How Do I Choose the Best Power Harrow?

The power harrow refers to a machine that uses a tractor's power output shaft to drive the working parts to carry out the work of smashing the ground in a dry field through a universal joint drive shaft and a transmission system. It can be divided into reciprocating power harrow, horizontal rotating power harrow and vertical rotating power harrow according to the movement mode of the working parts. Power harrows in developed countries not only continue to improve in function, continue to increase in variety, and are increasingly perfect in structure, but also develop in a series and large-scale direction. In recent years, China's power harrow products have also been developed, especially horizontal rotary power (rotary gear) harrows, which are widely used in northern dryland areas ^[1] .

The main working parts of the reciprocating power harrow are two rows of nails, which are driven by the tractor's power output shaft for horizontal reciprocating motion, and the directions of the movement of the two rows of nails are opposite. The ability to crush soil is strong during operation, without disturbing the soil layer, a good effect can be achieved in one operation, and the ability to adapt to different soil conditions is strong. At the rear of the machine, a soil crushing roller (roller harrow) can be connected to level and compact the topsoil.

The reciprocating power harrow consists of a vibration damping device, a frame, a flywheel, an eccentric swing fork, a central swing arm, a nail (beam), a depth-limiting wheel, and a crushing roller (rolling harrow). The driving mechanism of the nail teeth (beam) adopts an eccentric swing fork type, which is directly driven by the tractor's power output shaft. There is no transmission device. The effect of soil fragmentation can be adjusted by changing the forward speed of the tractor. Because the working part reciprocates during the operation to produce strong vibration. A spring shock absorber is installed on the harrow's suspension to buffer the vibration and keep the operation stable ^[1]

The main working part of the horizontal rotary power (rotating teeth) harrow is a row of vertical shaft rotors, each of which is equipped with two upright rake blades (nail teeth). During operation, the rotor is driven by the power output shaft through the transmission system, while rotating, it advances, hits the soil block, and loosens the soil in the plow. The rotor of the rake is "door"

The overall structure of the vertical rotary power harrow is similar to that of a rotary tiller. The main difference is the working parts, which have many types such as "square teeth" and "plate teeth". The working part is installed on the tooth seat, which is fixed on an axis perpendicular to the advancing direction and parallel to the ground. The tooth seat is arranged on the shaft in a spiral or the like. Beveled square teeth are made of square or hexagonal steel. During operation, the power of the tractor is transmitted to the gearbox through the universal drive shaft, and the working parts are advanced while rotating perpendicular to the ground through the transmission system to break the soil. This type of driving harrow is suitable for crushing soil and preparing land on hard soil, and the working depth can reach 26cm ^[1]

Drive harrows and rotary cultivators are both machines for organizing soil through rotary gears on rotary shafts driven by gear boxes. The two are usually used after the ground is loosened; the soil is broken and stirred to create suitable Seed sprouts grow into seedbeds. Overall, the two have many similarities and many differences. Take the Zirkon power harrow and Maschio rotary tiller as examples.

Lectra Chicone Drive Harrow

In terms of type, the power-driven harrow can be divided into reciprocating power harrow, horizontal rotating power harrow, and vertical rotating power harrow according to the movement mode of the working parts; among them, the horizontal rotation (rotating tooth) type is the most common. The rotary harrow can stir the deep-turned land, break large soil blocks, and fully mix the residue with the soil; after mixing the straw fiber with the soil, it can gradually degrade and increase the content of soil organic matter and increase soil fertility On the other hand, returning straw to the field can also improve soil moisture retention and reduce damage to soil caused by evaporation and wind. The power harrow usually works in conjunction with a roller. The roller can play the role of crushing and leveling the soil. After finishing the two sets of devices, the soil will form an ideal seed bed with dense and dense soil. The working depth of the power harrow is usually in the range of 10-30 cm, most of which are about 15 cm. Compared with rotary tillers, power harrows are more expensive and require greater power output from supporting tractors ^[2] .

Maschio Rotary Tiller

Rotary tiller is a tillage machine that completes ploughing and harrowing operations with tractors. It can shred the stubble buried below the ground surface, which is convenient for planter operation and provides a good seed bed for later seeding. Rotary cultivator is divided into horizontal axis type and vertical axis type, of which the former is widely used in China, the latter is mainly used in paddy fields, and is widely used in Japan. Compared with the drive harrow, the rotary tiller has a shallower depth of operation, but has a stronger crushing capacity and requires less power. Horizontal blade rotary cultivator can be divided into fixed type and movable type from the blade structure. The former has better soil crushing effect, but the latter can effectively avoid overload damage caused by stones and other debris in the land to the machine.

Multiple factors such as soil conditions, tractor power, and previous crops need to be fully considered when selecting a drive harrow or rotary tiller. Both the rotary tiller and the power harrow are driven by gear boxes, but the load levels between the two are very different. Overall, rotary tillers are lighter in weight and lower in cost. In China, the popularity of rotary tillers is much higher than that of power harrows. In addition to lower prices and less power requirements, rotary tillers can run faster and have better soil crushing effects. However, in developed countries in Europe, the market share of rotary tillers is decreasing year by year. This is mainly due to the serious defects in the rotary tiller's operating effect: After the rotary tiller crushes the soil, it is not conducive to soil conservation. The fine soil on the surface will gradually evaporate and drift away with the wind, causing serious soil erosion and sand desertification. The influence of European regions dominated by black clay is more pronounced. In addition, after the soil is broken by the rotary tiller, in addition to the evaporation of water, the microbial community will also be severely damaged; and the activity of the microorganisms is closely related to the soil fertility. After continuous use of rotary tillers on the same land for many years, there will be a hidden danger that soil fertility will continue to decline. These are the main reasons why European farms are gradually abandoning rotary tillers.