DFM Software Solutions cc Highly Specialized End-User Applications for the Agricultural Market Tel / Fax: +27 21 904 1154 PO Box 730, Eerste River, Cape Town, 7103 Email: dfm@dfmsoftware.co.za 124 Fairview Road, Penhill, Eerste River, Cape Town, South Africa, 7100 THE DFM CONTINUOUS LOGGING SOIL MOISTURE PROBE -FUNCTIONAL SPECIFICATIONS 2010-
Background: It has been noted and acknowledged that there is a growing demand for irrigation scheduling, in order to timeously calculate water dosages when trying to avoid under-and-over irrigation. With several types of soil moisture monitoring devices (i.e. soil moisture probes) being manufactured globally, it was found that they were either: Inaccessible to local farmers Were expensive and not cost effective Or had little or no impact on the decisions made when it came to irrigating Different perceptions exist between irrigators regarding the definition of irrigation scheduling and its implementation on the farm. Amongst these imminent issues, it was found that a negative relationship exists between the use of subjective scheduling methods, like intuition and the irrigation scheduling figures that would be reported in the form of data from various probes being used. Computer models used for irrigation management decisions incorporate and link formalized knowledge from certain practiced disciplines. This allows for the making of complex calculations that would otherwise never be realistically carried out, also noting that the implementation has often been restricted due to their complexity. With the ever increasing and impending water restrictions that are being placed on farmers (specifically speaking), it became essential to be able to plan ahead and use the resources available. When taking this into consideration, one would like to cut down on costs whilst attaining a higher yield on harvests. The implementation of irrigation scheduling would not appear to be complicated noting that there are many alternatives that one could use, however, many farmers make use of a number of different methods and combine these to make better informed decisions. The problem with this is that there is often room for error and misinterpretations, which may lead to miscalculated decisions. The DFM Continuous Logging Soil Moisture Probes (hereinafter referred to as the DFM Probe) has thus been manufactured with the above mentioned in mind. Due to our wide network of agents situated throughout South Africa, we are able to distribute our product nationally at low costs to our clients. Whereas most probes are sold within the region of +/- 800 American dollars (the equivalent of R6000), we have cut production costs down to a minimum, thus halving the price of what a standard conventional probe would cost. The DFM Probe allows, with the use of data controlled flow charts, easier interpretation of data using our end-user application; namely DFM Probe Utilities. The improvement from previous models is that continuous logging as opposed to the previous snap shot readings as well as effective depth wetting which is now manageable, leads to more effective and
efficient irrigation. The continuous readings fill in the gaps and show events that could never be seen with conventional monitoring devices. Hence, root zone management is made accurate, affordable and effective. The constant change between Micro and Drip irrigation can be easily managed as the volumes of the area become smaller or larger. This is done by means of effective management on depth irrigation which can be readily calculated by data interpreted from probes. As mentioned before, the complexity of a program designed to incorporate and link formalized information can be somewhat daunting when unfamiliar. DFM Software Solutions has taken this into account Our interface, although complex in the background, is user friendly and easy to interpret in the foreground, allowing for better data flow and its management and interpretation thereof. The technology level of the farm, size of the farming operation and the types of crops produced on the farm determine the selection of the scheduling methods. Corporate farming enterprises and farms with high valued crops are often inclined to invest in precise irrigation scheduling methods. As there is now a market for precision irrigation scheduling, DFM Software Solutions is now one of the leading competitive distributors of soil moisture probes within South Africa, with more than 10 years of experience behind our name. Functions pertaining to the DFM Continuous Logging Soil Moisture Probes When taking into account the harsh African sun, the casing of the probe was designed to with stand heat and direct sunlight for up to 60 degrees Celsius. The outer shell of the probe is made of UV stabilized PVC whilst the inner shell (cast from solid resin) can withstand temperatures of between 70 to 80 degrees Celsius. The head of the probe (which is exposed to the most sunlight) has a 3mm thick UV stabilized PVC top cap, which can also withstand harsh climates. As opposed to other probes found on the market, the DFM probe itself can keep a backup of its data for up to six months when set to default (hourly interval readings). Our clients are able to perform the necessary maintenance on their probes themselves, which makes it more cost effective and independent of consultation fees etc. The DFM probe, capable of measuring up to 1.8m s deep, is not influenced by salinity levels making the data more reliable. Some of the advantages pertaining to the use of continuous logging probes can be summed up into the following factors: Continuous logging: Helps prevent over and under watering whilst promoting root development Creates a balance between air and water whilst preventing unnecessary crop stress Improves fertilizer uptakes whilst optimizing salinity management Saves on energy costs whilst sustaining resources such as water and electricity Facilitates crop manipulation Manages soil water buffer
Informed irrigation decisions can be made with the aid of the DFM Probe Utilities, converting these decisions into improved Yields, quality and profitability which is something many of our clients will agree upon. How is this possible you may ask? Put simply, this can be done by keeping the soil water content within an allowable depletion level in order to achieve optimal transpiration and yield. What would be the implications of over irrigating should one not use a DFM probe? Should there be an excess of water as a result of over-irrigation, the free water surrounding the plant pushes out available oxygen whilst smothering the root system. The plants stomata will eventually shutdown with the following results: The plants metabolism will begin to slowdown Poor nutrient uptake occurs Nutrients are lost via percolation Pathogens become a direct result Unnecessary water is wasted Resources such as electricity are also wasted Over- irrigation is thus a major setback for roots, crops and trees and recovery becomes very slow. Each time the above mentioned conditions occur, crop development is impacted greatly end a decrease in yields pertaining to the crop can be recorded. Applying surplus or deficit water to selective sections of the root zone stimulates vegetative growth for seasonal crops and stimulates reproductive growth for fruit production. To manipulate water availability, one has to accurately measure the water use of the plant. It is essential to know exactly how much water the plant is using. Traditional crop factors and evaporation may give a general indication but the actual water use varies significantly from site to site depending on the stage of growth of the plant, row spacing or crop density, as well as the terrain etc. Under irrigation can often lead to a shutdown in the plants stomata as well with some effects such as water buffer deficits, physiological disorders (i.e. fruit size, fruit drop and creasing) as well as salt accumulation. This is indeed a setback for crops but the recovery is not as drawn out. In fact, one of its advantages is that it promotes root growth. With real time measurement, we can make an informed decision on the following factors: Where are roots active? How deep are we irrigating? Are we over / under irrigating? Are we using or loosing fertilizer? Are our plants active during heat waves? How long since we last leached? How effective is rainfall?
Linked with DFM Probe Utilities, the client is able to view the latest probe readings or probe history on his personal computer without being forced to connect to the internet or any other WAN / LAN system, as these are not always available. Furthermore, the programme can be used without the aid of a third party or consultant. It is important that the client can operate the system independently, but in turn, an independent consultant should also have access to this data to assist the client in making the right informed decisions. Often, this is an option that is available to many of our client, of which they more than not make use of. To give the consultant access to the probe data, the following options have been made available. For farms with email access, an intelligent mailing system has been designed to synchronize the consultant s database with the client s database, at no extra cost. If no email access is available on the farm, the consultant is able to create a dialup connection to the central point radio to update his database, as well as send back relevant settings and parameters. A great advantage to using DFM Probe Utilities is that no crop relevant data needs to be setup, i.e. crop factors, canopy ratings or root system evaluations. Everything is automatically incorporated in the real-time readings taken by the probes. They also take into account weather conditions, salt contents, soil layering, water runoff etc. All these factors are built into the process of interpreting the data whilst eliminating the unknown. DFM Probe Utilities calculates the actual crop factor of the plants in their environment, making it an ideal basis of calculation to work out a 7day irrigation schedule. With this, one can clearly see that no two fields have the same crop factors. The actual crop factor and daily water consumption figures will clearly show the health status of the plants and the software will point out irregular water usage. Whilst some clients have reported feedback of yield increases of up to 40% and energy savings of up to 16, 6%, others reinforce the idea that they could not have imagined the difference the DFM probe has made in their practice. From the many systems we have installed locally and internationally, the DFM probe continues to gather momentum in its reputation, whilst we will continue to find new ways of finding solutions to the problems experienced by the agricultural industry. We gladly welcome any feedback you may have. Alternatively, you can view our website at the following address: www.dfmsoftware.co.za