The primary aim of land preparation (or Land Prep) is to provide the best soil conditions for crops to flourish and achieve optimal growth, yield and survival, for ultimate estate preservation.
Land preparation practices form a fundamental and important departure point for commercial farming and agricultural operations. When done correctly, this process not only enhances the harvest, but also greatly assists in controlling crop disease and pest invasion.
What does Land Preparation involve?
Preparing agricultural land from scratch involves many stages of land preparation and land clearing. This article will provide a very high level introduction of the first six stages, which farmers carry out before planting and which relate to services which Unitrans Africa provides to several customers across Southern Africa.
Bush clearing consists of cutting and removing bushes and shrubs from the area selected for field and road establishment. This debris must be disposed of in a suitable manner to ensure negative environmental impact is limited as far as possible. In Africa, much of the virgin territory, which makes way for agricultural usage, typically requires clearing of shrubs, brush, trees, grasses and other wild plants.
Mechanically breaking up compacted layers of soil is known as deep ripping. The heavy equipment uses tines working at depth to break up these layers. Not all soils and crops respond positively to deep-ripping every season, but when they do, benefits usually last for multiple seasons. As a result understanding and taking into account all mechanical requirements, as well as the soil moisture content, timing factors and soil types are important considerations on deciding on a land prep programme.
Tillage is the umbrella term for digging, stirring or overturning soil, to prepare the seedbed, aerating the soil, suppressing weeds and later incorporating manure, fertiliser or activating pesticides. Minimum tillage, or conservation tillage, is the practice of reducing the amount of soil disturbance when preparing the land for planting. Too much tillage can affect the quality of the soil, as this process disrupts the earth structure and can reduce plant residue in fields. This residue helps to cushion the soil in heavy rain and prevents surface run-off and soil erosion.
As every growing season is different, land preparation managers need to
- inspect the land frequently,
- determine tillage requirements, and
- keep up-to-date with soil conservation practices.
In areas where rainfall is low, more shallow tilling (less than the usual 15cm-20cm depth) is sufficient.
Ploughing and harrowing
These two operations are the main activities done at the pre-planting stage. Ploughing (manipulation or turning of the soil) occurs at a deeper level compared with tilling and is typically between 30cm and 60cm. The depth will depend on the planned crop, how deep the roots will grow and, of course, what kind of soil is present – key considerations for land preparation managers to consider. If the soil is compacted, ploughing will help to break down this barrier to promote root development and drainage of the soil which is vital to ensure good crop development. The addition of manure, fertiliser, compost or lime into the planned crop’s root zone can also be done during ploughing.
Harrowing is normally done after ploughing and is used to break down the soil further into smaller pieces. This provides improved aeration and helps with reducing weeds and weed seeds, as well as controlling pests. All this helps to get a better and more even topsoil, which is best for young roots to develop after germination. There are several kinds of harrows, but the most common are:
- Disc harrows;
- Harrows with tines or spikes; and
- Chain or chain-disc harrows.
The last stage before planting is land levelling. This prepares the field for irrigation, aiming to achieve a uniform application of water with surface irrigation. Ideally, slight slopes are needed to prevent water clogging and control soil erosion after heavy rainfall.
Detailed engineering surveys and layouts assist with this process and with the introduction of precision farming, more accurate implementation can be done. Increased use of GPS levelling or laser levelling, can flatten the cropland to an even plane with a variation of less than ±20 mm.
Within the Unitrans Africa footprint across Eswatini, Zambia, Malawi, Mozambique, and Tanzania, customers have access to comprehensive tailored solutions in the agricultural sphere. Access to real-time decision making and innovative precision farming, artificial intelligence, business analytics and informative reporting has become key to provide improved and expert land preparation services. If you would like to find out more information regarding tailor-made solutions to aid you in your land preparation activity or explore sustainable mechanised farming methods contact Unitrans Africa via email.