Tillage cultivators

Mechanical tillage (cultivation) continues to be one of the principal nonchemical means of weed control (Anderson, 1983). Primary tillage is the initial ground-breaking in preparation for crop production. Secondary tillage is performed... 

An annual estimated cost of approximately 938,835,000 is required for labor and equipment to apply 204.5 million kilograms of herbicides to 147.6 million hectares of cropland in the United States (Table IV). Mechanical tillage to control weeds between cropping seasons and interrow tillage of crops has been used for centuries as a very effective method of weed control. Approximately 50% of all tillage between crops is done to control weeds. The number of cultivations required for effective weed control within a row crop varies from two to five during a cropping season. 

Yang CH, Crowley DE, Menge JA (2001) 16S rDNA fingerprinting of rhizosphere bacterial communities associated with healthy and phytophthora infected avocado roots. FEMS Microbiol Ecol 35 129-136 Yemefack M, Jetten VG, Rossiter DG (2006) Developing a minimum data set for characterizing soil dynamics in shifting cultivation systems. Soil Tillage Res 86 84-98... 

Various forms of soil cultivation, or non-cultivation, exist ranging from mouldboard ploughing to no-tillage, as listed below (from CTIC and Conservation Technology Information 1998) ... 

Mulch tillage or mulch ripping the soil is tilled prior to planting with chisels, disks, sweeps or blades weed control is obtained with herbicides and/or cultivation... 

No tillage or zero tillage the soil is left undisturbed from harvest to planting except for nutrient injection. Planting or drilling is accomplished in a narrow seedbed or slot created by coulters, row cleaners, disk openers, in-row chisels. Weed control is accomplished primarily with herbicides. Cultivation may be used for emergency weed control... 

Organic farming systems rely more on mechanical weed control and in certain crops on considerably more intensive soil tillage as the use of synthetic herbicides is prohibited. This can have negative effects on other key species of soil meso-fauna, i.e. a reduction of population of Collembola with organic cultivation (Krogh 1994). 

Botto, J.F., Scopel, A.L., Ballare, C.L. and Sanchez, R.A. 1998. The effect of light during and after soil cultivation with different tillage implements on weed seedling emergence. Weed Science 46(3) 351-357. 

Many of our current technical innovations in mechanical weed control can trace their development from earlier forms of the same tillage device. Even the plows and cultivators used through the 1900s tended to be little more than large, hardened steel replacements of the wooden tools used centuries earlier. On the other hand, herbicides radically changed agricultural production within a few years of their introduction. Novel application equipment is now required by the herbicide user, as is the knowledge to use each new herbicide product effectively. 

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