After a wildfire, rain washes away soil for years. A new study reveals massive losses and hidden risks in a global map.

Johns Hopkins University geneticists and a small army of researchers across the country, including students, are working to catalog the vast and largely unknown soil microbiome of the United States.

From the lava plains of the Alvord Desert to the fertile alluvium of the Willamette Valley, Oregon’s secret wealth is lying all around us. It’s an ingredient forged from stars, fire and ice and, ...