Activity Tasks :
March 11th : In a small group we removed all Poa labillardierii and Lomandra longifolia from the bed. We used mattocks to form a circumferential trench around the grass and then levered the grasses out of the ground. We set these aside for division, propagation and planting elsewhere. We then started weeding out the rope twitch, which is extensive in this bed due to its rhizomatous growth habit and the lack of any form of cultivation in this bed for some time. We discovered localised areas within this bed of very poor drainage and water logging. The soil dug up in these areas had a nasty smell indicating quite poor anaerobic conditions. In addition, all the native pelargonium was pulled out using a pitchfork. We had not previously located and isolated the irrigation system in this bed and I caused a puncture in the poly pipe which required repair the following day.
March 12th : With assistance from Roy Baker, we repaired the puncture in the irrigation system. This was done by first digging a trench with a shovel and exposing the site. We cut the section of pipe with a hand saw and later Roy obtained replacement piping which we cut to size, filing the edges and attaching to the two ends with plastic couplings. This was a cheap and reasonably quick process. We then flushed the entire section of the irrigation system to remove internal debris and cleaned the filters on each sprinkler.
March 17th : We continued the process of manually weeding out the rope twitch present with a pitch fork and exposing the irrigation system fully to prevent further damage to it. We then carried out some pH testing using battery operated metres. These metres were calibrated first with known neutral (pH 7.0) solution. A 20g sample of soil was then mixed thoroughly for
about a minute with 100mL of distilled water, making sure no organic matter contaminated the soil sample. The meter was placed in the solution, being careful to avoid placing the meter in the soil sediment. To measure the pH we tested a couple of different sites in the bed instead of doing a composite analysis (soil samples taken from many different points in the one site and mixed together). This was because the soil profile at various sites demonstrated it was not
an homogenous area. Results are seen in the photo below.
In the main border there were mixed pH readings of 6.3 and 7.4 where the westringias and hakea had been growing respectively. In the carpark border, pH 6.6 in the clay loam and 6.3 in the sandy loam. In the car park side border, pH 7.3 where a sad acid-loving camelia was growing and 6.4 on the other end.
Soil texture analysis in this bed showed areas of sandy loam to clay loam.
March 18th and 19th : Worked on the main border where turf had been removed for a new section of this border. This area had a hard clay based soil which required breaking up first with a square mouth shovel. Shallow root masses were removed with a garden fork and then a pick-ended mattock was used to break up the clay even further. This was quite a physical exercise and proved more efficient when we worked in sequence, one person following on from the other person in a given area. We then leveled the bed as best we could with a metal rake, using the bottom end to level and the toothed end to break up clods and rake up surface debris. The last job was to place compost which had been previously calculated by the cubic metre in piles one metre apart and then spread by metal rake over the bed to a thickness of about 100mm.
OH&S issues : Constant issues included presence of cars and general public accessing area. These were addressed by wearing high visibility vests, placing signs and fluorescent witches hats around the area. There were no underground electrical issues in this bed. Holes left behind following the removal of the grasses became an issue and had to be addressed by leveling these holes. Risks of exposure to sun, potential allergens and insects was managed by wearing the appropriate P.P.E. Unused tools were placed in a corner leaning on a wall cl
ose to but away from the work site to prevent injury. Risk assessment sheets were completed for each day. Examples in photos below :
P.P.E. : full sleeve shirt, broad brimmed hat, glasses, steel cap boots, long trousers, fluorescent vests.
Environmental Work Practises : Proper disposal of the rope twitch had to be thought about to limit its spread. We used separate bins for the rope twitch and transported this to a separate section of the compost area. Solarisation by exposure to full sun is a safe and environmentally sound method of disposal of rope twitch. We ensured that we cleaned all equipment that we used prior to returning them to prevent spread of the weed.
Reflection : It's important to know the location and isolate any underground piping or cables in an area being cultivated. We could have asked for the plans for the irrigation system before we started digging up the area. We could consider using the herbicide fusilade (targets monocotyledons non-specifically) but this would make it difficult to grow other grasses in the bed. Working efficiently means knowing how to use a hand tool effectively, with the least amount of physical exertion and working in a co-ordinated fashion.
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