Skip to content

July 2022 – Tine Drill vs Disc Drill by Nick Swayne

The classic age-old debate which farmers love to discuss over a pint in the local pub at the end of a busy day’s drilling is still widely and hotly contested. Like most important debates in life there never seems to be a clear answer or a definitive winner. Although most drill manufacturers will try to convince you that their own drill, whatever it may be will work in all conditions, we all simply know this just isn’t the case. Drills can be temperamental things even at the best of times, often leaving you wondering if they have been dragged out of the ‘shed on the wrong side’ that day. For all their faults and flaws, it must be said that the field always gets drilled one way or another. At times, the end of drilling and the finish line seems a mere spec in the distance. Especially on those bad days, and there are plenty of bad days when working with machinery. Having had the pleasure/displeasure of using both types of drills I can assure you they both give you headaches and moments of toil when spanners are thrown, and toolboxes are kicked in anger.  A las I digress, back to the matter in hand…

Tine drills are undoubtably in my experience the easier drills to maintain out in the field. The most regular maintenance task on these drills is changing the points once they are worn out. Admittedly a quick 2-minute job of swapping the points over is not always the case. Inevitably there is always that one point whose roll pin will just not hammer out. Frustration begins to set in as you hit it harder and harder which usually results in your thumb subsequently being caught in friendly fire. Regarding depth of seed, it can be challenging to get tine drills set up correctly. Most tine drills are on a fixed frame which can result in varying depth of seed across the width of the drill when going across uneven ground. Compared to disc drills which generally have independent movement on each coulter allowing for a more accurate depth to be achieved. It must be said however that this is not the case for all tine drills, for example the Dale drill does allow coulters to move independently.

As we all know Blackgrass is becoming an ever-increasing problem on many farms and minimal soil disturbance is a key aspect to trying to prevent Blackgrass germination. Tine drills, even when on minimal 1-inch points inevitably disturb more soil than disc drills. For weed germination this is seen as a negative but in some scenarios, it can be argued that there can be quicker crop establishment where more soil is moved. Whether this is due to mineralisation or better seed to soil contact, or perhaps it is a combination of the two. It can also be said that the extra soil movement is beneficial in terms of pest suppression as slugs and their eggs are more likely to be destroyed. So, the jury is still out on this debate I’m afraid. 

Perhaps the biggest and most common downfall with Disc drills is the open slot effect which can be seen at times. Most of the time this occurs when the soil conditions are too wet. The easy fix to this problem is to have patience and wait until more favourable drilling conditions arise. But we all know in practice this isn’t always applicable with hectic workloads and timeframes to abide by. The issue with open slots is that the seed is left vulnerable, whether this be from chemical damage from Pre-emergence sprays landing on bare seed or from attack by the dreaded slugs. In favourable drilling conditions there is no denying that disc drills can achieve a superb seedbed regarding soil disturbance. In good conditions it can be a challenge to even spot any evidence of drilling as the drill folds the slot back on top of the seed perfectly as if nothing has happened.

The use of cover crops is becoming ever-more popular, with farmers often wanting the option to direct drill straight into the standing crop. Tall, thick cover crops can send shivers down even the hardiest drill-men’s spine when they are asked to drill on the green, with the phrase “it’ll be fine” echoing in their ears. Tine drills are a nuisance for bulldozing dense crops which wrap around the tines and end up being dragged halfway up the field before eventually being dumped in big heaps. Most drill-men who have a conscience will do their best to level these heaps out. 

If you are looking to drill into tall, dense crops such as mustard which can grow to 6 feet tall then disc drills are phenomenal at this. In the picture below you can see exactly this scenario when we drilled straight into a mustard crop. The discs slice through the biomass which means you don’t get the bulldozing to the same effect that you do with tine drills. One thing to be aware with disc drills however is the hair-pinning effect which can be caused by lots of chopped straw. This occurs when the straw is pushed into the slot created by the disc and the seed then sits on top resulting in a poor seed to soil contact.  

In conclusion, which is the better drill? Both drills in my opinion have their place on the farm with each one working better in different situations. Disc drills are better suited to drilling into cover crops, but in my experience can have higher upkeep costs and require more maintenance. They don’t work well on land with high stone content as the discs bounce over the stones, and the wear on the machines can be very high. In wet autumns they are not very versatile either due to the previously stated reasons of leaving open slots. Tine drills have their flaws, but in my opinion, they offer a farmer greater flexibility and a wider drilling window. They allow you to drill a crop even when conditions are not favourable and although establishment will not be perfect, in some years having a crop in the ground is still deemed to be a success. As the saying goes though it is “horses for courses” and every farmer will have their own preference on this matter. If you want ultimate flexibility, then perhaps having one of each in your shed is the best bet. Although you might need to buy a lottery ticket first.