Gauteng Smallholder February 2016 | Page 37

From page 34 POLLINATORS Unfortunately, modern industrial-scale monoculture in larger and larger fields and landscapes means the removal of habitats that pollinators may need. When pollinators become increasingly rare in an ecosystem, other species will usually fulfil a similar role, even if less optimally. Thus the losses may be subtle and unnoticed at first, making any early warning system for pollinator loss quite complex. When losses start to take effect, reduced seed set is the first result. Then follows increased inbreeding within a crop or population ~ again, an effect not readily apparent to non-specialists. The primary threats to pollinators are alteration of their habitat, leading to loss of breeding sites and food resources, and the wide use of pesticides on crops in ways that kill beneficial insects as well as crop pests. As current habitat and forage resources dwindle, landowners need to protect and maintain existing pollinatorfriendly vegetation and plant more pollinator-friendly plants (as long as they are appropriate to the specific localities to prevent hybridisation or invasions). Soil fertility can complement the needs of pollinators in and around farm fields. A healthy, nutrient-rich soil that contains organic matter is good for crops and allows certain types of pollinators to complete their life cycles. Flowers of crops, on the other hand, provide nectar and pollen that is necessary for pollinators to survive. The following practices will protect pollinators and improve the soil's fertility and structure: K Minimal tillage of soil. K Crop rotation with legumes. Butterflies on lavendar K No burning. K Planting of cover crops such as legumes on unplanted lands will provide nitrogen to the soil and nectar and pollen to pollinators. K Intercropping (the growing of two or more crops closely together) will create diverse farming systems. K Planting of trees in and around fields will mimic the natural environment and allow beneficial insects to multiply. Leaving areas of a smallholding uncultivated will provide the necessary habitat for pollinators to thrive. For example carpenter bees depend on logs for their nests, honeybees may build nests in 35 www.sasmallholder.co.za Sunbird on aloe tree cavities or termite mounds, while mason bees use clay and leaf cutter bees use leaves. A strip of uncultivated land around a smallholder field can also act as a windbreak which helps to reduce soil erosion. The removal of invasive weeds before they go to seed will ensure that they do not invade natural areas. Natural areas are important safe havens for pollinators and ensure that other ecosystem services continue. Not only do natural enemies of crop pests benefit from these areas, but they also serve as carbon sinks that reduce greenhouse gases.