How can farmers keep topsoil on their land? check all that apply. a. close their gates b. keep plants growing c. plant trees to shield fields from the wind d. do not plow when extremely heavy rains are expected?

Answers;
Do not plow when extremely heavy rains are expected
Plant trees to shield field from the wind
Keep plants growing.

Explanation;
Soil erosion is the wearing away of a field's top soil by the natural physical forces of water and wind or through forces associated with farming activities. Preventing top soil erosion is critical in agriculture; this is normally done using various measures such as Planting grass and shrubs, mulching, avoid soil compaction among other methods. 

It's either -limiting factors or -scarce resources but i'd go with my first answer since the food and water are abundant they really aren't scarce