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Vegetables in Cambodia are commonly sold in informal markets lacking food safety standards and controls. Currently, data on microbial contamination of vegetables in Cambodian informal markets are limited. The purpose of this study was to investigate Salmonella enterica and indicator organisms (generic Escherichia coli and coliforms) on the surface of fresh vegetables sold in informal markets in Cambodia. A sample of loose-leaf lettuce, tomatoes, and cucumbers were collected from 104 vendors at four informal markets in Battambang and Siem Reap provinces during rainy and dry seasons. Detection methods for Salmonella enterica were adapted from the Food and Drug Administration's Bacteriological Analytical Manual (FDA BAM). Quantification of coliforms and generic E. coli populations was conducted by plating onto E. coli/Coliform count plates. Salmonella enterica was most prevalent on lettuce during the dry season (56.5%, 95% CI [41.0, 70.8]) compared to the rainy season (15.4 95% CI [7.5, 29.1]), whereas no significant seasonal differences were apparent for tomatoes and cucumbers. Regardless of season, levels of Salmonella enterica were highest on lettuce (5.7 log CFU/g, 95% CI [5.5, 5.9]), relative to cucumbers (4.2 log CFU/g, 95% CI [3.8, 4.6]) and tomatoes (4.3 log CFU/g, 95% CI [4.1, 4.6]). For generic E. coli, prevalence was higher during the rainy season (34.0%, 95% CI [25.4, 43.8]) as compared to the dry season (9.1%, 95% CI [4.9, 16.5]), with the highest prevalence estimated on lettuce. Similarly, the level of coliforms on lettuce and tomatoes was greater during the rainy season (6.3 and 5.3 log CFU/g, 95% CI [5.7, 6.8] and [4.7, 5.8], respectively), relative to the dry season (5.2 and 3.9 log CFU/g, 95% CI [4.7, 5.7] and [3.4, 4.4], respectively). In summary, these results indicate seasonal patterns for microbial prevalence in lettuce, and an overall high level of bacterial contamination on raw vegetables sold in Cambodian informal markets.

Highlights Soil type, operational speed, machinery weight, and power size affected corn seeding rate and seeding efficiency Corn growth and yield was affected by seeder type, so utilization of appropriate machinery is very important Having cover crop residue on the land can maintain soil moisture for a longer time than tilled land Abstract.Conservation agriculture (CA) is gaining popularity in Cambodia to sustain soil fertility, productivity, and profits. However, the adoption remains slow due to the low engagement so far of local services into CA machinery and technology. Therefore, this paper aimed to compare different no-till seeders and residue retention methods for corn (Zea mays L.) sowing and to determine their effects on growth and yield. The experiment was conducted in Rattanak Mondul District, Battambang Province, in the wet season of 2019. Sunn hemp (Crotalaria juncea L.) was grown as a cover crop for 74 days prior to corn. Each main plot was 14 × 34 m and was subdivided lengthwise with 4.0-m buffers for operations of two different seeders, namely one-row Morrison seeder mounted on 14 kW Oggun tractor and four-row Brazilian seeder mounted on 56 kW John Deere tractor. The results show that using Brazilian seeder saved around 50% of seed and 80% of time, when compared with Morrison seeder. Plant population, plant diameter, and kernel characteristics were also significantly greater with Brazilian seeder, when compared to the Morrison seeder. A combination of the Brazilian seeder and Cambodia made crimper plots had larger ear size and weight. Volumetric Moisture Content (VMC) was significantly affected by residue retention with higher VMC for rolled and crimped residue compared to disked/incorporated residue. The study demonstrates that using no-till equipment such as roller crimpers and no-till planters is feasible in Cambodia’s small farming systems although more research is needed to study long-term effects on crop yields and soil health. Keywords: Battambang Province, Conservation agriculture, Green manure, Soil improvements

In northwest Cambodia, the majority of smallholder households own livestock. Poor consistency in feed supply throughout the year is a major constraint to livestock performance. Another critical cha...

A total of 60 crossbred pigs (Yorkshire × Duroc, initially 56.5 kg) were used in a 42-day trial to evaluate the effect of replacing a commercial high protein supplement with soybean meal and/or a base mix in rice bran-based diets on pig growth performance. Pigs were allotted to pens by body weight and pens were randomly assigned to dietary treatments in completely randomized design. There were 4 dietary treatments with 3 or 4 replicate pens per treatment and 4 pigs per pen. Dietary treatments were: 1) 80% rice bran with 20% high protein supplement (RBS20), 2) 95% rice bran with 5% high protein supplement (RBS5), 3) 97.5% rice bran with 2.5% base mix (RBB2.5), and 4) 92.5% rice bran with 5% soybean meal and 2.5% base mix (RBSBB). The base mix included vitamins, macro and trace minerals, L-Lysine, L-Threonine, and DL-Methionine. Overall (d 0 to 42) average daily gain was greater (P < 0.001) for pigs fed RBSBB and RBS20 diets than pigs fed the RBS5 or RBB2.5 diets. Pigs fed the RBS5 diet had reduced (P < 0.004) average daily feed intake compared to all other treatments. Similarly, feed efficiency (feed/gain) was improved (P < 0.004) for pigs fed RBSBB and RBS20 diets compared with pigs fed RBS5 or RBB2.5. For economics, income over feed cost was the greatest (P < 0.01) for the diet containing soybean meal and base mix compared to pigs fed the RBS20 diet, SBS5, and RBB2.5. In conclusion, feeding pigs a rice bran diet with base mix and soybean meal had similar growth performance and increased economic return compared to feeding a rice bran diet with high protein supplement. Use of soybean meal and base mix provides an opportunity for increased economic return for pig farmers.

A total of 60 castrated male pigs (Yorkshire x Duroc, initially 17.36 kg) were used in a 42-day trial to evaluate the effect of complete feed feeding level and morning glory on growth performance of growing pigs. Pigs were allotted to pens and randomly assigned to three dietary treatments: A) completed feed fed ad libitum; B) complete feed fed at 75% of intake of treatment A, and C) treatment B with ad libitum availability of morning glory. The design was a completely randomized design (CRD) with five pens (replications) of each treatment with four pigs per pen. Average daily feed intake (dry matter basis) was higher (P < 0.001) for pigs fed treatment A (1420 g/d) compared to treatment B (1048 g/d) as expected, with treatment C intermediate (1178 g/d; 1048 g/d complete feed + 130 g/d morning glory). Average daily weight gain of pigs fed ad libitum was greater (P < 0.001) than pigs restricted fed with pigs which provide morning glory intermediate (871, 674 and 714 g, respectively). Feed efficiency improved (P < 0.024) for pigs fed the restricted feed level compared to pigs fed complete feed ad libitum or pigs restricted fed but provided morning glory (1.63, 1.56 and 1.65, respectively). For economics, feeding complete feed ad libitum improved (P < 0.001) income over feed cost compared to restricted feeding or providing morning glory (USD 41.48, 33.42, and 33.89/pig, respectively). In conclusion, feeding growing pigs a complete diet ad libitum resulted in the greatest growth rate and profitability. Offering morning glory (Ipomoea. aquatica) to pigs fed a restricted level of complete feed did improve final body weight, but the extra cost of feeding morning glory offset this advantage resulting in similar profitability on an income over feed cost basis.

The lack of hygiene and sanitation practices and insufficient infrastructure in Cambodian informal markets may increase the risk of food contamination, specifically raw vegetables, which in turn may increase the chances of contracting a foodborne disease. The aims of this study were i) to quantify the prevalence of Salmonella enterica based upon seasonal differences (rainy and dry) between surface types (food contact surface [FCS] and non-food contact surface [NFCS]) and between location of vendors within the market (inside and outside), and ii) to characterize Salmonella enterica serotypes abundance in informal markets in Cambodia. A total of 310 samples were screened for Salmonella enterica prevalence following the U.S. Department of Agriculture guidelines and confirmed by PCR. Whole Genome Sequencing was performed and the serotype for each isolate was determined in-silico using SeqSero 1.0 on draft genomes. A total of 78 samples were confirmed positive for Salmonella enterica . During the dry season, Salmonella enterica was more prevalent on FCS compared to NFCS (estimated probability of detection [confidence interval]: 0.41 [0.25,0.59] and 0.17 [0.08, 0.32], respectively; P=0.002), though no differences were apparent during the rainy season. Further, there was no evidence of any differences in Salmonella enterica prevalence based on location within the market (P=0.61). Sixteen Salmonella enterica serotypes were detected across multiple surfaces. The most common serotypes were Rissen (n=18), Hvittingfoss (n=11), Corvallis (n=10), Krefeld (n=8), Weltevreden (n=6), and Altona (n=6). The availability of accurate data on the prevalence of Salmonella enterica in informal markets is crucial for the development of effective surveillance and implementation of suitable intervention strategies at the domestic level, thus preventing future foodborne illness.

Soil organic carbon (SOC) pools, particularly labile pools, and soil enzymes are good indicators of short-term impacts of soil management. We hypothesized that labile SOC pools drives C accumulation and enzyme activity can be an efficient indicator for C build up in short-term conservation agriculture. The aims of this study were to quantify the impacts of tillage and crop rotations with diverse crop residue inputs on changes in SOC labile pools and enzymatic activities in rice-, soybean- and cassava-based cropping systems designated as RcCS, SbCS and CsCS, respectively. The four treatments in each cropping system consisted of: conventional tillage (CT), no-till in which main crops (rice, soybean and cassava) were grown in a one-year frequency pattern (NT1) and, no-till in which the main crops were grown in bi-annual rotations with maize (NT2 and NT3). After 5 years experiment period, greater hot-water extractable organic C (HWEO-C) stocks of 61%, 55% and 53%, and permanganate oxidizable C (POX-C) stocks of 23%, 21% and 32% were attributed to NT than those in CT soils under RcCS, SbCS and CsCS, respectively, at 0–5 cm soil layer. The pyrophosphate extractable organic C (PEO-C) and chemically stabilized organic C (CSO-C) stocks were almost constant in each depth among treatments, except 0–5 cm in CsCS. The β-glucosidase activity was 18%, 28% and 49% greater in NT than those in CT soils at 0–5 cm under RcCS, SbCS, CsCS, respectively. Arylsulfatase activity was 36% and 39% greater in NT than in CT under SbCS and CsCS, respectively but no significant differences in RcCS. A strong and positive correlation (P

Rice is one of the most important agricultural commodities throughout the Mekong River Basin including the Tonle Sap Lake floodplains in Cambodia. Recent increases in hydropower dams along the Mekong River have likely altered the surface water hydrology impacting the arable areas and soil qualities for rice production in the Tonle Sap lowland. Along with the hydrological impacts, the region’s rice farming is facing a rapidly changing climate. It is critical to understand how the hydrological changes associated with dam development impact the region’s rice production in a changing climate. The aims of this study were to assess the impacts of recent increases in hydropower dams on the timing and areas of rice cropping in the Tonle Sap floodplains and to evaluate the effects of changing hydrology, rising temperature, and adaptive farming practices on rice productivity using a process-based rice crop model: ORYZA (v3). The effect of dams on arable areas for rice was identified by a remote-sensing method based on the PhenoRice algorithm for the period of 2001–2019 in two rice-growing provinces: Kampong Thom and Battambang. The PhenoRice method identified an increase in rice growing areas as well as shifts in both timing and location of rice cropping towards the sources of irrigation during the dry season since 2010. The ORYZA model simulated a substantial yield reduction with an increase of 2 °C in air temperature in the region. The model predicted that the rice productivity in the region is sensitive to soil organic carbon content which is expected to change with surface water hydrology. The model also predicted that region’s rice yield can increase by optimizing the timing and amount of N fertilization. The findings from this study highlight how hydrology, climate, and agronomic practices can interact to impact rice production in the Lower Mekong Region and provide insights for effective water management and agronomic practices to attain food security in the region in a changing climate.