(18)the term "improvement" means any work or product of a work which adds to the value of the holding, and includes-(a)the erection of dwelling houses, buildings appurtenant thereto and farm buildings;(b)the construction of tanks, wells, channels, dams and other works for the storage or supply of water for agricultural or domestic purposes;(c)the preparation of land for irrigation;(d)the conversion of single-crop into double-crop land;(e)the drainage, reclamation from rivers or other waters or protection from floods or from erosion or other damage by water, of land used for agricultural purposes, or of wasteland which is culturable;(f)the reclamation, clearance, enclosure, or permanent improvement of land for agricultural purposes;(g)the renewal or reconstruction of any of the foregoing works or alterations therein or additions thereto; and(h)the planting or protection and maintenance of fruit trees, timber trees and other useful trees and plants;
