Advanced Modeling of Potato Productivity Using Soil Physical Properties and Vegetation Index Transformations

Global potato production reached approximately 383 million metric tons in 2025, with Indonesia contributing around 1.22 million metric tons (0.32% of global output). However, the sustainability of Indonesia’s potato production is increasingly threatened by soil quality degradation in key growing regions. Existing predictive studies have largely focused on soil physical properties, with limited incorporation of remote sensing technologies. This study investigates the potential of Unmanned Aerial Vehicle (UAV) as a high-resolution, non-invasive tool to estimate potato yield through vegetation index transformations. Utilizing a split-plot experimental design across elevation gradients, we integrated soil physical properties with UAV-derived vegetation indices—Visible Atmospherically Resistant Index (VARI), Green Leaf Index (GLI), and Normalized Green-Red Difference Index (NGRDI). Results reveal that Total Nitrogen (TN), Base Saturation, and Bulk Density significantly influence yield variability, and can be accurately estimated using NGRDI, GLI, and a modified GLI (GLI CS), respectively. A multiple linear regression model was developed to predict potato yield: y = 24.22 + 7.26(NGRDI) + 9.87(GLI) + 28.42(GLI CS). This research demonstrates the efficacy of UAV-based spectral analysis in enhancing yield prediction models, offering a scalable and precise approach for sustainable potato cultivation. Future work should incorporate machine learning to improve model robustness and assess applicability across varied agro-ecological contexts

The Influence of Organic and Inorganic Amendments on Phosphorus Chemistry in Two Acidic Soils of Southwestern Ghana

A study in southwestern Ghana compared the effects of organic and inorganic additives on P availability and related factors in two acidic soils, Ankasa and Abenia. Different amounts of P as KH2PO4 were applied: 0.067 g kg-1 for Abenia and 0.041 g kg-1 for Ankasa. Soil samples were treated with cow dung, Chromolaena odorata, and poultry droppings for six weeks to increase standard P requirement and neutralize exchangeable Aluminum. Data analysis was performed using GenStat (version 14). An analysis of variance (ANOVA) was conducted for the soil amendments, followed by Tukey’s comparison test at a 5% significance level to identify significant differences among the soil amendments. The result showed that higher rates of organic amendments significantly increased pH, available P (Bray 1 and NaHCO3-P), NaOH-P, and reduced exchangeable Al concentration. Poultry droppings and cow dung impact notably improved soil quality. At the same time, CaCO3 had similar effects on soil pH. However, it did not significantly affect P availability or NaOH-extractable P. CaSO4 and CaCO3 had minimal impact on phosphorus distribution, suggesting that altering pH or exchangeable Al does not necessarily change P fractions. Poultry droppings, rich in P, could be a potential alternative to lime in enhancing P availability and reducing soil acidity

Spatial Distribution of Soil Properties and Soil Fertility Status in the Paddy Rice Field of Oransbari

Soil properties and soil fertility status of paddy rice fields are considered important factors related to the yield and production of rice; therefore it is essential to understand those properties across the farm.  The objectives of this research is to quantify the soil properties and soil fertility status of paddy-rice soil and their spatial variability in Oransbari. Forty-two composite soil samples (0-30 cm) were taken across paddy rice fields and analyzed for soil chemical properties and fertility status.  Geostatistical analysis and ordinary kriging interpolation methods were used to quantify soil variability and its fertility status across the farm.  The results showed that total soil Nitrogen ranges from 0.11% to 0.17%), organic-C (1.47-6.94%), C/N ratio (11-47), total-P (13-99 mg 100 g-1), available-P (30-227 mg kg-1), total-K (27-54 mg 100 g-1), soil pH (5.83-6.93), base saturation (70-100%), and CEC is 30.51-51.23 me 100 g-1. The spatial variability of all soil characteristics exhibited medium and fit the stable model, except for available Phosphorus and Potassium.  Most rice paddy fields in Oransbari showed high soil fertility status, which indicated that high-yield rice production can be achieved for this region, however, land management factors should be considered for sustainable land use

Application of Rice-Husk Biochar to Coarse-Textured Ultisols and the Effects on Soil Fertility Indicators at Different Amendment-to-Sampling Intervals

The low fertility status of the highly weathered tropical soils offers the opportunity to study the potential and optimum application rate of biochar as an organic soil amendment, especially for the dominant coarse-textured Ultisols. Despite the relatively fast mineralisation of organics in these soils and the need to synchronise nutrient release crops critical stages of nutrient requirement, the time corresponding to peak effects of biochar remains unclear. The effects of rice-husk biochar (RHB) on the soil fertility of sandy-loam Ultisols at 0, 7.5, 15, 30, and 60 Mg ha-1 equivalents in 2-kg soils were assessed at 0, 2, 4, 8, and 12 weeks of incubation (WOI). Treatments were prepared in batches to enable concurrent sampling for all five incubation intervals. The RHB enhanced soil fertility across the incubation intervals, with optimal rates as 15 Mg ha-1 for soil pH and 30 - 60 Mg ha-1 for macronutrients availability. Relative to the its non-application, RHB increased soil pH-H2O, total N, available P, exchangeable bases, exchangeable acidity, apparent CEC and base saturation by 4-30%, 43-100%, 30-202%, 13-240%, 14-675%, 21-126% and 7-82%, respectively. Soil pH tended to decrease after, while available P progressively decreased before 8 WOI, when treatment effects were generally most pronounced. At an all-encompassing optimal rate range of 30-60 Mg ha-1, RHB could reduce soil acidity and enhance the macronutrient status of coarse-textured Ultisols over at least 12 weeks, soil fertility restoration effects of which are likely to be most pronounced around 8 weeks

Study of the Quality of Biogeotextile Materials as Semi-Organic Mulch on Saline Land

Degraded land affects almost all ecosystems and can harm the progress and quality of human life, so it needs attention. Saline soil is a land degradation with high salt content that causes toxic effects, increases root osmotic pressure, and inhibits plant growth. One solution is using organic mulch processed into biogeotextiles because it can provide solutions for erosion control and soil stabilization while minimizing negative impacts on the ecosystem. This research was conducted from May to August 2023 in the experimental garden of the Faculty of Agriculture UPN ‘Veteran’ East Java. This study used a group randomized design with one factor,  the type of geotextile material consisting of reed grass (RG), straw (ST), pandanus odorifer (PO), and sugarcane bagasse (SB). This research was conducted with a litterbox of 20x20 cm filled with 100 g of biogeotextile material. The results obtained show that pandanus odorifer biogeotextile material is the best biogeotextile material because it can last a long time on the soil surface, but can still be adequately mineralized, according to the results obtained, reducing the C/N ratio and C-Organic but increasing total nitrogen. Decomposition is closely related to the materials’ quality rather than external factors. The quality of the material, namely lignin, organic carbon, C/N ratio, and nitrogen, influences the decomposition process. Furthermore, this technology can be applied to improve soil productivity and to keep soil healthy

Effect Application of Cellulolytic Bacteria Consortium And Palm Kernel Ash on Red Chili Plants in Peat Soil

Limited agricultural land in Indonesia makes peatland an alternative land for agricultural intensification. Peat soil has a low fertility, so applying cellulolytic bacteria and palm oil shoot ash is recommended. This study aimed to determine the effect of cellulolytic bacteria consortium and oil palm shoot ash on the growth and yield of red chilies on peat soils. The research was conducted in Empat Balai Village, Kampar. The study used a factorial in a completely randomized design (3x3) and three replications. The first factor was the cellulolytic bacteria consortium (0, 20, and 30 mL polybag-1), and the second factor was palm ash (0, 3, and 6 Mg ha-1 equivalent to 0.126 and 252 g polybag-1). The application of cellulolytic bacteria consortium and its interaction with oil palm shoot ash had no significant effect on all observed variables. While, the application of palm ashes significantly affected plant height, stem diameter, number of fruits, and fruits weight

Spatial Analysis of Available and Suitable Land for Oil Palm in Ketapang Regency

Oil palm plantations are a leading sub-sector in Indonesia's agricultural sector which is experiencing rapid growth. Ketapang Regency, as the area with the largest oil palm plantation area in West Kalimantan, has great potential for further development. This study aims to analyze the suitability of land for oil palm plantation development using the Multi-Criteria Decision Making (MCDM) approach integrated with the Geographic Information System (GIS). The Analytical Hierarchy Process (AHP) method is used to determine the weight and value of subcriteria that affect land suitability. The criteria used include slope, land cover, spatial pattern, soil texture, effective depth, drainage, temperature, rainfall, and distance from the road. The results of the analysis show that most of the Ketapang Regency (79.56%) is included in the S1 (highly suitable) and S2 (suitable) categories, with the dominance of the S2 category (67.11%). However, only 3.17% of the regions met the S1 category, while most of the regions (23.29%) were in the S2 category. The results of the overlay with the Regional Spatial Plan (RTRW) and existing land use show that most of the appropriate areas are located outside the protected area. This study concludes that Ketapang Regency has great potential for the development of oil palm plantations, but development must consider regulations and environmental impacts. Further research recommendations include an evaluation of the socio-economic impacts, biodiversity, and climate change on the sustainability of oil palm plantation development in Ketapang Regenc

Influence of Land Use and Land Cover Variations on Soil Carbon Sequestration Potential in the Northern Madhupur Tract, Bangladesh

AbstractThis study examines the effects of diverse land use and land cover (LULC) types on soil physico-chemical properties and carbon sequestration potential in the northern Madhupur Tract, Bangladesh. Soil samples were collected from seven LULC types – sal forest, social forest, orchard, bare land, agricultural land, protected area, and built-up area across three depths (0–15 cm, 16–40 cm, and 41–70 cm) between April and September 2022. Key parameters analyzed included texture, bulk density, pH, electrical conductivity (EC), total nitrogen, available phosphorus, exchangeable potassium, available sulfur, organic carbon (OC), and soil organic carbon (SOC). Soil texture ranged from clay loam to clay. Bulk density was the lowest in built-up areas (1.57–1.62 gcm⁻³) and the highest in protected areas (1.97–2.20 gcm⁻³). Orchard soils had the highest surface moisture (23.26%). Surface soils showed the highest EC (0.82 dSm⁻¹), total N (0.11%), available P (118.6 ppm), and OC (1.07%), while pH increased with depth, peaking at 6.15. SOC stock differed significantly among land uses (F = 6.56, p < 0.05), highest in social forests (138.67 tha⁻¹) and built-up areas (134.04 tha⁻¹). Corresponding CO₂ mitigation potentials were 508.93 t C ha⁻¹ and 491.34 t C ha⁻¹. Agricultural land had the lowest SOC stock (85.31 tha⁻¹). Enhancing carbon storage through better land management is vital for sustainability and climate resilience

Changing of Sandy Soil Chemical Properties with Azolla microphylla and Quail Manure

Uncontrolled land conversion causes reduced land area for plant cultivation. The alternative used for rice cultivation is the marginal land such as sandy soil, however, several constraints led to very low productivity, so it needs proper management such as the addition of organic matter. The purpose of this study was to determine the changes in the chemical properties of sandy soil treated with Azolla microphylla and quail manure. The pot research was carried out in the Greenhouse of the Faculty of Agriculture, Universitas Sebelas Maret, with a factorial Completely Randomized Design (CRD) method, with 2 factors. Factor I was Azolla microphylla (A) (A0= 0, A1= 50, A2= 100, A3= 150 tons ha-1). Factor II was quail manure (Q) (Q0= 0, Q1= 20, Q2= 40 tons ha-1). Azolla microphylla and quail manure were incubated for 14 days under anaerobic conditions. The results showed that the application Azolla microphylla and quail manure increased chemical properties on sandy soil significantly. The addition of Azolla microphylla (100 tons ha-1) and quail manure (40 tons ha-1) increased the chemical properties of sandy soil such as cation exchange capacity (CEC), available-P, ammonium, available-K, available-Ca, electrical conductivity (EC) and redox potential (Eh)

Water Table Control Model for Maize Cultivation of C Typology Land on Tidal Lowland Reclaimed Area of South Sumatra, Indonesia

Tidal lowland productivity in type C is still low. Most of them have only been able to cultivate rice twice a year. The third cultivation of corn often fails due to a lack of water. The research objective is to determine an operational model for water management in the field for maize cultivation at several planting times. Model area is conducted at a tertiary block of reclaimed tidal lowland, Telang Jaya Village Primer 8 Delta Telang I, of  Banyuasin District. There are three planting times treatments: the fourth week of April, the second week of June, and the first week of July, 2021. A water management model was applied to control the drainage system, in which the water level in the tertiary channel is maintained at a depth of 50 cm. When groundwater drops below 70 cm, and there is no rain, pump irrigation is provided. Results of the field experiment showed that the maize crop showed similar growth quality at each phase. Land with a planting period of June and July still requires water addition using pump irrigation. It was applied on 14th and 18th August. Moreover, the maize cultivated at the end of April did not require pump irrigation. All treatments have generally similar production with an average magnitude of 8.0 Mg ha-1. The highest production is 8.73 Mg ha-1, which is planted in the first week of July