Soil Preparation Techniques

Preparation of Soil by Mechanical Agitation

• Tillage is the agricultural preparation of soil by mechanical agitation of various types.

• Primary tillage such as ploughing tends to produce a rough surface finish, whereas secondary tillage tends to produce a smoother surface finish.

• Harrowing and rototilling often combine primary and secondary tillage into one operation.

• Tillage can refer to the land that is tilled, and cultivation can refer to any kind of soil agitation.

• The steel plow allowed farming in the American Midwest, but caused the Dust Bowl.

• Reduced tillage leaves between 15 and 30% crop residue cover on the soil or 500 to 1000 pounds per acre of small grain residue during the critical erosion period.

• Intensive tillage leaves less than 15% crop residue cover or less than 500 pounds per acre of small grain residue.

• Conservation tillage leaves at least 30% of crop residue on the soil surface, or at least 1,000 lb/ac of small grain residue on the surface during the critical soil erosion period.

• Zone tillage is a form of modified deep tillage in which only narrow strips are tilled, leaving soil in between the rows untilled.

• No-till farming reduces costs and environmental change by reducing soil erosion and diesel fuel usage.

• Site preparation is the work that is done before a forest area is regenerated.

• Burning is commonly used to prepare clearcut sites for planting.Site Preparation Techniques for Tree Planting

• The type of tree crown can affect the accuracy of measuring site preparation, as densely growing trees with short crowns can be overestimated, while open-grown trees with long crowns can be underestimated.

• The US Forest Service emphasizes the need for providing shade for young outplants of Engelmann spruce in the high Rocky Mountains. 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.

• Site preparation can be done to facilitate access by planters or to improve access and increase the number or distribution of microsites suitable for planting or seeding.

• Mounding is a site preparation technique that creates raised planting spots, which can improve outplant performance on sites subject to low soil temperature and excess soil moisture.

• Mounding can increase soil temperature, and outplants on mounds have 3 times as many days with a mean soil temperature greater than 10°C than control microsites.

• Mounds received over 4 times the total daily light energy that reached control microsites, which is important for photosynthesis.

• The orientation of linear site preparation can make a difference in tree growth. South, east, and west-facing microsites have significantly greater stem volumes than north-facing and untreated microsites.

• In Minnesota, N-S strips accumulated more snow, but snow melted faster than on E-W strips in the first year after felling. Snow-melt was faster on strips near the center of the strip-felled area than on border strips adjoining the intact stand.

• In Ontario, 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. scarifier, or rolling chopper).

• Scarifying teeth, like Young's teeth, were sometimes used to prepare sites for planting, but their most effective use was found to be preparing sites for seeding, particularly in backlog areas carrying light brush and dense herbaceous growth.

• The Ontario Department of Lands and Forests began testing new equipment from Scandinavia and elsewhere that seemed to hold promise for Ontario conditions, primarily in the north. Testing was begun on the Brackekultivator from Sweden and the Vako-Visko rotary furrower from Finland.

• Wang et al. (2000) recommended that sheltered plantation site preparation should be used for transplant stock.