I don't think petite is a height so much as a body shape. I have seen tall women shopping in the petite section because they have a short waist or shorter arms or wanted a skirt that fits them better than the regular ones, and I have seen smaller women shopping in the junior/misses/womens section for similar reasons.
Sweet clover needs a high pH, 6.0 or higher, for proper nodulation to occur, and it has a higher calcium requirement as well. Sweet clover is able to obtain phosphorus from relatively unavailable soil phosphates and will grow on soils where alfalfa, red clover or ladino will fail.
The acidity or alkalinity of soil is measured by its pH. Neutral soil has a pH of about 6.5, while anything higher is alkaline and anything lower is acidic. Green beans grow best in neutral or near-neutral soil, though they can tolerate a pH anywhere between 5.5 and 7.5.