Final answer:
The best practice for a farmer to sustain soil nutrients is to rotate the types of crops planted after each harvest, which maintains soil fertility and reduces the need for pesticides.
Step-by-step explanation:
The best way for a farmer to sustain the nutrients in the soil of her farm would be B. Change the types of crops that are planted after each harvest, known as crop rotation. This agricultural practice improves soil fertility, diversifies crops, and reduces the need and cost associated with pesticides by naturally interrupting the cycle of weeds, insects, and diseases.
Planting legumes such as soybeans, for example, can help maintain nitrogen in the soil, as they have the ability to fix atmospheric nitrogen into a form that plants can use. Conversely, neglecting to rotate crops and relying on pesticides and synthetic fertilizers could lead to nutrient-poor soils, increased salts, pesticide resistance, and other issues that are detrimental to the sustainability of the farm.