Productivity in partly mechanized planting operations of willow short rotation coppice

Biomass for energetic use can be procured from various sources including willow short rotation crops (WSRC). The feasibility of willow crops, however, is dependent on the costs incurred by operations such as the plantation, maintenance, harvesting and transport. In small scale applications, cost balancing often results in the use of equipment designed for general agricultural purposes to carry on the operational management of WSRC. This study evaluated the productive performance in planting operations of WSRC for a planting equipment consisting of regular farming tractors used to propel machines designed to support planting on single twin rows. Planting equipment consisting of 4 different types of farming tractors fitted with willow planting equipment was tested in 14 filed plots to be able to compute the main performance indicators such as the net and gross productivity rates. An evident variability in terms of time consumption on categories was observed at plot-level, and the planting time was related to a great extent to the operated area. The size of areas subjected to planting operations was the most important factor that affected productive performance. Variation of net productivity rate was explained largely by the ratio of the length of headland returning maneuvers to total length covered in a given plot. The model developed for the total study time shows that, in the observed conditions, it may take more than 7 h to plant one hectare. The equipment taken into study stands for a flexible option for small-scale farmers which could increase the utilization rates of their farming tractors by using them in other agricultural operations when needed. In addition, the studied equipment fits well to very narrow and small-sized plots, as such situation is typical to Romania and other European countries.