scholarly journals Rising levels of soil acidity in Meghalaya: Evidences and Imperatives

2021 ◽  
Vol 23 (3) ◽  
pp. 297-303
Author(s):  
MANOJ KUMAR ◽  
Keyword(s):  
Soil Acidity ◽  
Principal Component ◽  
Northeast India ◽  
Mean Value ◽  
Current Status ◽  
Acidic Soils ◽  
Exchangeable Acidity ◽  
Exchangeable Al ◽  
Eigen Values ◽  
Garo Hills

In order to examine the current status of soil acidity in Meghalaya, representative soil samples (n= 497) were collected (during 2015-2016) from across the state and analyzed for soil acidity and associated parameters. Averaged across the samples, pH of the soils was found to be very strongly acidic (4.94). Nearly 20 % of the soils had pH below 4.50, 59% below pH 5.0 and 80% below pH 5.50. Only 3.4% of the samples recorded pH more than 6.0. East Khasi Hills District had the maximum percentage (95.1%) of strongly acidic soils (pH ≤ 5.50) while Garo Hills had the least (50.2%). All other districts recorded more than 85% of the strongly acidic soils. Average exchangeable acidity, exchangeable Al and effective CEC were found to be 1.60, 1.27 and 3.86 meq/100g soil, respectively. Mean base saturation was recorded below 60%. Aluminium saturation (percentage of effective CEC being occupied by exch. Al) ranged from 1.5 to 79.7% with its mean value being as high as 33%. Principal component analysis provided three PCs with Eigen values >1 and together they explained 83.2 % of the variance in total dataset. The soil acidity in Meghalaya is on rise, with 80.2% of its soils being strongly acidic (pH ≤ 5.50) in contrast to the previous reports of 53% soils being strongly acidic. This calls for widespread adoption of soil acidity ameliorative measures in agriculture of Meghalaya, Northeast India.

scholarly journals Optimisation of Charcoal and Sago (Metroxylon sagu) Bark Ash to Improve Phosphorus Availability in Acidic Soils

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1803
Author(s):  
Prisca Divra Johan ◽  
Osumanu Haruna Ahmed ◽  
Ali Maru ◽  
Latifah Omar ◽  
Nur Aainaa Hasbullah
Keyword(s):  
Soil Ph ◽  
Soil Acidity ◽  
P Availability ◽  
Acidic Soils ◽  
Inorganic P ◽  
Exchangeable Acidity ◽  
P Fixation ◽  
Metroxylon Sagu ◽  
Sago Bark ◽  
Fe Ions

Soil acidity is an important soil factor affecting crop growth and development. This ultimately limits crop productivity and the profitability of farmers. Soil acidity increases the toxicity of Al, Fe, H, and Mn. The abundance of Al and Fe ions in weathered soils has been implicated in P fixation. To date, limited research has attempted to unravel the use of charcoal with the incorporation of sago (Metroxylon sagu) bark ash to reduce P fixation. Therefore, an incubation study was conducted in the Soil Science Laboratory of Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia for 90 days to determine the optimum amounts of charcoal and sago bark ash that could be used to improve the P availability of a mineral acidic soil. Charcoal and sago bark ash rates varied by 25%, whereas Egypt rock phosphate (ERP) rate was fixed at 100% of the recommendation rate. Soil available P was determined using the Mehlich 1 method, soil total P was extracted using the aqua regia method, and inorganic P was fractionated using the sequential extraction method based on its relative solubility. Other selected soil chemical properties were determined using standard procedures. The results reveal that co-application of charcoal, regardless of rate, substantially increased soil total carbon. In addition, application of 75% sago bark ash increased soil pH and at the same time, it reduced exchangeable acidity, Al3+, and Fe2+. Additionally, amending acidic soils with both charcoal and sago bark ash positively enhanced the availability of K, Ca, Mg, and Na. Although there was no significant improvement in soil Mehlich-P with or without charcoal and sago bark ash, the application of these amendments altered inorganic P fractions in the soil. Calcium-bound phosphorus was more pronounced compared with Al-P and Fe-P for the soil with ERP, charcoal, and sago bark ash. The findings of this study suggest that as soil pH decreases, P fixation by Al and Fe can be minimised using charcoal and sago bark ash. This is because of the alkalinity of sago bark ash and the high affinity of charcoal for Al and Fe ions to impede Al and Fe hydrolysis to produce more H+. Thus, the optimum rates of charcoal and sago bark ash to increase P availability are 75% sago bark ash with 75%, 50%, and 25% charcoal because these rates significantly reduced soil exchangeable acidity, Al3+, and Fe2+.

scholarly journals Extent, Distribution, and Causes of Soil Acidity under Subsistence Farming System and Lime Recommendation: The Case in Wolaita, Southern Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fanuel Laekemariam ◽  
Kibebew Kibret
Keyword(s):  
Soil Fertility ◽  
Soil Ph ◽  
Soil Acidification ◽  
Soil Acidity ◽  
Farmyard Manure ◽  
Southern Ethiopia ◽  
Subsistence Farming ◽  
Exchangeable Acidity ◽  
Management Interventions ◽  
Exchangeable Al

Soil acidity is one of the most important environmental threats to the Ethiopian highlands where the livelihood of the majority of people is reliant on agriculture. Yet, information regarding its extent, distribution, causes, and lime requirement at a scale relevant to subsistence farming systems is still lacking. This study (1) investigates the extent and spatial distribution of soil acidity, (2) identifies factors attributing to soil acidification, and (3) predicts the lime requirement for major crops. A total of 789 soil samples were collected from arable lands in the Wolaita area which is mainly characterized by poor soil fertility and soil degradation in southern Ethiopia. Results revealed that the landscape is characterized by a gentle slope followed by strongly sloppy > flat > hilly topographies. Clay is the dominant soil textural class. A soil pH map, which is generated using geospatial analysis, demonstrates that 3.3, 78.0, and 18.7% of the total area were under strongly acidic, moderately acidic, and neutral soil reactions, respectively. The exchangeable acidity (Cmol(+)/kg) varied from nil to 5.1, whereas exchangeable Al ranged from 1.4 to 19.9 Cmol(+)/kg. The soil pH has shown a significantly ( p  < 0.001) negative association with clay content (r = −0.33), exchangeable Al (r = −61), exchangeable acidity (r = −0.58), and inorganic fertilizer application (r = −0.33). Increased rates of diammonium phosphate (DAP) (r2 = 0.91) and urea (r2 = 0.88) markedly elevated soil acidity. Conversely, manuring showed a significant ( p  < 0.001) and positive relationship with pH (r = 0.37) in which the increasing rate of manure significantly reduced acidification (r2 = 0.98). DAP and urea applications above 75 kg/ha lowered soil pH units by 0.56 and 0.48, respectively, <25 kg/ha while at the same time farmyard manure (FYM) at 4 t/ha raised pH by 0.75 units over the unfertilized field. Residue management significantly ( p  < 0.001) influenced soil pH wherein it ranged from 6.09 (complete residue removal) to 6.61 (residue incorporation). Changes in land use, cropping intensity, and socioeconomic status were also significantly attributed to soil acidification. To curb the effects of soil acidity, the lime requirement for common bean growing fields varied from zero to 6.6 t/ha, while for maize it was between zero and 4.3 t/ha. It is concluded that soil management interventions such as maintaining and incorporating crop residues, integrated use of organic and inorganic fertilizers, liming, and enhancing farmers’ awareness should be advocated to overcome soil acidification and improve soil fertility. In addition, introducing crops with traits that tolerate acidity and Al toxicity is also suggested.

scholarly journals Soils Acidity Characterization, Mapping and Lime Recommendation of Jimma Arjo District, East Wollega Zone of Oromia Region, Ethiopia

2021 ◽  
Author(s):  
Fayisa Olana Bulo ◽  
Hailu Shiferaw Desta
Keyword(s):  
Soil Fertility ◽  
Soil Acidity ◽  
Nutrient Status ◽  
Soil Reaction ◽  
Acidic Soils ◽  
Exchangeable Acidity ◽  
The Difference ◽  
Analytical Services ◽  
The Right

Abstract Background: Soil fertility is one of the major constraints of agricultural production and productivity. Soil fertility atlas shows plant nutrient status and is useful for decision making in fertilizers and other amendments advisory service for farmers. The objectives of this research were to study the farming activity, assess the acidity status of the soils, map and recommend the right amount of lime for acidic soils. Result: A total of 199 soil samples were collected across Jimma Arjo district at 1.5 km grid interval from a depth of 0 - 20 cm for annual and 0 - 50 cm for perennial crops. The total area of the district was 76,574 ha. Soil reaction (pH), electrical conductivity (EC) and exchangeable acidity (EA) were done at Nekemte Soil Research Center. Exchangeable bases (Ca, Mg, K, Na) were analyzed by wet chemistry analysis at Yara Analytical Services, England. Critical levels adopted by the Ethiopian Soil Information System (EthioSIS) project were used for characterization of the soil properties. Soil reaction (pH) ranged from 4.45 to 6.87 in which 17.1 and 78.4% of the total area was covered by strongly acidic soils and slightly acidic soils, respectively. Agricultural lime (Ag-lime) was required for 17.87% of the total area and 12.63%, 4.36% and 0.88% of the total area require lime at a rate of 0 - 1, 1 - 2, and 2 - 4.1 tons/ha respectively. Conclusion: The highland areas of the district are more populated and there is high pressure on soil, cooler temperature and higher rainfall than lowlands which resulted in soil acidity of the highlands. The magnitude and extent of soil acidity in the area is expanding and liming is very important as an entry point to mitigate further expansion. The observed dependency of the soil acidity on landscape position could be a proxy indicator of the difference in fertility status of the two landscapes.

scholarly journals Effects of Unburned Lime on Soil pH and Base Cations in Acidic Soil

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Athanase Nduwumuremyi ◽  
Vicky Ruganzu ◽  
Jayne Njeri Mugwe ◽  
Athanase Cyamweshi Rusanganwa
Keyword(s):  
Extraction Method ◽  
Soil Acidity ◽  
Block Design ◽  
Base Cations ◽  
Research Station ◽  
Acidic Soils ◽  
Exchangeable Al ◽  
Four Levels ◽  
Materials Used

Sustainable agriculture is threatened by the widespread soil acidity in many arable lands of Rwanda. The aim of this study was to determine the quality of unburned limes and their effects on soil acidity and base cations in acidic soils of high land of Buberuka. The lime materials used were agricultural burned lime and three unburned lime materials, Karongi, Musanze, and Rusizi. The test crop was Irish Potato. All lime materials were analyzed for Calcium Carbonate Equivalent (CCE) and Fineness. A field trial in Randomized Complete Block Design was established in 2011 at Rwerere research station. The treatments comprised of the four lime materials applied at four levels: 0, 1.4, 2.8, and 4.3 t ha−1 of CCE. Soil cations (Ca2+, Mg2+, K+, and Na+) were determined by extraction method using atomic absorption spectrophotometer for Ca and Mg and flame photometer for K and Na. The Al3+ was determined using potassium chloride extraction method. Experimental soil baseline showed that the soil was very strongly acidic (2.8 cmol kg−1 Al3+). The unburned limes were significantly (P<0.001) different in terms of CCE and fineness. A higher CCE was recorded in agricultural burned and Rusizi unburned limes (86.36% and 85.46%, resp.). In terms of fineness, agricultural burned and Musanze unburned lime were higher (70.57 and 63.03%, resp.). Soil acidity significantly affected from 4.8 to 5.6 pH and exchangeable Al reduced from 2.8 cmol kg−1 to 0.16 cmol kg−1 of Al3+. Similarly all cations affected by unburned limes application, significantly (P<0.001) Ca saturation increased from 27.44 to 71.81%, Mg saturation from 11.18 to 36.87% and significantly (P<0.001) Al saturation reduced from 58.45 to 3.89%. The increase of Mg saturation was observed only with Karongi unburned lime application. This study recommends therefore, the use of 2.8 t ha−1 of CaCO3 of Rusizi or Musanze unburned lime as alternative to the agricultural burned lime for improving soil acidity and base cations in acidic soils.

scholarly journals Genetic Diversity in Fiber Related Traits of Tossa Jute (Corchorus Olitorius L.) Germplam

2021 ◽  
Vol 18 (2) ◽  
pp. 27-37
Author(s):  
MT Islam ◽  
BN Shompa ◽  
J Rahman
Keyword(s):  
Genetic Diversity ◽  
Plant Height ◽  
Quantitative Traits ◽  
Principal Component ◽  
Mean Value ◽  
Base Diameter ◽  
Eigen Values ◽  
Cluster Distance ◽  
Transgressive Segregants ◽  
Total Divergence

Genetic diversity of twenty-one genotypes of tossa jute was studied through Mahalanobis D2 statistic and principal component analysis for 15 quantitative traits related to yield at the research farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. The genotypes were grouped into four clusters. Cluster III contained the highest number of genotypes (nine), while cluster II had the lowest number of genotypes (three). The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the genotypes of different clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the cluster. The highest intra-cluster distance was noticed for the cluster I and the lowest for cluster IV. The genotypes from cluster I could be selected as parents for hybridization for producing transgressive segregants. The highest inter-cluster distance was found between clusters I and IV followed by clusters I and III and the lowest was between clusters III and IV. Cluster IV recorded the highest mean value for plant height, base diameter, root length, leaf area, fresh weight with and without leaves, dry fiber weight and dry stick weight. In the total divergence, the highest contribution was recorded in plant height (65.1%) followed by base diameter (16.6%). The first two principal components, whose eigen values were greater than one, accounted for 81.7% of the total variations among the genotypes for fifteen fiber related traits. Considering the magnitude of cluster distance, cluster means for different characters and contribution of characters towards divergence, the genotypes G17, G18 from cluster IV; G1, G2, G5, G10, G16 from cluster I and G4 from cluster III could be selected as promising parents for hybridization program. SAARC J. Agri., 18(2): 27-37 (2020)

scholarly journals Genetic diversity analysis of parental lines for hybrid development in rice (Oryza sativa L.)

2013 ◽  
Vol 37 (4) ◽  
pp. 617-624 ◽  
Author(s):  
MJ Hasan ◽  
Umma Kulsum ◽  
MMH Rahman ◽  
MMH Chowdhury ◽  
AZMKA Chowdhury
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa L ◽  
Principal Component ◽  
Mean Value ◽  
Cluster Distance ◽  
Parental Lines ◽  
Almost All ◽  
Yield Maximization ◽  
Hybrid Development ◽  
Panicle Weight

Genetic divergence of 40 parental lines comprising 30 restorer and 10 maintainer lines were studied through Mohalanobis's D2 and principal component analysis for eleven characters. Genotypes were grouped into five different clusters. Cluster V comprised maximum number of genotypes (thirteen) followed by cluster I and II. The inter-cluster distance was maximum between clusters I and V (13.495) indicating wide genetic diversity between these two clusters followed by the distance between cluster I and 11 (9.489), cluster IV, and cluster V (8.969) and cluster I and cluster III (8.039). The minimum inter-cluster distance was observed between cluster II and cluster III (3.034) followed by cluster 111 and cluster IV (3.834) and cluster II and cluster V (4.945) indicating that the genotypes of these clusters were genetically close. The intra cluster distance in the entire five clusters was more or less low which indicated that the genotypes within the same cluster were closely related. Among the characters panicle weight contributed most for divergence in the studied parental lines. Difference in cluster means existed for almost all the characters studied. Highest mean value for number of effective tillers (7.8), days to 50% flowering (95.5), panicles/m2 (192.6), panicle weight (2.9), spikelet fertility (84.8), number of grains/panicle (177.8), days to maturity (123.6), and grain yield/plot (1065.5) were observed in cluster I indicated the parental lines fallen in this cluster having the genetic potentiality to contribute better for yield maximization of hybrid rice. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14386 Bangladesh J. Agril. Res. 37(4): 617-624, December 2012

scholarly journals Student Attendance Management System using Principal Component Analysis Method

2020 ◽  
Vol 9 (4S2) ◽  
pp. 9-15
Keyword(s):  
Management System ◽  
Iris Recognition ◽  
Principal Component ◽  
Cost Effective ◽  
Analysis Method ◽  
Academic Institutions ◽  
Student Attendance ◽  
Eigen Values ◽  
Cost Effective Technique ◽  
Day By Day

Attendance taking and maintaining is a tedious job in the academic institutions where the time of class is restricted. The manual attendance i.e., roll call or paper-based signature systems usually consumes more time and error prone and also possibility of recording proxy attendance is more. Attendance is one of the criteria in considering students’ eligibility for attending the external examinations and also for the promotion to the next semester / year, where these kinds of problems may cause severe effect on the academic institutions. As the strength of students in a class is increasing day by day; monitoring, awarding and maintenance of attendance has becoming a challenge for the academic institutions. As a solution, attendance can be recorded using anyone of the existing biometric techniques like fingerprinting, iris recognition, signature, face recognition etc. Face identification is the best method among all the earlier mentioned methods for implementing in the academic institutions as it does not require human intervention and it is a cost-effective technique. A novel student attendance recording and management system using a MATLAB application, LabVIEW, Camera interface and GSM is proposed in this paper. Students’ faces will be captured with the help of a camera connected to a computer and Eigen values of the captured images will be detected with the help of MATLAB executed by LabVIEW Mathscript node. LabVIEW, a graphical programming environment is adopted for acquiring face, processing and authenticating the student once the match is found. Authenticated student attendance will be updated, and a message will be sent with the help of GSM module interface to myRIO. Proposed system replaces the manual attendance system which improves the performance of existing system.

scholarly journals Crop Response to Soil Acidity Factors in Ultisols and Oxisols in Puerto Rico X1. Cassava.

1969 ◽  
Vol 69 ◽  
pp. 145-151
Author(s):  
Edmundo Rivera ◽  
Fernando Abruña ◽  
José Rodríguez
Keyword(s):  
Puerto Rico ◽  
Manihot Esculenta ◽  
Cation Exchange Capacity ◽  
Soil Acidity ◽  
Exchange Capacity ◽  
Manihot Esculenta Crantz ◽  
Cassava Leaves ◽  
Exchangeable Al ◽  
Decreasing Ph ◽  
The Tropics

Cassava (Manihot esculenta Crantz), one of the major sources of carbohydrates throughout the tropics, was found to be very tolerant to high soil acidity in two Ultisols and one Oxisol. About 85% of maximum yields were obtained when Al saturation of the effective cation exchange capacity of the soil was around 60%, but highest yields were attained at about pH 5.3 with no exchangeable Al. Soil acidity factors did not affect the chemical composition of the cassava leaves, except for Mn, which increased with decreasing pH of the Oxisol. Tolerance of cassava to soil acidity was also confirmed by the fact that yields of 12 commercial varieties were not affected by Al saturation levels varying from 0 to 60% in an Ultisol.

scholarly journals Crop Response to Soil Acidity Factors in Ultisols and Oxisols in Puerto Rico. XII. Tomatoes

1969 ◽  
Vol 69 (3) ◽  
pp. 357-365
Author(s):  
Edmundo Rivera ◽  
José Rodríguez ◽  
Fernando Abruña
Keyword(s):  
Puerto Rico ◽  
Cation Exchange ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Soil Acidity ◽  
Exchange Capacity ◽  
Crop Response ◽  
Exchangeable Al

The effect of acidity factors of two Ultisols and one Oxisol on yield and foliar composition of tomatoes was determined. Yields were not markedly reduced by acidity in the Ultisols until pH dropped to around 4.6 with 45% Al saturation of the cation exchange capacity (CEC), and no yield was produced at about pH 4.1 and 80% Al saturation. In the Oxisol, tomato yields dropped steadily from 39.7 t/ha, when there was no exchangeable AI, to 17.5 t/ha at the highest level of acidity, pH 4.4 and 43% AI saturation. In all soils, yields were closely correlated with soil pH, exchangeable Al and Ca and Al/Ca.

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