Table of Contents
|Title:||Possibility of Using Ceramic Pots Manufactured Locally in Irrigation Applications|
|Authors:||Al-Mohammed, Fadhil Mohammed|
|Type of Study:||Experimental|
|Journal:||Journal of Kerbala University, Volume 13, Issue 2, 2015, 172-183.|
Objectives of the study
“The main objectives of this paper are to examine seepage volume through the local manufactured ceramic pot’s walls and surface wetting edge around the pots under different conditions and to study viability of applying ceramic pot irrigation in loamy sand soil.” 
|Type of experiment:||Lab study; On campus field study|
|Place:||Technical Institute of Karbala, Al-Furat Al-Awsat Technical University (32˚ 34′ 35” N, 44˚10′ 24” E)|
|Timespan:||19.12.2013 – 8.4.2014 (winter season)|
|Crops:||Green onion (no more information provided)|
|Soil Type:||Loamy sand|
|Number of pitchers:||9|
|Parameters analysed:||Seepage volume, surface wetting edge, yield response, root distribution|
2. Materials and Methods
3. Test Procedure
4. Results and Discussion
4.2 Radius of Wetting Edge
4.3 Yield Response
4.4 Root Distribution
6. Recommendations for Further Studies
Note: Acknowledgement and References are both numbered as section 7.
Description of the experiments
Nine pitchers purchased from local markets were used in this experiment.
|Pitcher||Volume (ml)||Height (cm)||Average wall thickness (cm)||Maximum outside diameter (cm)||Neck diameter (cm)||Base diameter (cm)||Surface area (cm2)|
|1-9||~ 3.150||~ 37||—||19||—||10||—|
|Depth (cm)||Bulk density (kg/m3)||Specific
|Soil moisture content (cm3/cm3) under -10kPa and -1500kPa||Moisture
Note: The description of the experimental set-up is incomplete, sometimes incrompehensible and confusing. Information is not fully provided in section 3 labeled “Test Procedure”, instead the reader has to gather information distributed all over the paper to reconstruct the exact experimental set-up. The set-up itself displays several flaws, see comment section.
The plot size of the experiment was 10m x 20m. “Seepage volume and wetting edge experiments were carried out in winter season during the period from 19-12-2013 to 8-4-2014 by using ceramic pots with three replications. Tests for comparison were done for three cases.” 
Case 1: The clay pots were exposed to atmospheric pressure.
Case 2: The clay pots were buried in the soil.
Case 3: The clay pots were buried in the soil “with planting the wetted surface soil surrounding the ceramic pots with green onion transplants.” 
“Experiments were supplied with water from a main tank which is supplied with water from the city main pipe of potable water supply network.” 
In cases 2 and 3 “a planting hole about two times as deep and three times as wide as the ceramic pot was adopted.” 
In case 3 “green onion plants were planted in the wetted area surrounding the buried clay pots after three days of the operation of the ceramic pot system as shown in Fig.(3). Green onion plants were arranged with a unicenter circles in a radius 10 cm, 18 cm, and 26 cm in 12, 22, and 32 plants respectively. Crop spacing and cultivation procedure were as per horticultural recommendations (…)” 
Note: No details are provided concerning the question if the planting description applies to each of the three pots or if the numbers “12, 22, and 32 plants” relate to individual pots so that 12 plants were planted around pot 1, 22 around pot two and 32 around pot 3. Based on some images it seems that around each of the three pots three plant circels were planted.
The seepage volume was calculated “at any time by multiplying the vertical distance for water falls down by the cross sectional area of the water supply tank.” 
“The wetted area that surrounding each ceramic pot was measured in 12 constant radial lines by
using graded ruler, the average value was adopted.” 
Seepage values “vary with the interaction between the ceramic pot and its environment. The average accumulated seepage volume values for the first, second, and third cases are 159.6 l, 239.8 l, and 316.5 l respectively. The difference of accumulated seepage volume between the second and third cases is 76.6 l, which represent the effect of green onion consumptive use during the period from plants to harvest.” 
Radius of Wetting Edge
This concerns the experimental cases two and three.
“Field observation shows that wetted surface area is surrounded the ceramic pots for the second and third cases. After 38 days it has been noticed that these areas became dry for the second state ceramic pots as shown in Fig. (7). Observation were shown that these wetted areas still continue for the third case ceramic pots which is due to the canopy which is responsible for decreasing the direct sunlight. Radius of wetting Rw may be defined as the horizontal distance between the axial line of the clay pot and wetted edge for the surface wetted area that surrounds the clay pot. Knowing Rw may help us designate the area which is used for planting different crops. The results showed that the average value of Rw after 35 days is 33.6 cm.” 
“the average value of Rw [radius wetting edge] after 35 days is 33.6 cm.” 
This concerns only case three.
“the average yields, water requirements, WUE are 2.9 kg, 316.5 l, and 9.1 kg/m3 respectively.” 
“(…) the green onion plants had formed mats of roots all around the ceramic pot without penetrating the wall of the ceramic pots (…). 
“Observations have also shown that the green onion have shallow rooting.” 
The author provides a list with ten points in the conclusions section of which nine present selected results, no conclusions. Only no. 7 might be regarded as a conclusion, but see the comment section.
“Ceramic pot system is a suitable irrigation system to irrigate green onion in loamy sand soil.” 
The study displays several flaws which are discussed in the following.
The author states under nos. 1 and 2: “The seepage volume for the first case increases gradually per the first 100 hrs, after that seepage volume values becomes relatively stable with oscillation.” “The seepage volume values for the second and third cases increases at the beginning of trial, these values decrease slowly towards the end of the experiments.” 
The max. yield variance in “case 3” is 26.5% but the author does not address this significant divergence.
Recommendations for Further Studies
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