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 bottom line is to know where you want the mash pH. Dark malt is more acidic that pale malt. This is important to know when testing the water prior to adding the grist (grains). The pH of the water should test somewhere between 5.8 and 6.5 so the mash pH settles into that sweet spot after the grain is added. The pre-grain water should test closer to 6.5 for darker grains and closer to 5.8 for paler grains. You will need to adjust the pH to keep it in the proper range.