Sub-Surface Irrigation | DNA Systems
Sub-Surface Irrigation
DNA Irrigation Systems Investment
Limited Water Allocation Case Study
The following analysis is based on the results from a DNA Irrigation installation in the Ceres Valley, situated in the Western Cape Province of South Africa. Prior to installation, the trees were irrigated at 36 liters per hour. With DNA technology installed, this was reduced to 16 liters per hour, a reduction of 56%. As such, the water allocation previously required to irrigate 1 hectare can now irrigate 2 hectares of trees.
The increase in land value due to the conversion from non-arable to arable is notable. A R165,366 per hectare DNA Irrigation investment, will produce a 100% gain in irrigation capacity where the additional capacity is currently valued @ R250,000 p/hectare.
This is an immediate financial gain of R84,634. Even with a limiting irrigation allocation, it is possible to effectively double the irrigated land size.
The additional yield from the extra hectare that can now be utilized is 65 tons of apples per annum. At R4,000 per ton, this equates to additional revenue of R185,000 per year.
In addition, weeds died off naturally from lack of surface water and became mulch.
Sub-Surface Zonal Irrigation
- Each tree / vine is now a specific delivery zone with its own specific volume of water and nutrients delivered at its own specific hourly delivery rate off a single main irrigation line.
- The area surrounding the “root bowl” is now a specific “delivery zone”.
- Savings on irrigation water enables farmers to increase the number of trees or vines for a given water allocation. This increase in farm capacity may be greater than 50%.
DNA Irrigation Systems Investment
- One Hectare = 1,666 apple trees
- Irrigation of 36 litres per hour per tree was reduced to 16 litres per hour per tree, a 55% reduction *
- DNA P1 units reduce water wastage and allow two trees to be irrigated with the amount of water previously used by only one tree, with a 9% cushion.
- Productive farm size is now twice the number of hectares with original limiting water allocation
- There is a substantial reduction in pumping time and power consumption. Savings of 50%+ have been achieved via the use of DNA sub-surface irrigation.
*Water saving based on 2023 Ceres farm installation / test
Cost of DNA Irrigation
Cost Per Tree / Costing per Hectare
| Item | Cost |
| DNA P1 two units per tree (R36.00 per unit) | R72.00 |
| Two pressure volume controllers | R7.30 |
| Class 3 main supply pipe 20mm / 1.3 meter (say) | R7.00 |
| Flexible supply line (300mm for two units) | R3.20 |
| Total peripherals cost per two trees | R17.20 |
| Total cost of DNA materials per tree | 99.20 per tree excl. |
– – – – – – –
| COST of DNA INSTALLATION PER HECTARE: | R165,366 per hectare excl. |
NB: the cost of doubling the irrigated farm size is just R165,366 per hectare
NB: an additional income of R185,000 per additional hectare can be expected
NB: the above assumes a yield of 65 tons per hectare / 100 tons per hectare is possible (CSRI)
Results
In Summary
DNA ENABLES 100% INCREASE IN THE PRODUCTIVE FARM ACHERAGE WITH THE ORIGINAL LIMITING WATER ALLOCATION:
- The DNA installation will double the available irrigated land size.
- Annual additional yield: 1 hectare becomes a 2 hectare farm @ 65 tons Apples / total farm yield now 130 tons apples.
- Annual additional revenue from the added 1 hectare (65 tons @ R4,000 per ton) = R260,000 per annum for 25 years
- Increase in land value from non-arable to fully irrigated, additional one hectare productive apple orchard valued at R700,000
- The 1 for 1 orchard gain via DNA Irrigation will increase the farm retail value by 80%+
CONVERTING 1 HECTARES LAND WITHOUT WATER TO THE DNA SYSTEM WITHOUT FARMING:
- Cost of converting 1 Hectare to DNA is currently R165,366 per hectare
- Currently, average farm land with irrigation water is R250,000 per hectare
- There is an immediate financial gain of R84,634
- Return on investment: 151%
BENEFITS FROM USE OF DNA IRRIGATION SYSTEM: (Estimated)
- 10 hectare farm (say) now irrigating 20 hectares @ 250,000 water value per hectare = R2,500,000 gain
- 20% labour saving weeding
- 50%+ saving in weedkiller / marked reduction in weed growth
- 30%+ nutrient saving
- 50%+ reduction in pumping wear and tear on pumps
- 50%+ reduction in electricity
- NB: Annual apple tonnage gained on additional (say) 10 hectare = 650 tons x 25 years
- Farm appreciation of R7 Million + additional 650 tons fruit per annum
- Additional income @ R4,000 per ton = R2,600,000 per annum
Introducing the P1 System
Sub-Surface Zonal Irrigation
Introduction to P1 system
- Sub-surface irrigation is the most efficient technology for irrigating fruit trees and vineyards.
- The DNA Irrigation system produces efficiencies and enhanced returns that quickly pay back the initial investment.
- The DNA system utilizes UV resistant Polypropylene plastic with an expected lifespan of 20+ years with reasonable use.
- The DNA system enables “short cycling” irrigation, producing water savings and reduced pumping times of 50%+.
- Using sub-surface zonal irrigation, the farmer can closely control the volume of water and nutrients going directly to the root bowl.
- The DNA “deep root irrigation” ensures optimal root bowl temperatures and root bowl health in hot climates.
- Healthy trees ensure quality fruit and maximum returns on the orchard or vineyard.
- The DNA technology also offers additional advantages where every tree / vine can receive specific water and nutrient rationing by
volume – one tree or vine potentially differing from the next according to requirements – off a single main supply line.
- Each tree / vine is now a specific delivery zone with irrigation water and nutrients delivered directly to the root bowl.
- The reduction in pumping times can exceed 50%+.
- Power requirements are greatly reduced.
- NB: Savings on irrigation water enables farmers to increase.
the number of trees or vines for a given water allocation. - The increase in farm capacity for a given volume of irrigation water might be as high as 50%+.
The DNA system has two options:
- (a). of supplying a specific
controlled irrigation volume per hour, or - (b). the water supply can be unconstrained by a volume controller and is instead controlled via “short cycling” based on controlled pumping times.
Both options (a) and (b) bring benefits and ultimately, soil conditions will determine. This water flow is controlled by the dripper assembly “fins” and drips off the bottom of the fins. Specifically, the soil surrounding the fine root bowl system is not washed away or disturbed. Importantly, the dripper assembly causes a drop in water pressure.
Installation Connecting to Existing Surface Dripper Piping
It is an easy matter to convert current surface mounted ”drip feed” systems to a water-efficient sub-surface drip feed system. The farm will now benefit from zonal irrigation without having to change the existing surface dripper piping.
- NB: The flexible feeder lines are shown here for the purposes of illustration but typically these would be buried just under the surface.
The sub-surface system requires only one water supply line. Installation is quick and easy to maintain. There is a reduction in piping, reduction in weed growth and savings on labour. The DNA system can accommodate and improve mature orchards / vineyards with existing irrigation systems – or – it can be installed up front with new plantings.
P1 Sub-Surface Zonal Irrigation System
Slow Release Soil Amending Medicator
The slow release soil amending medicator is an optional devise that is designed to be added or removed as required from the main body of the dripper assembly. The Medicator has two incoming water lines, one of which is the main feed to the dripper assembly (say) 8 litre per hour while the second incoming line feeds the Medicator at a lower rate of (say) 1 litre per hour.
- NB: Both Medicator lines are fed off the single main supply line.
Both the general irrigation water and the slow release medicated water are mixed within the dripper assembly body prior to root bowl delivery. In an orchard of say 10,000 trees, it might be found that (say) 60 trees are requiring soil amending such as additional nutrients or medication. The Medicator delivers slow release soil amending products over an extended period which might be a number of days. Once the trees have recovered, the Medicator can be removed and stored away until required again / the DNA Irrigation system will then revert to the normal delivery of water and other nutrients.
Introducing the P2 System
Soil Amending, Water Retentive, Mini-Reservoir
Deep-Root Soil Amendment Irrigation Technology
- DNA Irrigation is an Industrial Design Group dedicated to developing unique value adding technologies.
- The DNA Irrigation sub-surface moisture retentive reservoir combats water percolation in dry sandy soils.
- The DNA system offers deep root irrigation, is soil amending and produces healthy orchards, vineyards and valuable fruit.
- Sub-surface deep-root irrigation brings substantial water savings that can average 50%+.
- NB: A limited water allocation of (say) 20 hectares can now irrigate 40 productive hectares.
- The deep root DNA moisture retentive “reservoir” creates nutrient rich soils at the capillary root zone.
- NB: Farmers with percolation issues now have an irrigation solution that will cut extended pumping times by 50%+
- A general improvement in crop condition does bring obvious financial advantages to all.
DNA Irrigation Technology | Pre-Mix Materials
Agronomists now have the ability to optimise water and nutrient efficiency while still ensuring healthy trees and fruit. DNA Irrigation soil amendment technology is suited for use in any soil types or structure but it is most certainly especially valuable when used in dry sandy soils such as typically found in semi-arid or fully arid environments.
Currently, dry sandy soils are converted for agricultural use at great cost, often requiring that clays and other such materials are trucked in and mixed into the 0.5m top soil, using large machines at great expense / often with poor results. The DNA sub-surface reservoir is a cost effective method of soil amendment for dry sandy soils, altering the soil composition. The reservoir also provides instant on-going direct physical access to the root bowl region so that alterations or additional materials can be introduced to the root bowl region at any time, as and when required.
The water retentive reservoir provides nutrient rich moisture at the root bowl, the capillary and the general root systems seek out the reservoir in much the same way that farm animals seek out watering points. The ideal reservoir pre-mix will limit soil compaction within the reservoir body, this allows for a free exchange of nutrient rich moisture to the surrounding exchange medium.
- NB: The sub-surface mini reservoir maintains surrounding soils at optimum moisture levels for multiple days while also cutting pumping times, reducing overheads and wastage levels.
The pre-mixed materials / ingredients contained within the reservoir body are specifically chosen to meet the surrounding soil conditions while also accommodating the needs of each tree / vine.
NB: A typical sample of the dispenser pod pre-mix might contain any of the following in applicable percentages:
- Vermiculite / moisture retention, also adds structure producing drainage
- Superabsorbent Potassium Polyacrylate Polymers (SAP) / water retention
- Perlite, Leca / break up the reservoir content into draining and retaining pockets
- Nitrogen / Healthy green leaves
- Phosphorus / strong roots and blooms
- Potassium / encourage healthy plant growth
Vermiculite
Vermiculite is a naturally occurring mineral, it is sterile, non-toxic, will never go bad, it is resistant to mould and it can hold a lot of moisture. Adding vermiculite to the pre-mix provides soil structure, this limits compaction within the dispenser pod, increasing oxygen availability, while providing moisture retention and a free flow of nutrient-rich moisture from within the pod to the surrounding soils.
Vermiculite: Sterile, resistant to mould, adds structure and drainage.
Superabsorbent Potassium Polyacrylate Polymers (“SAP”)
NB. SAP’s create hydro-mulching within DNA Irrigation sub-surface reservoir and can increase surrounding soil moisture by 32% while reducing pod pre-mix density by 8.5% compared to native soils.
“SAP” is mainly used for agriculture and has 3 advantages:
- SAP (Kalium) has a beneficial effect on plants;
- SAP will not cause soil salinization;
- SAP is nature friendly and environment friendly.
Potassium Polyacrylate
- For fruit trees, Potassium Polyacrylate (“SAP”) can increase yield and reduce the fruit cracking rate. With young trees or transplanted tree species, it can improve the survival rate.
- The SAP is available in agricultural specifications where there is a starch component making it bio-degradable and it will continue to decompose in the soil. The decomposed material is water, carbon di-oxide and ammonia gas and this will not pollute the soil, further it is non-toxic to the human body and the pH value is neutral equal to 7. NB: When mixed with “slow-release fertilizer“ or “bacterial fertilizer activator“ it will perform the function of a slow release
agent for slow release fertilizer. - Several water-soluble fertilizers such as urea, auxin and root agents (strong acid and alkaline products cannot be mixed) but they can be dissolved in water and by adding potassium polyacrylate particles to the solution to absorb it, you have (as mentioned above) the advantage of a slow-release fertilizer for fertilizers.
- The reservoir prevents the loss of fertilizer and medicine and achieves the triple effect of balanced water supply, fertilization and drug administration. This significantly improves the efficacy of fertilizer and medicine, and reduces the amount of fertilizer and medicine required.
Soil Amendment Technology Offers The Following
- Advantaged Agronomy
- Deep-root soil amendment
- Deep-root nutrient distribution
- Deep-root zonal irrigation
- Close control on water usage
- Moisture retentive materials
- Controls sandy-soil water loss
- Reduction in fertilizer usage
- Pumping time cut of 50%+
- Electricity saving of 50%+
- Irrigation saving of 50%+
- Labour saving of 20% (estimated)
- Fast and easy installation
- UV protected long lasting HDPE / PP material
- Reduced surface salts build up
- Increased usable irrigation water of 50%+
LECA
Leca, “light-expanded clay aggregates” has been in use for a long time. Leca pebbles are tiny clay pebbles that are quite light. If you crush one, you can see that the inside is very porous, filled with a lot of air, and has a hard clay shell surrounding it. Leca is typically dominantly placed towards the bottom half of the pod. This spread of Leca can significantly enhance pre-mix drainage since nutrient rich water passing through the pre-mix will exit the pod along the full length of the pod with the greater volume exiting the pod in the lower half, carrying nutrients and oxygen.
- Leca in the DNA reservoir pre-mix soil aids in the long-term preservation of the pre-mix structure. This implies that the premix will not deteriorate or get more compact with time.
- Leca is not water retentive, the use of Leca in the pre-mix guards against pre-mix compaction within the reservoir. Importantly, it helps with water drainage from within the reservoir, outward to the surrounding soils and very importantly, it assists with oxygenation of these soils.
- Usually, when you apply fertilizers to your soil, they come in the form of salts in your water. These salts need something to grasp onto so the roots can absorb them. Unfortunately, Leca has a very low, almost zero cation exchange capacity (CEC), which means it is not good at binding nutrients. However, it is important to note that Leca does not significantly impact the CEC of soil, this will assist in delivering nutrient rich water from within the pod to the surrounding soils.
- Although the cation exchange capacity of the organic material is high, the Leca’s value is relatively low. Consequently, we advise using Leca at a ratio of 1 to 5 (Leca to pod pre-mix). Most of the time, it is preferable to place the larger Leca towards the bottom of the pod and mix the smaller Leca with the bulk of the pre-mix material. Ideal transfer from within the pod to surrounding soils can be achieved in this manner
Perlite
- Perlite is durable, clean, lightweight, and simple to use. It is neither acidic nor alkaline. Perlite is highly porous, and due to its expanded nature, it can help with drainage.
- Adding perlites to your pre-mix can improve drainage from within the pod, allowing more water to escape from the pod and giving your roots more oxygen.
- It is advised to add 20 to 30 percent of perlite to your pre-mix mixture by volume.
- Generally speaking, Leca and Perlite add are both excellent choices for adding to the pre-mix as they do enhance drainage and limit pre-mix compaction.
- Perlite has a very low cation exchange capacity (3 meq/100g), which is also something you need to be aware of when adding it to your pre-mix material.
Pumice
- Pumice helps aerate the soil while also assisting in the absorption and gradual release of water. It has ideal drainage while maintaining the proper balance of water and oxygen.
- Pumice will preserve water, functioning as tiny sponges to collect the nutrient-rich water and hold it until the soil needs to be hydrated while also bringing oxygen to the root zone and promoting air circulation.
- Pumice does not dry out rapidly.
- Pumice retains moisture for a slightly longer period, this can be advantageous when the ideal percentage is used in the pre-mix material.
- The recommended amount to utilize pumice in your pre-mix is 20 to 30 percent of the soil mix volume.
NB: DNA pre-mix structure is determined by the immediate needs of the surrounding soils and type of trees / vines etc.
Bottle Exploded View
- The standard dispenser pod will hold 3.5liters of nutrient and water retentive materials.
- The pod is split into a top and bottom half, this is so that the bottom section can be replaced with a longer section that will increase the internal volume of the pod if required.
- This additional length will also increase the depth to which the dispenser pod will enter the soil, accommodating trees of differing sizes, age, type and root configuration making the device compatible across a wide range of species and also soil conditions.
- The device is long lasting and hardy, it is designed for commercial use on farms or private homes.
The DNA system has two options:
- of supplying a specific controlled irrigation volume per hour or
- the water supply can be unconstrained by a volume controller and is instead controlled via “short cycling” based on controlled pumping times.
Both options (a) and (b) above, bring benefits and ultimately, soil conditions will determine. Each tree / vine is now a specific deep root delivery zone with its own specific volume of soil amending matter, rich in nutrients and moisture. Water bourn nutrients and live soil enhancing microscopic matter, leaches out from within each sub-soil reservoir. Nutrients are delivered at a specific rate in accordance with the needs of each tree / vine from a single main irrigation line. The soil surrounding the “root bowl” is now a specific deep-root “delivery zone”. NB: Savings on irrigation water enables farmers to increase the number of trees or vines for a given water allocation. This increase in farm capacity might be as high as 100%+.
Diagram View
