Molecular identification of isolates from local microorganisms as potential biofertilizer

<p>Local microorganisms (MOL) are liquid fertilizers commonly used by farmers to help increase crop production. Beneficial microbes in MOL need to characterize their interactions and ability to produce growth drive compounds. The purpose of this research is to identify the superior microbial isolates from MOL made by farmers from Cibodas Lembang Bandung, Indonesia that can produce phytohormones as biofertilizers. The results of the microbial selection of MOL derived from three best microbes are 1A-2 NFB, 4A-1 NFB, and 4B-1 NFB with the ability to produce auxin, i.e., 19.41 ppm, 17.18 ppm, and 10.59 ppm, respectively. The compatibility test between the three isolates showed negative results so that it was possible to apply three microbes as a consortium. The results of a molecular identification with a 16S rRNA analysis indicate strain microbe 1A-2 NFB: <em>Bacillus cereus</em> (99.88% homology), 4A-1 NFB: <em>Bacillus cereus</em> (99.76% homology), and 4B-1 NFB: <em>Lysinibacillus</em> sp. (99.88% homology).</p>

Rubber bark dust-zeolite composite improved mechanic strength of soft paddy soil through improved microstructure

<p>Soft paddy soils are not a stable soil structure that leads to the decline of rice production in Kedah, Malaysia. The soil had high compressibility and water content, and low soil strength thus the agricultural machines could not be operated above this soil. Therefore, this study was conducted to improve the mechanical strength of soft soils in paddy fields using an organic amendment. The organic amendment used in this study was made from amended materials comprising clinoptilolite, kieserite, humic acid, and rubber bark dust. The study was carried out in the paddy field area of Alor Pudak district, Kedah, Malaysia, and it was divided into five treatments of amendment dose, i.e: 0 kg (control or P0), 125 kg (P1), 250 kg (P2), 375 kg (P3) and 500 kg (P4) with each plot size about 0.20 ha. The soil samples were then analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), and the unconsolidated undrained triaxial compression test (UU-test) to characterize their amended properties. The XRD results clearly exhibited changes in the mineralogical composition of all treated plots with an increasing smectite content (1200 to 1300 intensity). Furthermore, the SEM results showed that clay particles in the treated plots have been flocculated to form close-knit, more stable soil structures. After the organic amendment application, the mechanical strength of the treated plots increased to an optimum level (50 kPa in P2) for resisting mechanical pressure from agricultural machinery. Overall, this study of the efficacy of organic amendment offers new insight into a soft paddy soil remediation method that is more effective and economical than the conventional method.</p>

Rice-husk biochar effects on organic carbon, aggregate stability and nitrogen-fertility of coarse-textured Ultisols evaluated using Celosia argentea growth

There are insufficient data supporting the enormous potential of biochar in highly weathered tropical soils. This glasshouse study assessed rice-husk biochar (RHB) effects on soil organic carbon, aggregate stability and nitrogen fertility of sandy-loam Ultisols which were evaluated using spinach (<em>Celosia argentea</em>) growth. Five RHB rates 0, 5, 10, 20, and 40 g per two-kg-soil (0, 7.5, 15, 30 and 60 t ha⁻¹, respectively) were studied under 0, 4, 8, and 12 weeks of incubation (WOI). Batched potting of treatments enabled sowing on one date. Treatment effects on soil quality were assessed at sowing and spinach growth six weeks later. Soil organic carbon generally increased with RHB rate, with the greatest increments (37%) in maximum rate relative to no-biochar control for 8 WOI. Aggregate stability also generally increased with RHB rate, the range being 7.21%-17.21% for 8 WOI, beyond which it decreased in 10 and 20 but not 40 g pot^–1. Total nitrogen was always highest in maximum rate, increasing with rate only for 8 WOI. Treatment affected plant height more clearly than leaf count. Optimum rates were 5 or 10 g pot^–1 for 8 and 4 WOI, respectively (plant height) and 10 g pot^–1 for 8 WOI (leaf count). Soil organic carbon influenced soil aggregate stability (R² = 0.505) which in turn was quadratically related to plant height (R² = 0.517), indicating stability threshold for spinach. Adding RHB at 40 g pot^–1 (≈ 60 t ha⁻¹) to coarse-textured tropical soils is suggested to sustain its soil aggregating effect beyond the growth phase of short-cycle leafy vegetables which require a lower rate (10 g pot^–1) 8 weeks before sowing. The observed role of soil aggregate stability in spinach growth rather than the overall effects of RHB should guide further search for edapho-agronomic optimum rate of RHB.

The use of soil biostructures created by soil fauna ecosystem engineers fed with different organic matterials as inoculum source of arbuscular mycorrhiza fungi on cocoa seedling

<p><span lang="IN">Soil fauna as ecosystem engineers </span><span>have the ability to </span><span lang="IN">creat</span><span>e </span><span lang="IN">soil biostructure</span><span>s, with the capacity to </span><span lang="IN">sav</span><span>e</span><span lang="IN"> arbuscular mycorrhizal fungi (AMF) spores. </span><span>This study therefore aims to </span><span lang="IN">investigate the </span><span>AMF </span><span lang="IN">spore density in the biostructures created by cooperation between earthworms and ants with a different organic matter composition</span><span>,</span><span lang="IN"> and to analyze the </span><span>biostructures’ </span><span lang="IN">potential as a source of </span><span>AMF </span><span lang="IN">inoculum on cocoa seedlings. </span><span>In the first experiment, a </span><span lang="IN">combination of earthworms and ants composition</span><span>, as well as a </span><span lang="IN">mixture of <em>G. sepium</em> leaf (GLP), cocoa shell bean (CSB), and sago dregs (SD)</span><span>,</span><span lang="IN"> was tested</span><span>. Meanwhile, </span><span lang="IN">in the </span><span>second</span><span lang="IN"> experiment</span><span>, t</span><span lang="IN">he</span><span> effect of</span><span lang="IN"> biostructures on cocoa seedlings grown </span><span>i</span><span lang="IN">n unsterile soil</span><span>,was </span><span lang="IN">examined</span><span>. According to the results, the highest</span><span lang="IN"> AMF spore </span><span>density was obtained using </span><span lang="IN">20 earthworms+10 ants with 50%GLP+50%CSB + 0%SD treatment</span><span>. Furthermore, the t</span><span lang="IN">otal AMF spores </span><span>were </span><span lang="IN">positively correlated</span><span> with the total P value, but negatively correlated </span><span lang="IN">with </span><span>the </span><span lang="IN">C/N ratio</span><span>. Therefore, bi</span><span lang="IN">ostructure application increased AMF spores number in rhizosphere and </span><span>the cocoa seedling’s </span><span lang="IN">root infection</span><span>. Furthermore, </span><span lang="IN">biostructure</span><span>s</span><span lang="IN"> resulting from the collaborative activity </span><span>between</span><span lang="IN"> different soil fauna ecosystem engineers </span><span>were able to transmit </span><span lang="IN">AMF spore</span><span>s </span><span lang="IN">to </span><span>infected </span><span lang="IN">plant root</span><span>s</span><span lang="IN"> growing </span><span>i</span><span lang="IN">n non-sterile soil.</span></p>

Effects of Various Irrigation and Fertilizer on Water Efficiency and Tomato Yield (Solanum lycopersicum) in Alfisols

<p>Investing in irrigation is very important and strategic in the context of water supply for agriculture. Therefore, this study aims to identify the most efficient irrigation technique and type of fertilizer to maximize the yield of tomatoes (Solanum lycopersicum) in Alfisols. This study was a greenhouse pot experiment with a factorial completely randomized design with two factors consisting of four irrigation techniques (pottery, drip, 75% ETc manual, and 100% ETc manual) and types of fertilizers (without, organic, inorganic, mixed fertilizer). The results showed that pottery irrigation had the highest Nitrogen content in the soil and saved up to 50% water compared to 100% ETc. On the other hand, drip irrigation uses water of 75% ETc with similar plant yield results. The pottery irrigation was the most efficient irrigation method for growing tomato than 75% ETc manual irrigation, and 100% ETc manual irrigation with mixed fertilizers (I4P3) was the highest on tomato yield.</p>

Effects of rice husk biochar and raised bed on CO2 flux and shallot (Allium cepa L.) production on peatland

This study aims to assess the effect of rice husk biochar, raised beds, and chicken manure on the CO₂ flux and shallot production on peatland. This study adopted a factorial randomized block design with three factors and three replications. The P1 treatment was recommended by the Swamp Land Agricultural Research Institute by adding chicken manure (5 ton ha⁻¹) and rice husk biochar (5 ton ha⁻¹) while the P2 treatment was recommended by the Vegetable Research Institute by adding chicken manure (10 ton ha⁻¹). The raised beds heights were 20 cm (A) and 30 cm (B). Variance analyses were applied to each observation variable and followed by Duncan's Multiple Range Test at a 5% level. The P1A treatment was the best in improving the shallot production up to 10.88 tons and producing the lowest CO₂ cumulative flux up to 0.158 ton ha^-1 season^-1.

Ecotoxicological assessment of Zn, Cu and Ni based NPs contamination in Arenosols

Nanoparticles are increasingly used in many industrial fields because of their special properties. In this context, several questions arise related to possible negative consequences associated with nanoparticle (NPs) entrance into the ecosystem. The adsorption of NPs by soil can adversely influence its biological properties. In the present article, the influence of Cu, Zn, and Ni NPs on the biological characteristics of Arenosol is considered. Research aimed to study the effect of Cu, Zn, Ni NPs on the biological characteristics of sandy loam chernozem. Copper, Zn, and Ni NPs were added to the soil in concentrations of 100, 1,000, and 10,000 mg kg^-1. The effect of NPs on the biological properties of Arenosol was evaluated after 10-day incubation. The biological indices of the ecological condition of the soil, including the germination of radish, the length of the roots, the bacteria population, <em>Azotobacter</em> sp. count, the catalase activity, and dehydrogenases were studied. As a result of this study, it was revealed that the degree of indices changes depending on the concentration of Cu, Zn, and Ni NPs in the Arenosols. Microbiological characteristics (bacteria population, and <em>Azotobacter</em> sp. count) and phytotoxic feature (length of roots and radish germination) properties were most sensitive to contamination compared to the enzyme activity of Arenosol. Based on the soil integral index of a biological state, the strongest inhibitory effect on biological parameters of Arenosols relative to the control was exerted by Cu NPs (lower than control by 48-72%), while the greatest stability in Arenosol was found for Ni NPs (lower than control by 30-55%). The studied biological parameters allow characterizing the severity of nanoparticle exposure on Arenosols. Early diagnostics of the severity of soil contamination by NPs can be successfully used to quickly assess their impact on the soil condition and prevent possible adverse consequences.

Aggregate characteristics and aggregate-associated soil organic carbon and carbohydrates of soils under contrasting tree land use

<p><span>Protection of soil organic carbon and acid-hydrolyzable carbohydrates in aggregate-size fractions is important for appraising soil degradation and aggregation under land use types. Aggregate-associated soil organic carbon (SOC) and acid-hydrolyzable carbohydrates (R-CHO) in bulk soils and aggregate-size fractions of a sandy loam soil under Alchornea bush, Rubber, Oil palm and Teak plantations in southern Nigeria were studied. Results revealed significant differences in aggregate-associated SOC and R-CHO, bulk densities, total porosity, soil organic carbon stock and aggregate stability among the land use types. Greater SOC was stored in macro-aggregates &gt;0.25 mm, while greater R-CHO was occluded in micro-aggregates &lt;0.25 mm (p&lt;0.05). The highest mean weight diameter (MWD) was 1.01 mm in Alchornea soils and 0.92 mm in Oil palm plantation at 0-15 cm topsoil. Soil organic carbon stock in 0-15 cm topsoil was 77.7, 81.8, 92.2, and 67.5 kg C ha^-1 in Alchornea, Rubber, Oil palm, and Teak soils, respectively. Relationships showed a positive linear correlations between MWD and SOC (r = 0.793, p &lt; 0.05) and R-CHO (r = 0.789. p &lt; 0.05). Alchornea bush and Oil palm plantation increased macro-aggregate formation and macro-pores &gt;5 µm, therefore they have greater potentials to boost protection of SOC in soil macro-aggregates.</span></p>

Evaluation of phosphate sorption capacity and external phosphorus requirement of some agricultural soils of the southwestern Ethiopian highlands

<span>One of the most soil fertility management problems for crop production on acidic soils of the Ethiopian highlands is phosphorus fixation. The research was executed to assess the P-sorption capacity and to determine the external P requirement of different acidic soils in the Southwestern highlands of Ethiopia. Phosphorus sorption capacity (Kf) and its relation with selected soil characteristics were assessed for some major agricultural soils in the Ethiopian highlands to answer the questions, ‘What are the amount of P-sorption capacity and external P requirement of Nitisols, Luvisols, Alisols, and Andosols in Ethiopia?’. Twelve surface soil samples (at depth of 0-30 cm) were gathered and the P-sorption capacity was estimated. Phosphorus-sorption data were obtained by equilibrating 1 g of the 12 soil samples with 25 ml of KH₂PO₄ in 0.01 M CaCl2, having 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, and 330 mg P L^-1 for 24 hours. The data were adjusted to the Freundlich adsorption model and the relationship among P-sorption and soil characteristics was established by correlation analysis. Clay content and exchangeable acidity, organic matter, Al₂O₃, and Fe₂O₃ oxides have affected phosphorus-sorption at a significance level of (P &lt; 0.05). Alisols had the highest Kf value (413 mg kg^-1) but Nitisols had the lowest Kf (280 mg kg^-1). The external phosphorus fertilizer requirement of the soils was in the order of 25, 30, 32, and 26 mg P kg^-1 for Nitisols, Luvisols, Alisols, and Andosols sequentially. The Kf varies among different soil types of the study area. The magnitude of the soil’s Kf was affected by the pH of the soil, soil OM content, and oxides of Fe and Al. Therefore, knowledge of the soils’ P retention capacity is highly crucial to determine the correct rate of P </span><span>fertilizer</span><span> for crop production.</span>

Applicability of plastic mulch and conservation strip tillage for potato production in Bangladesh

<p>Application of plastic mulches in potato production is rarely used by farmers in Bangladesh although it has a good prospect for saving irrigation water, weed control, maintaining tuber quality, and increasing yield. A study was conducted in experimental farm at Rural Development Academy (RDA), Bogura, Bangladesh to evaluate the precision of irrigation water for potato production using different colored plastic mulches i.e, black and blue in combination with conservation strip tillage and control (no-mulch). Four different treatments were prepared where some of the phenological characteristics of plants as well as yield of potato were compared among treatments by applying the same amount of irrigation water. The results showed that treatment with black plastic mulch had the highest tuber growth as well as yield of 25.1 t ha^-1 compared to other treatments while other treatments such as blue plastic mulch, control, and strip tillage had a yield of 16.37, 13.75, and 15.75 t ha^-1, respectively. Potato plants having black plastic mulch took less time to mature in comparison to other treatments. Black plastic mulch restricts soil moisture evaporation and keeps the soil warm. In conclusion, potato production with various mulches has a great scope in a semi-arid region like Bangladesh and present experimental results will help to improve the understanding of potato growers for adopting best mulch management practices.</p>