I've also found if you let small children touch the seeds they come up better and produce better. They must transfer some sort of growth thing to the seeds. :)

James Underwood Crockett (Crockett's Victory Garden) says "Most seed catalogs and gardening literature advise a thin sowing of peas, but you'll never hear me say that. I've been planting them close together in thick rows since I was a child, and I've learned that if you are stingy with your peas they'll be stingy with you. Not only is the yield greater with the thicker sowing, but the dense foliage forms its own natural support as the peas grow, and needs only minimum help from the gardener on that score."

He goes on to say he plants his in a trench 4" deep and 6" wide, sowing the seeds across the bottom of the trench so that some actually touch each other and others are no more than 1" apart. He covers them with 1" of soil. As the season advances and the plants grow, he pulls soil from the sides of the trench to keep the roots cool and deep, which speeds pea harvest by ten days or so.

That is (almost) the method I have used for peas, and it worked well for me. I was just a bit stingier with my seed, I had none touching, but they were very close together.

Granny

Here is a link that might be useful: Annie's Kitchen Garden

It's a little hard to tell for sure, but are they talking about more yield per plant or more yield overall? I've read that using high yield/intensive spacing will give you a lower yield per plant, but a higher overall yield. If close spacing gets you 23% less per plant, but twice as many plants, you'd still come out ahead spacing them closer.

Bingo GB. That is one of Mel's main points. You can get twice as many peas from 1 plant per SF or plant 8 plants per SF. I'm off on the ratios, but it is more than twice the overall production with SFG spacing.

Yep, in a weird way, this proves Mel (and Crockett) correct.