Organic Farms Can Pollute Too   Organic agriculture can pollute
groundwater more than conventional synthetic chemical
fertilization systems, researchers have found.  Israeli
scientists measured the amount of nitrate, a form of nitrogen
that plants consume, in the deep soil beneath crops grown using
composted manure mixed into the soil. The team of biologists,
agronomists and geologists also measured the levels of nitrate
beneath crops fertilized with liquid synthetic fertilizer mixed
into drip irrigation water, a system known as fertigation. Much
higher levels of nitrate existed beneath the organic crops.
PHOTOS: Top 10 Genetically Engineered Crops  Soil directly
beneath organically farmed green houses contained a maximum of
724 milligrams of nitrate per liter (mg/L) of soil at a depth of
2.5 meters. At that depth, the roots of the plants were unable
to grab the nutrients, so the nitrate was destined to eventually
sink into the groundwater. Nitrate contamination beneath organic
crops averaged 357 mg/L. The r