Part of the permaculture design I am creating for Rukmapura Park hotel includes community gardens; to be used by Rukmapura Village residents. (The hotel is situated on the north west corner of Rukmapura Village; a 250 acre sub-division of Marharishi Vedic City, Ia).
In preparation of creating the plots, I am studying Four Seasons Harvest, by Eliot Coleman. According to Coleman, the first step in preparing a garden plot is to test the pH of the soil; this will help determine if the soil needs particular amendments.
The pH scale ranges from 0 to 14, and measures how acidic or alkaline a substance is. A pH of 7 is neutral; a pH less than 7 is acidic; a pH greater than 7 is alkaline, or basic. The ideal soil pH for vegetable gardening is between 6 and 7 (slightly acidic).
While, do it your self soil kits can be purchased relatively cheap, much more can be determined by professional testing (which you can have done for less than $20.). *DIY kits only tell you the pH (or you can even find kits to test for particular nutrients), but they don’t tell you the implications of the results, or what to do next.
Your county extension agent can direct you to professional soil testers in your area. The results will come with amendment recommendations, including instructions on how much of each amendment should be used.
Popular soil amendments include: limestone, peat moss, phosphate rock, bone meal, and green sand. Limestone counteracts acidity and is a good choice for soils with a low pH (below 6). Peat Moss–being acidic– is recommended as an amendment for alkaline soils (above 7).
Phosphate rock and bone meal are excellent sources of slow release phosphate, and green sand is a source of slow release potassium and trace elements (including zinc, copper, molybdenum, boron, and manganese).
Once I have determined the best location for the garden plots, I will pick-up a soil sample kit from the Jefferson county extension office, and within a few weeks I should know what amendments my client will need to purchase for the soil.