Processing of remote sensing information to retrieve leaf area index in barley: a comparison of methods

Precision Agriculture - Leaf area index (LAI) is a key variable in understanding and modeling crop-environment interactions. With the advent of increasingly higher spatial resolution satellites and...     

A new hoe share design for weed control: measurements of soil movement and draught forces during operation

This research introduces a new share design (L-share) that reduces the undesired random soil movement, providing a more controlled disturbance of the upper soil layer. Purpose: The aim of this study was to evaluate draught forces and soil movements when operating the new share. Materials and Methods: Experiments were conducted in a laboratory set-up using a soil bin with a fine loamy soil texture. The soil was compacted to a bulk density of 1500?kg?m^?3, with a penetration index of 486?kPa and a mean water content of 10%. The cultivation depths were 30, 50 and 70?mm and the operation speeds were 0.84, 1.67 and 2.31?m?s^?1. Cubes were used to measure soil movement by recording the displacement from their initial positions. The soil surface and furrow profile were measured by using a 2D laser range scanner. Results: The results showed that increasing operation speed and cultivation depths generally increased draught forces and soil movement. Changing the cultivation depth from 30 to 50?mm resulted in a 63% greater longitudinal force (F_x), and 71% greater F_x when increasing the cultivation depth from 50 to 70?mm. Conclusion: The study showed that the new L-share mounted on a modified spring tine only causes minor soil movement and thereby minimising the undesirable soil movement.