scholarly journals Assessing organic potato cropping systems at the end of the first cycle of four-year rotations using principal component analysis

2008 ◽  
Vol 88 (4) ◽  
pp. 543-552 ◽  
Author(s):  
K. Liu ◽  
A M Hammermeister ◽  
D G Patriquin ◽  
R C Martin

A single or a few variables may not be sufficient to evaluate management practice effects in a complicated cropping system, so six plant and 13 soil variables were integrated using principal component analysis (PCA) to examine nine 4-yr organic potato rotations. The rotations were combinations of three forage levels (0, 1, and 2 yr of forages) with three soil amendments (monogastric compost, ruminant compost, and alfalfa meal). Quantities of amendments were estimated by soil test recommendations and amendment nutrient availabilities. In the 4th potato year, one half of each original plot was not amended ("the 4th year unamended plots"), while the other half received soil amendments ("4th year amended plots"). The first three principal components explained 67 and 63% of the overall variation for the 4th-yr amended and unamended plots, respectively. PCA ordination plots indicated that, overall, the type of soil amendments had larger effects on soil and plant variables, but forage frequencies were influential for the amendments showing weaker effects. PCA loading plots indicated that plant nutrient uptake and potato total tuber weight would be the best single variables for characterizing the current cropping systems. Plant variables, except for potato petiole nitrate, were closely displayed, but they were not strongly correlated with soil variables, which may reflect the high background fertility of this site. Applications of soil amendments in the 4th yr affected the relationships among variables, most notably the strength of relationships between soil pH and soil N variables. The results suggest that PCA provides an effective way to compare complex cropping systems, especially in situations with high site heterogeneity. Key words: Principal component analysis, soil amendment, livestock system, forage, potato, organic crop rotation

Author(s):  
V.A. Mohanlal ◽  
K. Saravanan ◽  
T. Sabesan

Background: Blackgram [Vigna mungo (L.) Hepper] is a popularly known pulse crop in India for its nutritional quality and adaptability to many cropping systems. The crop is mostly cultivated in areas experiencing water stress which reduces the yield potential. Thus, it is imperative to assess the genetic variability present in the existing blackgram germplasm under drought condition. For this, principal component analysis was carried to visualize the complex dataset. This study was aimed to identify key traits and drought tolerant genotypes. Methods: Twenty-one blackgram genotypes were screened in the field condition for water stress where the experiment was laid out in RBD with two replications. Principal component analysis was carried out with thirteen traits in twenty-one genotypes of blackgram under normal and water stressed conditions.Result: In T0 and T1, more than 75% of total variability among thirteen traits was explained by five and four principal component axes respectively. Under water stress, pod length was highly correlated with seed yield per plant. Based on the interaction vectors and PC scores of genotypes, VBG-12062 had a positive interaction with seed yield. Thus, VBG-12062 can be a reliable candidate for breeding high yielding drought tolerant variety.


Author(s):  
T. A. Awobona ◽  
J. O. Adedapo ◽  
J. O. Emmanuel ◽  
O. Osunsina ◽  
J. A. Ogunsanwo ◽  
...  

This study analyzed the various determinants of land management practices in Chikun LGA of Kaduna State and determined most sustainable practice(s), with the specific focus on: Socio-economic characteristics of farmers; types of land management practices in relation to the determinant factors; effects of land management practices on the farm productivity; determine the most sustainable land management practice in the study area. A purposive sampling technique was adopted in collecting data from three hundred and eighty (380) rural farmers with structured questionnaires administered in Buruku, Chikun Local Government area of Kaduna State, Nigeria. Five land management practices showed positive effects on the farm productivity as compared to the mean of 3 points; these were cover crop, crop rotation, irrigation, organic manure and fertilizer application. Two land management practices as perceived to have good effects on farm productivity of respondents were agro-forestry and bush fallow as shown in the component one of the result of Principal Component Analysis (PCA). It was concluded that the farming population was ageing and was adversely affected the choice of best practices due to lack of education and knowledge to adopt the best land management practice. Sustainable land management practices has the potential to reverse the trend of food scarcity and environmental disasters, help to improve local livelihoods, restore natural ecosystems and also contribute significantly to climate change adaptation and mitigation. There is clear evidence that the productivity of soils in Buruku Village will continue to decline if strategic measures are not put in place to manage soil fertility in different soil units to support agricultural land.


2019 ◽  
Vol 37 (2) ◽  
pp. 215-228 ◽  
Author(s):  
Samson Oluseun Ojekalu ◽  
Olatoye Ojo ◽  
Timothy Tunde Oladokun ◽  
Sumoila Aremu Olabisi

Purpose The purpose of this paper is to examine factors influencing service quality of the property managers to the occupiers of shopping complexes in Ibadan, Nigeria. This was with a view to providing information that could enhance property management practice. Design/methodology/approach Primary data were used for the study. The study area was stratified into five axes using major roads where shopping complexes were highly concentrated. Systematic sampling technique was used to select 139 out of 276 shopping complexes in the study area. The data obtained were analyzed using mean ranking and principal component analysis. Findings The study found that ineffective employee’s compensation, high employee turnover, lack of continuous improvement culture, inadequate use of employee empowerment, inadequate staff, lack of teamwork, inability to see tenants as customer, lack of motivation, education and training of the property managers and poor planning among others were the most significant factors influencing service quality of the property managers using mean ranking. The study further found that professional and empowerment factor, teamwork and motivation factor, customer related factor, work volume and operation factor, skills and job satisfaction factor, top-management commitment factor, experience and communication factor as well as financial factor were the factors influencing service quality of the property managers using principal component analysis. Practical implications This study will aid the property managers of shopping complexes in identifying areas which needed to be improved upon in order to provide quality service to occupiers thereby enhancing tenant retention and loyalty. Originality/value Previous studies on factors influencing service quality have been focusing on hospitality, healthcare, real estate agency and library industries. This study is one of the very few studies that examined factors influencing service quality of property managers of shopping complex. Also, the paper underlines the need for property managers of shopping complexes to give required attention to factors influencing service quality for enhanced property management practice.


VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.


2020 ◽  
Vol 4 (11) ◽  
pp. 676-681
Author(s):  
V.V. Sapozhnikova ◽  
◽  
A.L. Bondarenko ◽  

Aim: to determine the association between clinical laboratory parameters, the production of cytokines (IL-17A, -23, -33, -35), and specific IgM and IgG in the serum of patients with Lyme borreliosis without erythema migrans. Patients and Methods: complete blood count, the concentrations of IL-17A, -23, -33, -35, and the levels of specific IgM and IgG were measured during acute infection and convalescence (n=30). The control group included age- and sex-matched healthy individuals (n=30). Statistical analysis was performed using the StatSoft Statistica v 10.0 software (parametric and non-parametric methods and multifactorial analysis, i.e., principal component analysis). Results: most (80%) patients with Lyme borreliosis without erythema migrans are the people of working age. In most patients, the combination of the specific antibodies against Borrelia afzelii and Borrelia garinii (76.7%) and severe intoxication and inflammatory process (100%) were detected. Moderate and severe disease associated with meningism was diagnosed in 90% and 10%, respectively. The mean duration of hectic period was 8.3±1.27 days. Abnormal ECG was reported in 40% of patients, i.e., conduction abnormalities in 20%, sinus bradycardia in 16.7%,and sinus tachycardia in 3.3%. The clinical laboratory signs of hepatitis without jaundice were identified in 26.7%. During treatment, the significant reduction in band and segmented neutrophil counts as well as the significant increase in platelet count were revealed compared to these parameters at admission. Abnormal cytokine levels (i.e., the increase in IL-17A, -23, -33 and the deficiency of IL-35) were detected. Conclusions: multifactorial analysis has demonstrated that the severity of immunological abnormalities in patients with Lyme borreliosis without erythema migrans is associated with fever, cardiac and liver disorders, the high levels of IL-23 and IL-33, and the lack of IL-35 and specific IgM and IgG. KEYWORDS: tick-borne borreliosis, Lyme disease without erythema migrans, clinical laboratory signs, cytokines, specific antibodies, multifactorial analysis, principal component analysis. FOR CITATION: Sapozhnikova V.V., Bondarenko A.L. Multifactorial analysis of clinical laboratory signs, the levels of IL-17A, IL-23, IL-33, IL-35, and specific antibodies in the serum of patients with Lyme borreliosis without erythema migrans. Russian Medical Inquiry. 2020;4(11):676–681. DOI: 10.32364/2587-6821-2020-4-11-676-681.


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