58 research outputs found

    Ammonia Volatilization and Phosphate Release from Compacted Mixed Fertilizers in Pure System and in an Acid Soil

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    Urea and phosphate rock (PR) have been widely used in Malaysian agriculture. However, ammonia (NH3) volatilization and slow release of P are two major problems encountered when urea and PR fertilizers were used. High pH, AI and Fe oxides content and low cation exchange capacity (CEC) have been identified as causing these problems in soil. Peat and triple superphosphate (TSP) may be mixed to supply humic substances from peat to reduce P fixation, N loss and proton (H+) from TSP to solubilize PR in water and soil. Thus, a study was initiated to investigate the effect of these mixed fertilizers on NH3 volatilization and dissolution of PR in a pure system and in an acid soil. Various combinations of urea, TSP, CIPR fertilizers and peat were compacted and studied in the two systems in the laboratory. In pure system, the N loss following addition of peat (5.09%) is better than TSP (28.15%). Four combinations of fertilizers gave the second highest P dissolution (70.53%) at day one and day 10 (71.15%) based on changes in P released (L\P) method after urea plus TSP and peat. Almost 40% of changes in Ca released (b.Ca) was detected in solution when any combination of TSP and Christmas Island Phosphate Rock (CIPR) was used in the mixture after 10 days. This is due to the production of phosphoric acid by TSP. Surface application of compacted mixed fertilizer on the soil showed that urea plus TSP and CIPR and urea plus TSP and peat managed to decrease the loss of N by nearly 50% compared to only urea. This is due to the production of Ca2+ by P sources and additional CEC by peat. Delay in the peak N loss differed with fertilizer combinations: urea + TSP +CIPR (3 days), urea + TSP + CIPR + peat (7 days), urea + TSP + peat (7 days) and urea + peat (5 days). The CIPR and peat mixture showed the highest L\P value (394.66 mg kg-1) after 90 days of incubation in soil. On average, the highest (310.98 mg kg-1) P dissolution as measured by b.P method was obtained using urea plus TSP, CIPR and peat. This was attributed to the protons supplied by TSP and Casink from peat which promoted the dissolution of PR in mixed fertilizer. Thus, compacted mixed fertilizer is an effective way to decrease NH3 volatilization and increase L\P in soil and pure system. However, this depends on the combination of the fertilizers used

    Improving Liquid Fertilizer Urea Efficiency Using Humic Acids Additives Extracted from Tropical Peat

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    One of the most important sources of organic matter is peat. Being organic in nature, peat are high in humic and fulvic acids. These substances can be reconstituted with N and K to produce ammonium and potassium-h u mates (organic fertilizer). This could be realized if they could be rapidly and cheaply isolated from peat soils. Factors which affect the humic and fulvic acids isolation from soils include extraction, fractionation, and purification periods. Thus, part of this study investigated whether a relationship could be separately established between extraction time, fractionation time, and the yield of humic acids ( HA) of tropical peat soil (hemists), as well as the relationship between both variables on the yield of HA of this soil. M odified standard procedures using 0 . 1 M KOH (analytical grade) were used to isolate humic acids from the soil. Results showed that, there was a quadratic relationship between extraction period and yield of HA. There was however no relationship between fractionation period and yield of HA. There was negative correlation between the yields of extraction and fractionation periods. This finding enables the isolation of HA of hemists in less than 10 h instead of existing average period of 2 to 7 days, therefore helping in facilitating the idea of producing for instance ammonium-humate or potassium-humate (N and K foliar organic fertilizers) from peat. The second part of the study was development of NH4'" -K-humate by reconstitution of humic and fulvic acids. The organic fertilizers developed via reconstitution were evaluated under laboratory conditions. E ffectiveness of organic fertilizer in enhancing N availability was the main concern of this study. This was d ue to high N loss by N fertilizer (e.g. urea) after surface application. Nine treatments namely urea (solid), urea (liquid), ammoniu m sulfate (solid), ammonium sulfate (liquid), humic acids + urea, fulvic acids + urea, humic and fulvic acids (acidified) + urea and humic, fulvic acids (unacidified) + urea a nd control (soil alone) were used in this study with the a i m of reducing N loss from urea application. A closed dynamic air flow system was used to esti mate N loss from soil. Usage of fulvic together with u rea decreased soil pH and as well as ammonia volatilization. However, the use of HA significantly reduced ammonia volatilization. This suggests the effectiveness of the organic based fertilizer formulated in controlling N loss and enhancing N availability. Besides being effective in controlling N loss, promotion of plant growth and development are other factors which should be considered in order to confirm the effectiveness of the formulated organic fertilizer. Hence, a pot experiment (third part of the study) was set u p with seven treatments excluding liquid ammonium sulfate. Results showed that, organic based N fertilizers enhanced N, P a nd K uptake. They also promoted N use efficiency particularly for the treatments with fulvic acids

    Reducing Egypt rock phosphate use in Zea mays cultivation on an acid soil using clinoptilolite zeolite

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    Insufficient supply of P for initial growth of crops does not only limit N uptake but it also leads to poor yield of crops. In acidic soils of the tropics, sorption of P occurs mainly on surfaces of Fe and Al oxides and hydroxides. Most of the P added through mineral fertilizers is fixed by high Al and Fe oxide concentrations and transformed into insoluble P compounds. Reduction of Al and Fe is important so as to ensure adequate supply and readily available P for crops uptake. A number of studies using zeolites as an amendment in the fertilization programs of crops have improved crops production, nutrients uptake, and nutrients use efficiency. However, there is dearth of information on the use of clinoptilolite zeolite (CZ) to reduce P fixation not to mention reduction of N, P, and K fertilizers use in agriculture. This study was conducted to: (i) determine dry matter production, nutrients concentration, nutrients uptake, and use efficiency of Zea mays (Hibrimas variety) by including CZ in the fertilization program of Zea mays planted on an acidic soil, and (ii) determine the effect of including CZ in the fertilization program of Zea mays on selected chemical properties of an acidic soil. Egypt rock phosphate (ERP), urea, and muriate of potash were used in this study. Seventy five percent (w/w) of the recommended N, P, and K fertilizers for Zea mays were combined with CZ. Standard procedures were used to determine soil pH, inorganic nitrogen, available phosphorus, exchangeable aluminium, iron, potassium, calcium, magnesium, and organic matter before and after planting. Zea mays were harvested at tasselling stage and measured for dry matter production, nutrients uptake and use efficiency. The effect of CZ application with 75% of fertilizers (E2) and 100% fertilizers (E1) were statistically similar for selected soil chemical properties, dry matter production, nutrients concentration, uptake of nutrients, and nutrients use efficiency except for N. Nitrogen use efficiency for E2 was better than that of E1. These findings suggest that adoption of CZ with 25% reduction of N, P, and K fertilizers are useful. Further field trials and economic analysis are recommended to confirm the findings of this study. These aspects are being investigated in our on-going field experiments

    Compost and crude humic substances produced from selected wastes and their effects on Zea mays l. nutrient uptake and growth

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    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation

    Simple method of purifying humic acids isolated from tropical hemists (peat soil)

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    The objectives of this study were: To investigate whether a purification period of HA isolated from Hemists peat soils could be reduced and to investigate whether distilled water could be used to purify HA isolated from Hemists peat soils. Standard procedures were used to extract and fractionate HA in a Hemists peat soil. The isolated HA was purified by suspending the HA 50 mL distilled water, centrifuged for 10 minutes, supernatant decanted and the liquor analyzed for K, Ca, Mg and Na by atomic absorption spectrophotometry. The entire procedure was repeated five times after which the purified HA samples were oven dried at 40ºC to a constant weight. Washing HA for 5 consecutive times (10 min for each washing) reduced the ash (mineral matter) content of the HA to an acceptance level of 2%. This finding was associated with significant decrease in K, Ca, Mg and Na contents with increased washing time. This observation also suggests that the distilled water used during the purification process served as Bronsted-Lowry acid thereby donating more H+ which may have replaced some of K+, Ca2+, Mg2+ and Na+ at the exchange sites of the HA. The C, carboxylic COOH, phenolic OH, total acidity and E4/E6 values of the purified HA were consistent with standard values, a further indication of the effectiveness of using distilled water in purifying HA from Hemists peat soil. Humic acids isolated from Hemists peat soil can be purified within one hour using distilled water without altering the true nature of HA

    Effects of extraction and fractionation period on the yield of a tropical peat soil (Hemists) humic acids

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    The isolation of humic acids from soils is laborious and time consuming. Factors that affect the yield of humic acids isolated from soils include extraction, fractionation and purification periods. This study was conducted to investigate whether a relationship could be separately established between extraction time, fractionation time, and the yield of humic acids of a tropical peat soil (Hemists), as well as the relationship between both variables on the yield of humic acids of this soil. Modified standard procedures using 0.1 M KOH were used to isolate humic acids from a tropical peat soil. Even though there was a quadratic relationship between extraction period and yield of humic acids, there was no relationship between fractionation period and yield of humic acids. There was negative correlation between the yields of extraction and fractionation periods. This finding enables the isolation of humic acids of Hemists in less than 10 h instead of the existing average period of 48 h, therefore helping in facilitating the idea of producing for instance ammonium-humate or K-humate (N and K foliar organic fertilizers) from peat soils

    Indole-3-acetic acid production by rhizobacteria Bacillus spp. to various abiotic stress factors

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    Indole-3-acetic acid (IAA) phytohormone plays an essential role in forming and initiating main, lateral, and adventitious roots in vegetative propagation. Plants are receiving IAA naturally from a diverse group of soil-plant associated rhizobacteria. However, IAA synthesis by rhizobacteria is influenced by abiotic growth conditions. Three indigenous Bacillus isolates were subject to in vitro assay for the effects of abiotic factors (temperature, salinity and pH) on growth and IAA production. All isolates grew well between 25 - 40°C, and only B. megaterium UPMLH3 was capable of synthesising IAA (21.18 µg/ml) at 40°C. All three bacterial growth under saline stress were slightly dropped over control (0% NaCl), but still producing IAA up to 1% NaCl condition. B. cereus UPMLH24 revealed high resistance to salinity up to 5% NaCl. The optimum growth of all three Bacillus spp. was at pH 7. B. cereus UPMLH1 and UPMLH24 discovered higher IAA production in slightly alkaline conditions (pH 8). Each rhizobacterium shows different physiology trait against each abiotic factor. However, the multiple tolerance ability of PGPR against abiotic factors is an indication that its ability to survive under harsh soil and plant environments while delivering benefits to the plant. Thus, B. cereus UPMLH1, B. megaterium UPMLH3 and B. cereus UPMLH24 might serve as potential biofertiliser, enhancing the growth performance of test plants at various environmental conditions

    Mitigating ammonia volatilization from urea in waterlogged condition using Clinoptilolite zeolite

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    Besides causing environmental pollution, ammonia volatilization from nitrogenous fertilizers such as urea reduce urea-N use efficiency in agriculture. Amending urea with Clinoptilolite zeolite may reduce ammonia loss from urea as well as improving chemical properties of soils. This study was conducted to determine the effects of amending an acid soil with Clinoptilolite zeolite on ammonia loss and selected soil chemical properties. An acid soil (Typic Paleudults) was mixed with three rates of Clinoptilolite zeolite. Treatments were evaluated using closed-dynamic airflow system. Standard procedures were used to determine soil pH, total nitrogen, exchangeable ammonium, available nitrate, available phosphorus, exchangeable cations, organic matter, total organic carbon, and cation exchange capacity (CEC). Application of Clinoptilolite zeolite significantly reduced ammonia loss up to 25.33%, increased soil pH, exchangeable ammonium, available nitrate (treatment with highest amount of Clinoptilolite zeolite) and exchangeable cations. However, there was reduction in total titratable acidity, exchangeable Al3+ and H+ ions. Mixing acid soil (Typic Paleudults) with Clinoptilolite zeolite minimized ammonia loss from urea and improved selected soil chemical properties (under laboratory condition)

    Growth of tea nursery plants as influenced by different rates of protein hydrolysate derived from chicken feathers

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    The conversion of chicken feathers, generated annually worldwide on a large scale as a by-product of the poultry industry into value-added products, has economic and environmental benefits. Protein hydrolysate produced from feathers has attracted significant attention in agriculture as a potential plant growth stimulant. Therefore, a study was established with the aim to produce and characterize chicken feather protein hydrolysate (CFPH) and investigate the effects of this product on the early growth of nursery tea plants. Alkaline hydrolysis was used to produce CFPH with the yield of 165 mg amino acids per gram of feathers. Then, the produced CFPH was applied on nursery tea plants as a soil drench at different doses (0.5, 1, 2, 3, and 4 g L−1) in 2-week intervals until the 10th application. Commercially available fish protein hydrolysate (FPH) was included as a treatment to compare the effects with CFPH. The treatments were arranged in a completely randomized block design with three replications. CFPH and FPH significantly improved the shoot and root growth parameters. Plant height (+98%), leaf number (+61%), shoot dry biomass (+128%), root length (+94%), root surface area (+15%), and root dry biomass (+152%) were significantly increased by the application of CFPH (2 g L−1 dose) compared to control. Although the highest CFPH dosage (4 g L−1) showed a reduction in growth parameters, the values obtained were similar or higher than the untreated control plants. The chlorophyll content (a, b, and total) was enhanced by the CFPH dosage of 1 g L−1, whereas the highest photosynthetic rate was recorded in the CFPH 3 g L−1 treatment. The application of protein hydrolysates (PH) did not positively influence stomatal conductance and intercellular CO2 concentration. Leaf nitrogen, phosphorous, manganese, and copper were positively affected by the CFPH application. The effect of CFPH on growth parameters was more pronounced than FPH. Our findings reveal that CFPH produced by alkaline hydrolysis could be used as a growth booster in raising vigorous tea nursery plants, which are most suitable for field planting and subsequently higher yields

    Co-composting of pineapple leaves and chicken manure slurry

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    Background: The common practice of clearing pineapple (Ananas comosus) residues for land preparation for cultivation is by burning, an unsustainable agricultural practice that causes environmental pollution. Chicken manure produced from the poultry industry is also increasing. Inappropriate disposal or treatment can pose harm to the environment and humans. In order to reduce environmental pollution, pineapple leaves and chicken manure slurry were co-composted to obtain high-quality organic fertilizer. The shredded pineapple leaves were thoroughly mixed with chicken manure slurry,chicken feed and molasses in polystyrene boxes. Co-compost temperature readings were taken three times daily. Results: Nitrogen and P concentrations increased whereas C content was reduced throughout the co-composting. The CEC increased from 32.5 to 65.6 cmol kg−1 indicating humified organic material. Humic acid and ash contents also increased from 11.3% to 24.0% and 6.7% to 15.8%, respectively. The pH of the co-compost increased from 6.14 to 7.89. The final co-compost had no foul odour, low heavy metal content and comparable amount of nutrients. Seed germination indices of phytotoxicity test were above 80% of final co-compost. This suggests that the co-compost produced was phytotoxic-free and matured. Conclusion: High-quality co-compost can be produced by co-composting pineapple leaves and chicken manure slurry and thus have potential to reduce environmental pollution that could result from poorly managed agricultural waste
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