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