We at Kronos specialise in soil preparation equipment. We have many years of experience as a manufacturer of harrows behind us, having manufactured tens of thousands of them over a period of more than 80 years. Our present range of products comprises nine models ranging from 2.75m to 6.40m in working width. The rotary harrow has undergone considerable development during these years and its application range has also widened. Indeed, harrowing is experiencing a revival in many market regions.
The Various Applications of Rotary Harrows
At present, rotary harrows are used on many farms as all-purpose machines for a number of different soil treatment purposes. In particular, farmers concentrating on cereal crops use rotary harrows for mixing straw and other plant residues into the soil after harvesting.
When applying minimum soil treatment, a rotary harrow is well suited for the preparation of seedbeds. The same applies to livestock farms, where rapid mixing of the farm manure and farm manure compost into the soil is important prior to the sowing of cereal crops or beet. This method enables more efficient utilization of the nitrogen contained in farm manure.
Rotary Harrow Applications Include:
- Minimum soil treatment
- Stubble cultivation
- Seedbed preparation
- Mixing manure and compost into the soil
- Aeration of long-duration pasture and grassland
Minimum soil treatment
On many farms, a rotary harrow is well suited for minimum soil treatment, e.g. if non-plough soil treatment is applied. This particularly applies to soil treatment on cereal farms in connection with autumn seeding. On farms where plant diseases are not a problem, the seed of winter cereal crops can be sown directly into the cultivated soil.
If there is a risk of plant diseases being spread by the straw, the land must also be ploughed.
Harrowing and seeding of the furrow suffice in many cases, especially if a combine drill with disc coulters is available.
If stubble cultivation is applied in the autumn shortly after harvesting, the stubble and other crop residues can be efficiently mixed in with the soil. At the same time, a portion of the seeds of weeds can be made to sprout. On fields where a rich population of couch grass is a problem, it is always advisable to plough, unless chemical herbicides are used for couch grass control. It is also important to plough fields that carry a considerable risk of spreading of plant diseases through straw or other crop residues.
Stubble cultivation is carried out with 1-3 passes with a rotary harrow depending on the amount of plant residues to be ploughed into the soil. To achieve a good result, it is advisable to drive diagonally with respect to the harvesting direction.
When minimum soil treatment is applied, a rotary harrow is a good alternative tool at the time of spring works. The field can be ready for seeding after one pass with a 4-shaft rotary harrow. When growing cereals using the minimum soil treatment method, the preparation can be carried out rapidly with a rotary harrow, which mixes the plant residues with the surface stratum of the soil. The new generation of combine drills with discs both on fertilizer and seed coulters are particularly well suited for minimum soil treatment.
A rotary harrow is also a good choice for the preparation of seedbeds and crushing of turned-over soil when grasslands are being regenerated under difficult conditions.
Mixing of manure and compost
As regards the rapid mixing of manure or liquid manure and compost, the rotary harrow has always been the superior choice. The sideways movement of the blades mixes the manure with the surface stratum of the soil while the soil is being turned over the manure. The rapid ploughing in of the manure enables maximum utilisation of the valuable nitrogen.
Aeration of long-duration pastures
The increased growth and productivity of long-duration grasslands and pastures requires that the roots of grasses are provided with sufficient amounts of oxygen and that the exchange of air in the root system is adequate. The air space around the root system can be increased by making cuts and drilling holes in the soil. Furthermore, grasslands can be aerated by towing a rotary harrow at slow speed. If the soil is hard, the harrow can be fitted with additional weights.
On rough pastures with lots of stones it may be useful to use a finger harrow equipped with, for example, long tynes or a crusher roller.
Thanks to its versatility and efficient tilling method, the rotary harrow has once again come to enjoy great popularity. It is a fine choice for minimum soil treatment, e.g. in connection with the new generation of combine drills equipped with disc coulters when used under conditions which prevail in Finland. In addition, it can be used for seedbed preparation and the ploughing in of farm manure.
Under normal conditions, a rotary harrow is used at high working speed, i.e. 12-15 km/h.
At the speed of 13 km/h the approximate area
covered is as follows:
model 2750 3,5 hectares/h
model 3150 4,0 hectares/h
model 3700 4,8 hectares/h
model 4200 5,4 hectares/h
model 4800 6,2 hectares/h
More Spacious Harrow Frame Structure
In order to speed up and improve the efficiency of use of the rotary harrow, its frame structure has to allow unobstructed flow in conditions when there is an abundance of plant residues. A spacious and high frame structure prevents the harrow from becoming blocked and enables higher working speeds. Nevertheless, it is important for the straw to be well chopped. This requires that the chopper blades of the combine harvester are sharp and that the straw and chaff are spread efficiently. These form a sound basis for an outcome of good quality.
Flexible Shaft Suspension
To absorb the shocks and vibrations that the blades and shafts are subjected to, the shafts of the rotary harrow are equipped with flexible suspension, which also protects the blades against overloading. If there are many large rocks in the soil, the driving speed has to be decreased and the driving technique has to be adapted to the prevailing conditions.
Trailing Rotary Harrows
The biggest harrows are of the trailing type and are fitted with separate wheels for transportation. The safe transportation of harrows is ensured and the structure allows an attachment of different kinds of implements to the front and rear of the frame.
It is possible to attach, for example, various types of levelling boards to the front of the frame and various finger harrows, boards, rollers etc. to the rear of the frame.