Volume 10, Number 4 (July 2023):4823-4828, doi:10.15243/jdmlm.2023.104.4823 ISSN: 2339-076X (p); 2502-2458 (e), www.jdmlm.ub.ac.id
Open Access 4823 Research Article
Viability of Aspergillus costaricaensis in a coffee husk carrier material and its effect on soil fertility and growth of coffee seedlings
Desak Ketut Tristiana Sukmadewi*, I Gusti Bagus Udayana, I Putu Aditya Agus Saputra, Desak Ayu Diah Prawerti
Agrotechnology Study Program, Faculty of Agriculture, Universitas Warmadewa, Denpasar, Bali, Indonesia
*corresponding author: [email protected]
Abstract Article history:
Received 28 November 2022 Accepted 19 April 2023 Published 1 July 2023
Planting media is an important factor affecting coffee nurseries. Farmers in Wanagiri Village have problems in coffee cultivation because they have soil with a slightly acidic pH. This affects the availability of phosphorus (P) and potassium (K) in the soil. P and potassium K solubilizing fungi can be used to increase the availability of P and K in the soil. This study aimed to analyze the viability of Aspergillus costaricaensis fungi on coffee husk carriers and the effect of A. costaricaensis biofertilizer on planting medium and the growth of Arabica coffee seedlings. The method consisted of the preparation carrier material, viability test of A. costaricaensis on coffee husk carrier, and test of the effect of A. costaricaensis on the planting medium and growth of arabica coffee seedlings. There were four fertilization treatments, i.e., P1 (organic fertilizer), P2 (100% NPK), P3 (organic fertilizer + biofertilizer), and P4 (organic fertilizer + biofertilizer + 50% NPK). Coffee husk carrier material maintained the viability of A. costaricaensis during the nine weeks of storage. The number of populations that could be maintained was log 7.67 (4.7 x 107 CFU g-1). The application of biofertilizer combined with organic fertilizers (P3) increased soil pH to 7.13, and it could potentially reduce the use of NPK fertilizer. Based on the observed growth parameters, it was shown that the treatment of biofertilizers combined with organic fertilizers increased the growth parameters of plant height and stem circumference of Arabica coffee seedlings.
Keywords:
biofertilizer carrier material coffee
fungi nutrient
To cite this article: Sukmadewi, D.K.T., Udayana, I.G.B., Saputra, I.P.A.A. and Prawerti, D.A.D. 2023. Viability of Aspergillus costaricaensis in a coffee husk carrier material and its effect on soil fertility and growth of coffee seedlings. Journal of Degraded and Mining Lands Management 10(4):4823-4828, doi:10.15243/jdmlm.2023.104.4823.
Introduction
Soil fertility is an important factor that plants need to survive and produce well. Soil fertility is largely determined by the availability and amount of nutrients in the soil (Erwiyono and Prawoto, 2008). On soils in mountainous areas, topographical factors greatly affect the availability of nutrients in the soil (Pujiyanto et al., 2001). Areas with steep topography have a higher erosion rate so that fertility levels at a certain time will decrease, and also, the chemical properties of the soil are relatively easy to change following natural
processes such as erosion (Wibawa, 2000). Climate variations and relatively high rainfall in most parts of Indonesia result in a level of alkaline leaching in the soil that is quite intensive so that the base content in the soil is low and the soil becomes acidic (Mahmud and Chong, 2022). This causes most of the soil in dry land to react acidly (pH 4.6-5.5) and is poor in nutrients, which are generally formed from mineral soils. One of the plantation areas in Bali Province, which is located in the highlands and has soil conditions with a slightly acidic pH, is the village of Wanagiri.
Open Access 4824 Wanagiri Village is one of the regions that produce
Arabica coffee. Coffee is a commodity that has high economic value. Coffee plays an important role in the national plantation sector. Apart from being a source of foreign exchange for the state, coffee is a source of income for 14.116 million farmers in the plantation sub-sector in Indonesia (BPS, 2018). Currently, coffee is the fourth main commodity after oil palm, rubber, and cocoa, which is a plant commodity in the country's foreign exchange earnings in the plantation sector.
Coffee farmers in Wanagiri Village are still experiencing several obstacles in the cultivation process, so the resulting coffee production is not optimal. One of the obstacles encountered by farmers is related to the planting medium used in the coffee nursery process. The growth of coffee plants is highly dependent on the quality of the seeds used by farmers at the start of planting. Therefore, planting media and fertilizers are important factors that must be considered to get quality coffee seeds that, in the future, can produce coffee plants with maximum production. A good planting medium is a planting medium that can absorb and provide sufficient amounts of water and nutrients for plant growth (Fadhlan et al., 2017). Various types of planting media can be used, but what must be considered is the planting media's ability to provide nutrients, oxygen, and other nutrients to support plant growth. Thus, it is very important to use the right planting medium to produce optimal-growth plants (Faadhilah et al., 2021).
Based on the preliminary research conducted, it was shown that the soil in Wanagiri Village used as a planting medium in coffee nurseries has a slightly acidic pH and the availability of low P nutrients and moderate K nutrients. The slightly acidic pH is thought to cause a decrease in the availability of P and K nutrients. The preliminary research shows that the soil in Wanagiri Village has symptoms of chemical degradation.
Chemical degradation is indicated by acidification, nutrient depletion and leaching, and nutrient imbalance (Wahyunto and Dariah, 2014). This is because an activator is needed to increase the availability and absorption of P and K nutrients. One of the fertilizers that can be used as an activator is P and K solubilizing biofertilizer. One factor that influences the effectiveness of biofertilizers is the carrier used. Carrier materials will affect the ability and shelf life of biofertilizers. One of the potential carrier materials to be developed is a coffee husk.
Coffee production and processing produce coffee husk waste that has not been used optimally. The coffee agro-industry can produce coffee husk of around 60%
of the starting material (Wardhana et al., 2019).
Therefore, this study aimed to analyze the viability of A. costaricaensis fungi on a coffee husk carrier material and to analyze the effect of A. costaricaensis biofertilizer on the planting medium and growth of Arabica coffee seedlings.
Materials and Methods
A. costaricaensis viability test on a coffee husk carrier material
The carrier material used was dried and mashed using a blender. The carrier material that has been blended was then sieved. The carrier material used was coffee husk from Wanagiri Village, Sukasada, Buleleng, Bali.
Coffee husk was added with dolomite as much as 20%
by weight of the coffee husk. Measurement of pH-H2O of the carrier material was carried out using a pH meter. Moisture content was measured by heating an oven at 105 °C for 24 hours. The carrier material was then packed in heat-resistant plastic bags. Sterilization was carried out using an autoclave at 121 oC with a pressure of 1 atm for 15 minutes. Sterilization was carried out twice (Putri et al., 2010; Jena and Rath, 2014). The fungi used in the manufacture of biofertilizers was A. costaricaensis. These fungi were used because the fungi can dissolve P and K. This is due to the soil condition in Wanagiri Village, which has low P and moderate K contents. The population of A. costaricaensis fungi used was 106 CFU mL-1. The addition of A. costaricaensis into the coffee husk medium by injection and mixed evenly. The water content of biofertilizers does not exceed 35% to maintain conditions that are not anaerobic. Calculation of the microbial population to determine its viability on the carrier was carried out every two weeks for nine weeks. Calculation of the total microbial population was carried out using the Total Plate Count (TPC) method on Potato Dextrose Agar (PDA) media (Putri et al., 2010; Jena and Rath, 2014).
Test of the effect of A. costaricaensis biofertilizer on growing media and growth of Arabica coffee seeds
The experimental design used in testing the A. costaricaensis biofertilizer on the planting medium
and growth of Arabica coffee seedlings was a randomized block design with a single factor. The number of experiments carried out was four treatments with four replications, so there were 16 experimental units. The treatment used in this study is shown in Table 1. The data obtained were analyzed using the Excel program.
Table 1. Fertilization treatment on Arabica coffee seeds.
Treatment code
Description P1 Organic fertilizer P2 100% NPK Fertilizer
P3 Biofertilizer + Organic Fertilizer P4 Biofertilizer + Organic fertilizer +
50% NPK Fertilizer
The planting medium used in this study was coffee plantation soil in Wanagiri village combined with organic fertilizers and A. costaricaensis biofertilizers.
Open Access 4825 The soil was air-dried and sieved using a sieve with a
size of 2 mm. Samples of the sifted soil were taken for initial soil analysis. The results of the initial soil analysis are presented in Table 2. The initial soil analysis in Wanagiri Village (Table 2) showed slightly acidic soil pH, with high organic C and total N.
Available P showed low results, while available K showed moderate results. These results support the application of P and K solvent biofertilizers used in this study 3 kg of absolute dry-weight sifted soil was put into the pot. The size pot used is a pot that has a volume of 3 kg. The Arabica coffee seeds used were Arabica coffee seeds that were one year old. The organic fertilizer was produced by coffee farmers in Wanagiri Village, made from the basic ingredients of a mixture of coffee husks, goat manure, cow manure, rice husk, and EM4. The results of the analysis of organic fertilizers are presented in Table 3. The analysis of organic fertilizers showed that the pH and C/N ratio parameters met the standards required by the Ministry of Agriculture. The available P and K results were very high, so they are suitable for use in soils deficient in P and K nutrients. The biofertilizer used was A. costaricaensis with coffee husk as a carrier. The biofertilizer used contained a fungal population of 107 CFU g-1. Treatment with biofertilizer used as much as 5 g. The NPK fertilizer used was NPK 16-161-16.
Treatment with NPK used 2 g NPK.
Table 2. Characteristics of the soil and organic fertilizer used in this study.
Parameter Soil Organic
Fertilizer
pH (H2O) 6
(Slightly acidic)
6.66 (Neutral) Water content
(%)
6.64 14.77
Organic Carbon (%)
5.82 (Very high)
17.89 (Very high)
Total N (%) 0.77
(Very high)
1.85 (Very high)
C/N ratio 7.55
(Low)
9.6 Available P
(ppm)
10.31 (Low)
151.33 (Very high) Available K
(ppm)
158.04 (Medium)
513.60 (Very high) Results and Discussion
Viability of A. costaricaensis on the coffee husk carrier material
The research results presented in Figure 1 shows that the A. costaricaensis population tended to increase every week. The population of A. costaricaensis in the first week was log 6.66 (4.6 x 106 CFU g-1), in the third week was log 7.18 (1.5 x 107 CFU g-1), in the fifth week was 1.71 x 107 CFU g-1, and in the seventh week
4.95 x 107 CFU g-1. This coffee husk carrier material could maintain the fungi population for up to nine weeks of storage. The number of populations that could be maintained until the ninth week was log 7.67 (4.7 x 107 CFU g-1). The population could be held by the biofertilizer standards set by the Ministry of Agriculture.
The appropriate carrier material is very important for the biofertilizer formulation process. A good carrier material will protect microbes during storage and transportation. In addition, formulations with good carrier ingredients will also provide optimal conditions to increase microbial activity and ability after inoculation to plants (Suryantini, 2019). This will ensure that the microbes used can be applied in the right way and can interact positively with plants. An important characteristic of coffee husks is thought to support the ability of coffee husk to maintain the A. costaricaensis population because it has a low
moisture content, which is suitable for A. costaricaensis during the storage period. The water
content of the coffee husk used was 2.02%. This water content was low because the coffee husk got drying treatment before use. The low water content was relatively stable to protect the coffee skin from damage during storage.
Figure 1. Fungal viability on coffee husk carrier material during nine weeks of storage.
A good carrier material is a carrier material that can maintain a stable microbial population, not experiencing its growth phase as when microbes are grown on media that has high nutrition. Based on the literature shows that coffee husk has a fat content ranging from 0.883%-1.1%; this fat content is relatively low. Likewise, the protein content is also relatively low, which is only around 6-8%. The crude fiber content of the skin ranges from 30-36%, which is relatively high. The total fiber content in the coffee husk can represent its lignocellulose content. Crude fiber consists of cellulose, hemicellulose, and lignin.
Coffee husk lignin content ranges from 21.6%- 35.90%. The lignin content is relatively high. This high lignin content can be a barrier in the process of hydrolysis of cellulose and hemicellulose into simpler compounds (Wardhana et al., 2019). This low nutrient
1 3 5 7
W - 0 W - 1 W - 3 W - 5 W - 7 W - 9 Log Population of Fungi (CFU g-1)
Incubation Time (week)
Open Access 4826 content prevents the growth cycle of A. costaricaensis
from running quickly, thereby supporting the coffee skin to maintain the stability of the A. costaricaensis population during storage.
Effect of A. costaricaensis biofertilizer on planting media and growth of Arabica coffee seeds
The application of biofertilizer combined with organic fertilizers (P3) increased soil pH to 7.13 (Figure 2).
This pH range can increase the availability and absorption of nutrients for plants. The P3 treatment, which received the addition of biological fertilizers, showed that the pH tended to increase every week compared to the other treatments, which tended to fluctuate.
Figure 2. Soil pH measurement in six weeks after planting.
Description: P1: Organic Fertilizer, P2: 100% NPK fertilizer, P3: Organic Fertilizer+ Biofertilizer, P4: Organic
Fertilizer + Biofertilizer + 50% NPK fertilizer.
Overall, all treatments showed an increase in the final pH compared to the initial soil pH. The increase in soil pH in all treatments that received the addition of organic fertilizers was thought to be because the organic fertilizers used had been well decomposed.
Decomposed organic matter will increase soil pH because, in the process of mineralizing organic matter, it will release minerals in the form of basic cations (Sudadi et al., 2020). This is in line with research by Sudadi et al. (2020), which showed that adding 18 t organic fertilizer ha-1 could increase soil pH to 7.
The addition of biofertilizers is also thought to help organic fertilizers decompose properly so that it correlates with an increase in soil pH. Research by Silitonga et al. (2019) also showed that the application of phosphate-solubilizing fungi significantly affected soil pH and soil available P.
The application of A. costaricaensis biofertilizer and organic fertilizer also affected total N, available P, and available K of the soil studied (Table 3).
Treatments The P3 and P4 treatments gave higher available P than the P1 and P2 treatments. The highest content of available P was shown by the P3 treatment (6.84 ppm). The highest total N content (0.42%) was observed for the P1 treatment, while the highest (270.96 ppm) was observed in the P2 treatment. The contents of available K in the P3 and P4 treatments were close to that in the P2 treatment, although NPK fertilizer was not used at a dose of 100%. This shows that treatment with the addition of organic fertilizer and A. costaricaensis biofertilizer has the potential to reduce the use of NPK at a dose of 100%. It is also strongly influenced by the initial soil conditions. The application of organic and biofertilizers increases the chemical fertility of the soil and the release of nutrients. This will increase the availability of nutrients in the soil, especially P and K nutrients.
Table 3. Changes in soil chemical properties due to the application of A. costaricaensis biofertilizer and organic fertilizer in six weeks.
Treatments Total N
(%)
Available P (ppm)
Available K (ppm)
P1 (Organic fertilizer) 0.40 4.29 259.25
P2 (100% NPK fertilizer) 0.39 3.89 270.96
P3 (Organic Fertilizer+ Biofertilizer) 0.42 6.84 264.42
P4 (Organic Fertilizer + Biofertilizer + 50% NPK fertilizer) 0.37 5.38 266.23 The application of A. costaricaensis biofertilizer and
organic fertilizer improves plant height and stem circumference of the coffee seedlings. Planting media that received the addition of biofertilizers and organic fertilizers experienced the highest increase in plant height in the sixth week compared to the other treatments (Figure 3). The lowest plant height was shown by plants treated with 100% NPK fertilizer. The increase in plant height was obtained successively from the highest to the lowest, namely P4 (4.38 cm),
P3 (4.25 cm), P1 (3.88), and P2 (3 cm). Planting media that received the addition of biofertilizers combined with organic fertilizers gave the highest plant stem circumference (Figure 4). The lowest plant stem circumference was shown by the treatment, which received the addition of 100% NPK fertilizer. The plant stems circumference was obtained successively from the highest to the lowest, namely P3 (1.38 cm), P1 (1.15 cm), P4 (0.88), and P2 (0.80 cm). The treatment of biofertilizers combined with organic 0
1 2 3 4 5 6 7 8
W 0 W 1 W 2 W 3 W 4 W 5 W 6
Soil pH
Observation Time (week)
P1 P2 P3 P4
Open Access 4827 fertilizers was able to increase the growth parameters
of plant height and stem circumference of Arabica coffee seedlings. This is in line with the results of an increase in soil pH obtained in the treatment with the addition of biofertilizers combined with organic fertilizers.
Figure 3. Plant height increase at six weeks after planting.
Description: P1: Organic Fertilizer, P2: 100% NPK fertilizer, P3: Organic Fertilizer+ Biofertilizer, P4: Organic
Fertilizer + Biofertilizer + 50% NPK fertilizer.
Figure 4. Plant stem circumference increases at six weeks after planting.
Description: P1: Organic Fertilizer, P2: 100% NPK fertilizer, P3: Organic Fertilizer + Biofertilizer, P4: Organic
Fertilizer + Biofertilizer + 50% NPK fertilizer.
Increasing the pH increases the availability of nutrients, especially P and K nutrients. These P and K nutrients are needed in various important processes of plant growth. The nutrient element phosphorus (P) has a role in the process of photosynthesis, respiration, energy production, nucleic acid biosynthesis, and as a constituent component of several plant structures (Balemi and Negisho, 2012). Nutrient K has many
important roles in plant metabolism, including being directly involved in several physiological processes (Farhad et al., 2010). Previous research by Pratama et al. (2016) showed that some microbes were able to dissolve K feldspar sources so that they could increase plant height, dry weight, crown, and root dry weight.
The biofertilizer A. costaricaensis plays an important role in the process of P and K solubilizing and in increasing the absorption of available nutrients. One of the mechanisms that occur is suspected through chelating cations that bind P (Khan et al., 2009;
Sharma et al., 2013). In the cation chelating mechanism, the mechanism that occurs is that the carboxyl groups or hydroxyl groups of organic acids can form complexes with P-binding cations such as Ca2+, Mg2+, Fe2+, and Al3+ so that P is released and becomes available to plants (Walpola and Yoon, 2012;
Sharma et al., 2013). Several previous studies have stated that the release of K from K-carrying minerals such as feldspar can be carried out by microbes by producing organic acids. Feldspar (KAlSi3O8) reacts with organic acids to cause an ion exchange reaction between H+ ions and K+ ions, thereby releasing K+ ions which are bound to silicates. In the reaction between feldspar, which is a primary mineral, and organic acids, it also forms secondary K minerals (Fu et al., 2009).
Conclusion
Coffee husk carrier material could maintain the viability of A. costaricaensis during the nine weeks of storage. The number of populations that were able to be maintained until the nine-week was log 7.67 (4.7 x 107 CFU g-1). The population that could be maintained is in line with the biofertilizer standards set
by the Ministry of Agriculture. The application of A. costaricaensis biofertilizer with organic fertilizers
(P3) can increase soil pH to 7.13. This pH range can increase the availability and absorption of nutrients for plants. Treatments with the addition of organic fertilizer and A. costaricaensis biofertilizer could potentially reduce the use of NPK fertilizer at a dose of 100%. Based on the observed growth parameters, it was shown that the treatment of A. costaricaensis biofertilizers combined with organic fertilizers was able to increase the growth parameters of plant height and stem diameter of Arabica coffee seedlings. This is in line with the results of an increase in soil pH
obtained in the treatment with the addition of A. costaricaensis biofertilizers combined with organic
fertilizers. Increasing the pH increases the availability of nutrients, especially P and K nutrients.
Acknowledgements
The authors thank the Ministry of Education, Culture, Research and Technology of the Republic of Indonesia for funding this research through the Matching Fund Program.
0 1 2 3 4 5
W 1 W 2 W 3 W 4 W 5 W 6
Plant Height (cm)
Observation Time (week)
P1 P2 P3 P4
0 1 2
W 1 W 2 W 3 W 4 W 5 W 6
Stem Circumference (cm)
Observation Time (week)
P1 P2 P3 P4
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