Oranges [photo] 


OFOS: A workable solution in fruit production

There is a close, reciprocal relationship between yield and quality of fruit. High yield almost always leads to the production of a poorer quality fruit. Despite the fact that factors such as climate, rootstock, origin of scion and irrigation affect the yield and quality of fruit, a balanced fertilizer programme plays an important role in the continuous production of high quality fruit.

In today's highly competitive markets, it is important to strike a balance between production and fruit quality. Therefore, fertilizer application has to adapt to the challenges within a particular region, as well as the market's specific quality requirements.

The influence of nutrients on yield and quality

Continuously high yields, pressure on the effective use of irrigation water and the consequent reduction in root growth puts pressure on available nutrients in the available soil volume. Consequently, the balanced application of such elements is extremely important.

Each nutrient has a specific effect on yield and/or quality. This impact is the core in Omnia's approach to balanced fertilization. Programme-based nutrition in continuous production systems creates the opportunity for high-tech applications that can be used easily and practically at farm level.

Optimising fertilizer with efficient irrigation management

Good irrigation management plays a critical role in the production of large, high-quality crops. When the producer puts more emphasis on his irrigation, production and quality increase accordingly. Although older orchards frequently have irrigation systems with limited delivering volume as well as frequency, pressure differences and are far from the water source, fertigation can now be successfully applied with minor changes and good governance. Irrigation systems dictate the viability of fertigation.

Irrigation pump room with Omnia liquid tanks

Irrigation pump room with Omnia liquid tanks

What is OFOS?

The Omnia "Fertigation Optimisation System" (OFOS) can be used in a wide range of irrigation systems, from the highly advanced short-cycle drip systems to simple long-cycle micro irrigation.

Sophisticated irrigation system supported by OFOS

Sophisticated irrigation system supported by OFOS

Scientific work done in the last century by Professor Martinez in Spain has proved that sap flow, as well as photosynthetic productivity, dramatically decrease in fruit trees in the days after irrigation. It is therefore important to maintain the right nutritional balance during the irrigation cycle. The success of OFOS lies therein that the right amount and concentration of nutrients in irrigation water are transported to the feeder roots. The concentration of nutrients in the irrigation water provides a significant contribution to fertigation, which makes OFOS unique.

The producer can manipulate the concentration of nutrients without numerous products or highly advanced injecting equipment. He can also manipulate the plant nutrient concentration between growth stages with minimal management inputs in order to meet the plant's requirements.

Omnia's extensive knowledge and involvement at producer level is used to develop workable solutions. The unique South African production environment, high technical standards and simplicity were accommodated with this development.

OFOS consists of different facets including the following:

  • specifically formulated products within a two- or three-tank system;
  • computer-based nutrition programme;
  • proven management and control system;
  • user friendly monitoring system;
  • plant nutrition concentration (Michaelis-Menten principle) as the basis;
  • science-supported recommendations; and
  • local agronomic research and support network.

The formulation of fertilizer mixtures to provide for certain plant nutrient needs is a common practice, but the CUSTOM OMNI™ product range has been formulated in such a manner that growers continue to keep the initiative in their particular circumstances.

The programme that the producer uses for his recommendation is very simple and a person with intermediate computer training can master it. The OFOS application is already in an advanced stage and is linked to a central database.

The management and control systems are also maintained within the OFOS software. By making simple inputs to the programme, extensive control and management information can be obtained. This information can help save costs as application and calculation mistakes are reduced. One of the control functions is to determine how much fertilizer was indeed applied over time.

The monitoring, especially of irrigation and plant nutrition, makes future recommendations easy. The progress of the fertilization programme can be carefully monitored throughout the season and hence timely adjustments can be made.

The development of the Michaelis-Menten concept, especially as researched by Bar Yosef, which underlies the management of nutrient concentration, has been used as the basis of the OFOS programme. The secret is the management of the concentration of elements in the plant nutrition programme. Such concentrations are specific for the soil, crop and growth stage. The OFOS programme can help the producer with this process.

Michaelis Menten concept

Michaelis Menten concept

By manipulating the concentrations of nutrients in OFOS, the programme makes a proposal regarding product selection, volume, dilution and application rate. Each element has optimum values in parts per million (ppm) where plant roots can optimally use such elements.

Customers who use this programme consistently give positive feedback regarding effectiveness in fruit quality. Furthermore, the continued high production from year to year is beneficial because the planning and procurement of packaging can be done better.

Subsequently, the programme has other benefits such as the central storage of block data regarding the soil, water and leaf analyses and yield which can be used during the season.

By Uys Meiring, Senior Technical Advisor: Specialities