Multi-dimensional evaluation of site-specific tillage using mouldboard ploughing

Abstract

Due to the lack of high-resolution data on soil compaction using proximal sensing technology, mouldboard (MB) ploughing is carried out at uniform speed and depth, which does not necessarily respond to tillage needs due to compaction level and depth that are spatially variable across the field area. This study aims at simulating the comparative performance of different site specific tillage (SST) schemes (e.g., speed and depth) and uniform tillage of a MB plough using a high resolution soil packing density (PD) maps. An on-the-go soil sensing platform was used to predict and map topsoil PD in a Luvisol field in Belgium and two Cambisol fields in Spain. All fields were divided into three management zones, to each of which different tillage speed and depth were assigned based on PD maps. A MATLAB simulation code was developed to predict and compare the power efficiency, fuel consumption, emission of carbon dioxide (CO₂) from diesel combustion and total operating time of uniform, SST depth, SST speed, and hybrid SST depth and speed MB ploughing schemes. Results revealed that the degree of soil compaction varies from field to field and within fields, which necessitates SST tillage practices. It was found that the depth control was the best performing SST in fields having large areas with low (PD < 1.55) and medium (PD = 1.55 – 1.70) compaction levels, resulting in the largest reduction in draught (33.7 % – 57 %), fuel consumption and CO₂ emission (29.6 % - 50.1 %), while using the same operational time as that of the uniform tillage. However, in cases when the majority of the field area was highly compacted (PD > 1.70), potential savings were smaller at 22.5 %, with the speed control emerged as a more effective control scheme. It is recommended to validate the simulation results of SST of MB ploughing in fields to enable assessing the impacts they have on crop responses and soil quality.