Germinal experts Paul Morgan, William Fleming and Harley Brown-Keech hosted a webinar on how clover reduces input costs by providing homegrown forage and enhances nitrogen use efficiency, vital for sustainable livestock production.
Below, you can watch the webinar and read through the detailed Q&A compiled by the panel for our viewers.
Watch: How clover can power sustainable livestock production
Clover Q&A
How much carbon do we lose when we plough a hectare of 25-year-old ley to make a seedbed?
The carbon lost in an old sward will vary greatly with the varying soil type, level of organic matter and weather conditions, but the general consensus is that the carbon released will be replaced by the new sward in 18-24 months through higher photosynthesis.
What are the actual figures for DUP and RDP in grass vs clover?
Grass and white clover only have RDP whereas, red clover has DUP. Protein levels vary across the season in all species, the general rule is that 40-50% of red clover protein is DUP.
Do large-leaf white clovers fix more nitrogen compared to small-leaf varieties? Also, does red clover fix more N than white clover?
No, leaf size doesn't affect the N fixed, the total amount of clover will have more of an impact on the N fixed. Both red and white clover fix similar amounts of N.
I have been growing AberSheep in pastures but receiving no nitrogen and as understorey in the wheat crop but never see pink or red nodules indicating production of available nitrogen. Do you have anything I should be investigating?
The areas to investigate are phosphate levels as clover is phosphate-hungry. The other elements to look at next are Sulphur, then Boron and other micronutrients.
How do clovers manage in soils waterlogged for 7 months? It will be late April before I can think of reseeding. Is later seeding a negative?
Not necessarily, as it is better to go into good conditions than be dictated by the calendar.
John Gilliland (ARC Zero project) said that legumes require a pH of 6.5 to allow them to ‘sweat’. He said this also dramatically reduces nitrogen. So, is it 6 or 6.5?
Our breeders say that clovers work better at pH 6.5 as this gives the best environment for the soil rhizobia and mycorrhizae to work with the clover to fix N.
Is white clover seed rate and soil temperature the same as for red clover?
Soil temperatures are the same: 8°C to fix N. Seed rates are different, white clovers we normally work at 1kg in an acre mix whereas red clover is 3kg/acre in a mix
Could you provide more details on clover establishment into existing swards, introducing clover into the permanent pasture?
The crucial aspect is seed-to-soil contact. First eat the sward down tight then depending on the level of thatch the existing sward will need to be harrowed to open/remove the thatch.
Once sown and rolled keep the sward eaten down until the clover seed germinates then remove the stock. It can be useful to apply some prilled lime to help neutralise the decaying thatch and help clover seedlings through this potentially challenging layer.
Is Aberlasting available commercially in the UK?
Yes, in Aber clover blends as a DoubleRoot variety.
Clover and ryegrass are described as in a symbiotic relationship. What’s in it for the clover?
The clover has a companion grass that takes the extra N that the clover doesn't need. The competition of the N lifters encourages a clover to compete.
Do you need some nitrogen fertiliser when initially establishing clover?
Phosphate is the crucial element for the establishment, and the soil N status will dictate if any N at seeding is required. If any is added when sowing, a small amount of 30-50kg/ha.
Why would you blend clovers in a mix, e.g. for cut and graze awards?
A variety of leaf sizes for adaptability across the season and method of utilisation.
How easy is it to direct drill clover after grass has been established?
See answer 8.
Can high levels of phytoestrogens in red clover affect dairy cow fertility?
There is no impact on dairy cows that we are aware of in red clover silage. If grazing swards with high inclusion of red clover there can be an increased risk of bloat.
Will birdsfoot trefoil self-seed or will it need topping up every year?
No, as not enough heat units from flowering to seed set. Management and weather conditions will dictate when topping up is needed.
Irish farmers like to combine grass with white and red clover in grazing swards. Any opinion on the potential for GB?
Yes, but the class of stock will dictate levels of inclusion.
For any questions regarding clover mixtures, sowing, establishment or management, please ask a Germinal expert.