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selection: The process of identifying plants or animals with desirable characteristics such as high yield or disease resistance as part of the activity of breeding new varieties. An individual chosen from a group in a breeding programme on the basis of distinctive characteristics. Farmers benefit from selection processes to improve crop and livestock productivity.

shade plants: Plants which prefer to grow in the shade. Farmers benefit from growing shade plants to diversify crops and optimize land use.

spray irrigation: a system of irrigation using sprinklers which are located along a boom. Some booms rotate and can distribute water over a large circular area. Using spray irrigation ensures efficient water distribution, promoting healthy crop growth and sustainable water use.

secondary substances: Chemical substances found in plant leaves, believed to be a form of defence against herbivores. Farmers benefit from understanding secondary substances to improve crop protection and resistance.

salivary: Referring to saliva. Farmers benefit from recognizing the importance of salivary health in livestock for optimal feeding and digestion.

swidden farming: same as slash and burn agriculture. Properly managing swidden farming ensures sustainable land use and agricultural productivity.

straight fertiliser: a fertiliser that supplies only one nutrient such as nitrogen. Compare compound fertiliser, mixed fertiliser. Properly managing straight fertilisers ensures precise nutrient application, supporting healthy crop growth and better yields.

salt: Sodium chloride as part of the diet. Salt is used to preserve food by keeping it in salt or in salt water. Farmers benefit from using salt for preserving food and maintaining animal health by supplementing diets.

swayback disease: an often fatal disease of lambs caused by copper deficiency in the ewe’s diet. Lambs become unsteady and unable to walk. The disease is often a problem when there has been no snow during the winter. Managing swayback disease ensures sheep health and productivity, supporting farm profitability.

spider: one of a large group of animals, with two parts to their bodies and eight legs. Class: Arachnida. Managing spider populations on farms promotes ecological balance and reduces pest issues, supporting healthy crop growth.