| It's a dirty job, but many are eager to do it. | | | | found the acidity of our soil "adequate," the |
| Today's home gardeners have been learning the hard | | | | phosphorus high and the potassium low. And although |
| way what their rural forebears knew all too well: | | | | the report included a two-page list of fertilizers to |
| Good plants need great soil, or, in gardening | | | | correct a nitrogen deficiency, the lab doesn't test for |
| vernacular, a $1 plant needs a $10 hole. | | | | nitrogen. The two labs' measurements of organic |
| There are a few plants that don't need soil to grow, | | | | content in our soil differed by more than 100%. |
| but you wouldn't want them around your house. Dirt | | | | Our home-chemistry experiments began with the |
| is most plants' equivalent of bacon and eggs or | | | | No-Wait Soil Test Kit, which required some waiting. |
| burgers and fries -- except plants prefer nitrogen, | | | | Ordered by mail from Heirloom Seeds in West |
| phosphorus, potassium and other minerals to stay | | | | Elizabeth, Pa., the kit demanded, not just suggested, |
| healthy, to bloom and to reproduce. Because so | | | | using distilled water, which required a trip to the |
| many Americans live in new houses, where dirt has | | | | grocery store. All of the do-it-yourself kits involved |
| been removed for construction and then replaced, | | | | some variation on comparing the color of test fluids |
| the quality of their soil can range from fecund to | | | | to an enclosed palette. Again, with No-Wait, the |
| barren. | | | | nitrogen was the fly in the ointment; after four |
| Traditionally, soil analysis was done by agricultural | | | | attempts, the test fluid remained stubbornly clear |
| colleges for farmers, who need to know what kind | | | | when it needed to turn pink or, even better, red. In |
| of fertilizer to use for maximum yield. Now, a | | | | direct opposition to EarthCo, No-Wait found our |
| cottage industry of commercial testers has sprung up | | | | phosphorus low and our potassium high. |
| to give home gardeners the dirt on their earth. | | | | The Rapitest Soil Test Kit, made by Luster Leaf |
| This particular cranky consumer fared poorly in | | | | Products Inc. in Woodstock, Ill., isn't particularly rapid |
| science classes and liked the idea of shipping a soil | | | | if, like ours, your soil is more clay than sand. To |
| sample to professional laboratories for analysis. But | | | | create a liquid sample, your soil must settle in water, |
| many gardeners prefer the do-it-yourself kits sold at | | | | which can take as long as 24 hours. Then you mix |
| most garden centers and by mail order. We tried | | | | some of the liquid and capsules of mysterious |
| some of each: two labs, one at a university and one | | | | powder in four containers and match the resulting |
| commercial, and three home tests, all of which | | | | hues with the patented "color comparators." Once |
| promised to be user-friendly even to chemistry | | | | again, we flunked nitrogen. We had surplus potassium |
| dunces. | | | | and adequate phosphorus. |
| We collected the soil sample from our Garrison, N.Y., | | | | AccuGrow Soil Test Strips, made by Environmental |
| garden according to rigorous guidelines prescribed by | | | | Test Systems in Elkhart, Ind., came with a 24-page |
| the University of Massachusetts at Amherst: digging | | | | manual introduced by a cartoon gardener named "C. |
| down about six inches in a dozen parts of the | | | | Moore Green." This was by far the simplest test. |
| garden, mixing the samples and letting them dry. We | | | | After a brief preparation of soil with solutions |
| harvested enough dirt for all five tests. | | | | identified only as M and A, two strips (each with two |
| We shipped about two cups of soil to the university | | | | test patches) were inserted in the fluid for a minute |
| and requested the standard soil test. Two weeks | | | | or less. All four patches roughly turned the desired |
| later, a report arrived in the mail. Our soil is too acid, | | | | colors, although some of the gradations were subtle |
| has medium levels of phosphorus and potassium, and | | | | indeed and required squinting. (This test in turn |
| its nitrogen (NO(3)-N) level is "10 ppm." Huh? Although | | | | showed low potassium and nitrogen and too much |
| the explanatory pamphlet emphasized that nitrogen | | | | phosphorus.) |
| "is essential" to plant growth, there was no indication | | | | Sylvie Brouder, associate professor of plant nutrition |
| whether our 10 ppm (parts per million) was low, | | | | and soil fertility at Purdue University in West |
| medium or high. Steven Bodine, director of the lab, | | | | Lafayette, Ind., explained why the tests showed |
| says testing for nitrogen is tricky and only extreme | | | | such different results. Most soil-testing labs were |
| results, such as 50 ppm, are useful for making | | | | developed for regional growers, and their methods |
| recommendations. | | | | and equipment have evolved to support different |
| The lab's advice for amending our soil had a | | | | areas' growing conditions. Choosing a lab close to |
| one-size-fits-all quality and involved mixing in copious | | | | home is most likely to yield useful results. Ms. Brouder |
| amounts of manure, wood ash and bone meal. In our | | | | also suggests asking for recommendations from a |
| neck of the woods, putting bone meal in the garden | | | | local nursery or garden center. |
| is like laying out a smorgasbord for woodchucks. | | | | The home kits can point arrows in the right direction |
| A St. Louis laboratory, EarthCo, offers a basic soil | | | | -- especially regarding the acidity of your soil -- but |
| test whose results can be easily downloaded from | | | | shouldn't be regarded as exact science. A balanced |
| the company's Web site. The report is colorful and | | | | fertilizer (we use organic because we have |
| easy to understand, offering both numerical data and | | | | omnivorous dogs), healthy additions of compost and |
| an interpretation: Our 4.8 pounds of potassium per | | | | a layer of mulch will treat most soil problems. And |
| 1,000 square feet is low. But the results were | | | | don't forget to water. |
| significantly different from the university lab. EarthCo | | | | |