Performance test of emitters made from sago midribs in drip irrigation systems

Increasing water use efficiency can be done by using the right irrigation system according to the needs of the plants. One option for efficient water supply is a drip irrigation system. The research aims to obtain conditions with high drip uniformity values. The study was conducted by testing the level of drip uniformity at several water source head pressures conducted with three replications. The indicator of uniformity is based on the coefficient of variance. The test results show that the uniformity value is higher at lower pressures than at higher heads. The uniformity value indicated by the coefficient of friction at high head pressure for the end and the middle section is better than the lower head pressure. The test results for the middle samples with heads of 19 cm, 62 cm, and 113 cm were 44.92, 23.40, and 9.16, respectively, while for the end samples with heads of 30 cm, 66 cm, and 115 cm were 46.39, 14.43 and 10.36, respectively. These values indicate that the relationship between head pressure and coefficient of variation is inversely proportional. The low coefficient of variation means that the water distribution is evenly distributed. So it can be said that using sago midrib material is feasible as an emitter. In addition, the resulting discharge value is small, so it qualifies as an emitter.


Introduction
Water utilization in agriculture needs to be done effectively and efficiently.This aims to overcome the limited availability of water.Increasing the efficiency of water use can be done by using the right irrigation system according to its needs.One option for efficient water supply is the drip irrigation system.The provision of water through this system is made directly on the surface of the planting media or continuously under the surface of the planting media with a low discharge [1].
The development of efficient methods of providing water to plants will continue to be carried out, starting from developing techniques and systems for regulating water use.In addition, the irrigation system also needs to consider techniques or methods that are applied or emulated by farmers on both large and small scales, which of course, by utilizing tools and materials that these farmers can reach.Therefore, a simple irrigation system is needed and can be made by farmers themselves, so innovation is necessary for the field of irrigation that is easy to apply and at a low cost.
Drip irrigation is a method of irrigating plants at a specific point, namely the plant's roots.Drip irrigation requires emitters that are designed to produce low water delivery.The drip irrigation system can save water usage because giving water is done little by little.In addition, drip irrigation systems can also save time because watering is done automatically [2].
Farmers usually utilize sago plants only to take sago starch from the stem as food or non-food ingredients, such as acetone-butanol-ethanol fermentation substrate, biodegradable plastic, sorbitol, MSG, and others.Meanwhile, the abundant sago midrib waste is still underutilized [3].So innovation is needed to reprocess the waste into valuable materials.The inside of the sago midrib, which has a cavity and can pass water, can be used by farmers to create a drip irrigation system as an emitter.
Based on the above issues, this research needs to be done to analyse the performance of emitters made from sago midribs in the form of water discharge and coefficient of variation and to determine the appropriate head pressure for the use of emitters made from sago midribs.This research is used as material knowledge for farmers to utilize sago midrib waste as emitters in drip irrigation systems.

Research tools and materials
The tools used in the research were scissors, a cutter, a stopwatch, vernier callipers, hoses, cross hose connections, digital scales, plastic cups, smartphone cameras, pens, and books.The materials used in the research are water, dry sago midrib, rubber, lighters, and heat insulation.

Research procedure
The research procedure that will be carried out is as shown below:

Irrigation Installation.
The first step of this research was to make an irrigation installation (Shown in Fig. 1).The emitters used were created from the inside of dried sago midribs with a length of 3 cm and a diameter of 1.7 cm for each sample.The sago midrib material was then wrapped using heat insulation to be paired with the hose connection later.The diameter of the insulation is adjusted to the diameter of the material used.The hose connection used uses a cross-type connection so that the water flow can flow towards the side, to the emitter, and to the hose, which is the head pressure indicator.The head pressure used varied.In addition, the planting distance between plants is adjusted to the general plant distance of 70×70 cm.The following is the design of the irrigation network used:

Performance test. The performance test is performed by calculating the following parameters:
1. Emitter discharge Discharge is the amount of water flowing in a unit of time that comes out through the emitter.Measurements are made by recording the amount of water the emitter releases at a specified time.The emitter output discharge is calculated using the following formula: where: Q = emitter discharge (m 3 /s), V = volume of water collected (m 3 ), t = time (s).

Coefficient of variation
The coefficient of variation of the emitter is a value that compares the standard deviation of the discharge produced by the dropper with the average amount of dropper discharge (Shown as Tabel 1) [4], where the coefficient of variation of the dropper in this study was calculated using the formula: Cv = s Qa (2) where: Cv = coefficient of variation of the emitter, s = the standard deviation of the discharge, Qa = average discharge (m 3 /s).

Data analysis.
The resulting data will be analyzed using the Microsoft Excel program.The objectives of analyzing the data are: 1. Knowing the feasibility of implementing emitters made from sago midribs in drip irrigation systems.2. Understanding the relationship between pressure and drip discharge.

Emitters made from sago midribs
The emitters are made from the inside of dried sago midribs (Fig. 2).This material can be used as an emitter because it has properties that can pass through water.The amount of voids in the material influences the ability to pass water.In addition, the property of passing water is expressed by the value of hydraulic conductivity [6], where the hydraulic conductivity value of sago midrib material ranging from 5.53 cm/hour -22.52 cm/hour has qualified to be used as an emitter.variation (%) when using emitters with high head pressure is good enough if applied to an irrigation system that has many points [5] because it has a value of 9.16% and 10.36%. Figure 3. shows that head pressure greatly affects the coefficient of variation.The difference in the variation value is due to the difference in force at the pressure head [10].A small variation value means the water discharge is almost the same at each pressure.In addition, it is known that the tip is more consistent in distributing water at a height of 60-120 cm.

Conclusion
Based on the research results, the discharge produced by emitters made from sago midribs is slight, ranging from 0.001-0.129cm 3 /s, so this material is suitable as an emitter in drip irrigation systems.The flow discharge produced by this emitter varies according to the sample section and the applied head pressure.The end and central areas with high head pressure had large mean discharge values of 0.129 and 0.080 cm3/s, respectively, and small coefficients of variation of 9.16 and 10.36, respectively.These values indicate that sago midrib material can be used as an emitter in drip irrigation systems.

Figure 3 .
Figure 3. Graph of coefficient of variation.

Table 1 .
Classification of coefficients of variation.