Description
Ploughing is one of the most important agricultural techniques that dates back to ancient times. By means of an agricultural tool named a “plough”, soil can be prepared for seed sowing or planting. The main purpose of ploughing consists in breaking and turning up the first layer soil in order to let soil incorporate air and bring fresh nutrients up to the surface, bury leftovers of previous crops and control weeds.
In order to obtain the ideal soil for planting, in climate regions where possible, it is recommended to start ploughing before the cold season and leave the overturned vegetation to decompose when the soil is still warm.
PRE-CONDITIONS FOR IMPLEMENTATION
- Tilling should not be practiced too intensively or repeatedly, as this can lead to the depletion of soil microorganisms and soil biodiversity in the long run due to the land being constantly disturbed and not being allowed to naturally regenerate.
- Breaking up the soil particles to allow increased aeration can also cause a loss to the existing water content of the soil. This risk can be reduced by covering the soil with mulch or cover crops which helps to reduce/slow water evaporation rates.
- Finally, tilled land is more prone to erosion and surface runoff, particularly when practiced frequently. One solution to this problem, especially when a field is heavily irrigated, is to construct sediment basins slightly downstream from the tilled area in order to capture runoff.
- In general, methods employing less frequent and intensive tilling result in higher economic benefits due to lower labor and machinery costs. This can lead to an increased net farm income, although additional need for pesticides and fertilizers under minimal/conservation tilling methods can reduce these economic gains.
METHOD OF APPLICATION
Materials required:
- Safety gear (such as garden gloves)
- A garden hoe to remove rocks and obstructive vegetation in the preparation stage
- String, or other material, to mark your land
- Soil amendments (if using)
- Rake
Additional materials for manual tilling:
- Garden fork or broadfork for loosening the soil
- Long cultivating fork for turning over the soil
Additional materials for mechanized tilling:
- Rototiller
- Fuel (if using a non-electric tiller)
Steps of Implementation:
- Prepare the land
Remove any rocks, and tree and shrub roots, as well as any other unwanted debris that might get in the way of tilling your land. There is a risk that leftover debris could damage your rototiller. Tilling works best when the land is neither too moist nor too dry (thus typically best to do during springtime).
- Mark out the area to be tilled
Using string, or an alternative material, mark out the edges of the rows you want to till.
- Loosen the soil
Use a gardening fork to dig into the soil and break up compacted earth by moving the tool back and forth. The aim at this stage is not to turn the soil over, but simply to loosen and aerate it. Note that loosening the soil before turning it over may not be necessary if you are using a mechanized tiller. If reducing disturbance to the soil is a priority, it is advisable to stop at this step.
- Turn over and mix the soil
If tilling using a manual approach, use a large cultivating (garden) fork to run through the earth and steadily turn over the topsoil, dislodging weeds, breaking up compacted surface soil, and loosening and mixing the soil. If you are using soil amendments, use the rake to remove the uncovered weeds before adding the soil amendments. Then, go over the area a second time with the cultivating fork.
If you are using a mechanized tiller, work the machine along the rows at a steady pace, giving the machine time to work thoroughly through each patch of soil. Till row by row as if you were mowing grass. It is recommended not to go back over already tilled land in order to avoid over-tilling.
COMMON METHODS OF TILLING
There are a number of different methods you can use to till your land. Several specialized tools and methods also exist for tilling land. This is the case for both manual and mechanized tilling. Tilling can also be practiced at different levels of mechanization - from implementation using a hand-held tool to a tractor driven-plow. Tilling methods thus also range across different levels of intensity.
Common methods of tilling include:
Type of tilling | Description |
Double digging | A manual but intensive method of tilling whereby the entire layer of topsoil is removed in order to expose the subsoil, amend it, and aerate it. Double digging impacts deeper soil than a rotiller typically can. This method is often used when farming a piece of land for the first time. |
Conventional tillage system | Typically, two rounds of tilling are used in this system. A first, more intensive round, aimed at creating seed beds, followed by a less intensive secondary till, to refine the soil for planting. |
Conservation tillage system | Conservation tillage comes in various forms (see below) but generally involves conserving a minimum of 30% of soil cover and keeping plant residue from past seasons. |
Minimum tillage | Minimum tillage - or reduced tillage - is a subset of conservation tillage and involves minimizing the intensity and depth of soil disturbance, as well as reducing the area of land being tilled. |
Strip tillage
|
Strip tillage is a method of conservation tillage wherein only the precise area where plants and crops are grown is tilled, while the area between the rows remains untilled. |
Contour tillage | This tilling method is used on sloped land. Tillage is implemented along the elevation contour lines, perpendicular to the slope of the land. The perpendicular earthen ridges that the tillage creates act like barriers that slow down runoff water, thus minimizing soil erosion. |
Soil ripping | Soil ripping is used as a sustainable alternative when tilling may be damaging to the land. Using the soil ripping method, deep vertical lines are dug into the soil (as opposed to turning over the topsoil). This allows for water infiltration and aeration at the roots of crops. Soil ripping minimizes soil erosion and is usually practiced when the soil is still dry. |
Zero tillage | With zero tillage systems, the earth remains undisturbed, and seeds are sown directly into plant residue from the previous season through direct seeding, sod seeding, or surface seeding. Zero tillage is typically associated with higher pesticide use as a trade-off for the weed prevention properties of tilling. |
COSTS
The costs and benefits of various tilling methods depend on a large array of factors that are hard to generalize e.g., specific crop rotation, cultivation methods, local climatic and ecological conditions, level of mechanization of the tilling process, and fertilizer and pesticide use. Thus, the examples of costs shown below should not be generalized across all contexts. They aim to provide a rough insight into the costs of certain tilling systems.
Estimation of socioeconomic factors implementation of local conventional tilling practices, minimum tillage, and zero tillage on maize production in the Central province of Zambia
Cost | Conventional tillage (Disc harrowing) | Minimum tillage
(Soil ripping) |
Zero tillage
(Direct seeding) |
Machinery | 138USD | 128.5 USD | 97.5 USD |
Hiring and labor | 245.5 USD | 235.5 USD | 201.5 USD |
Herbicides* | 52 USD | 52 USD | 52 USD |
Total** | 435.5 USD | 416 USD | 351 USD |
*Only costs of herbicides and not fertilizer is included for the sake of heterogeneity
**Average values over two seasons (2019/20 and 2020/21), (Source: Omulo et al., 2022).
CASE STUDIES
- Minimum tillage on smallholder land in Southern Tanzania: https://www.mdpi.com/2073-445X/9/12/513
- Minimum tillage on smallholder land in Kenya: https://www.sciencedirect.com/science/article/pii/S0959652619303051
- Strip tillage in Bangladesh: https://www.researchgate.net/publication/281477260_Strip_tillage_planting_method_for_better_wheat_establishment
- Economic and ecological benefits of reduced tillage in the UK: https://www.agricology.co.uk/sites/default/files/Economic%20and%20ecological%20benefits%20of%20reduced%20tillage%20in%20the%20Uk%20-%20Final.pdf
- Comparison of the costs of various machinery in Illinoi: https://farmdocdaily.illinois.edu/2020/08/cost-management-tillage-operations.html