Most plants grow best in loamy soils, according to Purdue University. Sandy loam soil has more sand than a normal loam soil, and the sand content alters its drainage, texture and ability to retain nutrients. Gardeners may want to amend sandy soil to make it less sandy, or plant specific crops that grow well in sandy conditions.
Purdue University explains that loam soil has relatively equal amounts of sand, clay and silt particles. Sandy loam soil has more sand particles, which means that the soil has more large particles than less sandy soil. According to the University of Georgia, sand particles are 0.05 millimetres to 2.0 millimetres in diameter, which gives soil a course feel. Sandy loam soils usually have more than 60-percent sand content.
The American Horticultural Society explains that sandy soils have more drainage than soils with more small particles. The high rate of drainage in sandy soils can cause some plants to wilt, although soils with good drainage are less likely to become waterlogged and cause plant roots to rot. Succulents and other desert plants grow better in sandy loam soils than most plants.
Soils with lots of drainage, like sandy loam soil, also tend to have good aeration. According to the University of Arizona, aeration helps soil organisms survive. These organisms often benefit plants by helping them absorb nutrients.
Sandy soils do not hold nutrients well, according to the Purdue University. Washington State University recommends adding composts to improve soil nutrient levels. Synthetic fertilisers also help add nutrients to sandy loam soil, but they usually cost more. Synthetic fertilisers also get washed through sandy soils easily, which means that they end up polluting groundwater sources and leaving the soil too quickly for plants to absorb a lot anyway.