Effect of watertable depth and salinity on growth dynamics of Rhodes grass (Chloris gayana)

2016 ◽  
Vol 67 (8) ◽  
pp. 881 ◽  
Author(s):  
Sebastián Chiacchiera ◽  
Nicolás Bertram ◽  
Edith Taleisnik ◽  
Esteban Jobbágy
Keyword(s):  
Growth Dynamics ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Rhodes Grass ◽  
Negative Effect ◽  
Salinity Levels ◽  
Use Efficiency ◽  
Chloris Gayana ◽  
Positive Effect ◽  
Pampas Region

Depending on their depth, watertables can have a positive effect on plants by supplying water, a negative effect by creating waterlogged and/or saline conditions or a neutral effect. Rhodes grass (Chloris gayana), a tropical perennial forage adapted to saline soils, floods and droughts, is a viable choice for the lowlands in the Pampas region of Argentina. The effects of the depth and salt concentration of the watertable on the growth dynamics and biomass accumulation of Rhodes grass were quantified in a greenhouse experiment. The experiment consisted of 10 treatments, resulting from the factorial combination of five watertable depths (25, 75, 125, 175 and 225 cm) and two salt treatments (EC 1.4 and 20.5 dS m–1). The presence of non-saline watertable at a depth of 25 cm produced a 5-fold greater biomass and showed an increase in water consumption of equal magnitude compared with deeper watertables. The increase in shoot biomass was explained primarily by higher tiller and stolon density, which increased 3.3- and 7.7-fold respectively, at watertables that were 25 cm deep compared with deeper treatments. Furthermore, groundwater use efficiency was 30% higher in non-saline watertables at 25 cm depth. Similarly, at this depth, the leaf blades were 50% longer compared with the deepest watertables evaluated. In contrast, the presence of saline watertables at 25 cm depth had a detrimental effect on the production of biomass and its components, whereas the effect at 125 cm and greater depths was neutral. Therefore, Rhodes grass is a species that can take advantage of the widespread shallow watertable environments of the Pampas region as long as the salinity levels are low.

scholarly journals Evaluation of Some Rhodes Grass (Chloris gayana) Genotypes for Their Salt Tolerance, Biomass Yield and Nutrient Composition

2019 ◽  
Vol 9 (1) ◽  
pp. 143 ◽  
Author(s):  
Ashenafi Worku Daba ◽  
Asad Sarwar Qureshi ◽  
Bethel Nekir Nisaren
Keyword(s):  
Soil Salinity ◽  
Management Practices ◽  
Germination Percentage ◽  
Soil Salinization ◽  
The Other ◽  
Forage Production ◽  
Rhodes Grass ◽  
Salinity Levels ◽  
Chloris Gayana ◽  
The Impact

The livestock productivity in Ethiopia is seriously constrained by the shortage of fodder due to increasing soil salinization. Therefore, restoration of salt-affected lands into productive soils through salt-tolerant forages and improved irrigation and crop management practices is crucial for enhancing the productivity of the livestock sector in Ethiopia. In this three-year study, pot trials were conducted to evaluate the impact of five different soil salinity levels (i.e., 0, 5, 10, 15, and 20 dS m−1) on plant growth, biomass production, and nutrient quality attributes of three Rhodes grass (Chloris gayana) genotypes (ILRI-6633, ILRI-7384, CV-massaba). Increasing soil salinity negatively affected germination percentage (GP) and mean germination time (MGT) of all genotypes. For all salinity levels, the highest GP was observed for ILRI-6633 and the lowest for CV-massaba. Plant height and chlorophyll content for ILRI-6633 was higher than the other two genotypes. The crude protein (CP) content was higher in low dry matter-producing genotype (ILRI-7384). The performance of ILRI-6633 at all salinity levels was superior to the other two genotypes. CV-massaba genotype performed better under low to medium soil salinity conditions. Therefore, ILRI-6633 and CV-massaba genotypes have excellent potential to increase forage production in salt-affected areas of Ethiopia.

Physiological causes for decreased productivity under high salinity in Boma, a tetraploid Chloris gayana cultivar

2001 ◽  
Vol 52 (9) ◽  
pp. 903 ◽  
Author(s):  
M. de Luca ◽  
L. García Seffino ◽  
K. Grunberg ◽  
M. Salgado ◽  
A. Córrdoba ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
High Salinity ◽  
Leaf Growth ◽  
Salt Gland ◽  
Dry Matter Accumulation ◽  
Rhodes Grass ◽  
Salinity Levels ◽  
Chloris Gayana ◽  
Excretion Rates ◽  
Area Expansion

Rhodes grass (Chloris gayana Kunth) is widely cultivated in the semi-arid tropics and favoured for salt tolerance; nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in the tetraploid cultivar Boma, the physiological causes for such decrease. Experiments were carried out in vegetative plants in the greenhouse. At high salinity (200 mM NaCl), an early reduction in leaf area expansion was observed, and, later, decreased dry matter accumulation, suggesting that the central effect of salinity was a limitation of leaf growth. This was evaluated in 2 closely related Boma clones, exhibiting different degrees of salt tolerance. Growth, ion accumulation and excretion, sugars, and proline concentrations were measured under a range of salt concentrations (0–200 mM NaCl). Differences between the clones in leaf expansion were expressed only at high salinity, but were not associated with differences in water potential or hydraulic conductance in the expanding region. At all salinity levels, the proportion of dry leaves was higher in the clone which also had lower salt gland density and Na excretion rates. Less efficient Na extrusion, associated with high oxidative stress, may be the main cause for leaf senescence and differences in productivity between these clones.

scholarly journals Effects of different N, P, K and Ca levels on tomato yield, quality and fertiliser use efficiency

2020 ◽  
Vol 66 (No. 11) ◽  
pp. 569-575
Author(s):  
Feng Qu ◽  
Jiao Zhang ◽  
Xueqiang Ma ◽  
Junzheng Wang ◽  
Zixing Gao ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Comprehensive Evaluation ◽  
High Yield ◽  
Tomato Yield ◽  
Negative Effect ◽  
Use Efficiency ◽  
Yield Quality ◽  
Fertiliser Use ◽  
Positive Effect ◽  
Optimal Formula

The experiment aimed to obtain a quadratic regression mathematical model of the comprehensive evaluation score of yield, quality, and four macroelements (N, K, P and Ca). The suitable nutrient solution was chosen and verified via computer simulation of the model and the highest comprehensive score in all treatments. Results showed that P, K and Ca had a positive effect on the comprehensive evaluation value of tomato, whereas N showed a negative effect. The optimal formula calculated using the regression equation could promote high-yield and high-quality tomato. The single-plant yield, soluble protein, vitamin C, total sugar, lycopene, and elemental utilisation of K and Ca in the tomato were 13.93, 78.95, 3.29, 20.98, 51.91, 16.69 and 24.14% higher than those in the special formula treatment of Japanese Yamazaki tomato, respectively. In summary, the optimal nutrient solution formula of tomato cultivation was obtained, in which the N, P, K and Ca levels were 24.83, 4.50, 9.49 and 5.73 mmol/L, respectively.  

Working Memory, Mental Prospection, Time Orientation, and Cognitive Insight

2013 ◽  
Vol 34 (3) ◽  
pp. 159-169 ◽  
Author(s):  
Sevtap Cinan ◽  
Aslı Doğan
Keyword(s):  
Working Memory ◽  
Structural Equation ◽  
Factor Model ◽  
Time Orientation ◽  
Equation Modeling ◽  
Cognitive Insight ◽  
Confirmatory Factor ◽  
Negative Effect ◽  
Positive Effect ◽  
Three Factor

This research is new in its attempt to take future time orientation, morningness orientation, and prospective memory as measures of mental prospection, and to examine a three-factor model that assumes working memory, mental prospection, and cognitive insight are independent but related higher-order cognitive constructs by using confirmatory factor analysis (CFA). The three-factor model produced a good fit to the data. An alternative one-factor model was tested and rejected. The results suggest that working memory and cognitive insight are distinguishable, related constructs, and that both are distinct from, but negatively associated with, mental prospection. In addition, structural equation modeling (SEM) showed that working memory had a strong positive effect on cognitive insight and a moderate negative effect on mental prospection.

Estimasi Pengaruh Faktor Internal Bank dan Stabilitas Makroekonomi terhadap Profitabilitas dengan Mediasi Rasio Pembiayaan Bermasalah di PT Bank Muamalat Indonesia

2020 ◽  
Vol 3 (2) ◽  
pp. 93-108
Author(s):  
Annisa Siti Fathonah ◽  
Dadang Hermawan
Keyword(s):  
Secondary Data ◽  
Financial Statements ◽  
Significant Positive Effect ◽  
Return On Assets ◽  
Internal Factors ◽  
Macroeconomic Factors ◽  
Operating Income ◽  
Significant Negative Effect ◽  
Negative Effect ◽  
Positive Effect

This study aims to determine and analyze how much influence the bank's internal factors such as Equity, Operational Costs per Operating Income (BOPO), Financing Deposit to Ratio (FDR), Non Performing Financing (NPF) as a mediator and external or macroeconomic factors namely inflation and Gross Domestic Product (GDP) on profitability represented by Return on Assets (ROA) at Bank Muamalat Indonesia for the period 2008-2018. The data used in this research are secondary data obtained from the publication of quarterly financial statements from 2008 to quarter 2 of 2018. The method that used in this research is path analysis with SPSS 20.0 as the analytical tool. The results of the study partially test the hypothesis (t-test), in substructure I shows that the capital variable has a significant negative effect on NPF, BOPO and inflation has a significant positive effect on NPF, FDR and GDP do not significantly influence NPF at Bank Muamalat Indonesia. In substructure II partially, Capital, BOPO, significant negative effect on ROA, FDR and NPF has a significant positive effect on ROA, Inflation and GDP does not significantly influence ROA while simultaneously significantly influencing ROA. Based on the sobel test, capital has a significant effect on ROA through NPF, BOPO has a significant effect on ROA through NPF, FDR has a significant effect on ROA through NPF, Inflation has a significant effect on ROA through NPF, while GDP has no significant effect on ROA through NPF.

Employee Engagement Dan Stress Kerja Pengaruhnya Terhadap Kepuasan Kerja Dan Turnover Intention di Aman Villas Nusa Dua – Bali

2020 ◽  
Vol 2 (1) ◽  
pp. 60-79
Author(s):  
Wayan Arya Paramarta ◽  
Ni Putu Kurnia Darmayanti
Keyword(s):  
Job Satisfaction ◽  
Employee Engagement ◽  
Work Stress ◽  
Turnover Intention ◽  
Secondary Data ◽  
Qualitative And Quantitative ◽  
Library Research ◽  
Analysis Technique ◽  
Negative Effect ◽  
Positive Effect

The aims of this study was to explain the effect of employee engagement and work stress on job satisfaction and turnover intention at Aman Villas Nusa Dua-Bali. The type of data used in this study is qualitative and quantitative data, with data sources namely primary and secondary data. Data collection method is interview, distributing questionnaires to respondents and library research, while the data analysis technique used Smart PLS 3.2.8. The results of this study showed that employee engagement had a positive effect and significant on job satisfaction, work stress had a negative effect but not significant on job satisfaction, employee engagement had a negative effect and significant on turnover intention, work stress had a positive effect and significant on turnover intention, job satisfaction had a negative effect but not significant on turnover intention, employee engagement had a positive effect but not significant on turnover intention trough job satisfaction, work stress had a positive effect but not significant on turnover intention trough job satisfaction at Aman Villas Nusa Dua-Bali.

The Factors Influencing Tourist Visitations Number in Curug Silawe

2019 ◽  
Vol 2 (3) ◽  
pp. 553-561
Author(s):  
Novian Hangga Prakosa ◽  
Fafurida Fafurida
Keyword(s):  
Economic Value ◽  
Consumer Surplus ◽  
Sampling Technique ◽  
Travel Cost ◽  
Analysis Tool ◽  
Literature Study ◽  
Factors Influencing ◽  
Negative Effect ◽  
Value Estimation ◽  
Positive Effect

The purposes of this research are to identify the influence of travel cost, income, distance, access, facilities, natural beautiness, and age on the number of individual visits to Curug Silawe and to estimate the economic value of Curug Silawe through individual travel cost method. The population in this study are tourists that visited Curug Silawe with sample of 98 respondents taken by the quota accidental sampling technique. The data collection method used are literature study and questionnaire. The analysis tool used are OLS linear regression and economic value estimation. The results showed the variables that influence the number of individual visits to Curug Silawe are income, distance and age. Income and age has a positive effect. While distance has a negative effect. The economic value of Curug Silawe reached IDR 1,109,930,140.48 per year. This value is obtained from consumer surplus obtained per individual per year of IDR 308,656.88. Tujuan dari penelitian ini adalah untuk mengidentifikasi pengaruh biaya perjalanan, pendapatan, jarak, akses, fasilitas, keindahan alam, dan usia pada jumlah kunjungan individu ke Curug Silawe dan untuk memperkirakan nilai ekonomi Curug Silawe melalui metode biaya perjalanan individu . Populasi dalam penelitian ini adalah wisatawan yang berkunjung ke Curug Silawe dengan sampel 98 responden yang diambil dengan teknik quota accidental sampling. Metode pengumpulan data yang digunakan adalah studi literatur dan kuesioner. Alat analisis yang digunakan adalah regresi linear OLS dan estimasi nilai ekonomi. Hasil penelitian menunjukkan variabel yang mempengaruhi jumlah kunjungan individu ke Curug Silawe adalah pendapatan, jarak dan usia. Penghasilan dan usia memiliki efek positif. Sedangkan jarak memiliki efek negatif. Nilai ekonomi Curug Silawe mencapai Rp1.109.930.140,48 per tahun. Nilai ini diperoleh dari surplus konsumen yang diperoleh per individu per tahun sebesar Rp308.656,88.

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

Pengaruh Etika Bisnis Islam Terhadap Kesejahteraan Pedagang (Studi Kasus Pedagang Pusat Pasar Medan)

2019 ◽  
Vol 4 (1) ◽  
pp. 185
Author(s):  
Ya’ti Ikhwani Nasution
Keyword(s):  
Free Will ◽  
Quantitative Research ◽  
Statistical Tools ◽  
Independent Variables ◽  
Islamic Business Ethics ◽  
Negative Effect ◽  
Data Collection Technique ◽  
Questionnaire Method ◽  
Market Center ◽  
Positive Effect

The purpose of this study is to find out whether there is an influence of Islamic business ethics with the variables of unity, equilibrium, free will, responsibility, benevolence and the welfare of traders in the Pusat Pasar Medan. This research is a quantitative research and the analysis used is multiple regression analysis. The data collection technique used is the questionnaire method obtained directly from the respondent, namely the Pusat Pasar Medan Trader. Analyzed using statistical tools, namely SPSS Version 22. Based on the results of data processing has shown that there is a significant influence as partially and simultaneously among the unity, equilibrium, free will, responsibility and benovelence towards the welfare of traders in the Medan Market Center. For unity, free will, responsibility and benovelence have a positive effect on the welfare of traders in Medan Market Center. While the equilibrium variable has a negative effect on the welfare of Medan Market Center traders. The adjusted R square value is 0.345. This means that 34.5% increase in welfare can be explained by independent variables, namely the variables of unity, equilibrium, free will, responsibility and kindness. While 65.5% is explained by other factors.

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