Chapter 10: Discussion & Conclusions for Native Flowers… ….… 201
10.3 Comparison of turf and native flower results
The experiments of growing the turf and the native flower specimens with specific greywaters sourced from the shower and the laundry were conducted as separate stand alone trials. Different soils were used because instant turf would in many cases be grown on a bed of sandy loam soil, whereas the native flowers would be grown in a garden bed. The turf specimens were subjected to greywater treatments through the four seasons, whereas the native flowers received greywater treatments during the cooler months. Scaly Buttons for 36 weeks from April 9, 2008 and Small Vanilla Lilies for 23 weeks from May 22, 2008. Some of the greywaters that were added to the native flowers differed to those applied to the turf species, notably the maximum urine level in shower water was halved to 0.5% v/v. Despite these differences some comparisons on how the turf and native flowers reacted to the treatments can be made.
The following Figure 10.5 is compiled from Figure 5.2 (Tall Fescue), Figure 6.3 (Kikuyu), Figure 9.2 (Scaly Buttons), and Figure 9.11 (Small Vanilla Lilies).
Tall Fescue (Spring) - 30/12/07 to 19/4/08
0 2 4 6 8 10
M/Gro Shower Water ECTW ECDR CPTW SHU CPDR SHU/5 Treatment
Average Daily Growth (g/m2 dry weight)
Kikuyu (Spring) - 29/2/08 to 16/4/08
0 2 4 6 8 10 12
M/Gro Shower Water ECTW ECDR CPTW SHU CPDR SHU/5 Treatment
Average Daily Growth (g/m2 dry weight)
Scaly Buttons (Foliage)
0 10 20 30 40 50 60
SHU/5 ECDR Water Shower ECTW CPTW CPDR M/Gro CPTW Shower
SHU/2 Treatment
Foliage Dry Weight (g)
Small Vanilla Lilies (Foliage)
0 5 10 15 20
SHU/5 ECDR Water Shower ECTW CPTW CPDR M/Gro CPTW Shower
SHU/2
Treatment
Foliage Dry Weight (g)
Figure 10.5 – Comparison of Turf and Native Flower results
Sampling of the turf clippings occurred several times during the experimental period which lasted more than a year, and so for each turf species one set of growth results from before winter are shown in Figure 10.5. The destructive sampling of the total foliage from the two native flower species could only be done when the growth experiment was ended. Despite the different sampling periods for these two independent experiments, the similarities between growth results produced by the greywaters and the reference treatments for all four species can be clearly seen. In Figure 10.5 above it can be seen that Miracle-Gro® solution and shower waters containing urine (SHU or SHU/2, and SHU/5) produced more growth in the turf species Tall Fescue and Kikuyu, and in the native flowers Scaly Buttons and Small Vanilla Lilies, than produced by Water and the greywaters which did not contain added urine.
The main difference in the treatments is that shower water containing 1% v/v urine (SHU) was applied to the turf species, and shower water containing 0.5% v/v urine (SHU/2) was applied to the native flowers. Compared to the constant amount of M/Gro that was applied each fortnight to the turf and the native flowers, the turf samples treated with SHU received a greater amount of total urine (and hence nitrogen), than the native flowers treated with SHU/2. The total amount of urine added to the turf was further increased because during the warmer months the watering often had to be done daily, while the native flowers, which grew during the cooler months, often did not need to be watered as frequently. Apart from the differences in growth results due to SHU and SHU/2, as explained above, all four plants were not harmed by the different greywaters and showed growth responses when treated with urine or plant food. The significant increased growth produced by Miracle-Gro® All Purpose plant food in the native flowers, especially the Scaly Buttons, confirms that these two native flowers can be grown successfully with the aid of high phosphorus containing commercial fertiliser.
The maximum level of 0.5% v/v urine was chosen for use on the native flowers after observing that during very hot drying conditions the turf samples appeared to be receiving too much nutrient when SHU was being applied daily. It is now considered that, for the native flowers, reducing the urine level was an error of judgement. It was overlooked that the major growth of the native flowers occurred during the cooler
months, when the requirement for watering was less frequent than if the growth occurred during the hot months. With less frequent watering less total urine ends up being added to a plant over an extended period. It therefore may have been feasible to have used the blend SHU (1% v/v urine in shower water) for watering of the native flowers, and this may have produced different results than those observed for these two species.