Martin Poyser is one of the pillars of the Hayslope farming community. He's also Hetty's guardian. But Martin spends a lot of Adam Bede playing second, third, and even fourth fiddle to his outspoken wife.
So what's the deal with Martin? He's a respectful, cheerful man, unless you're a farmer who doesn't know his farming. In that case, Martin Poyser, Farmer of Farmers, becomes "as hard and implacable as the northeast wind" (14.17).
He's the father of a thriving family. He sits in the tip-top place of honor on feast days. In short, he's a model resident of Hayslope, the kind of hardworking, no-nonsense type that Adam—if he's lucky—will be in a couple decades.
In short, Martin is tapped into Hayslope's past traditions and future hopes like few other characters. If you want to take the community's temperature, search Adam Bede for a few Martin Poyser passages.
Hetty's crime, for instance, doesn't just hurt Adam. It rattles Martin Poyser and overturns his pride in having "a family which had held up its head and paid its way as far back as its name was in the parish register" (40.17). Martin Poyser isn't a big-shot character, but he is the voice of Hayslope values: tradition, family, unity. When he suffers, the community suffers with him. And when the community suffers… well, Martin feels the burn.