Eka Tarwaca Susila Putra

Sugarcane is a strategic crop supporting national sugar self-sufficiency, where fertilization efficiency plays a crucial role in sustainable production. This study evaluated the effects of reduced NPK fertilizer rates on vegetative growth, chlorophyll content, and leaf anatomical traits of sugarcane. The experiment was conducted in Sleman Regency, Yogyakarta, using a randomized complete block design with five NPK fertilizer rates: 100% (850 kg ha⁻¹), 80% (680 kg ha⁻¹), 60% (510 kg ha⁻¹), 40% (340 kg ha⁻¹), and 20% (170 kg ha⁻¹). Results showed that reductions in NPK fertilizer significantly affected vegetative growth parameters, chlorophyll a and total chlorophyll contents, and leaf epidermal thickness, while other anatomical traits remained relatively stable. Moderate fertilizer rates (510–680 kg ha⁻¹) produced growth and physiological responses comparable to the recommended rate. These findings indicate that partial reduction of NPK fertilizer can improve nutrient-use efficiency without substantially compromising sugarcane growth.

This study evaluated whether reducing the dose of soil amendment and enriching it with vermicompost and biochar could maintain soil properties and support the growth of pineapple (Ananas comosus (L.) ‘GP3’) cultivated on degraded Ultisols. This experiment aimed to assess the effect of reducing the dose of soil amendment and decreasing the inorganic fertilizer application to 75% of the recommended dose on soil properties, nutrient uptake, and plant growth. The experiment used a split-plot design with varying doses of enriched compost combined with vermicompost and biochar, and two levels of inorganic fertilizer (75% and 100% of the recommended dose). Soil properties, nutrient uptake, and plant growth were measured and analyzed using Dunnett's test at ? = 0.05. The results showed that reducing the dose of enriched compost and decreasing the inorganic fertilizer by 25% generally resulted in soil properties, nutrient uptake, and plant growth comparable to those obtained using a higher dose of compost only and a full dose of inorganic fertilizer. Soil properties indicators generally remained stable across all treatments, with a small and transient decrease in soil nitrogen, which only occurred in the 25CVB1 treatment at later stages of plant growth. Although Ca and Mg uptake in the 25CVB3 treatment was lower at 4 months after planting, at 8 months after planting, the uptake levels were comparable across all treatments. These findings indicate that compost enriched with vermicompost and biochar allows for reduced doses of soil amendment and inorganic fertilizers without compromising soil quality or pineapple growth, thus providing a sustainable and cost-effective management strategy for pineapple cultivation on Ultisols.

Increasing soil salinity led to a decline in rice yield, particularly in the coastal areas of West Aceh affected by the 2004 tsunami. This study aimed to examine the characteristics of soil salinity in the coastal rice fields of West Aceh during the rainy and dry growing seasons, and to evaluate its impact on rice yield. Soil sampling was conducted using purposive sampling during two growing seasons: the dry growing season (April-September 2024) and the rainy growing season (October 2024-March 2025). Clustering analysis showed that three clusters (sodic and saline-sodic) formed during the dry season, while two clusters (sodic and non-saline non-sodic) formed during the rainy season. The Suak Pante Breuh site changed cluster membership, being sodic in the dry season and non-saline non-sodic in the rainy season. Among all soil chemical properties, soil electrical conductivity (EC) and sodium adsorption ratio (SAR) showed the strongest negative correlations with rice yield, particularly during the dry growing season (r = -0.55; r = -0.50). This study found that rice yield was more affected by salinity than by sodicity. This was illustrated in the Suak Timah 5 site, which was classified as sodic during the rainy season but showed similar rice yields to non-saline and non-sodic sites. In contrast, during the dry season, this site was classified as saline–sodic and recorded lower rice yields than other locations that were classified as sodic.

Coastal rice fields often have sandy textures, high salinity, low organic matter, and frequent waterlogging caused by seawater intrusion. These conditions, together with fluctuating rainfall, alter soil chemical properties and negatively affect crop cultivation. This study aimed to evaluate soil chemical properties, assess water quality, and analyze their relationship with rice productivity in the coastal rice fields of Pangandaran, West Java, Indonesia. Composite soil samples were collected from areas of 5-7 ha and analyzed for their chemical properties. Water quality was assessed based on the levels of dissolved oxygen (DO), nitrate, phosphate, electrical conductivity (EC), and pH. Data were analyzed descriptively, and Principal Component Analysis (PCA) was applied to group the sampling points. The results showed that organic C and total N were low to moderate, while available-Si and exchangeable K+ were very low. In contrast, P?O?, exchangeable Na+, and exchangeable Mg2+ were very high, whereas cation exchange capacity (CEC) and exchangeable Ca2+ were low to moderate. Based on EC and water table depth, PCA grouped the 20 sampling points into three clusters: high salinity (points 16-19), waterlogging (points 2-7), and relatively normal conditions (points 1, 8-15, 20). Average rice productivity was 2.48 t ha-1 in cluster 1, less than 1 t ha-1 in cluster 2, and 3,63 t ha-1 in cluster 3. These findings highlight the need for site-specific land and water management strategies to sustain rice cultivation in coastal areas.

Beet tubers are perishable horticultural commodities, cannot be stored for long, and are commonly consumed in fresh conditions. Postharvest handling of beet tubers needs to be carried out to maintain their freshness Chitosan and other packaging used in postharvest handling of fresh beet tubers have not yet been reported. This study aims to determine the effect of chitosan coating and types of packaging on beet tubers on the physical quality of beet tubers. The study was a randomly designed group with two factors; the first factor was chitosan concentration, and the second factor was the kinds of packaging. Chitosan concentration consists of 5 levels, namely 0, 0.5%, 1%, 1.5%, and 2%, and the type of packaging includes no packaging (Without), plastic packaging with holes (Perforated), ordinary plastic packaging (Ordinary) and plastic vacuumed (Vacuum). The beet tubers were soaked in chitosan solution of 0, 0.5%, 1%, 1.5%, and 2% for 1 minute, air-dried, then were packaged with no packaging, plastic packaging with holes, ordinary plastic packaging, and plastic vacuumed. . The physical quality parameters observed were moisture content, weight loss respiration rate,electrolyte leakage, total dissolved solid (TDS), ascorbic acid, betacyanin, betaxanthins, tuber firmness, damage percentage, and visual quality rating (VQR). Data were analyzed using Anova variant analysis and then continued with Tuckey tests with a 95% confidence level using R studio software. The results showed that chitosan coating did not affect the physical quality of beet tubers, while packaging affected the quality of beet tubers. The most suitable packaging to maintain the physical quality of beet tubers is plastic packaging with holes (perforated).

Cocoa derived from cuttings is expected to overcome the limitations of grafting and hybrid seed propagation. This study aimed to determine the typology of cocoa seedlings derived from cutting, grafting, and hybrid seeds and the similarity among propagations, and assess the biochemical content of budwood cuttings and its relationship with the success rate. This research was conducted at the greenhouse of the Indonesian Coffee and Cocoa Research Institute, East Java, from April to December 2022 by adopting a completely randomized design. A single-factor experiment was performed on propagation methods, namely hybrid seed (HS), orthotropic cutting (OC), plagiotropic cutting (PC), orthotropic grafting (OG), and plagiotropic grafting (PG). The growth characteristics, anatomical characteristics, and biochemical contents of cuttings were observed. Results showed that compared with PC, OC generated a larger root pith diameter that played a role in the improved growth performance. The leaf area, net assimilation rate, and relative growth rate in OC were similar to those in HS. The time to produce OC was similar to PG to meet the minimum standard requirements of ready-to-plant seedlings. However, the root volume, area, and length in OC were below those in HS and still needed to be improved. The cuttings derived from the budwood garden had higher sucrose contents than those from the production garden. Therefore, obtaining OC and PC samples from a budwood garden is recommended to achieve a high success rate.

The Indonesian population has not yet met the high demand for soybeans by domestic production. Researchers aim to increase soybean (Glycine max L.) production and optimize land use through intercropping with oil palm during the immature plant phase 1 (IP-1). This study evaluated the effectiveness of Rhizobium sp. and Bacillus spp. inoculation in enhancing the growth and yield capacity (physiological activity, growth, and productivity) of soybeans planted between rows of IP-1 oil palms at PT Perkebunan Nusantara (PTPN) IV, Serdang Bedagai Regency, North Sumatera. The field study employed a factorial randomized complete block design (RCBD) with two factors and four blocks as replicates. Data from the experiments were analyzed using analysis of variance (ANOVA), least significant difference (LSD) testing at a 5% significance level, Spearman correlation, and structural equation modeling (SEM). The results showed an interaction effect between Rhizobium sp. and Bacillus spp. inoculation on the treatment variables of plant height, number of leaves, total dry weight, nutrient uptake (N, P, and K), IAA and GA3 hormones, total Bacillus in soil, total Bacillus in roots, pod dry weight, and yield. In treatment without Rhizobium sp., soybean plants inoculated with Bacillus spp. showed a significant contribution to all treatment variables. However, in soybean plants inoculated with Rhizobium sp., the addition of Bacillus spp. did not significantly affect the physiological activity, growth, and yield of soybeans. The performance of Bacillus spp. in boosting the physiological capacity and development of soybeans slowed down in the presence of Rhizobium sp. This indicated a potential antagonistic relationship between Bacillus spp. and Rhizobium sp.

Seawater intrusion causes salinity and waterlogging in the coastal agricultural land of Pangandaran, Indonesia. Both limiting factors cause a decrease in soil chemical properties. The decline in rice yield occurred due to the low soil chemical properties. The study aims to identify the soil’s chemical properties based on limiting factors and to reveal its relationship with rice productivity in the coastal agricultural land of Pangandaran. Soil sampling was conducted using a purposive sampling method, and the samples were analyzed in the laboratory. Various soil properties are grouped into three clusters using hierarchical clustering. The cluster of waterlogging high salinity has very high Na-exchangeable with EC ranging from 0.21 - 4.93 dS m-1, while the other two clusters contain high Na-exchangeable and EC ranging from 0.101 - 0.581 dS m-1. Rice productivity under waterlogging-low salinity is <1 t ha-1, no waterlogging-low salinity is 3.63 t ha-1, and waterlogging-high salinity is 2.48 t ha-1. There are negative correlations between Na-exchangeable, water depth, and duration of waterlogging to rice yield (R2= -0.33; R2= -0.58; R2= -0.90). Multiple stresses cause limiting factors, and low soil chemical properties can inhibit plant development. The presence of waterlogging-low salinity has a strong impact on decreasing rice yield. Finally, our study provides an overview of the coastal agricultural land of Pangandaran based on multiple stresses. Furthermore, improved soil properties are needed with good management techniques to make it suitable for rice cultivation.

A coastal rice field is generally characterized by salt-affected soil and low soil quality for rice cultivation. Identifying soil chemical properties in these areas is necessary to determine soil management options for rice production. Therefore, soil samples were collected from 33 sampling points in the Wedung Sub-district of Demak Regency in the late dry season of 2021 to evaluate the variation among soil chemical characteristics in a coastline rice field. Soil samples were obtained beneath the topsoil (0-20 cm soil depth) and observed for electrical conductivity, exchangeable potassium, sodium, calcium, magnesium, and cation exchange capacity. Soils in the research field were categorized as slightly salty (0.75-2 dS m-1) to lightly salty (2.0-4.0 dS m-1) with very high sodium (>2 cmol(+) kg-1). Exchangeable potassium was dominated by moderate (0.3-0.7 cmol(+) kg-1) and low categories (0.2-0.3 cmol(+) kg-1). Based on soil calcium-to-magnesium ratios, around 6% of all samples were classified as calcium-deficient. The range of soil cation exchange capacity was 22-30 cmol(+) kg-1 and classified as high soil cation exchange capacity. Rice productivity in the salt-affected soil was around 4 t ha-1. Strategies for soil and controlling plants, such as soil amelioration and salt-tolerant rice cultivars, should be pursued to support plant growth and enhance rice productivity in the salt-affected soil, particularly in the coastal area.