Briant Orchard Irrigation Case Study
AgFirst Engineering was approached to design an irrigation system for 10 hectares of Kiwifruit, with provision in the system to allow for future expansion of 20 hectares of orchard.
There were some key considerations that needed to be taken into account when designing the system. Due to the heavier nature of the soils onsite, a key consideration was to reduce rutting issues down orchard rows with the use of orchard machinery as this has proven to be a big issue with orchard operations in this area. The Briants’ required a high quality system providing precise application of crop wailer requirements. Automation was another key factor, however the system needed the ability to be monitored and easily adjusted according to the specific requirements onsite.
AgFirst Engineering chose a high quality drip tube product from Israel that has high application uniformity and has the most developed dripper filtration technology on the market to avoid dripper blockages. The product selected ensures that the water is applied as a concentrated application on each orchard plant row. Due to the high water demand at specific times in the growing season in the Kiwifruit orchard, a high drip emitter flow rate was selected at close spacing to ensure the desired volume of water can be applied in a short time-frame.
The initial Kiwifruit development is divided into nine irrigation zones, with the ability to run two zones at once.
As there are three different soil types present on the block, soil moisture monitoring was installed on each soil type to enable the monitoring of available soil moisture levels for each different soil type. The soil monitoring is connected to telemetry, where each soil monitoring site is displayed with real time data that is easily accessed on the internet. This enables the Briants to precisely know when to start and stop the irrigation system and to help schedule the amount applied in each application. This has proven to be a big success.
The system is automated with a user friendly controller and infield hydraulic control valves. The controller enables simple adjustments of runtimes and run days according to the onsite requirements that are monitored.
Irrigation water is pumped from the Waipaoa River. An automated disc filtration unit was installed to prevent the drip emitters from blocking and to also minimise the amount of time required to maintain the filtration system. The automated unit has a bank of disk filters which automatically backflush on a time basis or once the pressure differential across the filters reaches a specific level.
An automated fertigation unit was installed at the pump site that is linked into the controller to apply fertiliser when irrigating. This is another factor why drip tube was selected as it provides an application of fertiliser directly to the plants root system, minimising fertiliser wastage.