Tillage

Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking.

Hoofed animals could also be used to till soil by trampling, in addition to pigs, whose natural instincts are to root the ground regularly if allowed to.

However, the earliest evidence of plow usage dates back to around 4000 BCE in Mesopotamia (modern-day Iraq) [timeframe?].

It could be pulled with human labor, or by mule, ox, elephant, water buffalo, or a similar sturdy animal.

This aspect is discussed in the 16th-century French agronomic text written by Charles Estienne:[1] A raw, rough, and tough soil is hard to till and will neither bring forth corn, nor any other thing without great labor, however the seasons be temperate in moisture and dryness ... you must labor it most exquisitely, harrow it and manure it very oft with great store of dung, so you shall make it better ... but especially desire that they may not be watered with rain, for water is as good as poison to them.The popularity of tillage as an agricultural technique in early modern times had to do with theories about plant biology proposed by European thinkers.

In 1731, English writer Jethro Tull published the book "Horse-Hoeing Husbandry: An Essay on the Principles of Vegetation and Tillage," which argued that soil needed to be pulverized into fine powder for plants to make use of it.

[3] The steel plow allowed farming in the American Midwest, where tough prairie grasses and rocks caused trouble.

Intensive tillage often involves multiple operations with implements such as a mold board, disk, or chisel plow.

By reducing the number of times the farmer travels over the field, significant savings in fuel and labor are made.

[14] Some specific states where zone tillage is currently in practice are Pennsylvania, Connecticut, Minnesota, Indiana, Wisconsin, and Illinois.

Its use in the USA's Northern Corn Belt states lacks consistent yield results; however, there is still interest in deep tillage within agriculture.

According to English Heritage in 2003, ploughing with modern powerful tractors had done as much damage in the last six decades as traditional farming did in the previous six centuries.

Site preparation may be designed to achieve, singly or in any combination, improved access by reducing or rearranging slash and ameliorating adverse forest floor, soil, vegetation, or other biotic factors.

Broadcast burning is commonly used to prepare clearcut sites for planting, e.g., in central British Columbia,[26] and in the temperate region of North America generally.

[29] Deficiencies of copper and iron in the foliage of white spruce on burned clearcuts in central British Columbia might be attributable to elevated pH levels.

However, in another study[32] in the same Sub-boreal Spruce Zone found that although it increased immediately after the burn, phosphorus availability had dropped to below pre-burn levels within 9 months.

Nitrogen will be lost from the site by burning,[26][32][33] though concentrations in remaining forest floor were found by Macadam (1987)[26] to have increased in two out of six plots, the others showing decreases.

The Picea/Abies forests of the Alberta foothills are often characterized by deep accumulations of organic matter on the soil surface and cold soil temperatures, both of which make reforestation difficult and result in a general deterioration in site productivity; Endean and Johnstone (1974)[34] describe experiments to test prescribed burning as a means of seedbed preparation and site amelioration on representative clear-felled Picea/Abies areas.

Results showed that, in general, prescribed burning did not reduce organic layers satisfactorily, nor did it increase soil temperature, on the sites tested.

[35] Forest managers interested in the application of prescribed burning for hazard reduction and silviculture, were shown a method for quantifying the slash load by Kiil (1968).

The need to provide shade for young outplants of Engelmann spruce in the high Rocky Mountains is emphasized by the U.S. Forest Service.

Acceptable planting spots are defined as microsites on the north and east sides of down logs, stumps, or slash, and lying in the shadow cast by such material.

Wang et al. (2000)[38] determined field performance of white and black spruces 8 and 9 years after outplanting on boreal mixedwood sites following site preparation (Donaren disc trenching versus no trenching) in 2 plantation types (open versus sheltered) in southeastern Manitoba.

Hall (1970),[39] in Ontario at least, the most widely used site preparation technique was post-harvest mechanical scarification by equipment front-mounted on a bulldozer (blade, rake, V-plow, or teeth), or dragged behind a tractor (Imsett or S.F.I.

Drag type units designed and constructed by Ontario's Department of Lands and Forests used anchor chain or tractor pads separately or in combination, or were finned steel drums or barrels of various sizes and used in sets alone or combined with tractor pad or anchor chain units.

Hall's (1970)[39] report on the state of site preparation in Ontario noted that blades and rakes were found to be well suited to post-cut scarification in tolerant hardwood stands for natural regeneration of yellow birch.

On sunny days, daytime surface temperature maxima on the mound and organic mat reached 25 °C to 60 °C, depending on soil wetness and shading.

During the first growing season, mounds had 3 times as many days with a mean soil temperature greater than 10 °C than did the control microsites.

A disk-trenching experiment in the Sub-boreal Spruce Zone in interior British Columbia investigated the effect on growth of young outplants (lodgepole pine) in 13 microsite planting positions: berm, hinge, and trench in each of north, south, east, and west aspects, as well as in untreated locations between the furrows.