**10.6 Pest and disease control**

Crop diversification, which favors species combinations over monocultures, is one of the most cost-effective ways to combat pests and disease, and it has sparked a lot of attention in recent years [27].

### **10.7 Improvement of soil fertility**

One of the most important constraints for sustainable crop production is low soil fertility. In smallholder systems, poor farming practises, mostly continuous cropping with limited external inputs, have gradually depleted soil fertility. Interaction of crop species with beneficial soil biota helps in maintaining biogeochemical cycling of both organic and inorganic nutrients in the soil and maintaining soil quality [28].
