[RM.04]The picture below shows a soil texture triangle. Image of a soil texture triangle. Each side is labeled one of the three main soil types—silt, clay, and sand—and is divided into percentages, from 0 to 100. Each point in the triangle corresponds to a different soil texture, consisting of a different combination of silty, sandy, and clay soils. For instance, the top part of the triangle contains soils that range from approximately 50 percent clay to 100 percent clay. All these different soils are considered clays. Soils located farther down the triangle contain an increasingly small percentage of clay; for example, silty clay soils are primarily silt, with more clay than sand, and sandy clay soils are primarily sand, with more clay than silt. Soils located in the middle of the triangle contain roughly equal percentages of clay, sand, and silt; these soils are called “loam.” There are silty loam soils, which contain more silt than clay or sand; clay loam soils, which contain more clay than silt or sand, and sandy loam soils, which contain more sand than silt or clay. There are also silty clay loam soils and sandy clay loam soils.

One farmer plans to grow soybean. Soybeans grow best in medium loam soil. Which of these is the most likely soil sample that the farmer would select to grow soybeans?

sample containing 30 percent sand, 35 percent clay, and 35 percent silt
sample containing 25 percent sand, 15 percent clay, and 60 percent silt
sample containing 40 percent sand, 15 percent clay, and 45 percent silt
sample containing 55 percent sand, 30 percent clay, and 15 percent silt