One aspect of precision farming is using technology for field levelling, commonly called GPS Levelling. This benefits commercial farmers with not only a more level farmland, but ultimately reduces soil erosion, saves water and helps with a more even harvest yield.

The Importance of Field Levelling in Drainage Design

Slope and topography are important considerations to think of in Agricultural Field Design. Although most agricultural fields are commonly perceived to be flat, gentle sloping undetectable by sight is usually present.  This then requires that Field Levelling is done before planting. By using agricultural software and GPS-guided equipment, precision Field Levelling can provide important benefits to commercial farmers in Field Layouts, especially when considering drainage design.

This is especially important in furrow irrigation, as used in many cane fields. With this process, it is important to have a gradual slope between the feeder and drainage furrows – typically around 0.5%.

Correct land design also eliminates ponding, which is detrimental to both crop growth, as well as field operations. Ponding alters the soil compaction in an area and is a prime spot for vehicles to get stuck in the mud after heavy rains. Even though plants need a good supply of water, high water velocity through the furrows can cause erosion of the soil, removing some of the nutrients intended for the plants. A good field design thus allows effective drainage, whilst keeping water velocity to a minimum and thereby allowing maximum uptake by the plants.

Some of the Benefits of Agricultural Software

The use of technology in agriculture has provided many advantages, amongst which are:

• Saving time – The move from laser to GPS levelling around 2007 has provided the ability to level larger fields in shorter time periods, due to less frequent establishment of a reference base.
• Better field design – An investment in precision software enables both accurate and more efficient field designs. Instead of a fixed gradient throughout a field, a varying gradient is used. This has allowed field levelling operations to be done, with the added bonus of moving less soil. This, in turn, increases working speeds and significantly lower costs.

Real-Time Kinematic (RTK) Positioning and Surveying

Before the field levelling process begins, an RTK base is set up to enhance the positioning of the GPS system in a global co-ordinate system. By installing standardised concrete benchmarks next to some of the fields, a permanent static point of reference for the surveying equipment is created. These permanent base positions (or markers) allow for fields to be surveyed annually from an identical position allowing accurate and repeatable results season after season.

Soil and land preparation are essential for GPS Field Levelling

Soil preparation is done before levelling to loosen the top soil. Ploughing and harrowing generally produce clean and well prepared fields, which are much faster to level, since the scrapers will easily be able to move soil to where it is required.

After this stage, the fields are surveyed by mobile rover, which maps the existing topography of a field. Based on the existing profile, the new field is designed using state-of-the art field design software. Gradients throughout the fields are designed to fall in a specific range, so that runoff is efficient but not too fast, all whilst top soil removal is kept to a minimum. The maps created by the design software are readily accepted by the control systems installed on the tractors and ejector-scrapers used to level the fields. The tractors are then driven via auto-steer systems while the soil scraping and ejecting is done by automated control systems linked to the GPS technology.

The advantages of Levelling

Field levelling is a practice which should be done regularly in order to maintain optimum field profiles. Farmers usually report increases in yield on fields which have been levelled, since nutrients and water are better absorbed by the roots and nutrient runoff is minimised.

Another major benefit of field levelling is accessibility by machinery, especially when guided by GPS steering. For example, in cane fields, controlled traffic is an increasingly common practice which restricts vehicle wheels to specific lanes between cane rows and can be readily implemented on accurately designed fields. This greatly reduces compaction in the soil where the cane roots grow, which, in turn, allows better growth and yield, even after multiple ratoons.

Unitrans Africa provides the complete Precision Farming Package

As part of a large range of agricultural services offered to clients, Unitrans Africa has developed significant experience in field design and GPS levelling over the years. First introduced in Kilombero, Tanzania, in 2000, the company has pioneered the use of field levelling in the cane industry in central and southern Africa and have integrated it as a tool to optimise cane production.

Field designs are incorporated on the Unitrans Africa cloud-based storage, which allows anonymous comparisons of various farming operations of individual fields, or even areas. This forms part of the Unitrans Africa undertaking into precision agriculture, and allows farmers to gain a complete set of information on their fields.

In addition, Unitrans Africa is proud to have built business partnerships with some of the biggest sugar companies on the continent. This includes Illovo Sugar Africa and Tongaat Hulett who amongst them have several sugar operations on estates across Malawi, Mozambique, Tanzania and Zambia, Unitrans Africa also recently concluded a major deal with Companhia de Sena, owned by Tereos, the second largest sugar producer in the world.

Together with other precision agriculture practices, which Unitrans Africa offers (soil sampling, VRA fertiliser application, drone surveying and yield mapping), GPS field levelling is part of the process to address all aspects of farming aimed at reducing costs and increasing yields.

Find out more about Unitrans Africa’s values of innovation, honesty, excellence, unity, safety and constancy, as well as how we might be able to provide comprehensive agricultural solutions to your farming operations by contacting them via email.