including wildlife trusts and individuals cut small sites with scythes. This is fast, low tech, low impact and versatile. The hay can then be raked up and composted. Once mastered, the scythe is a fantastically useful tool, much more adaptable to different situations than a strimmer. And much much quieter! If you don’t have the strength, then the old Allen scythe is motorised and does it for you.