TERRA : Journal of Land Restoration

Effects of Vermicompost on Soil Physical Properties, Organic Carbon Content, and the Growth, and Yield of Carrot (Daucus carota L.) on Inceptisols

Raisha Amanda April Amertha — 2025-10-25

Carrot (Daucus carota L.) is a root vegetable cultivated year-round, particularly in subtropical and highland regions, serving as a vital source of vitamins and minerals. In Indonesia, favorable environmental conditions—such as temperature, rainfall, humidity, and soil type—support carrot cultivation. Among the dominant soil types, Inceptisols are widely distributed but often constrained by low organic carbon content and suboptimal physical properties. However, studies on the long-term effects of organic amendments, particularly vermicompost, on soil quality and crop performance in highland Inceptisols remain limited. This study evaluated the effects of long-term vermicompost application on selected soil physical properties, organic carbon content, and the growth and yield of carrot plants cultivated on Inceptisols. The experiment was conducted from November 2023 to February 2024 in Air Duku Village, Selupu Rejang Subdistrict, Rejang Lebong District, at an altitude of 1,054 meters above sea level. The site had received vermicompost applications for nine consecutive years. A randomized complete block design (RCBD) was employed, with five vermicompost doses (5, 10, 15, 20, and 25 tons ha⁻¹), each replicated three times, resulting in 15 experimental plots. Soil and plant analyses were performed at the Soil Science Laboratory, Faculty of Agriculture,University of Bengkulu.Application of 15 tons ha⁻¹ vermicompost significantly improved pF1 (37.89%), soil organic carbon content (4.15%), and root weight per plant (198.68 g). The 20 tons ha⁻¹ dose significantly increased soil permeability (6.17 cm h⁻¹) and total plant weight (36.17 kg plot⁻¹), while 25 tons ha⁻¹ enhanced water retention at pF2 (43.95%) and pF3 (39.63%). These findings demonstrate the potential of vermicompost to improve soil quality and carrot productivity in highland Inceptisols and support its integration into sustainable vegetable farming systems.

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Effects of Azolla pinnata Compost and Carbonate Lime (CaCO₃) on Soil Chemical Properties, Nitrogen Uptake, and Yield Components of Sweet Corn Grown in Ultisols

Febri Yunarto — 2025-11-06

Ultisols, covering approximately 705,151 hectares in Bengkulu, represent a marginal soil type with considerable agricultural potential. However, they are limited by low nutrient availability, low pH, low organic carbon, and high concentrations of exchangeable aluminum (Al) and iron (Fe). These constraints significantly affect the growth and productivity of crops such as sweet corn, which is sensitive to acidic conditions and nutrient deficiency. Soil fertility improvement through organic matter application and liming is a promising approach. Azolla, an aquatic fern with high nitrogen content due to its symbiosis with Anabaena azollae, was used in composted form. This study aimed to determine the optimum application rates of Azolla compost and carbonate lime (CaCO₃) for improving nitrogen up take, growth, and yield of sweet corn in Ultisols. The treatments consisted of four Azolla compost levels (0, 5, 10, and 15 tons ha-1) and three lime rates equivalent to neutralizing 0, 1, and 2 units of exchangeable Al. A factorial experiment was arranged in a completely randomized design with three replications. Data were analyzed using analysis of variance (ANOVA), followed by orthogonal polynomial testing. Azolla compost significantly improved soil pH, organic carbon content, stem diameter, plant height, ear weight, biomass (fresh and dry), and nitrogen uptake. Lime applica tion significantly increased soil pH, stem diameter, and plant height. No significant interaction occurred between the two factors. Although positive responses were observed, the yield remained below the potential of the Bonanza F1 variety, likely due to high rainfall and suboptimal treatment levels. These findings support the integration of Azolla compost and lime into soil fertility management practices for sustainable sweet corn production on acidic tropical soils.

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Trait Evaluation of 9 Bird’s Eye Chili (Capsicum frutescens L.) Hybrids on Coastal Area

Emilda Tri Mauli — 2025-10-23

Soil in coastal areas are less suitable for agriculture due to various constraints causing low soil fertility. Until now, there has been no available bird’s eye chili variety tolerant to coastal stress conditions. This research aims to characterize nine bird’s eye chili hybrids grown on coastal land. The research was conducted on coastal land in Kuala Alam Nusa Indah, Ratu Agung District, Bengkulu, from August 2024 to February 2025. The experiment was arranged in a Randomized Complete Block Design (RCBD) with three replications. The traits observed consisted of both quantitative and qualitative variables related to bird’s eye chili growth and yield. Quantitative data were analyzed using ANOVA at a 5% and 1% significance level, followed by a Scott-Knott test, α = 5%, to assess data grouping. Qualitative data were descriptively analyzed by comparing with reference to the descriptor for capsicum. The results showed that the tested hybrids differed in all traits. The results showed that the hybrid H3 (A11 × A7) showed the highest production potential with long fruit and large yields despite slower days to flower and a small stem diameter, while hybrid H8 (A39 × A29) excelled more equally in most traits, including fast days to flower, highest plant height and dichotomous height, large stem diameter, large number of branches, high leaf greenness, long fruit with large diameter, and a high fruit weight. Overall, H3 and H8 bird’s eye chili hybrids are potential to be adapted varieties to coastal areas with improvements in several characteristics.

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Interactive Effects of Soil Type and Chicken Manure Dosage on the Growth and Soil Response of Curly Lettuce (Lactuca sativa L.)

Eggye Andrew Sebayang — 2025-11-10

Andosols and Latosols are widely distributed tropical soils with distinct limitations for horticultural production. Andosols, despite their high porosity and water retention, often exhibit phosphorus fixation and structural instability, while Latosols are characterized by low nutrient reserves and poor cation exchange capacity due to intense weathering. Addressing these constraints, this study investigates the interactive effects of chicken manure fertilizer dosage and soil type on the growth performance of curly lettuce (Lactuca sativa L. var. crispa), aiming to enhance crop productivity and soil quality through organic input management. A factorial experiment was conducted from February to March 2025 at INSTIPER Yogyakarta (118 m asl), using a Completely Randomized Design (CRD) with two factors: soil type (Andosols and Latosol) and chicken manure dosage (0 g, 250 g, 500 g, and 750 g per polybag). Each of the 8 treatment combinations was replicated three times, with two plants per replication, totalling 48 experimental units. Growth parameters measured included plant height, leaf number, shoot and root biomass, and leaf area index, while post-harvest soil analyses evaluated moisture content, pH, organic carbon, total nitrogen, and physical properties. Data were analysed using ANOVA and Duncan’s Multiple Range Test at a 5% significance level. Results demonstrated a significant interaction between soil type and manure dosage on leaf number and fresh shoot weight. The optimal growth response was observed at the 500 g dosage in Andosols, indicating improved nutrient availability and organic matter contribution. Chicken manure also enhanced soil fertility by increasing organic carbon and total nitrogen, especially in Andosols. The study provides novel evidence that tailored organic fertilization can mitigate inherent soil limitations in tropical agroecosystems, promoting sustainable lettuce production through integrated soil fertility management.

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