The agriculture sector is an important economic sector in Malaysia, contributing 7.3% (US 23.89 Million) to the national GDP. The crops planted in Malaysia can be grouped into two, industrial crops such as palm oil, rubber, and cocoa and crops for domestic market rice, vegetables, varieties of fruits, tapioca, and others. The oil palm remains as the main contributor to the GDP of the agricultural sector, which is 37.9 %, followed by other types of agriculture (25.1%), livestock (14.9%), fisheries (12.5%), forestry & logging (6.9%), and rubber (2.8%). Inorganic fertilizers executed more than 90 % of fertilizers used by all types of farming systems in Malaysia to achieve high yield production of crop plants. On top of that, the agriculture sector generated at least 168 million tons of biomass, including timber and oil palm waste, rice husks, coconut trunk fibers, municipal waste, and sugarcane waste annually. Another fact is Malaysians generated about 16 688 MT of food waste per day. These put the country in a position to promote the use of biomass as a renewable source for agricultural input. Repurposing food wastes and residues are among the initiatives taken by the government and other organizations in Malaysia in adapting circular agriculture. This paper will discuss the challenges faced to repurpose food wastes and residues into agricultural input, such as compost and animal feeds which include, awareness, technologies, transportation, and others.
Keywords: food wastes, agricultural residues, compost, animal feeds, agricultural inputs.
Malaysia is in Southeast Asia, covering an area of 329 960.22 km², with dense evergreen tropical rainforest. Close to the Equatorial line, with Latitude 1° and 7° North and Longitudes 100° and 119° East, Malaysia experiences the uniform and high temperatures, humid with heavy rainfall throughout the year. Malaysia retains a forest cover of about 54.5% of its total land area. The flora of the Malaysian rainforest is among the richest in the world and named as one of the 12 megadiverse countries, with an estimated 15 000 species of vascular plants.
Agriculture remains an important economic sector and are grouped into two; industrial crops such as oil palm, rubber, cocoa, kenaf, and domestic agriculture crops such as rice, coconut, tapioca, and other tubers, varieties of fruits and vegetables. Population recorded working in the agricultural sector in 2018 is 1 570.3 thousand people. Contributed 7.3 % (US 23.89 Million) to Gross Domestic Product (GDP) in 2018, the oil palm is the main contributor to the GDP of the agricultural sector at 37.9 %, followed by other agriculture (25.1%), livestock (14.9%), fisheries (12.5%), forestry & logging (6.9%), and rubber (2.8%) (DOSM 2019).
Malaysia is known for its diversity of ethnic products and offers infinite varieties of cuisines ranging from expensive restaurants to street foods. As the population is increasing, the need for food has also risen. The proliferation of street foods with relatively affordable prices, an increase in income, and the eating-out culture led to an increased in food wastes. The average food wastes generated in Malaysia was 16, 688 tons per day in 2017 and sometimes increased to about 30, 000 tons per day in festive seasons (Wahari 2018). To fulfil the demand, Malaysia imported US 14 Billion of food annually although, the country also produced for its domestic use.
Malaysia depends heavily on inorganic fertilizers for crop production. Malaysia used an average of 1,723.4 kg/ha fertilizer for crop plantation (Knoema 2016). The United Nations (UN) Comtrade database (2019) reported that Malaysia's fertilizer imports valued US 814.73 Million in 2019. Recently, the conversion or repurposing of food wastes and other agricultural residues to fertilizers and animal feed has been encouraged by the government as an approach to circular agriculture since the synthetic input becomes expensive. Besides, the government is committed to mitigating climate change through a green technology approach. The repurposing will help to serve problems such as the short life of the landfill, pollution, pests and diseases related to it, burning, and flash floods. The rest of this paper will discuss the wastes and residue generation, several initiatives to repurpose the food wastes and residue, and the challenges upon repurposing the wastes.
Food wastes refer to food appropriate for human consumption but is discarded, whether it is kept beyond its expiry date or left to spoil (FAO 2013). Globally about 1.3 billion MT of food are wasted (FAO 2011). The amount is equal to one-third of all food produced for human consumption. Often this is because food has spoiled, oversupply, individual consumer shopping/eating habits, or it does not reach the market due to transportation problems.
Malaysians produced 33, 130 MT of solid wastes daily, which consists of 45 % of food wastes and organics (MGHL 2012). Malaysia is projected to generate about 49, 670 MT daily of solid wastes .. If the trend of waste disposal does not change, Malaysia might now generate 22, 351 MT of food wastes and organics daily. The volume of food wasted is contributed by many factors, including households, hoteliers and restaurant outlets, commercial activities such as organized events, conferences, seminars, and many more. Ugly and misshapen are food products that are usually being rejected by retailers, and supermarkets of which food are typically found in the landfill.
The cost of waste disposal at a landfill in Malaysia is relatively inexpensive and easy (Lim et al. 2016). Thus, many waste disposal operators are comfortable with the practices. However, the decomposition of organic wastes at the landfill creates various environmental problems such as groundwater pollution, toxic gas emissions, odor, and leachate. Methane, which is 21 times more potent than CO2 in terms of its contribution to climate change, is one of the greenhouse gases released from the landfill. According to Ventour (2008), one ton of food waste is accountable for 4.5 tons of CO2, and in Malaysia is generating about 15, 000 tonsof food wastes daily. With the current amount of food wastes dumped to the landfill, it might shorten the time to reach its maximum capacity of the landfill, yet to identify a suitable location for a new landfill is another problem. Therefore, the composting of food wastes needs to be increased to 8% by the year 2020 compared to 1% in 2009 (Perithamby 2009). Composting of food wastes is a potentially viable technology for municipal solid waste management in Malaysia (Tan et al. 2014). These activities will very much support the idea of circular agriculture as the nutrients from t food wastes can be put back into the agriculture system.
Agriculture wastes or residues are the unwanted produce as a result of various agriculture operations. It includes manure, other wastes from farms, poultry houses, and slaughterhouses; harvest wastes; fertilizer run-off, pesticides that enter the water, air, or soil; and salt and silt drained from fields. (OECD, 2001). The residue is usually discarded and ends up in the landfill because of its low nutritional value and they don’t have the proper economic value to turn it into other products. Expanding of agricultural areas for food and feed production will usually have an increment of waste production, whether it is the crop residue, agro-industry by-products, and livestock manure.
Globally it is estimated that about 998 million MT of agricultural waste swere produced yearly (Perithamby 2009). Malaysia annually produces approximately 168 million tonnes of biomass that include timber, oil palm waste, rice husks, coconut trunk fibres, municipal waste, and sugarcane wastes (Ozturk et al. 2017). About 1.2 million MT of agricultural wastes is disposed to landfills annually. Synchronously it is noted that livestock production was in an upward trend for goats and poultry. The goat population increased by about 53% between 2005 and 2015, and poultry increased by about 74% over the same period (Agrofood Statistics 2015). The amount of waste (manure) production calculated based on the estimate that for 1000 kg of live weight of livestock will produce 5.27 kg manure/day, on a wet weight basis (Overcash 1973). Composting and repurposing the agriculture for animal feeds are ways to avoid the nutrients from being wasted and, at the same time, served as a conflict solution method for the limited grazing area in Malaysia and ventures into the circular agriculture holistically.
REPURPOSING FOOD WASTES AND OTHER RESIDUALS INITIATIVE
With the current issues, such as high synthetic input for agriculture, degraded land, climate change, urbanization, and diet change of the population faced by Malaysia, agriculture seems to become one of the sectors that can contribute to resolving the issue. The conventional agricultural production system, the linear process of 'take-produce-consume-discard' wasted various materials along the chain from production to consumers. These include food wastes and other agriculture residues discarded for various reasons. To reduce the wastes, changes from linear to close loop system agriculture by repurposing the materials, substances, and by-product back to the loop is essential. The loop system or circular agriculture approach will reduce both resource use and discharges into the environment. In Malaysia, although the legal framework for circular agriculture is still lacking, several initiatives to reduce the environmental impact have been taken.
Food for the needy
Reducing food wastes is fundamental for circular agriculture. When the food is discarded to landfills, the entire chain involved in producing the food, water, fertilizer, planting, harvesting, packing, and transporting are wasted. To reduce food wastes, the Government agencies, together with private sectors and NGOs, have collaborated to solve the matter. The outcome of the project collaboration work between the Ministry of Housing and Local Government Malaysia (MHLG), collaborated with the Ministry of the Environment Japan (MOEJ) in 2010, is more on the adoption of the 3R concept, it leads to other initiatives and planning to reduce food wastes. These include the establishment of the MYSaveFood program coordinated by The Malaysian Agricultural Research and Development Institute (MARDI) and the Ministry of Agriculture and Agro-based Industry (MAFI). For this, MARDI received a grant from FAO to conduct a food loss and waste project in early 2016. The program promoted the reduction of food loss and food waste in Malaysia.
Through the national communication campaign targeted to consumers across a broad cross-section of society, ministries, organizations, households, and schools, the program getting off the ground by setting up MYSaveFood network. Many stakeholders participated in this network as they realized the importance of the initiative. The program updates the information from local and international sources on ways of reducing food loss and food wastes and advocating the voluntary approach through awareness, persuasion, and education, appealing to the public and stakeholders in the food and beverage industry. Yayasan Food Bank Malaysia, What A Waste (WaW), Happy Bank Crew, Persatuan Kechara Soup Kitchen, Grub Cycle Sdn. Bhd, The Lost Food Project, Food Aid Foundation, are among the active NGOs in the network. They are redirecting the food surplus from receiving various places/companies/hotels/supermarkets/events/individuals to the needy. Not only the food is saved the needy also get their food supplies.
Biogas for energy
Another method to repurpose the wastes is to turn it into energy. These include food wastes and agricultural residue, also the livestock's manure. There are three ways to turn these wastes into renewable energy, thermal treatment using an incinerator, biological digestion, and landfill gas. However, to avoid them from ending up at the landfill or incinerator biological-based approach using the Anaerobic Digestion System is the best choice. Calculated based on the 2018 population, the production of biogas in Malaysia from food waste and sewage estimated was 285 MW of energy and nutrients (Sarika 2019).
The effort to transform the food wastes into a biogas is still small and scattered. An agency such as SIRIM Bhd. has developed an Anaerobic Digestion System to generate energy from food waste. The system has been demonstrated effective at participating food courts in Port Dickson and Sepang local council. With the capacity of 500 kg waste/day, it able to produce 5 kilowatts of electricity. With the introduction of the digester in Sepang local council, the council expected to save up to US1.13 million in food waste disposal costs at landfills and cut back on the emission of some 9 000 MT of greenhouse gasses through its anaerobic waste digesters within the span of 10 years.
Besides SIRIM Bhd., Putra University Malaysia (UPM) also demonstrated a showcase pilot plant for food waste digestion into a biogas from the 2.2 MT/day of organic waste generated in UPM. According to Zulkifli et al. (2019), at a maximum conversion of the organic fraction, the system can generate 715 kWh of electricity and flammable fuels. Meanwhile, based on the 2010 food waste data Hoo et al. (2017) claim that roughly 60 Mm3 of CH4, which is equivalent to 16.3 MW electrical power, is possible to be generated yearly. This calculation is using the Intergovernmental Panel for Climate Change (IPCC) methane gas emission from the biological treatment equation. The revenue by selling the electricity through Feed-in-tariff (FiT) is approximately the value estimated at US10.1 Million.
Along with that, Malaysia generated about 68 million m3 Palm Oil Mill Effluent (POME) and, if all the effluents were digested anaerobically, based on calculation, it is likely to generate over 500 MW of electricity for the mills (Sarika 2019). Not to mention the manure from livestock production, with 0.7 million cattle, 1.6 million pigs, and 308 million chickens (FAOSTAT 2019), potentially generated 1043 MW of energy and will also address the issues faced by farms related to odors and flies.
Compost for agriculture
Generally, organic wastes naturally will be degraded, but this uncontrolled degradation will create problems such as leachate, odor, and several toxic gasses that will be released and pollute the surrounding area. Composting is the human intervention to control the degradation process and indirectly will promote a cleaner environment. Composting is a method to restore nutrients taken from the soil with the help of microorganisms.
There are many ways to do composting that have been introduced worldwide. One can choose a suitable method based on the amount of wastes, cost, human capital, and others. Windrow (Nur Fatin et al. 2014), static pile (Brodie et al. 2013), in-vessel methods (Malakahmad et al. 2017), worm composting (Furlong et al. 2017), and black soldiers fly larva (Sarpong et al. 2019) are among the composting methods that are available to transform food wastes and agricultural residues into compost. With characteristics such as water holding capacity, availability of nutrients needed by plants, and rich in beneficial microorganisms, compost is a good soil conditioner that can improve the soil health and food web, which is part of the focus of circular agriculture.
In Malaysia, the industry, institutions, PBTs, schools, prison, community also individuals taking efforts together to reduce food wastes and agriculture residues by composting. Example of the work are; MARDI through the green campus project launched in 2017 focused on composting the landscape wastes and other organics (Abdul Rahman et al. 2020), University of Malaya (UM) with the Zero Waste Campaign (UM ZWC) aims to spearhead the development of an integrated and sustainable waste management model (Sumiani and Keng 2016), Petaling Jaya City Council, the household home composting program in Petaling Jaya (2009) and “Redirect: Bin 2 Garden” is a composting project carried out at school, the SK Sungai Ramal Dalam (SKSRD), Kajang. Perhaps many other initiatives are not officially documented and scattered. There is also collaboration work with JICA for a Public-Private Partnership (PPP) in Cameron Highland, Pahang, Malaysia. The project entitled SDGs Business Verification Survey with the Private Sector for Food Waste Composting and Creating of Recycling Loop is collaboration between Japan International Cooperation Agency (JICA), Merry Corporation, and Solid Waste And Public Cleansing Management Corporation (SWCorp) as the Malaysia focal point with an attempt to redirect the food wastes and agricultural residues into compost. The project involved various agencies such as MARDI, Department of Agriculture (DOA), and Alam Flora Sdn. Bhd., the municipal waste operator in Cameron Highland.
One of the problems of animal production in Malaysia is the high cost of feeds that is about 40-60% of the production cost. For the ruminants, the grazing area is limited, and for chicken, the grain corn very much relies on the imports. At the same time, the amount of agricultural residues from rice straw, banana trunk, palm oil front, palm oil kernel, sweet corn stover, grain corn stalk, oil palm kernel is abundant. Besides that, there is also a small volume of by-products from the banana, tapioca, rice, soya bean, coffee, and cocoa processing that also can become animal feeds. The problems of these residues are the high fiber content, low protein, and energy that need to be partly processed before fed it to animals.
As an example, palm kernel cake (PKC), a by-product of the extraction of oil from oil palm kernels, is known to contain complex carbohydrates, mannans complexes, mainly used as one of the main components for feed meal formulation for the ruminant industry but not digested easily, in the stomach of the non-ruminant and its use is limited. Solid-state fermentation techniques using selected microorganisms managed to improve the protein content of PKC by some 10 -15 percentage units, and at the same time, decrease the crude fiber content (Sharmila et al. 2014). Thus, make it usable for non-ruminants but is limited to a certain amount. Meanwhile, from rice production, wastes such as broken rice and rice bran are produced. Both broken rice and rice bran are common ingredients in poultry and pig’s rations. Although rice bran produced by small miller generally is not defatted and therefore poses a problem in terms of shelf life, it is still widely used by smallholder farmers to feed their livestock including, free-range poultry (Alimon 2005).
While circular agriculture for environmental sustainability has promoted continuing debates, like the need for land for planting food crops and land for grazing. Concurrently, scientists conducted various studies on using agricultural residues as animal feeds. Among those are the use of pineapple (Gowda et al. 2015), tapioca (Chanjula et al. 2007), banana (Ana Rochana et al. 2017), durian (Suphalucksana and Sangsoponjit 2016), and oil palm frond (Dahlan et al. 2008). In 2018, MARDI received a grant from the Ministry of The Energy, Science, Technology, Environment, and Climate Change (MESTECC) under the Malaysia Scientific Innovation project (MSI) and managed to introduce the technology of silage making to sweet corn growers in Kedah. From the projects, the farmers ensiled about 100 tons of corn stover in a month compared to 25 tons before they received the technology (Ghazali personal communication 25 September 2020). The project positively helps the grower by increasing their income as the silage were sold to farmers involve in rearing ruminants. The project is now is duplicated at Kelantan (KADA).
Recently, the black soldier flies (Hermetia illucens) larva, has been introduced as a composter for municipal solid wastes (Sarpong et al. 2019). There is also an attempt to use BSFL in the bioconversion of agriculture residues and livestock manure. BSFL bioconversion could not only perform a valuable function in the form of FW management but also generate a valuable biofertilizer product (Liu et al. 2020). Although BSLF contains high proteins that make it suitable for animal feeds Sarpong et al. (2019), in his study, reported that the BSFL has accumulated cadmium in the last stage of the larvae (prepupae), thus further research based on Malaysian condition need to be carried out before feeding it to the animals.
The growing medium is essential for root development and must have the ability to hold water and nutrients. Agricultural residues such as empty fruit bunch (EFB) from oil palm processing and coconut coir dust are among the growing medium that are widely used in Malaysia. At the same time, the coconut coir husk has abundantly been used in fertigation or soilless agriculture system. Before, the mesocarp from where the husk is collected, it is is generally disposed of to landfill or burnt. The mesocarp is durable and, when disposed of, it will take an exceptionally long time to degrade. Although coconut is known to have 1001 uses, however, without technologies, it is hard to tap them all. With technology, wastes have now been repurposed into useable agriculture products. In Malaysia, several factories and small farmers are producing coconut coir husk products from the coconut mesocarp, besides other industries producing various products from the coconut such as copra, coconut milk, coconut oil, and activated carbon from coconut shells.
Meanwhile, the rice husk, a by-product of the rice milling industry, is also now being used as a growing medium. Rice husk accounts for about 20 % of the whole rice grains (Esa et al. 2013). Some farmers use rice husk charcoal in their growing medium. The char is a product derived from pyrolysis systems, heated up to a temperature of 400-600°C in the absence of oxygen to vaporize a portion of the material, leaving a char behind. Recently rice husk has been used as a combustion agent in a steam boiler in a rice processing mill. The burning process produces ashes as a by-product that has been used as fertilizer.
Nutritive value improvement
Fermentation technologies are among the technologies that can play a role in converting agriculture by-products into food products. Nata de coco is an example of a coconut by-product that has been turned into a jelly-like substance and claims to contain dietary fiber that can help in indigestion. Currently, there are various innovations to divert agricultural by-products to food with improving nutritive values. Wastes from the brewing process, coffee, tofu and soy milk, misshapen vegetables and fruits, and many others are among that have been turned into food products. The advancement in fermentation technology and the enzymatic process might offer a different landscape for agriculture by-product usage in the future.
CHALLENGES IN REPURPOSING FOOD WASTES AND RESIDUES FOR AGRICULTURE
There is a lack of legal framework on circular agriculture in Malaysia. However, there are policies, strategies, work-plans, and foresights that promoted ecological balance to sustain and conserve biodiversity. However, it is not focused on the agriculture sector but indeed in a bigger perspective. Emphasis also is given to the reduction, reuse, recovery, and recycling of wastes as one of the ways to an improvement towards a cleaner environment. The government has made a moved to improve its waste handling procedures as an initial step with several initiatives implemented for repurposing food wastes and agriculture residues for agricultural use, but it is still in a silo and scattered. Challenges are identified along for this reason.
Although serious waste management efforts have been put forward, there are still hurdles that need to be solved. Malaysia's waste management involves seven ministries. In the Malaysia Plan 11, wastes such as municipals, agricultural, hazardous / schedule (solid and liquid) including mining construction and demolition, sewerage sludge, and radioactive wastes have been proposed to be managed by one ministry. But to date, business is still as usual and unchanged. In the case of Malaysia, the lack of continuous efforts on promoting a collective proposal for better policies and initiatives is one of the problems faced in repurposing food wastes and residuals for agricultural use. Political issues and changes in the ministry portfolio are also two of the reasons that broke the work momentum. Besides that, too many policies related to waste management, under the different ministries sometimes brought confusion, out of focus, and do not reach the grassroots. Therefore, having a holistic policy approach for circular agriculture is essential.
Data on waste generation such as the source, location, composition, volume, and characteristics are essential to plan for a suitable way or products that can be developed, from food wastes and agricultural residues. This kind of data is still insufficient for food wastes and agricultural residues. Detailed compilation and analysis of current waste data and status are extremely hard to get. It is also ambiguous which ministry should take charge of all the waste data on food and agriculture. The effort in collating waste data from the non-commodity crop plants is still lacking. For agriculture, only waste data from oil palm and rice are available. Data for wastes from other crops are still lacking.
When there is an insufficient number of human resources in managing food wastes and agriculture residues technology is essential. Technology also helps to speed up, improve quality, and produce diverse products. Financial support is significantly necessary to develop new technology, especially for the research agency and the universities. Available technology is sometimes not economically feasible, especially for the smallholders. Many technologies are being developed but, some are still in their infancy and immature stages and need government support for scaling up.
Transportation is one of the elements in solid waste management. Among the challenges that are relates to it is, usually costly. Taken the shortest route from the collection spot to the sanitary landfill should reduce the cost of transportation (Zainun et al. 2016). The impact of long-distance waste transportation will increase the consumption of fossil fuel and will take longer time to arrive at landfill areas. The same concept happened when it comes to transporting food wastes and agricultural residues to the processing location. However, the issue is more critical if wastes and by-products are for food or feed processing. Malaysia's climate is very conducive for molds and microorganisms to grow and multiply. Thus, to avoid food wastes or by-products from being contaminated by the unwanted microorganisms, the transport is equipped with a cooling or refrigerated system to stop the fermentation or degradation process from happening. These will add more to the costs. Thus, the data stoking, equipped with GIS location, will help in locating the waste generator and the repurposing location/mill.
Public awareness of waste management is increasing but at a slow pace. The campaign carried out by mySavefood program had received positive impact but needs to be done continuously and consistently. Generally, people will start to react to an issue when they are aware of how serious it is. Thus, there is a need to educate and encourage the public to appreciate food and teach them the way to manage food properly to avoid being wasted. Also, it is crucial to make the society understand that once the food is discarded, the efforts for producing food also become wasted. It is best if this is translated into a real cost for the food to reach the entire value chain. Also, the media can play an important role in awareness creation through the conventional platform or other alternatives. However, the most challenging is to change people's habits in handling waste, which the rate of waste classification is still low except the promotion of government comes with a payback.
Repurposing the food wastes and other agricultural residues will be challenging to the authorities, especially when relating to the financial aid for technology development. However, to materialize all the activities from planning for the policy, technology development, awareness campaign, promotion of technology, and monitoring progress will involve costs. Hence, the government should set priority for specially the fast track grants for matching technology that has been gone through the proof of concept stage with suitable target industry/community/ individual.
Food waste and agriculture residue generation in Malaysia is relatively high and may become a more complex problem in the future if not handled properly. Research for repurposing food wastes and other agricultural residues into other valuable products has been conducted and shows a positive outcome. Compost, biogas, feeds, improving nutritive food, planting mediums are those used in agriculture. The holistic approach in managing food wastes along the value chain can divert it to a more valuable product. Industries involved in producing food should take the initiative to record the wastes generated from their premise. These will help them to minimize their inputs, and at the same time optimize or maximize the produce.
Circular economy, or circular agriculture, in particular, can be adapted at various stages by a smallholder or a larger firm, and food producers. Courses, awareness, and workshops on product diversification might help in creating new ideas for product development from food wastes and other residues, especially for agricultural use. However, consideration should be given to soil nutrient value in the field by not taking all the plant residues out from where it is planted as an assurance to maintain the soil health which is vital for better crop yield. To conclude, the best example of circular agriculture for the smallholder in Malaysia is the organic farming system that circulates their wastes or residues within the system.
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