Category Archives: b_original_articles

Rusda Khairati, Rahmat Syahni*

Social Economic Department, Faculty of Agriculture, Andalas University, Padang 25162, Indonesia

Abstract

Rice field conversion is a transformation of rice field function from rice production to other uses. The accumulation of the case will threaten Indonesian food security in the future if early anticipation is not prepared. The objectives of this research were to figure out the amount of rice field conversion and to identify a path of the impact of population increase on the rice field conversion in Padang city, Indonesia. This research was conducted in Padang city from July to September 2017. Data was collected from Statistics of Padang city and official documents of Padang city from 2006 to 2017. Variables are the number of population, per capita income, land for settlement, length of road constructed, price of rice, and area of rice field. The methods of analysis were trend analysis and path analysis using IBM SPSS 23 and Smart PLS 3 softwares. The result showed that there was about 31.9 ha/year of rice field converted to other uses in Padang city within the last ten years. The population increase cause the indirect impact on the rice field conversion. The impact of population increase on the rice field conversion passes through per capita income and land for settlement as mediating factors.

 Keywords: Path analysis, Population increase, Rice field conversion

Ita Mowidu^*, Kamelia Dwi Jayanti, Yulindatanari Ridwan, Dolfie Tinggogoy

Faculty of Agriculture, Sintuwu Maroso University, Poso, Indonesia

Abstract

Iron can be in form of crystalline, amorphous and organic in the soil. The objective of this research was to study the effect of compost application on soil organic Fe composition, Fe uptake and the plant content as well as rice yield at Inceptisol, in Meko. The treatment used was the application of 5 t ha^-1 compost that was mixture of rice straw and cocoa pods with various composition. The treatments were K0: without compost, K1: 100% straw compost, K2: 75% straw compost + 25% cocoa peel (CP), K3: 50% straw compost + 50% CP, K4: 25% straw compost +75% CP, and K5: 100% CP compost. Observations regarding Fe-p (Iron-organic) were recorded using selective solvents 0.1 M Na-pyrophosphate, likewise, Fe uptake; and rice yield were also estimated. The results showed that the application of compost had a significant effect on Fe-p at 40 and 70 days after planting (DAP), the Fe content in rice at 14, 40, 75 days and harvest time, as well as on Fe uptake at 40, 75 DAP and harvest time; However, it had no significant impact on grain weight per clump. The peak of Fe-p formation occurred at 40 DAP because of high Fe reduction. Rice Fe levels > 500 mg kg^-1 during observation followed by Fe uptake which continued to increase with increasing plant age. The yield of rice increased by 7.90-27.30% compared to control and 2.60-21.04% compared to the average yield according to the description of Inpari-1 variety.

Keywords: Compost, Fe content, Fe uptake, Organic Fe

Irvan Subandar¹, Lukman Hakim^2*, Irfan Suliansyah³, Syakur Syakur²

¹Student of Doctoral Program of Agricultural Sciences, Universitas Syiah Kuala, Indonesia

²Faculty of Agriculture, Universitas Syiah Kuala, Indonesia

³Faculty of Agriculture, Universitas Andalas, Indonesia

Abstract

Stem rot disease caused by Sclerotium rolfsii Sacc. and soil acidity are the two problems that need to be addressed on peanut cultivation in peatland. Dolomite addition not only reduces soil acidity but also affect fungal pathogenicity. To study this, we used split plot design with dolomite dosages of 0, 10, and 20 t ha^-1 as the main plots, and peanut varieties viz. Hypoma-1, Hypoma-2, Jerapah, Talam-1, Talam-2, Talam-3, Bison, and Takar-2 as the subplots. Three replications were used for these combinations. Dolomite dosages and peanut varieties interacted significantly on the pathogenicity of S. rolfsii at 15 DAI and filled pod percentage. The highest pathogenicity (30%) was found in Takar-2-20 t ha^-1 dolomite, while the lowest pathogenicity (1%) was found on Hypoma-2-0 t ha^-1 dolomite. The highest percentage of filled pods was on Bison-10 t ha^-1 dolomite (79%), and the lowest was on Takar-2-0 t ha^-1 dolomite (29%). Singly, the highest pathogenicity of S. rolfsii was found on Takar-2, while Hypoma-2, Jerapah, Talam-2, Talam-3 & Bison were more resistant. Dolomite dosage singly was only affecting the growth and the percentage of filled pods. The highest filled pods were on 10 t ha^-1 dolomite, however if the increase to 20 t ha^-1 dolomite had insignificant effect to enhance filled pods. These results indicated that resistant-high-yielding variety of peanut is most likely to survive stem disease and being productive in peatland enriched with proper amount of dolomite.

Keywords: Stem rot disease, Sclerotium rolfsii, Peatland, Acidity, Pathogenicity

Yulnafatmawita Yulnafatmawita*, Hermansah Hermansah, Ratih Purwaningsih, Zainal Abdul Haris

Soil Science Department, Faculty of Agriculture, Universitas Andalas, Padang, Indonesia

Abstract

Soil erosion is a kind of the worst soil degradation phenomenon in the world which could be due to soil mismanagement. The research aimed to predict the amount of soil erosion and to find out the alternative controlling techniques was conducted at sugarcane plantation in Lawang, Agam Regency and soil laboratory of Universitas Andalas, Padang, Indonesia. Soil sampling was taken at 5 slopes (0-8%, 8-15%, 15-25%, 25-40%, and >40%). Soil parameters were collected and analyzed at field and laboratory to get soil erodibility data. Soil erosivity was calculated based on rainfall data in that area from the last 10 years. Soil erosion was predicted using USLE formula and tolerated erosion using Hamer concept. The results showed that eroded soil increased by steeper slope from 0 to 40%. The predicted soil erosion was higher than the tolerated one for each slope level except under rather flat area (0-8% slope). The erosion hazard level in the research site belonged to low (for 0-8% slope), medium (for 8-15%), and high (for >15% slope). Therefore, alternative techniques should be introduced to control the erosion, among which were soil hummock for all slope levels and terraces for steep slopes. Constructing traditional terrace at area having 8-15% slope, and perfect bench terrace at area having >15% slope would decrease the actual erosion from 34.73 to 18.52 t/ha/y (at 8-15% slope), from 147.4 to 6.55 t/ha/y (at 15-25% slope), from 415.4 to 18.46 t/ha/y(at 25-45% slope), and from 203.2 to 18.04 t/ha/y (at >40% slope).

Keywords: Conservation techniques, Predicted erosion, Slope, Sugarcane plantation, Wet tropical region

Kamaruzaman K, Irniza Rasdi*
Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

Abstract

The aim of this study was to show that the presence of mosquito predators in the ecosystem decreased the incidence of dengue cases. Data was obtained by daily inspection of 85 Aedes mosquito potential breeding point at 15 dengue outbreak hotspot localities with at least one mosquito predator present at the locality and the VEKPRO programme used in the monitoring of dengue cases in Malaysia. The mosquito predators identified were dragonfly, dragonfly nymph, gambushia fish, tadpole and frog. The study was done at the district of Petaling from 4th January, 2015 to 4th July 2015. The results show that the presence of mosquito predators hinder the breeding of Aedes mosquito in the ecosystem which is related to a decrease in dengue cases
Keywords: Aedes mosquito, Aedes larvae, Dengue cases, Mosquito predators, Breeding point

Noor Shaeda Ismail1, Irniza Rasdi*1, Emilia Zainal Abidin1, Sarva Mangala Praveena1
1Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

Abstract

Calcium carbide (CaC2) is used as a chemical fruits ripening agent. A specific amount of phosphine gas (PH3) released from the CaC2 reaction with moisture is known to be toxic to respiratory system. This study was carried out to evaluate the potential risk of the CaC2 and PH3 among mango farmers and fruit sellers. The sample size was 200 respondents recruited by universal sampling in Perak, Kedah and Perlis. The procedure to perform chemical health risk assessment (CHRA) was based on the Use and Standard of Exposure of Chemical Hazards to Health Regulations 2000. The permissible exposure limit for PH3 is 0.3 ppm 8. The average TWA for carbide wrapping and ripening in the farm (C) and at the fruit stall (D) was 0.033 ppm while for sales activities at the fruit stall (E) was 0.017 ppm. Thus, the magnitude rating for C and D was ≥ 0.1 O.E.L but < 0.5 O.E.L and for E was < 0.1 O.E.L. It was found that for respondents who were directly involved with the ripening process, the risk is significant for both CaC2 and PH3 and the risk were also found significant for those who were not involved directly with these chemicals such as staffs who only involved in sales especially in fruit stall. This study will be beneficial to famers where it can be used for them to understand the effect of carbide to human health and to increase awareness on the health impact of the use of CaC2 to workers.
Keywords: Calcium carbide, phosphine, Risk assessment

Umi Raihana Abdul Rahman, Sharifah Norkhadijah Syed Ismail*, Emilia Zainal Abidin, Sarva Mangala Praveena
Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Malaysia

Abstract

Landfill leachate contains many contaminants and it has been a concern due to its toxicity to the environment. This study aims to measure the heavy metals concentration (Cu, Cd, Pb, Ni and As) and physicochemical characteristic of the crude leachate discharged from municipal waste landfill. Leachate samples from a young landfill (less than five years old) and old landfill (10 years of age) were analysed for its physicochemical properties and heavy metals to the Malaysian wastewater standards and other international standards. Samples were analysed for heavy metals analysis using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) Optima 8300. The physicochemical characteristics of the leachate in young landfill were significantly higher (p< 0.05) than the old landfill. Cu (0.0265 ± 0.0007 mg/l) and Ni (0.1773 ± 0.0004mg/l). Significant relationship between physicochemical characteristic with Pb. From the results it was concluded that physicochemical characteristics and heavy metals showed that both landfill leachates had significant difference except for Cd, Pb and As.
Keywords: Municipal solid waste, Leachate, Landfill, Physicochemical properties, Heavy metals

Umi Raihana Abdul Rahman, Sharifah Norkhadijah Syed Ismail*, Emilia Zainal Abidin,
Sarva Mangala Praveena
Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Malaysia

Abstract

Objective of this study was to measure heavy metals accumulation in Mozambique Tilapia (Oreochromis mossambicus) exposed to crude leachate. Tilapia was exposed to leachate from municipal landfills at the volume of 2% to 20% v/v for 96 hours. Heavy metals were measured using inductive coupled plasma optical emission spectrometry (ICP-OES) Optima 8300. All heavy metals were higher in the gills compared to the muscles and the concentration was higher in old leachate. The highest element detected in fish gills was Cu (22.72 ± 0.60 mg/kg) followed by Ni (1.66 ± 0.021 mg/kg) and Pb (0.50 ± 0.011 mg/kg). Ni also was highly detected in fish muscle with the mean of 1.32 ± 0.024 mg/kg. Cd was commonly detected in muscle and gills of young and old leachate (0.14 ± 0.01 mg/kg). It was concluded that heavy metals detected pose a risk of metals exposure through Tilapia consumption.
Keywords: Heavy metals, Crude leachate, Tilapia, Bio-accumulation, Municipal waste

Qamarul Haziman Abdullah, Amir Izzwan Zamri* Tuan Zainazor Tuan Chilek, Fisal Ahmad, Shamsul Bahri Abd Razak, Wan Najma Farhaten
Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

Abstract

Extraction of chitin and chitosan from natural sources are universally acknowledged as they can be used in many applications. This study aims to determine the optimum extraction condition of the chitosan from moon crab (Matuta lunaris) and to determine the yield and chemical properties of the extracted chitosan. Chitosan from moon crab (Matuta lunaris) was extracted and optimized by using response surface methodology (RSM) using two variables with five levels which were the deacetylation temperature (60, 70,80, 90 and 100ºC) and deacetylation time (2, 4, 6, 8 and 10 h). Three major steps which were demineralization, deproteination and deacetylation were involved in the extraction process. A full factorial of optimal randomized design was implemented using Design Expert 11 software. Four responses of chitosan extracted were evaluated which were yield, degree of deacetylation, molecular weight and ash content in order to determine the optimum condition of extraction. The deacetylation temperature and time for optimum chitosan extraction condition were suggested at 84.62 ºC and 9.46 h, respectively. The selected conditions (84.62 ºC and 9.46h) gave actual response values28.96 ± 0.93% of chitosan yield, 56.68 ± 1.66% of deacetylation, 567.17± 13.91 kDA of molecular weight and 10.59 ± 0.62% of ash content in chitosan powder. The extracted chitosan will be used as clarifying agent injuice production in the future studies.
Keywords: Matuta lunaris, Moon crab, Extraction, Chitosan, Response surface methodology

Amir Izzwan Zamri*, Farhana Sukor, Fisal Ahmad, Tuan Zainazor Tuan Chilek, Shamsul Bahri Abd Razak, Qamarul Haziman Abdullah, Najma Farhaten Latiff
Faculty of Fisheries and Food Science,University Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

Abstract

In this study, hydrolysate was produced from Asiatic hard clam (Meretrix meretrix) meat by enzymatic hydrolysis using Alcalase® 2.4 L and the optimum hydrolysis condition was determined. Optimization was carried out with face centred central composite design in response surface methodology. The optimum condition of hydrolysis conditions was determined by three levels and four independent variables, which were temperature °C (45, 55, 65°C), enzyme to substrate level, % v/w, (1, 1.5, 2%) time, (60, 120,180 mins) and pH of the substrate (7.5, 8.5, 9.5). Degree of hydrolysis (%) (DH) was chosen as the dependent variable. The optimum conditions for enzymatic hydrolysis of Asiatic hard clam meat were obtained at temperature ºC, enzyme to substrate concentration (ES), hydrolysis time and pH of 65°C, 1%, of 60 minutes and pH 7.5 respectively. In this condition, the predicted and actual value of degree of hydrolysis (DH) obtained were 25.79% and 26.32 ± 0.35% respectively. Suggested model for the enzymatic protein hydrolysis of Asiatic hard clam meat was a two-factor interaction (2FI) model. Asiatic hard clam hydrolysate powder contained of moisture, crude fat, ash, crude protein of 60.09 ± 0.88%, 7.36 ± 0.10%, 2.18 ± 0.29%, and 8.12 ± 0.02% respectively. DH (%) and proximate analysis of hydrolysate from Asiatic Hard clam was compared with hydrolysate of two different species of mollusk which was green mussel (Perna viridis) and blood cockle (Anadara granosa) from previous studies.
Keywords: Protein hydrolysate, Meretrix meretrix, Hydrolysis