Lapwing and curlew need both cover to hide from predators and open spaces - with cover nearby - for the youngsters to learn to feed in safety.
So if you want them to continue to nest there (as opposed to just visit and feed), you will not top it
all hard, but leave a patchwork of different lengths of rushes with some patches of clear grass in between. The RSPB have some good materials telling farmers / landowners how to manage land for birds.
Basically, top a third each year, leaving a patchwork of rushes of different lengths as described above, after the year's hatch have fledged. And then, if the ground is not too wet to travel, the same again about 6-8 weeks later.
Using primitive native sheep such as Shetlands is a good plan.
Rushes managed thus are fab for sheep. They too derive cover and shelter from the varied rushes, and if you plan to breed them, they will have and shelter their lambs in there. They will eat the freshly growing shoots after you've topped, so will extend the effect of the topping.
Docks are best managed by regular topping, don't leave any of these! They will get worn out over time and you might find you don't need to top for them for a few years - but they will probably keep coming back, tenacious things.
Nettles do no real harm (apart from using up ground space), and give the cabbage white caterpillar something to eat. Top the grown plants and leave to wilt in the field, the sheep (or cattle or ponies) will then chomp them up enthusiastically. Sometimes they will follow the topper, they are so keen!
Thistles need to be topped when they are in flower - too soon and they just come back, too late and they have set seed. ("Top in June, he'll come back soon; too late in August, he's gone to dust; top in July he'll wither and die".) Herbivores will eat these after they're cut too.
The very best management for thistles long-term is native ponies such as Fells and Exmoors (other breeds are available
), who love to eat the flower heads. Over a period of a few years, if they graze the ground in summer, they will eradicate thistles.
I hate to tell you this but pulling ragwort can actually be counter-productive, unless you know what you are doing. If you pull off the flowering and leafy stems but leave some leafy "rosette" (flat on the ground) stems or root, it can turn it into a perennial plant, whereas the flowering plant is in the final year of its 2-year (biennial) lifecycle. So if you aren't sure you can get the whole plant and all its root, it's best to let it flower, then break off the flowerheads shortly before they set seed. (And dispose of them carefully, they will carry on making seeds even after cutting.)
Having said which, if there was a lot. you will have made a big impact for 2022 pulling them all before they went to seed. But you may have a similar crop this year, which were at the flat rosette (1st year) stage last year. So make sure you don't let any of them seed, and you will see a big difference from next year onwards. If you start to get big bushy ragwort plants, chances are they are now perennials, so need a thorough digging out, or may even need spot treatment with weedkiller.
Ragwort is at its most dangerous in hay, as the animals cannot distinguish it when it's dried, so will ingest it in sufficient quantities to get a toxic load over time. As a growing plant it is quite bitter, so mostly they might try a bit and then leave it alone as it wasn't good. It can also be dangerous if the ground is being hard-grazed and/or kept short by topping, as the flat rosettes (which are also toxic) may not be noticed by close-cropping herbivores and therefore be ingested in toxic quantities.
I worked on the Elveden Estate on the Suffolk / Norfolk border 40-odd years ago, and they used to let the ragwort-y fields grow long, along with the ragwort plants. As the plants started to flower, they would bring the beef cattle in. The cows and growing calves would eat everything down to a few inches high, with the exception of the ragwort and one or two other more-or-less inedible plants. After the beef were done, the sheep would be brought in. They liked the grass at the length the cattle had left it, and ignored the ragwort plants which now stuck out very visibly. (However I now wonder whether the sheep might still have eaten some of the plants which were at the rosette stage; I am not sure we knew that much about the 2-year lifecycle of ragwort in the 1970s.)
I should also mention, as it sounds like your ground is quite wet / boggy, that there is a Marsh Ragwort, which is not as toxic as the Common or Oxford Ragwort. (And if the ground is marshy and rushy, you are unlikely to be making hay of it, so that risk factor would not be there) But if there is loads of this ragwort and you plan on grazing the ground, then you may still want to control it.
Common Ragwort is the primary food plant for the cinnebar moth, by the way.
So in summary :
- Look after your rushes, maintaining them, and the patches between them, for ground-nesting birds and for sheep
- Top thistles when in open flower (but before they turn to thistledown), or graze with native ponies in summer
- Top docks, keep topping docks. Always top docks.
- Let nettles grow and top the grown plants, leaving the cut stems for the grazing animals to eat.
- Don't let ragwort set seed, but take care about how you remove it (don't leave rosettes or roots, take the whole plant). Never make hay that could contain ragwort.
- Top docks