Strip tillage and sowing: is precision planting indispensable in silage maize?

This work was aimed at assessing whether in silage maize it is possible to replace precision planting with a volumetric seeding in the perspective of developing hybrid machines to strip till and sow both high density crops like winter cereals and low density crops like maize. This in order to reduce the number of machines in the farm, simplify logistics and reduce amortization costs. Two experiments were carried out in 2014 and 2015. In the first year, two tillage-sowing treatments were compared in a randomized block design with 5 replicates: 1) strip-tillage plus volumetric band (0.1 m wide) seeding (ST-VBS) carried out by a Claydon Hybrid 6M at inter axle spacing of 0.6 m and with 35 kg ha-1 of seeds; 2) no-tillage plus precision line planting (NT-PLP) carried out by a sod drill Kinze 3100 at row distance of 0.71 m. In the second year, the same two treatments of 2014 were applied, but a third tillage-sowing treatment was also included: strip tillage plus precision line planting (ST-PLP) carried out by a strip tiller Khun Striger at inter axle spacing of 0.71 m plus the Kinze 3100, respectively, in two passages. In 2015, a randomized block design with 3 replicates was adopted. Both in 2014 and 2015 treatments did not differ significantly for actual seeding density and final plant density, individual plant growth indices (plant height, stem diameter, FW, DW) at early stem elongation, flowering and final harvest, neither for total FW and DW yield, nor for biomass composition (starch, protein, lipids, fibre and ash concentrations) at harvest. Results demonstrate that a silage maize crop can perform successfully when established by strip tillage associated with volumetric band seeding. If similar results are demonstrated for high density crops, this will support the strategy of developing hybrid machines to strip till and sow both high density crops and silage maize, which is relevant for many farming systems devoted to forage and biomass production for agro-energy purposes.