Kristamtini Kristamtini

Food‐associated bacterial communities may influence food quality, spoilage, and microbiological safety, creating a need for broad culture‐independent screening approaches. This exploratory study characterized bacterial communities in fresh and processed foods and screened for putative foodborne pathogen‐associated taxa using full‐length 16S rRNA metabarcoding. Food products obtained from three independent retail vendors in Semarang City, Indonesia, were combined through a two‐stage pooling procedure into six category‐level composites representing fresh foods (FF1–FF3) and processed foods (PF1–PF3). Oxford Nanopore long‐read sequencing of the nearly full‐length 16S rRNA gene was used for bacterial community profiling. Descriptive alpha‐diversity analysis showed that fresh‐food composites generally had greater taxon richness, whereas processed‐food composites showed higher Shannon and Simpson diversity values and lower taxon dominance. Lactic acid bacteria constituted a major component of both food categories, with higher cumulative relative sequence abundance in fresh‐food composites and substantial variation in dominant genera among food matrices. Low‐abundance sequence assignments corresponding to putative foodborne pathogen‐associated taxa were detected in both fresh‐ and processed‐food composites, with 13 such taxa observed across fresh foods and nine across processed foods. The higher cumulative relative sequence abundance in processed foods was largely concentrated in the fish‐ and seafood‐based PF2 composite and was predominantly associated with Vibrio‐related assignments. Full‐length 16S rRNA metabarcoding therefore shows potential for broad characterization of food‐associated bacterial communities, while suspected pathogen‐associated signals require confirmation using independent samples and targeted molecular or culture‐based methods.

Soil pollution with heavy metals poses a significant ecological challenge globally. Bacteria can be utilized for the bioremediation of heavy metals in the soil. This study evaluated the bioremediation potential of a bacterial consortium comprising Pseudomonas putida R2.13, Bacillus megaterium RK.3, and Stenotrophomonas maltophilia RG.3 on corn plants grown in heavy metal-contaminated soil. The study was conducted in two activities: the first involved an inoculant test assessing the growth of corn sprouts under varying inoculant levels (0, 10, 20, and 40 mL) and different concentrations of heavy metals (Hg, Cr, and Pb). The second was a greenhouse study employing a factorial randomized block design with the same inoculant levels and six distinct growing media compositions: a mixture of tailings, unpolluted soil, and compost (%). Results indicated that a 40 mL inoculant significantly mitigated Hg toxicity (up to 150 mg L ⁻¹ ), Cr (30 mg L ⁻¹ ), and Pb (1500 mg L ⁻¹ ) in corn sprouts. Furthermore, applying 40 mL of the bacterial inoculant in growing media M4 (10:45:45) resulted in a 58.63% remediation in Hg concentration from 49.53 mg L ⁻¹ , accompanied by a decrease in soil pH and bacterial population. These findings suggest that bacterial consortia can be applied for soil bioremediation and agricultural purposes.

Sorghum is an important food crop commodity in the midst of climate change conditions and the threat of a global food crisis. Sorghum, which has an adaptive advantage to all land conditions, is suitable for use as a food substitute for rice and wheat. The purpose of this study was to evaluate the economic value, farmers’ perceptions, and specific strategies for developing sorghum in Central Java and Yogyakarta, Indonesia. The research was conducted in Wonogiri Regency, Central Java, and Gunungkidul Regency, Yogyakarta from September to November 2022. The research was carried out through the observation of 120 respondents with indicators of farming characteristics and farmers’ perceptions of sorghum development, as well as focus group discussions (FGD) and depth interviews with indicators of internal and external factors for sorghum development. The analysis used is benefit cost (BC) to evaluate the economic value of sorghum farming, the Likert scale to determine farmers’ perceptions of sorghum, and Strength Weak Opportunity Threat (SWOT) to determine specific strategies for developing sorghum. The results showed that sorghum farming is feasible to develop in Wonogiri Central Java and Gunungkidul Yogyakarta because it provides a profit value greater than production costs with a BCR value of >1. The perception of farmers in Central Java regarding the development of sorghum is included in the very good category with an average value of 3.31, and the perception of farmers in Yogyakarta is included in the good category with an average value of 2.55. The operational policy strategy for developing sorghum in Wonogiri Central Java and Gunungkidul Yogyakarta is an expansion strategy (S-O).

Rice production in the karst dryland is still low, due to soil characteristics that lack nutrient availability. Meanwhile, upland rice has received less attention, and it has not been used to its full potential. This study aimed to evaluate the effect of various combinations of inorganic fertilizers, poultry manure, and upland rice varieties on the production and economic value of karst dryland in Gunungkidul, Yogyakarta. This experiment was arranged in a factorial design, with inorganic fertilizers, poultry manure, and upland rice varieties set in a randomized block design with three replications. The first factor was a combination of inorganic and organic fertilizer rates: 72 N kg ha⁻¹ + 26 P₂O₅ kg ha⁻¹ + 25 K₂O ha⁻¹ + 3 t ha⁻¹ organic, 92 N kg ha⁻¹ + 36 P₂O₅ kg ha⁻¹ + 30 K₂O kg ha⁻¹ + 2 t ha⁻¹ organic, 112 N kg ha⁻¹ + 46 P₂O₅ kg ha⁻¹ + 35 K₂O kg ha⁻¹ + 1 t ha⁻¹ organic. The second factor is the upland varieties of Inpago 8, Inpago 10, and Inpago 12 and lowland variety Inpari 42 Agritan GSR, as checked. Based on the study, we concluded that the combination of 92 N kg ha⁻¹ + 36 P₂O₅ kg ha⁻¹ + 30 K₂O kg ha⁻¹ + 2 t ha⁻¹ poultry manure fertilizers with Inpago 8 resulted in an IDR profit of 23,586,000 ha⁻¹, and it is the most recommendable fertilizer and variety combination to be developed in the karst dryland, in consideration of land fertility and sustainability.

The serious problems of sandy soils for crop development are low water-holding capacity, nutrient retention, and low content of all nutrients. The objective of the study was to increase the nutrient content of sandy soil and evaluate nutrient types that mostly affect the high shallot yield with reasonable economic values. The field experiment was conducted on the upland sandy loam soil. Six treatments consisting of complete nutrients, N-, P-, K-, Mg- and S-omission tests were arranged in a randomly completed block design with four replicates. The observed parameters included soil physicochemical properties, tissue nutrient content, growth, yield, and input-output of shallot cultivation. The results showed that N, P, K, Mg and S application successfully increased shallot bulb, achieving 11.43 t ha⁻¹ on sandy soil. The order of shallot tissue content was K > N > P~Mg > S, where the S, P, N, and Mg are limiting factors, as revealed by significantly lower relative yield (varying from 79 to 88%). The highest weight loss during storage occurred for S-omission treatment (40 to 60%), indicating insufficient S tissue is the most responsible for the quality of shallot. The complete nutrient treatment gave the highest income (7446.09 USD ha⁻¹) with a revenue cost ratio of 2.41 compared to other treatments. The tolerance limit for price reductions that do not cause losses was 58.59%.

The problem of rice farming in Indonesia is the increasing extent of nutrient-poor land due to the lack of addition of organic matter and continuously inundated irrigated rice fields, causing the production of greenhouse gas emissions, such as methane gas (CH₄), to increase. The study aims to determine the impact of organic fertilizers and rice varieties on rice yield, methane emissions, and the feasibility of farming in nutrient-poor rice fields. The study used a randomized block design in factorial with four replicates. The first factor is the type of organic fertilizers (compost of rice straw and goat manure), and the second factor is the variety of rice (Ciherang, Inpari 20, and Inpari 30). The results showed that the productivity of Inpari 20 (8.02 t·ha⁻¹) was significantly higher than that of Inpari 30 (6.10 t·ha⁻¹) and Ciherang (6.91 t·ha⁻¹). The highest yields of Harvest Dry Grain (HDG) to Milled Dry Grain (MDG) were the Inpari 20 (88.23%), Inpari 30 (86.94%), and Ciherang (85.04%). Methane (CH₄) emissions were highest in the Ciherang variety (56.4 kg h⁻¹ season⁻¹), followed by Inpari 30 (40.8 kg h⁻¹ season⁻¹), and lowest in Inpari 20 (22.3 kg h⁻¹ season⁻¹). Compared to Inpari 30 and Ciherang varieties, the Inpari 20 variety with rice straw compost has broad development viability in nutrient-poor paddy fields (highest R/C ratio and break-even point). More research on organic rice is needed to determine the productivity and emissions (methane, nitrite, carbon dioxide).

Storage of rice for a certain period of time can lead to decrease in the quality of rice, hence the purpose of this study was to determine the effect of storage method and duration on total sugar content, starch, and preference level of Inpari 43 GSR white rice and black rice Sembada Hitam varieties. The research was conducted at the Food Biochemical Chemistry Laboratory, Faculty of Agricultural Technology, Gajah Mada University The stage of this research is to cook the rice, and the storage time in two ways inside and outside the rice cooker is 0, 9, 18, and 27 hours, respectively. Then tested for sugar content, starch and level of preference. The experimental design used was factorial randomized design with 3 replications The stage of this research is to cook the rice, and the storage time in two ways inside and outside the rice cooker is 0, 9, 18, and 27 hours, respectively. Then tested for sugar content, starch and level of preference. The experimental design used was a factorial randomized design with 3 replications, while the Sembada Hitam variety had initial sugar content of 0.019%, and 0.007% when in stored in the rice cooker and 0.001% outside the rice cooker. The increase in starch content increased at 9 hours of storage in Inpari 43 GSR and Sembada Hitam varieties and a decreased at 18 and 27 hours. Based on the test of preference for color, aroma, taste and texture, panelists preferred 9 hours of storage in the rice cooker both on rice Inpari 43 GSR and Sembada Hitam because more suitable for consumption.

One of the advantages of ratoon technology was that the plant age becomes shorter so that it can utilize water in limited conditions. This study aimed to determine the feasibility (agronomy and economy) of cultiviting Rojolele local rice ratoon to anticipates drought. The study was conducted in the rice fields of Polaman, Argorejo, Sedayu, Bantul from May to December 2019. First planting as "Un-ratoon" treatment and second planting as "Ratoon" treatment. The un-ratoon and ratoon technology follows the Integrated Crop Management (ICM), but ratoon technology does not conduct seedbed and tillage. Morphological observations included plant height, number of productive tillers, leaf length, leaf width, panicle length, number of filled grains per panicle, number of empty grains per panicle, weight of 1,000 grains, weight of grain per hill and productivity. Observation data were analyzed using the Independent Sample T-test. An analysis of farming was carried out by calculating the B/C, R/C and MBCR (Marginal Benefit Cost Ratio). Ratoon cultivation technology was feasible to be developed because it has more than one BC ratio, RC ratio and MBCR value. With ratoon technology, period for crop maturity becomes shorter (45.66% decrease) so that it was a technological breakthrough to anticipate climate change (drought).

Rice (Oryza sativa L.) requires large amounts of silica for its growth. This study aims to determine the response of leaf anatomy and agronomic performance of several rice varieties to the application of Silica fertilizer. The study was conducted in the first rainy season of 2018 (November 2017 to March 2018 in Semanu, Gunungkidul, Indonesia. The study was arranged in factorial, the first factor was 4 rice varieties (V1 = Inpari blast, V2 = Inpari 42, V3 = Ciherang, and V4 = Inpari 33), the second factor is the treatment of Silica fertilizer dosage (P1 = 250 kg / ha of Silica fertilizer; P2 = 500 kg / ha of Silica fertilizer, P3 = 1,000kg / ha of husk ash, and P4 = 750 kg / ha of Silica fertilizer). Observing agronomic traits including plant height, number of productive tillers, number of filled grains per panicle, and productivity). In addition to observing agronomic traits, microscopic observations of leaf anatomy were also carried out with thick upper and lower epidermal cells, cuticles in the upper and lower epidermis, mesophyll thickness in major and minor intervenous regions. The data obtained were analyzed for variance (ANOVA = Analysis of variance) and Duncan’s advanced test using SAS version 9.2. The results showed that the administration of silica fertilizer increased rice growth and productivity as well as increasing the thickness of the epidermis and upper and lower cuticles both in major and minor intervenous. The highest productivity was achieved by Inpari 42 varieties in the application of 750 kg Silica fertilizer/ha (9.69 ton/ha Harvested Dry Grain).

Identification of local red rice was important to study for genetic diversity. The objective of the study was to identify the morphological characteristics to estime the genetic diversity and heritability in the broad sense of 11 local red rice cultivars. The quantitative data (plant height, leaf length, leaf width, number of productive tillers, panicle length, 1,000-grain weight and number of grain per panicle) were measured by their CVg values for determining their relationships and heritability. The results can be used for parent selection in a breeding program. Results showed that the number of productive tillers, leaf length and the number of grain content per panicle for 11 local red rice from Yogyakarta were efficient and effective characters in selection because the characters have wide of the coefficient of variation genetics and high heritability value.