Many different grain growing regions have struggled with cool springs that endanger seedlings to slow emergence and frost damage.

This is even a greater concern for barley, flax, & canola, which are all relatively sensitive to cool growing conditions and frost.

Direct seeding practices have gone a long way to protect the seedbed from moisture loss, but the residue retained on top of the seedbed will also deflect the heat of the sun.

During the day, blackened soil absorbs heat energy provided by the sun and the warmed air. At night, the black soil gives up some of its stored up heat which provides additional energy to the plant and protect it from freezing if frost is a danger. Producers who experience cool spring conditions may require options to increasing the exposure of the soil to the sun's warming rays, yet maintain a good seedbed to minimize the evaporative effects.

How to farmers obtain the benefits of blackened soil without losing the benefits from minimal disturbance or one pass seeding?

• Some farmers burn their stubble, which does not disturb the soil. The problem with this approach is that the loss of nutrients for subsequent years is significant along with reducing the soil tilth which in turn negatively impacts water infiltration and soil compaction. Uneven burning of the field will also establish two different and distinct growing characteristics in the same field.
• Pre-tillage using a cultivator or chisel plow will blacken the soil, but the disruption will leave a rough finish. Also, the toweling or smearing action caused by the bottom side of the sweeps basically seals off the established pathways which draw moisture into the soil.
• Some direct seeding systems create a high degree of soil disturbance around seed row, which does provide a larger black zone than a single seed opener system. However, the nitrogen toxicity caused by the close placement of fertilizer and the seedbed area fracturing can cause major emergence problems leading to maturity delays.

The 7200 Heavy Harrow - Your solution for dealing with cool spring seeding conditions.

The best option for soil blackening for spring seeding is using a Bourgault 7200 Heavy Harrow:

• Set the 7200 for maximum weight transfer of the booms onto the tines and position the tines in a near vertical position to achieve extensive blackening of the fields. Unlike tillage, the harrow tines do not close off the infiltration pathways in the soil as do the sweeps. It also has less impact on the firmness of the seedbed, especially if used in the fall.
• The 7200 Heavy Harrows allow you to incorporate the residue into the soil so you retain the valuable nitrogen, and improve the soils tilth.
• The 7200 Heavy Harrow stands alone in its ability to hydraulically transfer all of the boom weight onto the tines from the tractor seat. You can make adjustments as conditions change in the field without having to stop the tractor.