Geostatistical assessment of heavy metals and nutrients availability in soil of oil palm plantation affected by bauxite mining

This study describes the contamination of heavy metals (Cu, Zn, Mn, Pb and Fe) and their effect on K, Ca and Mg availability in oil palm cultivated areas affected by bauxite mining activities using the combinations of geostatistic and geospatial analysis. A total of 64 soil samples were collected covering a total area of 420.21 ha by grid sampling technique. Spatial distributions of the heavy metals were determined using semivariogram and mapped using ArcGIS. The mean concentrations of Cu (138.94 ± 79.08 mg kg-1), Zn (233.55 ± 79.16 mg kg-1), Mn (847.88 ± 267.02) mg kg-1) and Fe (249 703.71 ± 101 408.72 mg kg-1) in this study were greater than the background values, the 95% ‘Investigation Levels’ determined for Malaysia soil and Dutch target values. Geoaccumulation index showed that the contamination was in the order of Fe> Cu>Pb>Zn> Mn. Semivariogram analysis of pH, Mn, Zn and Fe was aligned with the principal component analysis results, showing the contamination source originated from a similar identical source. In correlation to the nutrients, only Kex., was found to be affected by the contaminants. These results provide a useful basis for the related agencies in identifying hotspots for future rehabilitation programs

Silicon uptake by selected plant species, and its role in growth promotion and basal stem rot resistance in palms

Silicon (Si) is the second most abundant and beneficial element for plant growth in higher plants. The differences in Si accumulation have been attributed to the Si absorbing ability of the roots. The most important aspect in this research is to make full use of the role of Si in conferring tolerance in plants against stresses. Thus, the goals of this research were: (i) to investigate the role of individual root and root system in Si uptake by selected plant species, and (ii) to assess the effects of GanoCareTM NRICH OCSpecial 1 (OCS 1) on vegetative growth and reducing the risk of Ganoderma disease in palms seedlings. To reveal the ability of root to take up Si, the study was conducted using the hydroponic culture system with modified Hoagland’s nutrient solution containing different amount of Si. The results showed that the Si uptake was higher in the root- than shoot-part of mangroves and oil palm under study with the values of 51.8% and 38.2%, respectively. In contrast, betel nut palms uptake 32.4% more Si in the shoot-than root-parts. The Si uptake per root dry matter and Si uptake per 4 cm of root was higher in mangroves than in oil palms and followed by betel nut palms. Based on the ability to take up Si, the different oil palm progenies and clones in the study were clustered using Jaccard Similarity Coefficient into 5 groups. The vegetative growth and selected physiological parameters of oil palm and betel nut palm seedlings and the effectiveness of OCS 1 (6: 6: 8: 2 + GanoCareTM) against basal stem rot (BSR) disease caused by Ganoderma boninense was performed under nursery condition. Results showed that the T2-seedlings of oil palm increased the total number of fronds (11.8%), seedlings height (15.4%), rachis length (9.3%), girth size (24.4%), chlorophyll content (10.2%), photosynthesis rate (21.0%), leaf area index (27.3%) and total biomass (18.3%) compared to control. Application of OCS 1 to betel nut palm seedlings increased the total number of fronds, seedlings height, rachis length, girth size, chlorophyll content and total biomass to more than 16.7, 12.3, 13.4, 31.3, 14.8 and 30.2%, respectively. The DI of oil palm (50.0%) and betel nut palm (44.4%) for T3-seedlings were significantly different (p≤0.05) compared to T2-seedlings with both values of 94.4%. The BSR disease incidence in oil palm and betel nut palm of T3- seedlings were reduced 52.6% and 67.4%, respectively. This supports the contention that the beneficial element in GanoCareTM may provide protection against Ganoderma infection in both palms. The results confirmed that an individual root and root system in selected plants’ play an important role in response to Si uptake ability. The higher uptake of Si in root-parts may provide good indicator for the plant to be resistant against root-infecting organisms. Hence, the addition of OCS 1 had successfully enhanced the growth and reduced the BSR disease in palm seedlings

Nutritional effects of calcium on oil palm seedling growth and suppression of Ganoderma disease

Basal stem rot (BSR) disease caused by the Ganoderma species was a severe problem to the oil palm (Elaeis guineensis Jacq.) industry. Nutrients were commonly used in the fertilizers to enhance plant growth and/also to protect against abiotic and biotic stresses. Therefore, manipulation of plant nutrients, especially calcium (Ca) as an option for prevention of BSR disease in oil palm. Thus, the goals of this research were to determine the optimum concentration of Ca in oil palm seedlings, to determine the effects of different Ca sources on vegetative growth in oil palm seedlings, to assess the effects of Ca formulation treatment in the nursery to suppress Ganoderma infection in oil palm seedlings and to investigate the Ca formulation in controlling Ganoderma disease in oil palm under field condition. The optimum concentration of Ca was determined by growing of oil palm seedlings using a modified Hoagland's nutrient solution containing different concentrations of Ca for three months in a controlled environment. Concentration of 1,000 ppm of Ca from CaCl2 in the nutrient solution provided the best growth performance and development of oil palm seedlings. Subsequently, a nursery evaluation was conducted to determine the best sources of Ca and accompanying anions with oil palm seedlings planted on a Beach Ridges Interspersed with Swales (BRIS) soil for six months in MPOB nursery, Bandar Baru Bangi. An increased in seedling height, girth, chlorophyll content, and total biomass was observed on a treatment of 1,000 ppm Ca as CaSO4. Further, oil palm seedlings were pre-treated with formulated fertilizer containing 1,000 ppm Ca as CaSO4, then challenged with G. boninense PER 17 using rubber wood blocks (RWBs) sitting technique during the nursery trial (12 months) and baiting technique in the field trial (21 months). In nursery and field trials, at this concentration, the formulated fertilizer provided a better growth performance and at the same time to prevent BSR, by considerably reducing 52.8 and 81.1%, disease incidence (DI), respectively. Hence, Ca supplementation in the fertilizer could provide an alternate prevention program for BSR disease in oil palm plantation

Effectivenes of organic and inorganic fertilizer in enhancing growth of ipomoea aquatica (water spinach) in two different types of soil

Planting a crop with high productivity and quality while ensuring the continuity of good soil quality and environmental sustainability is important. With the changes of climate and extensive anthropogenic activities, soil had become undesirable for crops planting. However, various measures can be done to improve this such as applying suitable types of fertilizer and soil amendments besides monitoring the quality of soil continuously. Fertilizer application in a way is helpful in providing essential nutrients needed by the plant while soil organic amendment able to improve its quality through biotic and physical changes. In this study, different combination of treatments was applied in two different types of soil to observe its effect on morphological growth of water spinach (Ipomoea aquatica), soil pH, and total organic carbon (TOC) in soil. Field experiment was conducted at Glasshouse Nursery Complex (GNC), International University Malaysia for five weeks. Combination of treatments consist of control (T1), biochar (T2), chicken manure (T3), combination of biochar and chicken manure (T4), and combination of biochar, chicken manure, and NPK fertilizer (T5). Two types of soil that were used in this study which are normal topsoil and oxisols type of soils. Results showed that the T5 were observed to have the highest average of plant grown in both normal top soil and oxisols soil. The pH of both soils treated with biochar and organic manure increased compared to control which reflect a positive effect towards nutrient availability for plant. Total organic carbon content also showed an increased trend with soil amendment and fertilizer applications. Hence, in overall growth of Ipomoea aquatica improved with application of fertilizer and organic amendments

Nutritional effects of different Calcium sources on growth of oil palm seedlings under nursery condition

Calcium (Ca) is an essential secondary macronutrient which necessary plant mineral frequently added to fertilizers to promote plant development and resistance to abiotic and biotic stressors. Applying Ca to soils suffices to meet crops’ Ca requirements. Regrettably, its function is obscure. Thus, it is critical to maintain enough nutrient availability through fertilizers or alter the soil environment for oil palm seedlings to grow and thrive. This study investigates the effects of different Ca sources on vegetative growth in oil palm seedlings. This experiment was carried out for nursery evaluation using 5-months old of oil palm seedlings with varying sources of Ca (C1–calcium chloride, CaCl2; C2–calcium sulfate, CaSO4; C3-calcium nitrate, CaNO3; C4–calcium carbonate, CaCO3; C5–calcium oxide, CaO, C6–calcium hydroxide, Ca(OH)2; and C7–water leach purification andneutralization underflow, NUF-WLP) and grown in a polybag containing beach ridges interspersed with swales (BRIS) soil within six months in Malaysian Palm Oil Board (MPOB) nursery, Seksyen 15, Bandar Baru Bangi. Five concentration levels of Ca (T1–200 ppm, T2–250 ppm, T3–300 ppm, T4–1,000 ppm, and T5–1,500 ppm) were used in a completely randomized design CRD) with ten replications for each. Based on the total biomass of oil palm seedlings at 24 weeks after treatment with various sources of Ca, the result confirmed that C2 oil palm seedlings were more significant in size and denser at the root than other Ca types. The result is an essential indicator that C2 effectively increased the total biomass of oil palm seedlings at 1,000 ppm of Ca (T4); hence it was the best Ca source to improve the growth and development of oil palm seedlings throughout the experimental period at p≤0.05

Nutritional effects of different calcium sources on growth of oil palm seedlings under nursery condition

Calcium (Ca) is an essential secondary macronutrient which necessary plant mineral frequently added to fertilizers to promote plant development and resistance to abiotic and biotic stressors. Applying Ca to soils suffices to meet crops’ Ca requirements. Regrettably, its function is obscure. Thus, it is critical to maintain enough nutrient availability through fertilizers or alter the soil environment for oil palm seedlings to grow and thrive. This study investigates the effects of different Ca sources on vegetative growth in oil palm seedlings. This experiment was carried out for nursery evaluation using 5-months old of oil palm seedlings with varying sources of Ca (C1–calcium chloride, CaCl2; C2–calcium sulfate, CaSO4; C3-calcium nitrate, CaNO3; C4–calcium carbonate, CaCO3; C5–calcium oxide, CaO, C6–calcium hydroxide, Ca(OH)2; and C7–water leach purification and neutralization underflow, NUF-WLP) and grown in a polybag containing beach ridges interspersed with swales (BRIS) soil within six months in Malaysian Palm Oil Board (MPOB) nursery, Seksyen 15, Bandar Baru Bangi. Five concentration levels of Ca (T1–200 ppm, T2–250 ppm, T3–300 ppm, T4–1,000 ppm, and T5–1,500 ppm) were used in a completely randomized design (CRD) with ten replications for each. Based on the total biomass of oil palm seedlings at 24 weeks after treatment with various sources of Ca, the result confirmed that C2 oil palm seedlings were more significant in size and denser at the root than other Ca types. The result is an essential indicator that C2 effectively increased the total biomass of oil palm seedlings at 1,000 ppm of Ca (T4); hence it was the best Ca source to improve the growth and development of oil palm seedlings throughout the experimental period at p≤0.05

Effect of micronutrients-enriched fertilizers on basal stem rot disease incidence and severity on oil palm (Elaeis guineensis Jacq.) seedlings

Basal stem rot caused by Ganoderma boninense constitutes a serious threat to oil palm industry in Southeast Asia, especially in Malaysia and Indonesia and in Papua New Guinea and Pacific Islands. It is also expanding in some oil palm growing countries in Latin America and Africa and will soon become a worldwide concern to oil palm cultivation. To date, none of the various control measures developed and tested to control the disease since many decade gives entire satisfaction. An experiment was carried out to see whether incorporation of micronutrients, Copper (Cu), Boron (B) and Manganese (Mn) could reduce the incidence and severity of this disease on oil palm seedlings inoculated with G. boninense. The concentrations tested were 2 mg B/kg of soil, 2 mg Cu/kg of soil and 2 mg Mn/kg of soil incorporated into the basic fertilizer NPKMg 14-10-10-2. Treatments were applied in solution for three months before inoculation, followed by soil application for eight months after inoculation. The results showed that although no significant difference was detected among treatments, the double combinations of these micronutrients, B+Cu, B+Mn and Cu+Mn, performed better than the single nutrients in reducing the incidence and the severity of BSR, while their triple combination rather increased these pathological parameters. These double combinations could therefore be field-tested for their further integration in oil palm fertilization programme

Importance of Silicon and Mechanisms of Biosilica Formation in Plants

Silicon (Si) is one of the most prevalent macroelements, performing an essential function in healing plants in response to environmental stresses. The purpose of using Si is to induce resistance to distinct stresses, diseases, and pathogens. Additionally, Si can improve the condition of soils, which contain toxic levels of heavy metals along with other chemical elements. Silicon minimizes toxicity of Fe, Al, and Mn, increases the availability of P, and enhances drought along with salt tolerance in plants through the formation of silicified tissues in plants. However, the concentration of Si depends on the plants genotype and organisms. Hence, the physiological mechanisms and metabolic activities of plants may be affected by Si application. Peptides as well as amino acids can effectively create polysilicic species through interactions with different species of silicate inside solution. The carboxylic acid and the alcohol groups of serine and asparagine tend not to engage in any significant role in polysilicates formation, but the hydroxyl group side chain can be involved in the formation of hydrogen bond with Si(OH)4. The mechanisms and trend of Si absorption are different between plant species. Furthermore, the transportation of Si requires an energy mechanism; thus, low temperatures and metabolic repressors inhibit Si transportation

Importance of silicon and mechanisms of biosilica formation in plants

Silicon (Si) is one of the most prevalent macroelements, performing an essential function in healing plants in response to environmental stresses. The purpose of using Si is to induce resistance to distinct stresses, diseases, and pathogens. Additionally, Si can improve the condition of soils, which contain toxic levels of heavy metals along with other chemical elements. Silicon minimizes toxicity of Fe, Al, and Mn, increases the availability of P, and enhances drought along with salt tolerance in plants through the formation of silicified tissues in plants. However, the concentration of Si depends on the plants genotype and organisms. Hence, the physiological mechanisms and metabolic activities of plants may be affected by Si application. Peptides as well as amino acids can effectively create polysilicic species through interactions with different species of silicate inside solution. The carboxylic acid and the alcohol groups of serine and asparagine tend not to engage in any significant role in polysilicates formation, but the hydroxyl group side chain can be involved in the formation of hydrogen bond with Si(OH)4. The mechanisms and trend of Si absorption are different between plant species. Furthermore, the transportation of Si requires an energy mechanism; thus, low temperatures and metabolic repressors inhibit Si transportation