BACKGROUND The purpose of this study was to quantify the physical exertion during tree planting work and to examine the relationships between exertion, task efficiency, and productivity. METHODS Heart rate (HR) was monitored on 34 tree planters while they worked. HR data was collected for a complete working day on 19 subjects and for shorter periods of time on 15 subjects. Video of work tasks...

Abstract This article argues that the interests of coffee and tea planters in colonial Sri Lanka shaped foundations wildlife conservation policies, which state only played a secondary role. By destroying forests highlands, they were principal architects ecological change on island nineteenth century. Their mode recreation, hunting, also their engagement with natural history. Some naturalists ow...

different conservation tillage practices are nowadays suggested as the best solution for prevention of soil from erosion. this could be done by leaving the previous crop residue on the soil surface. a new idea to plant in the conservation tillage system is the use of punch planters by which one can plant through a heavy depth of previous crop surface residue. the study was conducted using a 2?3...

In agrotechnical practice, it was found that between qualitative indices, which express the sowing precision achieved by planters determined in laboratory, and those under operating conditions, there are certain differences, sometimes quite significant. The decrease value of quality indices manifested increase number mistakes, either double planting holes (with at least two seeds), or missing h...