A farmer heard from a weekly farming podcast about they can increase soil fertility by increasing the soil's cation exchange capacity. To do this, she should apply...
A. Careful and specific quantities of fast-acting nitrate or ammonium fertilizer
B. Specific quantities of purified phosphate fertilizer
C. Precise amounts of sand and phosphorous blended
D. Clay mixed into the soil
E. Large quantities of silt alternating with sand.
