Tillage harrows

Conventional tillage mouldboard ploughing is followed by disking or harrowing, implying soil inversion... 

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. 

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). 

Rotary hoes or harrows are the first tillage operation used on organic farms. 

Anyone who attempts to discuss tillage is considerably handicapped by the lack of an exact, narrow definition of the term, and by a variation in usage of this and related terms in different communities. According to Webster s Dictionary to till means to turn or stir (as by plowing, harrowing, or hoeing) and prepare for seed to sow, dress, and raise crops from and to cultivate. By this definition the terms till, plow, cultivate, and even seed are nearly synonyms. 

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