Disc harrows

In table 1 some results from this study (2) of odour reduction are presented. The thresholds are mean values expressed as log dilution factors. Standard deviations are calculated on the averages of doubled ED-50 values, each value based on the reports of six observers at a time. As can be seen, incorporation of the manure largely reduced the emission of odour from the field. This mainly concerns the injection techniques, which in some cases reduced the odour to the background level. Conventional tillage implements such as a plow or a disc harrow also reduced the odour emission considerably. 

Surface spread Buried with plow harrow disc harrow injector... 

The work reported in this paper was part of a larger project whose principal objective was to measure the rate of volatilization of the herbicide trifluralin to the atmosphere from a field soil after surface application and incorporation to a depth of 7.5cm by cultivation with a disc harrow. In this experiment it was necessary to measure as accurately as possible the amount of the trifluralin residue in the soil on several days during the growing season and to calculate the rate of disappearance of the... 

Principal tillage tools include the hoe for removing weeds around the base of trees and the disc harrow for use between rows of trees. Power rototillers set for shallow cultivation are used occasionally between the tree rows. Tillage has the disadvantage of sometimes increasing disease and insect or mite problems (Yarwood, 1969), and in some soils it promotes the development of impervious layers, called plow or tillage pans (Meith and Connell, 1985). 

Disc harrows with sensors till the soil either in the direction away from the tree or in the direction towards the tree. This causes considerable displacement of the soil. The simple technology and favourable purchase price have led to increasing use of these machines recently. Disc harrows are more suitable for light soils. 

Fig. 4.5. Clemens Radius 859 flat share. Fig. 4.6. Spedo TPE disc harrow.

The other approach involves a very severe grazing and/or vigorous surface cultivation to expose soil and obtain a tilth. This can most conveniently be undertaken with disc harrows. Broadcasting seeds and fertilisers then takes place and the operation is concluded by rolling and pesticide application as previously described. 

This application was made between 0700 and 0830 a.m. in cool (air temp., 10 0 clear and windless weather. Both granular and emulsion formulations were incorporated to the 7.5cm depth with a disc cultivator within 15 minutes of application. A second cultivation to the same depth, but at right angles to the first, was completed within 2-3 hours. On May 20th both plots were spring-tooth harrowed for seed-bed preparation for soybean planting on the same day. The only subsequent soil disturbance was a row cultivation in late June to control a severe infestation of quack-grass control of broadleaf weeds was essentially complete with the trifluralin. 

Fine seedbeds are required for uniform emergence of baby leaf crops. This can be achieved using power harrows following discing. Baby leaves are commonly grown in beds to minimise compaction and aid harvesting. 

Broccoli does not root deeply. A firm soil with a good tilth is required. Compacted soils may require sub-soiling before ploughing and harrowing/discing. Broccoli can be grown in beds or on the flat with tramlines. 

A firm soil with a good tilth is required. Compacted soils may require sub-soiling before ploughing and harrowing/discing. 

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