Multiple choice Which method is used by the farmers to enrich the soil with nutrients? Rhizobium enhancement Harvesting crops Manure addition Insecticide sprays Reveal answer Fill a bubble to check yourself C Correct answer Explanation Rhizobium enhancement, harvesting crops and spraying insecticide have nothing to do with the enrichment of the soil with nutrients. Manure is the organic substance, rich in humus and helps increasing the soil fertility.