Liquid Organic Fertilizer Produced from Innards Waste of Catfish (Pangasius djambal) by Using Fermentative Microbes (EM4) and Molasses

Liquid organic fertilizer is a liquid fertilizer yielded from the decomposition of organic materials derived from varied wastes which contain more than one nutrient element. The study was aimed to determine the quality of liquid organic fertilizer made from catfish innards waste by adding fermentative microbes (EM4) and molasses. The research method used was experimental with different formulation consisting of 0% EM4 + 30% molasses (K1), 30% EM4 + 0% molasses (K2), 20% EM4 + 20% molasses (P1), 30% EM4 + 30% molasses (P2), and 40% EM4 + 40% molasses (P3). The percentage is calculated from the total weight of all raw materials used. Parameters measured include yield, pH, total lactic acid bacteria (LAB), Nitrogen, Phosphorus, and Potassium. The results showed that the best value for yield was shown in K2 at 34.73%, the pH value in P3 at 5.10, total amount of LAB in P3 at 2.104 cfu/g, the value of Nitrogen (N) in P3 at 4.30%, the value of Phosphorus (P2O5) in P3 at 0.41%, and the value of Potassium (K2O) in P3 at 3.11 ppm. It is possible to increase the content of phosphorus and potassium by adding with EM4 and molasses more than 40% each.


1.
Introduction Liquid organic fertilizer is a solution obtained by decomposing organic material in the form of plant residues, animal and human waste and contains many nutrients [1].Recently, the price of inorganic fertilizers has been getting higher, which can increase farmers' costs.Apart from that, inorganic fertilizers are addictive and can be dangerous, for example long-term excessive use can cause soil damage, hardening of the soil, water pollution and natural imbalance [2].The use of liquid organic fertilizer has several advantages, in other words the nutrients contained in liquid fertilizer are easily absorbed by plants and contain large numbers of microorganisms to overcome nutrient deficiencies [3].
Leftover fish or discarded fish can be used as raw material for organic fertilizer which has the nutritional value of N total, P2O5 organic and K2O organic found in the fish's body.If fish is not handled properly, the rest of the fish will be thrown away so that it cannot be used again and is wasted.Basically, fish waste is underused and thrown away, while the potential of fish waste, if used, will provide added value and can be utilized by processing it into liquid organic fertilizer.To anticipate this problem, there needs to be an innovation, namely using liquid organic fertilizer, which in this case can be used from fishery waste.
Currently, fish parts such as heads, tails, fins, bones and internal organs can produce waste from processing industries and households [4].Fish innards or belly contents are one of the wastes found in fish.Fishery waste usually consists of solid waste and liquid waste.Solid waste such as bones, heads, internal organs and even fish that are not the main catch can be a source of waste.This is because fish is a type of fishery product that easily declines in quality (most perishable food).The organs in the fish's body are called viscera, which are usually all parts of the fish except the muscles and bones.Fish waste weighs 10-15% (depending on the species) of fish biomass [5].The internal organs consist of the stomach, intestines, liver, gallbladder, pancreas, gonads, spleen and kidneys [6].The edible portion of fish is generally around 65%, leaving around 35% fishery waste [7].In general, the internal organs of fish generally contain a lot of nutrients such as nitrogen (N total), phosphorus (P2O5), and potassium (K2O), which are part of organic organic fertilizer [8].This waste is not utilized, so it is just wasted [9].Waste that is disposed of will pollute the environment, pollute the air and cause health problems for local people and this waste can be reprocessed into liquid organic fertilizer because it still contains the nutrients needed by plants.

Materials
The main ingredients used are catfish innards waste, EM4

Procedures
Making liquid organic fertilizer using catfish innards waste is carried out in stages consisting of preparing tools and research materials, then carried out using experimental methods, namely directly making liquid organic fertilizer with different formulations from catfish innards using EM4 as a bio activator and molasses as a source.nutrition of microorganisms.The parameters measured in the research were yield, pH, total lactic acid bacteria, nitrogen content, phosphorus content and potassium content.

The process of producing liquid organic fertilizer
Before carrying out the process of making liquid organic fertilizer, it is necessary to prepare the catfish innards waste [9], modified as follows: 1. Prepare tools and materials for making liquid organic fertilizer.2.Then, separate the catfish innards waste from foreign objects.3.After that, clean the remaining fish blood in the catfish innards waste with clean water.4. Chop the fish innards until fine. 5. Weigh the crushed catfish innards waste.Then proceed with the process of making liquid organic fertilizer from catfish innards waste as follows: 1. Prepare finely chopped catfish innards waste, fermentative microbes (EM4), molasses, clean water, and old coconut water.2. Mix all the ingredients into a transparent jar, then stir evenly (Researchers must maintain cleanliness and cover their mouths with a mask, so that they are aseptic).

Transparent plastic jar tightly closed with insulation.
IOP Publishing doi:10.1088/1755-1315/1328/1/0120193 4. Store in a shady place (not exposed to direct sunlight) for 14 days.5.After 14 days, the fermentation results are taken by opening the jar, filtered and its physical properties (smell, colour, etc.) and pH measurements are observed.6.Then the liquid organic fertilizer can be stored in transparent plastic bottles/clear glass bottles.7.So that liquid organic fertilizer is formed.
The process of of producing liquid organic fertilizer from catfish innards waste washing the catfish innards waste (b); filtering liquid organic fertilizer produced (c)

Formulation of the composition of the fermentation medium for catfish innards waste
The process of producing organic fertilizer from catfish processing waste using fermentative microbes (EM4) and molasses at different formulations can be seen in Tabel 1 below.
The formulation of the composition of fermentation medium for catfish innards waste is based on [10].In using variations in the concentration of EM4 and molasses.The determination of the levels of EM4 uses standards from the product usage instructions listed on the EM4 bottle and is then based on [9] with the addition of coconut water and clean water, in a ratio of 1: 7.

3.
Results and Discussion

The pH Value, Yield, and Total Number of Lactic Acid Bacteria
The pH value, yield and total number of lactic acid bacteria (LAB) in liquid organic fertilizer with different formulations using fermentative microbes (EM4) and molasses can be seen in Table 2.The pH value is one of the parameters that determines the final quality of liquid organic fertilizer.Based on Table 2, the highest pH value is 6.31 shown in treatment K1 and the lowest value in treatment P3 that is 5.10.Treatment K1 was significantly different from treatments K2, P1, P2, and P3.The pH factor plays a very important role in anaerobic degradation [10].Organic materials can be broken down by bacterial activity such as lactic acid bacteria which produce organic acids such as lactic acid and acetic acid.These organic acids are formed when proteins, carbohydrates and fats are broken down [11].General applies to all treatments where the pH drops at the beginning of the organic material decomposition process and rises again.The activity of bacteria producing organic acids such as lactic acid, acetic acid and pyruvic acid lowers the pH value at the beginning of the organic decomposition process.The formation of organic acids is the result of the decomposition of organic materials into lactic acid by LAB.
Enzyme activity that produces organic acids such as amino acids will cause the pH to decrease during the decomposition of organic materials.This is related to the mechanism of the enzymatic decomposition process, namely changing complex organic materials into simpler organic materials in the form of organic acids, thereby increasing the pH of liquid organic fertilizer.The acidity (pH) during the fermentation process is influenced by the amount of lactic acid, so that the more lactic acid bacteria there are, the lower the pH will be during fermentation [12].
The pH data shows that the pH in liquid organic fertilizer with a different formulation from catfish processing waste with the addition of fermentative microbes (EM4) and molasses meets the pH standard of 4 to 9 from the Decree of the Minister of Agriculture of the Republic of Indonesia Number 261/KPTS/SR.310/M/4/2019 [13].
The highest yield was shown on the K2 treatment, namely 34.73% and the lowest was in the P3 treatment, namely 25.04%.Liquid organic fertilizer products from catfish processing waste using fermentative microbes (EM4) and different molasses formulations have a significant effect on the yield where the K2 treatment is significantly different from K1, P2 and P3, however, K2 is not significantly different from P1.
The higher the concentration of EM4, the higher the yield produced, but the addition of molasses has no real effect on increasing the yield of liquid organic fertilizer.This is in accordance with the anaerobic process of the EM4 bio-activator which can decompose up to 70% of the raw materials, so that most of the raw materials decompose into liquid [14].Microorganisms not only break down organic materials into simpler ones, but also use organic materials for metabolic activities [15].
Anaerobic composting can decompose almost all organic materials [16].In addition, the EM4 bioactivator ingredient contains lactic acid bacteria cultures.The function of these bacteria is to help break down materials that are difficult to decompose [17].Research results [18] state that long composting increases the activity of microorganisms which absorb water and oxygen from the air, then convert carbohydrates, fats and waxes into water and CO2, so that the water content in the compost becomes higher.
It can be concluded that the highest increase in yield in making liquid organic fertilizer was obtained in the K2 treatment because the more EM4 added, the higher the yield produced.This is because the microorganisms in fermentation work well so that the decomposition process takes place well and perfectly.
Based on Table 2, the highest total number of lactic acid bacteria (LAB) was found in treatment P3, namely 2.1 × 10 4 cfu/g and the lowest was in treatment K1, namely 2.0 × 10 4 cfu/g.The addition of fermentative microbes (EM4) and molasses with different formulations had a significant effect on the total number of lactic acid bacteria, where LAB in treatment K1 was significantly different from P3 but P3 was not significantly different from K2 and P2.
The use of Effective Microorganisms (EM4) in producing liquid fertilizer aims to speed up the fermentation process.Effective Microorganisms (EM4) includes types of microorganisms that carry out fermentation, namely fermentation fungi (Saccharomyces sp.), lactic acid bacteria (Lactobacillus sp.), photosynthetic bacteria (Rhodopseudomonas sp.) and Actinomycetes [11].From the research carried out, it can be seen that the higher the concentration of fermentative microbes (EM4) and molasses, the greater the total number of lactic acid bacteria.This shows that the microorganisms contained in EM4 have a good influence on the quality of organic fertilizer, however the availability of nutrients in organic fertilizer is greatly influenced by the time needed for bacteria to decompose waste [19].
The fermentation process can be accelerated by adding bio-activators which are sources of microorganisms [20] [21].Because the sucrose contained in the sugar solution is an easily digestible substrate that is useful for the growth of microorganisms, the activity of microorganisms is influenced by the sugar concentration.The research that has been carried out shows that the higher the dose of EM4, the greater the number of lactic acid bacteria in liquid organic fertilizer with the best P3 treatment, namely 2.1 × 10 4 cfu/g.
Liquid organic fertilizer produced in different formulations from catfish processing fish waste using fermentative microbes (EM4) and molasses has a significant effect on the content of nitrogen produced.Nitrogen is one of the protein components that make up biological tissue.Table 3 shows that the highest nitrogen content was found in treatment K2, namely 5.16%, which was significantly different from treatments K1, P1, P3; while the lowest value was found in treatment K1, namely 1.61%.The nutritional content is optimized by adding ingredients derived from molasses, which act as additives for the growth of microorganisms.Molasses contains carbohydrates in the form of high sugar content (64%), a fermentation process that allows microorganisms to produce it perfectly [22].
The internal organs of fish generally contain many nutrients such as N (Nitrogen), P2O5 (Phosphorus), and K2O (Potassium), which are part of organic fertilizer [8].Apart from that, the addition of molasses additives which contain nitrogen compounds and the role of EM4 bacteria in perfecting the fermentation process.According to [7] the organic nitrogen produced is in the form of protein.Proteins are broken down using microorganisms into simpler compounds, namely Nitrogen.EM4 plays a more important role in producing nitrogen, while molasses does not have much of an effect in increasing nitrogen in liquid organic fertilizer with treatment K2, P1, P2 and P3 which meets the standard for liquid organic fertilizer, namely more than 2%.
Table 3 also shows the highest phosphorus value in treatment K1, namely 0.52% and the lowest value in treatment P1, namely 0.21%.Making liquid organic fertilizer with different formulations from catfish processing waste using fermentative microbes (EM4) and molasses.Phosphorus (P2O5) is an essential micronutrient that plays an important role in several processes such as assimilation, photosynthesis and respiration.Plants need phosphorus to form cells in the growing tissue of roots and shoots and to strengthen the stems, so that they are difficult to fall in ecosystems [23].The P 2 O 5 element is very important as an energy source so it can inhibit plant growth and metabolic reactions.The phosphorus content of plants supports the growth of flowers, fruit and seeds and encourages fruit ripening [24].For plants, phosphorus supports the respiration and assimilation processes, is used as a source of protein, helps increase and accelerate fruit yields, and strengthens plant stems.
The low phosphorus content produced in liquid organic fertilizer with the addition of fermentative microbes (EM4) and molasses is consistent with the low phosphorus content also being caused by the lack of microbial activity of the element P2O5 in the fertilizer material.Microorganisms can dissolve small amounts of soluble phosphate which will become soluble in the soil and fertilizer which will be absorbed by plants [25].Furthermore, this shows that the P2O5 element in fertilizer is related to the nitrogen element in the material.It can also be seen that the phosphorus element from making liquid organic fertilizer with a different formulation from processing catfish waste with fermentative microbes (EM4) and molasses meets the nutrient elements but does not meet the standard for liquid organic fertilizer, namely <2%.
Liquid organic fertilizer produced with different formulations from fish waste processing catfish using fermentative microbes (EM4) and molasses have significantly affected to potassium content.The highest potassium content was obtained in treatment P3, namely 3.11 ppm, which was significantly different to K2, however, not significantly different to K1.Meanwhile, the lowest value in the K2 treatment was 1.95 ppm.The increase of potassium content is due to the addition of greater molasses additives accompanied by the composition of K-forming elements in molasses [22].
Potassium is the main nutrient that plants need for flowers, stimulates the formation of leaves and fruit.Potassium can help to strengthen plant tissue so that it plays a role in forming plant antibodies that can fight disease and drought and can help support the formation of proteins and carbohydrates too.More potassium content is obtained from molasses so that the potassium content from making liquid organic fertilizer with a different formulation from processing catfish waste with fermentative microbes (EM4) and molasses meets the nutrients but does not meet the standards for liquid organic fertilizer as regulated in the Decree of the Minister of Agriculture of the Republic of Indonesia Number 261/KPTS/SR.310/M/4/2019,namely >2% [26].
If there is a lack of potassium, plants are not resistant to disease, drought and cold.Potassium deficiency can inhibit plant growth and the leaves become a little crunchy and shiny.Symptoms of potassium deficiency in plants will cause brown leaf edges, shortened segments and difficulty in growing plants.By comparing the correct composition of organic fertilizer materials and using good composting techniques, it will get high quality fertilizer that is easy for plants to use [27].

Conclusion
The best value of liquid organic fertilizer produced with different formulations from catfish processing waste using fermentative effective microbes (EM4) and molasses is shown by the P3 treatment (addition of 40% EM4 + 40% molasses) with the pH value 5.10.Meanwhile, the highest yield is produced by the K2 treatment (addition of 30% EM4 + 0% molasses), that was 34.73%.The highest total amount of lactic acid bacteria (LAB) is produced by the P3 treatment at 2.1 × 10 4 cfu/ g.The total N produced by the P3 treatment was 4.30% with the content of phosphorus (P2O5) was 0.41%, and the potassium (K2O) content was 3.11 ppm.The pH and nitrogen values have met the standards, while phosphorus and potassium have not met the standards for liquid organic fertilizer as regulated in the Decree of the Minister of Agriculture of the Republic of Indonesia Number 261/KPTS/SR.310/M/4/2019.Based on the results of this research, it is recommended to carry out further research to increase the content of phosphorus and potassium by adding much more EM4 and molasses so that it can meet the standard for liquid organic fertilizer > 2%.

Table 2 .
The pH value, yield, and total number of lactic acid bacteria in liquid organic

Table 3 .
The quality of liquid organic fertilizer assessed from the content of N, P2O5, and K2O