Characteristics of bokashi organic fertilizer from etawa goat feces

Livestock waste such as feces, urine, and leftover feed left without further treatment can harm the environment in the form of air, water, and soil pollution. Therefore, efforts are needed to process livestock waste into useful products in the form of organic fertilizers. Livestock waste that has the potential to be a source of organic fertilizer is etawa goat waste. Etawa goat feces processing technology in the form of bokashi fertilizer made from fermented livestock and agricultural wastes using EM-4. Bokashi fertilizer contains a variety of essential macro and micronutrients needed by plants and can improve soil fertility and quality. This research aims to determine whether bokashi fertilizer with the main ingredients of etawa goat feces has various formulations, specifically P1 (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi feces etawa goat with sawdust) has physical and chemical characteristics according to SNI organic fertilizer (Indonesian National Standard-2011). This research method uses a descriptive research design. The research data were obtained through laboratory analysis of various formulations of etawa goat feces bokashi fertilizer samples and compared the results with the solid organic fertilizer standard SNI (Indonesian National Standard)-2011. Based on the results of the research showed that etawa goat feces bokashi fertilizer with various formulations, specifically P1 (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi feces etawa goat with sawdust) has physical and chemical characteristics that are following the solid organic fertilizer standard SNI-2011, except for the C/N ratio and the number of macronutrients (N, P, and K).


Introduction
Livestock waste is the result of waste from livestock business activities which are currently increasing in number along with the increase in livestock business in Indonesia [1].The livestock waste such as feces, urine, and feed residues left without further treatment can harm the environment in the form of air, water, and soil pollution, being a source of disease, can trigger an increase in methane gas and also disturbances in aesthetics and environmental comfort.The lack of public concern to utilize livestock manure waste causes pollution of the residential environment due to the smell caused [2].
So that the treatment of livestock waste needs to be carried out to reduce environmental pollution.Livestock waste treatment can be done by using livestock feces as organic fertilizer in the form of manure, compost, and bokashi fertilizer [3].The processing of waste into organic fertilizer is quite safe and the manufacturing process is not too complicated so it can be made by the community themselves with simple raw materials that are easy to find.Waste from organic matter is processed into organic 1230 (2023) 012192 IOP Publishing doi:10.1088/1755-1315/1230/1/012192 2 fertilizer to increase its economic value [4].The most important thing in handling, preventing, and utilizing livestock waste has the principle of dealing with waste problems without causing new waste problems that have a more negative impact on the environment.
Livestock waste that has the potential to be a source of organic fertilizer is etawa goats or known as the breed of etawa goat (PE).Goat waste in the form of feces and urine contains potassium relatively higher than other livestock waste.Goat feces contain N and K twice as large as cow dung [5].Goat manure contains various essential macro and micronutrients needed by various plants and increases soil fertility.As it is known that the important nutrients needed by plants are elements N, P and K. Content of these elements in goat manure is N = 50.6kg / t, P = 6.7 kg / t, and K = 39.7 kg / t.Goat feces contain P higher than urine [6].
One of the etawa goat feces processing technologies is organic fertilizer in the form of bokashi fertilizer (organic matter rich in biological sources).Bokashi fertilizer is made from the fermentation of agricultural waste (manure, straw, garbage, husks, sawdust) using EM-4 [7].EM4 (Effective Microorganism-4) is a decomposing bacterium from organic matter used for the process of making bokashi, which can maintain soil fertility.The application of bokashi fermented with EM-4 is one way to improve the physical, chemical, and biological properties of the soil and can increase the availability of soil nutrients through natural processes so that soil quality becomes better [8].Many studies have shown that bokashi is of better quality compared to simple composting techniques.
Based on this information, this research aims to produce a formulation of bokashi fertilizer made from etawa goat feces with fillers (burnt husks, tea dregs, sawdust) to utilize organic livestock and agricultural waste.The bokashi fertilizer produced will be characterized through analysis in the laboratory to be tested for nutrient content.The bokashi fertilizer produced is expected to meet the criteria for organic fertilizer based on SNI -2011.

Methods
The research was conducted at Ternakita Indonesia Farm, Pucak Village, Tompobulu District, Maros Regency, South Sulawesi.Fertilizer analysis was carried out at the Soil Chemistry and Fertility Laboratory, Department of Soil Science, Faculty of Agriculture, Hasanuddin University, Makassar from October 2022 to November 2022.The tools used in this research were hoes, burlap sacks, analytical scales, machetes, cameras, ropes, plastics, thermometers, measuring cups, shovels, sprinklers (drills and sprayers), and other writing tools.While the materials used are pure etawa goat feces, EM-4, molasses, water, straw, burnt husks, tea dregs, and sawdust.This study used a descriptive research design.
Research activities include making bokashi fertilizer goat feces etawa.To get bokashi fertilizer with the best nutrient content, it is divided into four stages, namely formulation: a) P1 (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi feces etawa goat with sawdust).The stages of making 1 ton of bokashi fertilizer are: 1) Prepare the following ingredients 200 kg of straw, 600 kg of dried etawa goat feces, 1 liter of decomposer solution (EM4), and 1 kg of molasses; 2) Choose a fermentation place protected from rainwater and direct sunburn.3) Chopped straw, a mixture of organic ingredients (burnt husks, tea pulp, and sawdust) that has been prepared, stirring evenly with a hoe or shovel.4) Dilute the EM4 solution, take 1 liter of solution and mix with 200 liters of clean water and 1 kg of molasses.Then water on the mixture of raw materials while stirring.5) Set the humidity until it reaches 30-40%.To estimate the level of humidity, clench the mixture until it can coagulate but not to the point of releasing water.If the humidity is lacking, add enough water.6) Cover with plastic or tarpaulin, and let stand for up to 7-14 days.Keep in mind, to control the fermentation temperature to a maximum of 45 o C. When it exceeds this temperature, stir with it a hoe so that the temperature drops.7) After 14 days, bokashi fertilizer can already be used and applied directly.
Next is the analysis of the physical and chemical properties of P1 (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi feces etawa goat with sawdust).Analysis of the physical properties of fertilizer was carried out on several parameters, including color, texture, aroma, level of participating materials (%), and chemical 3 properties of fertilizer carried out laboratory analysis on several parameters, including water content with the gravimetric method, C-organic (%) with Walkey & Black method, macronutrients N with Kjeldahl method, P2O5 dan K2O with HNO3 : HClO4 method, pH with pH H2O 1:2.5 method, and ratio C/N.

Result and discussions
Table 1 shows the physical character of goat feces bokashi fertilizer with various formulations that can be used as organic fertilizer.Notes: P1 (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi etawa goat feces with sawdust) Based on the results of the table above, shows that P1 has a dark brown physical character, crumb/loose texture, and no smell (figure 2).P2 has a black-brown, crumb/loose texture, and no smell physical character (figure 3).P3 has a black-brown physical character, a crumb/loose texture, and no smell (figure 4).P4 has a dark brown physical character, crumb/friable texture, and no smell (figure 5).The physical character of goat feces bokashi fertilizer etawa various formulations above (table 1) shows that the fertilizer is well fermented, has matured, and is ready to be applied.The bokashi fertilizer brought in this study took ± 14 days to mature.
Bokashi color is one of the parameters that characterize the fermentation process to run well or not in the bombing.The fermentation process is the decomposition of organic matter with the help of microorganisms, where bokashi that are fermented longer tend to produce a darker color.This darkening bokashi illustrates that the fermentation process of etawa goat feces with EM-4 is running normally and shows the best bokashi character [9].This is in line with [10] that the length of fermentation time will affect the microbial decomposition process so that the longer the fermentation process causes a change in the color of bokashi will become darker, the ripe bokashi is characterized by a blackish brown color.The color of the bokashi material gradually starts from light brown, and dark brown, until the end of the process of bombing to blackish brown.According to the characteristics of a ripe bokashi, it has a dark brown to blackish color.
The change in the texture of bokashi which was originally hard textured turns into crumb/loose and already resembles the texture of the soil because when squeezed bokashi undergoes a very obvious deformation and is almost no longer recognized by the base material.This is due to the activity of microorganisms derived from the feces of goats etawa and EM4 [11].Microorganisms present in EM4 will quickly decompose the ingredients in the manufacture of bokashi so that the texture resulting from the decomposition process will gradually change, namely from hard lumps to at the end of the decomposition process to non-clumping (crumbly).Following the opinion [12] that microbial activity is between the surface of the area and the air.A wider surface area will increase the contact between microbes and the material and the decomposition process will proceed faster.The size of the particles also determines the magnitude of the space between materials (porosity).
The smell of bokashi fertilizer that initially smells bad turns no-smell (smells like soil) so it shows that the process of decomposition of organic matter has been going well and indicates that bokashi is ripe, according to the opinion [13] fertilizer that has matured will smell like soil, if it smells unpleasant it means anaerobic fermentation and immature compost.This is also following [10]), which states that mature fertilizer will smell like humus or soil when the compost smells foul indicating that the decomposition process has not been completed and the decomposition process is still ongoing.
The results of this study showed the content of follow-up ingredients produced by bokashi organic fertilizer from goat etawa feces with various formulations, that is P1 namely 1%, P2 namely 2 %, P3 namely 1%, and P4 namely 2% (table 1).This is following the SNI-2011 Organic Fertilizer Standard, which requires that solid organic fertilizers must not contain more than 2% follow-up material.Followup materials that usually appear in organic fertilizers, among others; glass, plastic, and gravel.The less participating material in organic fertilizer shows that organic fertilizer has a good quality [14].Table 2 shows the chemical character of goat feces bokashi fertilizer with various formulations that can be used as organic fertilizer.Based on the results of laboratory analysis, the water content produced by goat feces bokashi fertilizer with various formulations is P1 namely 22%, P2 namely 23%, P3 namely 18%, and P4 namely 17% (table 2).The water content value ranges from 17-22%, this figure is following the SNI-2011 Organic Fertilizer Standard which requires water content to be around 15-25% [14].This moisture content is related to the gray status of organic fertilizer tires.Moisture has a very important role in the metabolic process of microbes and indirectly affects the oxygen supply.In optimal health, microbial metabolism runs well so that it supports the decomposition process of organic matter in the manufacture of organic fertilizers.Microorganisms can utilize organic matter if the organic matter dissolves in water [15].Air levels are an important process in the metabolism of microorganisms involved in the decomposition process.Microorganisms can only take advantage of organic molecules dissolved in water.
The pH value produced by bokashi fertilizer etawa goat feces with various formulations is P1 namely 7.05, P2 namely 6.85, P3 namely 6.65, and P4 namely 5.95 (table 2).The value indicates a pH that goes to neutral, which is not too acidic and not too alkaline.The pH value ranges from 5-7%, this figure is following the SNI-2011 Organic Fertilizer Standard which requires water content to be around 4-9 [14].A neutral pH will make the activity of microorganisms in organic fertilizers run perfectly so that nutrients released from organic fertilizers are also getting better [10].The change in pH is strongly influenced by the results of biomass decomposition of manure following the research [16], the process of biomineralization of biomass mixture of manure with straw into simple and stable minerals causes changes in the pH of the biomass.At the beginning of the process, the demineralization process occurs into metal elements, so that the pH increases, while subsequently there is a release of organic acids (humus) so that the pH of biomass decreases.According to [17], the degree of acidity (pH) during the decomposition process is not influenced by water content but is influenced by the nitrogen content of compost organic matter resulting from protein synthesis by decomposing microorganisms.At the beginning of the fermentation process, the pH of POC will decrease due to the activity of microbes (bacteria) in converting organic matter into acidic organic acids to reduce pH.Over time with the emergence of microorganisms that will convert organic acids that have been formed so that the pH of the material rises again close to neutral after the fertilizer matures.
The results of the analysis of C-organic content in bokashi fertilizer etawa goat feces with various formulations, that is P1 namely 19.13%, P2 namely 30.70%,P3 namely 24.69% and P4 namely 17.19% (table 2).This is following the SNI-2011 Organic Fertilizer Standard, which requires C-organic content in fertilizer at least 15% [14].The content of organic matter (C-organic) plays an important role in agriculture because organic matter can regulate various soil properties (physical, chemical, and biological), then as a buffer for the supply of nutrients for plants.The quality of organic matter largely determines the speed of the process of decomposition and mineralization of organic matter.Low Corganic levels in organic fertilizers indicate that microorganisms use a lot of carbon in raw materials for their growth and indicate that microorganisms are working more in number [18].The results of the research [19] show that in the decomposition process there is a decrease in C-organic content, this is due to the addition of microorganisms that need organic carbon as food.The C-organic content in fertilizer raw materials can decompose well if the pile of raw materials can isolate enough heat.
Another parameter related to organic matter is the C/N ratio.The decomposition process is a process of decomposition of organic matter from a high C/N ratio to a low C/N ratio with an effort to activate microbes or decomposers (bacteria, fungi) [20].In this study, the C / N ratio produced in goat feces bokashi fertilizer with various formulations is P1 namely 13%, P2 namely 21%, P3 namely 19%, and P4 namely 12% (table 2).This value shows that only the P2 and P3 formulations meet the criteria for the C/N ratio of SNI-2011 organic fertilizer, which is between 15-25% [14].Meanwhile, the P1 and P4 formulations have not met the minimum SNI 2011 standards.As it is known that the C/N ratio is used to assess the maturity of organic fertilizers produced during the decomposition process, in addition, the C/N ratio can be used to predict the rate of mineralization of organic matter.The C/N ratio in the P2 and P3 formulations indicates that organic fertilizers are in optimal mature condition and can be used as a source of nutrition for plants otherwise for P1 and P4 formulations it shows that bokashi fertilizers are not yet in optimal mature condition so it still requires a longer decomposition time than other formulations [21].If the carbon content is too high, the decomposition process will last a long time, otherwise, if the nitrogen content is too high, the decomposition process will take place quickly but some of the nitrogen will be released/evaporated into the air.The process of decomposition involved various microorganisms that in their activity require carbon and nitrogen as sources of energy and cell formation.For this reason, the C/N Ratio is an important factor in the decomposition process of organic fertilizer [22].
Macronutrients are the elements that plants need in relatively large quantities.The results of the analysis of the content of the number of macronutrients (N, P, and K) in bokashi fertilizer etawa goat feces with various formulations, that is P1 namely 3.29%, P2 namely 1.96%, P3 namely 2.01% and P4 namely 2.12% (table 2).This value shows that the amount of macronutrients has not met the standard of solid organic fertilizer SNI-2011 [14].Therefore, efforts are still needed to increase the content of macronutrients in organic fertilizers based on animal manure.These efforts can be done in several ways, including; by adding organic matter rich in N, P, and K elements such as; fish waste, dry foliage waste, household waste, and vegetable and fruit waste [23].Macronutrients are nutrients needed in large quantities to support the process of plant growth and evolve [24].

Conclusions
Organic bokashi fertilizer etawa goat feces with various formulations, namely (bokashi pure etawa goat feces), P2 (bokashi etawa goat feces with roasted husks), P3 (bokashi etawa goat feces with tea dregs), and P4 (bokashi feces etawa goat with sawdust).It can be seen that from the results of the analysis of the physical characteristics of, all bokashi fertilizer formulations it is following the SNI-2011solid organic fertilizer standards, which are dark brown in color, crumbly in texture and no-smell and the content of associated ingredients is <2%.As for the laboratory results of chemical character analysis for the P1 and P4 formulations, several characters have fulfilled the solid organic fertilizer standards by SNI-2011, namely water content, pH, and C-organic, while the C/N ratio and the number of macronutrients are not yet following fertilizer standards solid organic SNI-2011.The P2 and P3 formulations have fulfilled the chemical character standards by SNI-2011, namely water content, pH, C-organic, and C/N ratio, but only the amount of macronutrients (N, P, and K) which have not to fulfill the established criteria by SNI-2011.Therefore, to increase the total C/N ratio in organic fertilizers, it is necessary to optimize the decomposition process, especially microorganisms which play an important role in the decomposition process which in their activities require carbon and nitrogen as energy sources and cell formation.Meanwhile, to increase the amount of macro-nutrient content in solid organic fertilizer made from etawa goat feces, it is necessary to add other organic materials such as fish waste, dry leaf waste, vegetable and fruit waste, and household waste.

Table 1 .
Physical character of bokashi fertilizer goat feces etawa various formulations

Table 2 .
Chemical character of bokashi fertilizer goat feces etawa various formulations Source: Soil Chemistry and Fertility Laboratory, Department of Soil Science, Faculty of Agriculture, Hasanuddin