Bioremediation of palm industry wastes using vermicomposting technology: its environmental application as green fertilizer

Responses of soil nutrients and rhizosphere microbial communities of a medicinal plant Pinelliaternata to vermicompost

Vermicomposting is an important strategy for restoring soil function and fertility. However, information on the effects of vermicompost application in intensive Pinellia ternata planting systems has rarely been reported. Here, we focus on the effects of different vermicompost levels and chemical fertilizer (CF) strategies on soil chemical properties, soil enzymes, and soil rhizosphere microbial communities (bacteria and fungi) in a field experiment. Compared to no added fertilizers (CK), vermicompost was more effective than the CF treatment in increasing P. ternata yield. We found that the 5 t ha-1 vermicompost treatment (VC2) significantly increased the tuber yield by 44.43% and 6.55% compared to the CK and CF treatment, respectively, and water-soluble exudates by 6.56% and 9.63% (P < 0.05). The vermicompost and CF treatments significantly increased the total phosphorus (TP), urease (Ure), and soil catalase (Cat) contents (P < 0.05). Compared to the vermicompost and CK treatments, the CF treatment significantly decreased soil organic carbon (SOC), C/N ratio, and soil acid phosphatase (Pac) (P < 0.05). Redundancy analysis (RDA) showed that Ure and total potassium (TK) were the major drivers in the bacterial community, whereas TP, total nitrogen (TN), Pac, and TK were the major drivers in the fungal community. We also found a positive correlation between soil enzyme activities, including between Ure and bacterial genera (Clostridium, Pseudoclavibacter, Stella, Hyphomicrobium, Mesorhizobium, and Adlercreutzia). In summary, vermicompost application promotes P. ternata soil microecosystems and improves soil fertility, soil enzyme activities, and rhizosphere microbial structure and function. Vermicomposting is a novel and promising approach to sustainable ecological cultivation of Chinese herbs via the promotion of soil properties and beneficial organisms.

Synergy of the Tropical Earthworm Pontoscolex corethrurus and Oil Palm Bagasse in the Removal of Heavy Crude Oil

The tropical endogeic earthworm Pontoscolex corethrurus, a non-standard species used in ecotoxicity, has been found in crude oil-contaminated habitats. We estimated the removal of total hydrocarbons from heavy crude "Maya" oil on an artificially contaminated soil with a median lethal concentration of P. corethrurus and an addition of oil palm bagasse. P. corethrurus had a high survival rate, and the addition of oil palm bagasse led to a greater growth and an increase in abundance of bacteria and fungi. The activity of P. corethrurus and the nutritional quality of oil palm bagasse had a significant impact on the removal of a larger amount of petroleum hydrocarbons from contaminated soil. We concluded that the endogeic earthworm P. corethrurus and oil palm bagasse acted synergistically to achieve a more effective removal of total petroleum hydrocarbons from soil. These results show the potential for using P. corethrurus to remove, either directly or indirectly, crude oil from soil.

How COVID 19 effect Malaysian paddy industry? Adoption of green fertilizer a potential resolution

The COVID-19 pandemic resulted in more than 4.3 million confirmed cases and more than 2,90,000 deaths worldwide. It has also given rise to fears of an imminent economic crisis and recession. Social distance, self-isolation, and travel restrictions have led to a reduction in the workforce across all economical sectors and have led to a loss of many jobs. Schools have closed down, and the need for commodities and manufactured goods has decreased. On the other hand, the need for medical supplies has increased significantly. The food sector is also facing increased demand as a result of panic buying and storing food products. In response to this global outbreak, we summarize the socioeconomic effects of COVID-19 on the various aspects of the world economy. In Malaysia, the COVID-19 epidemic has checked the resilience of the agriculture sector. Especially the Malaysian paddy industry as country imports 30% of its overall consumption from different parts of the world. The real price of rice triplicating for the consumers, which was alarming for nations in this pandemic situation. The Government of Malaysia introduced the National Agrofood Policy 2011-2020 (NAP4) in 2010 as a guidance document for the implementation of agricultural sector development programs and projects in Malaysia. The NAP4 's 10-year term is to be finished by the end of 2020. Several sectors demonstrate substantial success after approximately 8 years of introduction, while the other classes often lag behind the goal and progress quite slowly. Agricultural sector performance is affected by many problems and challenges. In acknowledgment of the poor success of this field, the Ministry of Agriculture and Agri-Based Industry has launched new approaches, policies, and programs that can change the agricultural sector more rapidly. The new direction is aimed at ensuring national food security and boosting farm and revenues. The authorized government agency needs to revise the policy formulation where Malaysia needs to set stages to revolutionize and modernize the rice farming to address the problem faced by the paddy sector in this pandemic situation to adopt GF. In this study, the researcher focuses on the improvisation of the policy to increase the paddy production sustainably.

Malek R. Inventory and composting of yard waste in Serdang, Selangor, Malaysia

Composting of yard waste is one of the waste management approaches in the Malaysian Agricultural Research and Development Institute (MARDI) in Serdang, Selangor, Malaysia. The yard waste inventory was developed in the headquarters' area and a pilot-scale study was performed on the potential compost product. The total amount of yard waste generated from June 2017 to December 2017 was 16.75 tonnes with an average generation of 0.60 tonnes per week on the dry weight (d.w.) basis. The collected yard waste consisted of three major characteristics, namely dry leaves, fresh green leaves, and grass cuttings, and a waste estimation technique was applied to determine the composition of these three elements. The acquired information was used to formulate the initial compost mixture. The wastes were then mixed with an appropriate amount of livestock manure and other wastes to obtain the optimum initial C/N ratio, which was then found in the analysis to range between 25:1 and 42:1. Meanwhile, the C/N ratios obtained from the matured compost product were from 10:1 and 15:1. Moreover, most of the compost yield ranged between 50% and 70% (w w-1 d.w. basis), while the percentage of the seed germination in the compost was over 95%. The viability of the project was indicated from the economic analysis, with benefit to cost ratio (BCR) values of more than 1. The results also suggested that the large scale composting of yard waste in MARDI was feasible and its applicability is continuous. This technique also fulfilled the objective of producing quality compost, which was suitable for agricultural use.

Bio-Optimization of Chemical Parameters and Earthworm Biomass for Efficient Vermicomposting of Different Palm Oil Mill Waste Mixtures

The present study reports mathematical modelling of palm oil mill effluent and palm-pressed fiber mixtures (0% to 100%) during vermicomposting process. The effects of different mixtures with respect to pH, C:N ratio and earthworms have been optimized using the modelling parameters. The results of analysis of variance have established effect of different mixtures of palm oil mill effluent plus palm press fiber and time, under selected physicochemical responses (pH, C:N ratio and earthworm numbers). Among all mixtures, 60% mixture was achieved optimal growth at pH 7.1 using 16.29 C:N ratio in 15 days of vermicomposting. The relationship between responses, time and different palm oil mill waste mixtures have been summarized in terms of regression models. The obtained results of mathematical modeling suggest that these findings have potential to serve a platform for further studies in terms of kinetic behavior and degradation of the biowastes via vermicomposting.

Effects of different vermicompost extracts of palm oil mill effluent and palm-pressed fiber mixture on seed germination of mung bean and its relative toxicity

Several treatment technologies are available for the treatment of palm oil mill wastes. Vermicomposting is widely recognized as efficient, eco-friendly methods for converting organic waste materials to valuable products. This study evaluates the effect of different vermicompost extracts obtained from palm oil mill effluent (POME) and palm-pressed fiber (PPF) mixtures on the germination, growth, relative toxicity, and photosynthetic pigments of mung beans (Vigna radiata) plant. POME contains valuable nutrients and can be used as a liquid fertilizer for fertigation. Mung bean seeds were sown in petri dishes irrigated with different dilutions of vermicomposted POME-PPF extracts, namely 50, 60, and 70% at varying dilutions. Results showed that at lower dilutions, the vermicompost extracts showed favorable effects on seed germination, seedling growth, and total chlorophyll content in mung bean seedlings, but at higher dilutions, they showed inhibitory effects. The carotenoid contents also decreased with increased dilutions of POME-PPF. This study recommends that the extracts could serve as a good source of fertilizer for the germination and growth enhancement of mung bean seedlings at the recommended dilutions.