So in this kind of situation large seeds are easier to deal with than small ones. Regardless, you must pull back some mulch and expose a little bare earth, and loosen it. I use a small asian-style hoe or a fork. Sow your seeds and moisten well and firm it with your hand or foot. if the days are hot, which I reckon they are about now, cover the furrow afterwards with a little fluffy dried mulch to shunt the extreme heat and keep the ground from drying out so quick. Sprouts from large seeds will work their way though some mulch no problem, tiny seeds like lettuce, carrots etc you have to keep a closer eye on.

Good luck.

I've written a bit about this elsewhere, but here are my recommendations for what is, in my opinion, an overly labor intensive practice. For direct seeded crops I prefer shallow tillage to create a seed bed (less than 2 inches), mechanical seeding when possible ( I prefer the pinpoint seeder), and mulching after the seedlings emerge. If you choose a strict no-till approach, rake off the seedbed too expose the soil. Create a straight furrow for each row of produce - I use a tilted board to create a v-shaped furrow. When the seeds are placed, they naturally roll to the bottom of the furrow, so you get an accurate planting depth. I fill the furrow with sifted compost, then use the flat side of the board to level the bed and make good soil contact with the seeds. I then place a temporary cover over the seed bed - usually old boards - and start looking underneath it after about a week to see if there is any emergence. Once you have some seedlings visible (they'll be in a remarkably straight line, because of the v-shaped furrow, making weeds easy to spot and remove), take away the temporary mulch and start adding thin layers of light permanent mulch (dried grass clippings, pine needles, shredded leaves, sifted compost). Do not bury the seedlings. About 2 weeks after emergence the plants should be tall enough to be able to mulch heavily enough to prevent further weed emergence.

No-till is a great technique for transplants. In my opinion, the best practice is to use no-till on a seasonally rotated basis, in other words, to till perhaps once every three years, and in the year that tillage is performed to use that bed for direct-seeded crops.

In a hot climate (like australia in summer) you want to look under the boards a lot sooner than a week.

yeah, thanks...confirms what i was thinking. Cheers.

No till on perennial vegetable beds.
For beets,carrots,kale,lettuce,mustard,spinach & turnips.
I turn summer garden under & sow the seeds.
I never had a problem with the soil or seeds in raised beds.
How did the fathers & mothers of organic gardening go from double dig to no till after a hundred year of telling us to till in OM.

Jolj, double-dig is not meant to be done multiple times per year, like typical broad-field mechanical cultivation. It is not even done once a year, so compared to traditional cultivation it is effectively no-till.

I am a huge fan of double digging, and most of my beds are prepared that way, but as pnbrown states, it is not a recurrent process. No-till is a practice to be used after soil conditions are already optimized, double digging is a part of the initial process of garden creation. Students of Masonobu Fukouoa, certainly one of the patriarchs of sustainable agriculture, practiced a form of no-till back in the 60's and 70's, and F.H. King wrote of similar practices in 1909. ( http://www.gutenberg.org/ebooks/5350 )Like many practices that are now well accepted by organic growers, the technique is actually well-established in agricultural history, it is the understanding of the science that has changed.

Here is a link that might be useful: Fukuoka

Glad to see Fukuoka mentioned. After reading "One Straw Revolution" I started looking for more ways to incorporate his method. If I had reliable rainfall I'd do it all that way.

Seeding by hand is fairly simple, just pull back sme mulch where the seeds will go, make a trench the proper depth and drop the seeds at the proper distance in the trench. Seeding with a mechanical seeder is a bit more difficult but follows the same, general, pattern. Do not put the mulch back until after those seeds have germinated and are growing quite well.