It rolls around your mouth, then spills slow and lazy off the tongue. Some words are like that, soft and friendly despite not being often heard. They provoke curiosity and interest, as much for their sound as for their meaning.
Tilth is one of those. I love it because it is so rarely heard, and for the ideas and images it represents. It's a quality of soil, a certain lightness, that plants desire and need. Fluffiness is part of it, but there's much more -- surface tension, particle size, density, and permeability are in there too. The ideal combination is the goal of organic gardeners and farmers everywhere, and we strive to reach it with every bed we dig. Depending on the starting point, this may mean a great deal of sweat and soil amendments.
You can't eyeball tilth. You've got to get your hands dirty. Every time I plant a crop, whether placing seeds directly in the earth or setting transplants in a bed, I run my fingers through the soil. Is it light enough? Is it too compacted, or too sticky? Will it give my plants the support and oxygen they need, and encourage them to bring forth the bounty I seek, whether leaf, or pod, or fruit?
Tilth matters because it is the soil, in the end and the beginning, that must be nurtured, groomed, and fed. Gardeners often misapprehend this, focusing their efforts on the plants and neglecting the soil that creates them. It's understandable; the plants are what they want, for food, ornament, or medicine, while soil may just seem like unimportant, lifeless dirt. Getting concepts like tilth is vital to the shift we need to make in thinking about nourishment: get the fundamentals right, and you don't need artificial, unhealthful and potentially damaging measures to grow a bean, a melon, or a lush tomato.
Like a lot of words, 'tilth' speaks volumes, if we just listen.