scholarly journals Estimation of soil nitrate in the spring as a basis for adjustment of nitrogen fertiliser rates

2000 ◽  
Vol 9 (1) ◽  
pp. 71-77 ◽  
Author(s):  
J. SIPPOLA

The performance of SOILN model, which simulates soil nitrogen dynamics, was evaluated in respect to its ability to predict nitrate content in soil in spring when growing barley. The data obtained in three year nitrogen fertiliser experiments on different soil types was used. Model was parametrised using the data of the first experimental year and validation results obtained in following years are presented. The results of the simulations of the springtime nitrate in the root zone showed a reasonably small deviation from the measured values. The coefficient of determination, R2 = 0.56 was significant. The regression equation was y = 4 + 0.66x where the constant term was not significantly different from zero and the slope deviated from zero. The mean value of measured nitrate in the root zone in spring was 16 kg/ha and that from the simulation was 15 kg/ha showing that the mean values were close to each other. The mean of deviations between measured and simulated values was 4 kg/ha and the maximum deviation 9 kg/ha. It is concluded that simulation estimated springtime soil nitrate concentration with reasonable confidence that further testing of estimating soil nitrate concentration in spring for adjustment of nitrogen fertilisation using SOILN model should be continued.;

1996 ◽  
Vol 26 (10) ◽  
pp. 1822-1827 ◽  
Author(s):  
Vitezslav Dvorak ◽  
Magda Oplustilova ◽  
Dalibor Janous

The relationship between leaf biomass and sapwood area was investigated in a 35-year-old Norway spruce (Piceaabies (L.) Karst.) stand in mountainous conditions. Fifteen trees were destructively sampled to determine the needle biomass in several needle age-classes and whorls and the corresponding sapwood areas at the whorl branch bases and in stems at breast height. Leaf biomass/sapwood area ratio and specific leaf biomass (g•mm−2) were calculated for different needle age-classes and also for different positions in the vertical profile of the crown. The leaf biomass/sapwood area ratios were described by linear regression with a high coefficient of determination. Specific leaf biomass analysed in whorl branches was highest in the upper whorls but was decreasing downward through the profile; remained stable in the middle crown layer; and decreased again in the lower crown parts. Specific leaf biomass assessments for stems showed the largest and most increasing values in the youngest three needle age-classes followed by a decreasing trend of the specific leaf biomass in older needle age-classes. The mean values of specific leaf biomass were 1.08 g•mm−2 for branches and 1.02 g•mm−2 for stems. The results of our study are consistent with the "pipe model theory."


Nativa ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 62-75
Author(s):  
Daniela Roberta Borella ◽  
Adilson Pacheco De Souza ◽  
Kalisto Natam Carneiro Silva ◽  
Leonardo Martins Moura Dos Santos ◽  
Elen Silma Oliveira Cruz Ximenes ◽  
...  

Objetivou-se descrever a dinâmica diária da temperatura (Tar) e umidade relativa do ar (UR) em ambientes protegidos com diferentes telas poliefinas de sombreamento, na região de transição Cerrado-Amazônia do Mato Grosso; ademais, foram avaliados os usos de regressões de estimativa de Tar e UR nos ambientes sombreados com base nas mesmas variáveis medidas em pleno sol. As avaliações micrometeorológicas foram realizadas em viveiros florestais modulares suspensos, alinhados no sentido Leste-Oeste, entre junho de 2017 e abril de 2019, sob telas pretas com níveis crescentes de sombreamento (35, 50, 65 e 80%) e coloridas/espectrais (termorefletora, vermelha, azul e verde, todas com 50% de sombreamento). Os dados do monitoramento micrometeorológico foram agrupados em função das estações hídricas regionais (seca, seca-chuvosa, chuvosa e chuvosa-seca), com separação da base de dados por decêndios. Foram empregados 70 e 30% dos dados para geração e validação das regressões, em cada agrupamento de dados, respectivamente. Na avaliação do desempenho estatístico das regressões foram empregados os indicadores estatísticos: coeficiente de determinação (R2), erro absoluto médio (MBE), raiz quadrada do erro quadrático médio (RMSE) e índice de Willmott (d). Houve dinâmica similar de Tar e UR entre a condição de pleno sol e as telas poliefinas pretas e coloridas ao longo do dia e do ano; porém, com aumento expressivo nos valores médios da Tar e UR nesses ambientes protegidos. Os valores de R² foram satisfatórios, demonstrando que mais de 60% da variável dependente (Tar nas telas de sombreamento) está relacionada à variável independente (Tar na condição de pleno sol). O d variou de 0,96 a 0,99, indicando que as regressões de estimativas da Tar e UR ajustadas apresentam desempenho satisfatório para todas as estações hídricas regional nos ambientes sombreados. Palavras-chave: ambientes protegidos; micrometeorologia; indicadores estatísticos; transição Cerrado-Amazônia.   Dynamics and estimates of air temperature and relative humidity in nurseries protected with different shading   ABSTRACT: The objective was to describe the daily dynamics of temperature (Tar) and relative humidity (RH) in protected environments with different polyolefin shading screens in transition region of Cerrado-Amazonia of Mato Grosso; in addition, the uses regressions of estimation of Tar and RH in shaded environments based on the same variables measured in full sun were evaluated. Micrometeorological assessments were performed in suspended modules forest nurseries, aligned to the East-West direction, between June 2017 and April 2019, under black screens with increasing levels of shading (35, 50, 65 and 80%) and colored / spectral (thermo-reflector, red, blue and green, all with 50% shading). The data of the micrometeorological monitoring were grouped according to the regional water stations (dry, dry-rainy, rainy and rainy-dry), with separation of the database for ten years. 70 and 30% of the data were used to generation and validation the regressions, in each data group, respectively. In the Statistical performance evaluation of the regressions were used the statistical indicators: coefficient of determination (R2), the mean error (MBE), root mean square error (RMSE) and Willmott's index of adjustment (d). There was similar dynamic of Tar and UR between the condition of full sun and the black and colored polyolefin screens throughout the day and year; however, with a significant increase in the mean values of Tar and UR in these protected environments. The R² values were satisfactory, showing that more than 60% of the dependent variable (Tar in the shading screens) is related to the independent variable (Tar in full sun). The d ranged from 0.96 to 0.99, indicating that the adjusted regressions of Tar and UR present satisfactory performance for all regional water stations in shaded environments. Palavras-chave: protected environments; micrometeorology; statistical indicators; Cerrado-Amazônia transition.


Soil Research ◽  
2016 ◽  
Vol 54 (2) ◽  
pp. 200 ◽  
Author(s):  
J. I. Marín-Guirao ◽  
J. C. Tello ◽  
M. Díaz ◽  
A. Boix ◽  
C. A. Ruiz ◽  
...  

Intensive horticultural practices in the greenhouse can cause proliferation of soil phytopathogenic organisms and pollution of groundwater from nitrate leaching. Among the different soil disinfection techniques, bio-disinfection through the addition of organic amendments (OA), with subsequent solarisation (biosolarisation) or without (biofumigation), is an efficient and economically viable alternative for the control of soil pathogens. This greenhouse experiment was conducted to initiate the process of conversion of a conventional tomato culture to organic farming. The effects of OA applied through biofumigation and biosolarisation in the first season on soil nitrate concentration and tomato fruit yield and quality were evaluated with the following treatments: control, no OA; T1, 0.3 kg m–2 of dehydrated pellets of Brassica carinata seed meal; T2, 0.8 kg m–2 of packaged and dehydrated B. oleracea var. italica; T3, T2 + 0.15 kg m–2 of dehydrated poultry manure; T4, T1 + 0.16 L m–2 of microbial cocktail. The experiment was carried out over the autumn crop cycle of two seasons (2011–12, 2012–13). Addition of OA increased soil nitrate concentration, more so with biosolarisation. Total and marketable yield of tomato and number of marketable fruits were higher in the biosolarised plots in the first crop after treatments. No effects were observed in the second crop after treatments. Except for tomato fruit firmness, quality attributes (size, soluble solids, acidity and colour) improved with some OA treatments. The supply of OA through biosolarisation is a soil disinfection technique with potential to minimise the impact of nitrate leaching and to provide improved yield and quality of tomatoes.


2017 ◽  
Vol 32 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Alicja Romaniak

Abstract The relation between the diurnal sum of atmospheric precipitation and the diurnal volume of rainwater runoff from four experimental hardened surfaces was the subject of a pilot study conducted within the area of the Departmental Agro- and Hydrometeorology Observatory in Wrocław. The selection and the structure of the experimental surfaces were preceded with an inventory-taking of the coverage of hardened surfaces within a Wrocław housing estate with high-rise multifamily buildings. That estate was the second location, next to the area of the Observatory, at which the study presented here was conducted. The surfaces included in the experiment were roof surfaces P1 and P2 covered with heat-sealable roll roofing, surface APB made of gravel-filled openwork concrete plates, and tarmac surface AS. The pilot study was conducted during the period from April to November, 2014. During that period, depending on the type of experimental surface, from 81 to 87 days with atmospheric precipitation were analysed. The mean values of the rainwater runoff coefficients for the eightmonth period were 0.77, 0.77, 0.33 and 0.67 for surfaces P1, P2, APB and AS, respectively. The range of variability of mean values of the coefficients of rainwater runoff from the experimental surfaces in a month is presented by the following relation: APB > P1 > AS > P2. The study did not reveal any direct effect of the number of rainfall days in a month on the value of the coefficient of determination describing the correlation between the diurnal sums of precipitation and the diurnal volumes of rainwater runoff.


1984 ◽  
Vol 35 (4) ◽  
pp. 385 ◽  
Author(s):  
DJ Rochford

Mean monthly temperature, salinity and nitrate concentration of eastern Australian coastal waters, at 0 and 50 m depth, for periods of up to 36 years have been determined. Using the seasonal changes in the mean properties it has been shown that the prime source of nitrates in coastal waters of eastern Australia between Evans Head and Eden is the intrusion, at various times in the spring-summer seasons, of subsurface slope waters, which are relatively rich in nitrates. Once present in the bottom layers of these coastal waters, these nitrates form a reservoir from which local processes of mixing in the autumn-winter seasons create a surface nitrate maximum, which persists for several months into the following spring. Off Evans Head and particularly off Laurieton, upwelling later in the spring creates a secondary nitrate maximum but these are of a transient time scale and little residual surface nitrate remains after the upwelling ceases. In summer, thermal capping, aided, particularly in the north, by surface salinity dilution, greatly limits the vertical mixing of nitrates to the surface, resulting in very low surface nitrate concentrations in summer. Off Eden, the spring introduction of nitrates by slope-water intrusions is impeded by a northward flow of Bass Strait waters which, because of their low nitrate content, act as a nutrient diluent. It is only when this northward flow ceases in early summer that these slope-water intrusions occur off Eden and provide the nitrate reservoir for the winter turnover. Off Maria I., slope-water intrusions are not an important contribution to the nitrate economy. The winter maximum in nitrate concentration at the Maria I. site is attributed to an onshore drift of nitrate-richer offshore waters, containing Sub-Antarctic elements. In spring, snow-melt waters mix with these winter waters off Maria I. and decrease both the salinity and nitrate content of these waters. In summer, subtropical waters of low nitrate content occur off Maria I.


2021 ◽  
pp. 1-7
Author(s):  
A Adekoya ◽  
MB Fetuga ◽  
C Jean-Pierre ◽  
AO Adekoya ◽  
ED Ajibola

Background: When standard instruments are unavailable for clitoral length measurement, improvisation with locally available tools could be of diagnostic value. Objective: The objective of this study was to determine how the clitoral length measured with a wooden spatula compared to that measured with a caliper. Methods: This was a comparative cross-sectional study. Three hundred and five term female infants were recruited from multiple health facilities in Sagamu, Ogun State, Nigeria. The clitoral length was measured with a sliding digital caliper and a wooden spatula (tongue depressor). All the measurements were taken within the first 72 hours of life and comparative analysis was carried out. Results: The mean (± SD) clitoral length using the sliding digital caliper and the spatula were 6.7 ± 1.6 mm and 6.5 ± 1.8 mm respectively. There was no statistically significant difference between the mean values of both measurements (t = 1.369, p = 0.171). Pearson’s correlation showed that both variables were significantly correlated (r = 0.693, p < 0.001) and the spatula length was a moderate predictor of the caliper length (Coefficient of determination [R2] = 0.48 and p < 0.001). Conclusion: The findings of this study suggest that the determination of clitoral length using a spatula, commonly found in all community settings, is similar to determination of clitoral length using a digital caliper, most often used for clinical research.


1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.


1986 ◽  
Vol 55 (01) ◽  
pp. 108-111 ◽  
Author(s):  
M Köhler ◽  
P Hellstern ◽  
C Miyashita ◽  
G von Blohn ◽  
E Wenzel

SummaryThis study was performed to evaluate the influence of different routes of administration on the efficacy of DDAVP treatment. Ten healthy volunteers received DDAVP intranasally (i.n.), subcutaneously (s.c.) and intravenously (i.v.) in a randomized cross-over trial. Factor XII and high molecular weight (HMW)-kininogen levels increased only slightly after DDAVP administration. The mean increase of factor VIII: C was 3.1 (i. v.), 2.3 (s. c.), and 1.3 (i.n.) - fold over baseline. Ristocetin cofactor (von Willebrand factor antigen) increased 3.1 (2.5), 2.0 (2.3) and 1.2 (1.2) - fold over baseline mean values after i.v., s.c. and i.n. DDAVP, respectively. The half-disappearance time of factor VIII and von Willebrand factor (vWF) after DDAVP ranged from five (factor VIII: C) to eight hours (vWF). The mean increase of fibrinolytic activity was more pronounced after i.v. DDAVP. The antidiuretic effect was moderate with no apparent differences between the routes of application. This study provides further evidence that both i.v. and s.c. DDAVP administration result in an appropriate and reliable stimulation of haemostasis. An additional advantage of s. c. administration is its suitability for home treatment.


2018 ◽  
Vol 4 (4) ◽  
pp. 519-522
Author(s):  
Jeyakumar S ◽  
Jagatheesan Alagesan ◽  
T.S. Muthukumar

Background: Frozen shoulder is disorder of the connective tissue that limits the normal Range of motion of the shoulder in diabetes, frozen shoulder is thought to be caused by changes to the collagen in the shoulder joint as a result of long term Hypoglycemia. Mobilization is a therapeutic movement of the joint. The goal is to restore normal joint motion and rhythm. The use of mobilization with movement for peripheral joints was developed by mulligan. This technique combines a sustained application of manual technique “gliding” force to the joint with concurrent physiologic motion of joint, either actively or passively. This study aims to find out the effects of mobilization with movement and end range mobilization in frozen shoulder in Type I diabetics. Materials and Methods: 30 subjects both male and female, suffering with shoulder pain and clinically diagnosed with frozen shoulder was recruited for the study and divided into two groups with 15 patients each based on convenient sampling method. Group A patients received mobilization with movement and Group B patients received end range mobilization for three weeks. The outcome measurements were SPADI, Functional hand to back scale, abduction range of motion using goniometer and VAS. Results: The mean values of all parameters showed significant differences in group A as compared to group B in terms of decreased pain, increased abduction range and other outcome measures. Conclusion: Based on the results it has been concluded that treating the type 1 diabetic patient with frozen shoulder, mobilization with movement exercise shows better results than end range mobilization in reducing pain and increase functional activities and mobility in frozen shoulder.


1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.


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