The effect of total water supply, and frequency of application, upon lucerne. II.* Chemical composition

1972 ◽  
Vol 23 (2) ◽  
pp. 253 ◽  
Author(s):  
RW Snaydon
Keyword(s):  
Water Supply ◽  
Nitrogen Concentration ◽  
Phosphorus Concentration ◽  
In Vitro Digestibility ◽  
Pan Evaporation ◽  
Water Application ◽  
Total Water ◽  
Class A ◽  
Class A Pan

Total water supply, expressed as a proportion of class A pan evaporation (Epan), and frequency of water application were varied independently during summer. The phosphorus concentration in the shoots of lucerne increased by 35% when the total water supply was increased from 0.1 to 1.0Epan; the nitrogen concentration was not significantly affected. The in vitro digestibility of leaf and stem fractions decreased with increasing total water supply, and the proportion of highly digestible fractions (leaf and flower) also decreased, so that total shoot digestibility decreased from 65% at 0.24 Epan to 55% at 0.58 Epan. Frequency of water application had no significant effect upon phosphorus or nitrogen concentration or in vitro digestibility. ____________________ *Part I, Aust. J. Agric. Res., 23: 239 (1972)

The effect of total water supply, and frequency of application, upon lucerne. I. Dry matter production

1972 ◽  
Vol 23 (2) ◽  
pp. 239 ◽  
Author(s):  
RW Snaydon
Keyword(s):  
Water Supply ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Early Winter ◽  
Pan Evaporation ◽  
Total Water ◽  
Efficiency Ratio ◽  
Class A ◽  
Matter Production ◽  
Use Efficiency

The total quantity of water supplied to an established lucerne stand, and the frequency of water application, were varied independently. The total quantity of water supplied during summer, autumn, and early winter was expressed as a proportion of class A pan evaporation (Epan), and ranged from 0.04 to 3.5 Epan. Dry matter production, at total water supply equal to Epan, varied between 8.6 kg ha-1 day-1 in early winter (May–June) and 97 kg ha-1 day-1 in summer (January–February), and was correlated (r = 0.99) with mean minimum temperature. The form of the response curve of log, dry matter production to water supply, relative to Epan, was similar during all seasons. Dry matter production increased approximately logarithmically with increasing water supply up to the equivalent of 0.5 Epan reached a maximum at about 1.5 Epan, and declined above this. A response surface was constructed, based upon total water supply and mean minimum temperature.Frequency of application, at a given total water supply, had no significant effect on dry matter production when total supply exceeded 0.5 Epan in any season. At a total water supply equal to 0.2 Epan, frequent small applications of water (5 mm) produced 50% more dry matter than less frequent large applications (20 and 80 mm) during summer, but only 30% as much as the less frequent applications in the subsequent autumn. Water use efficiency (ratio of dry matter production to total water supplied) was greatest at 0.5 Epan at all frequencies of application in summer. During the 6 months after irrigation treatments ceased, dry matter production was generally related to the amount of available water in the soil, but production was less, even 18 months later, on plots that had previously received the heaviest irrigation (130mm month-1). Frequency of application had no significant effect upon subsequent yield, but frequent small applications in one summer reduced the capacity of lucerne to extract soil water at low water potentials in the following summer.

Land Condition in the Tropical Tall Grass Pasture Lands. 2. Effects on Herbage Quality and Nutrient Uptake.

1995 ◽  
Vol 17 (1) ◽  
pp. 86 ◽  
Author(s):  
AJ Ash ◽  
JG Mcivor
Keyword(s):  
Nitrogen Concentration ◽  
Phosphorus Uptake ◽  
Phosphorus Concentration ◽  
In Vitro Digestibility ◽  
Nitrogen And Phosphorus ◽  
Tall Grass ◽  
Herbage Quality ◽  
Land Condition ◽  
Nitrogen And Phosphorus Uptake

Herbage quality (in vitro digestibility, nitrogen and phosphorus concentrations) of plucked samples, and above ground nutrient uptakes (nitrogen and phosphorus) were compared on plots differing in land condition at 10 sites in northern Australia. Over all sites there was a significant increase in digestibility and nitrogen concentration, and a significant decrease in phosphorus concentration, as land condition declined. Both nitrogen and phosphorus uptake decreased as land condition declined. The results indicate that diet quality may be higher from land in poor condition. However, the large decrease in pasture productivity associated with declining land condition may more than offset this apparent improvement in feed quality.

Growth and yield of rice under sprinkler irrigation on a free-draining soil

1985 ◽  
Vol 25 (3) ◽  
pp. 636 ◽  
Author(s):  
J Blackwell ◽  
WS Meyer ◽  
RCG Smith
Keyword(s):  
Irrigation System ◽  
New South ◽  
Sprinkler Irrigation ◽  
Sprinkler System ◽  
Growth And Yield ◽  
Pan Evaporation ◽  
Water Application ◽  
Class A ◽  
South Wales ◽  
Class A Pan

A line-source sprinkler irrigation system was used to study rice growth under irrigation on a free-draining soil in the Murrumbidgee Irrigation Area of New South Wales. Ponded rice was grown on the same soil for comparison. Seven levels of sprinkler water application were examined, ranging from 26 to128% of Class 'A' pan evaporation. Apparent efficiency of water use ranged from 3.4 kg of grain/mm for the highest yielding sprinkler treatment to 1.85 kg of grain/mm for the highest yielding ponded treatment. Excellent weed control was achieved by herbicides applied through a sprinkler system.

Yield response of bananas to trickle irrigation

1981 ◽  
Vol 21 (111) ◽  
pp. 448 ◽  
Author(s):  
T Trochoulias ◽  
RD Murison
Keyword(s):  
Water Potential ◽  
Root System ◽  
Yield Response ◽  
Pan Evaporation ◽  
Total Water ◽  
Trickle Irrigation ◽  
Class A ◽  
Distribution Studies ◽  
Gravimetric Sampling ◽  
Class A Pan

Supplementary trickle irrigation applied twice a week by single microtube at replacement rates of 0 (control), 20, 40, 60, 80, 100 and 120% of Class A pan evaporation (El from 1970 to 1976 increased bunch weight significantly (P= 0.02) above 40% E. Treatment 60% E gave a bunch weight of 27.6 kg compared with 25.7 for the control. The control, 20 and 40% treatments did not affect hand number from 1970 to 1976 while all other treatments increased hand number by 0.3 hands each year. Means of treatments over all years for fingers showed an annual increase of 4.6,4.0,5.8 and 5.0 fingers for 60,80,100 and 12O0Io treatments, respectively. Gravimetric sampling in 1974 showed the control plot had a lower water potential than other plots. There was little change in water potential in any of the other treatments. There was a significant linear decrease in water potential with increase in radius from the emitter. Root distribution studies showed that about 70% of the root systems in all treatments were concentrated in the upper 40 cm of soil. Forty per cent of the total root system was confined to a square, 60 x 60 cm, close to the base of the plant. Thus trickle irrigation with an emitter positioned near the base of the plant and a slow flow rate (3 litres/h) would reach most of the root system. Four out of the six years of the experiment were very wet (greater than 1700 mm rainfall). Only 29% of the total water over the 6 years in the 60% E treatment was provided by trickle irrigation. This experiment showed that 60% of Class A pan evaporation can be used as a reliable guide for the trickle irrigation of bananas on the East coast of Australia with free draining soils.

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA

Irriga ◽  
2001 ◽  
Vol 6 (3) ◽  
pp. 120-127
Author(s):  
Reginaldo Ferreira Santos ◽  
Antonio Evaldo Klar
Keyword(s):  
Spatial Variability ◽  
Pan Evaporation ◽  
Spring Season ◽  
Class A ◽  
Agricultural Sciences ◽  
E Mail ◽  
Center Area ◽  
Class A Pan

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA  Reginaldo Ferreira SantosCentro de Ciências Exatas e Tecnológica da UNIOESTE- CP 711CEP 858114-110, Cascavel, PR - Fone: 0XX45 2203155.  E-mail: [email protected] Evaldo KlarDepartamento de Engenharia Rural - Faculdade de Ciências Agronômica- UNESP - CEP 18603-970 - Botucatu, SP. CP: 237.  E-mail:  [email protected]  1  RESUMO O presente trabalho teve como objetivo avaliar a distribuição da evaporação no interior de uma estufa plástica, com uma cultura de pimentão, através da variabilidade espacial e comparar a evaporação dos microevaporímetros com os valores do Tanque classe "A". O experimento foi conduzido no Campus da Universidade Estadual Paulista - FCA/UNESP, no período de primavera, em estufa plástica de polietileno de baixa densidade (PEBD). Na distribuição da evaporação em estufa com orientação norte/sul, verificou-se que as maiores evaporações ocorreram nas extremidades sul e norte tendente ao lado oeste. Já as menores evaporações localizaram-se no centro. No período de primavera, a evaporação média nos microevaporímetros superestimou em 55% a evaporação determinada no Tanque classe "A". UNITERMOS: evaporação, geoestatística, estufa.  SANTOS, R.F, KLAR, A.E.  EVAPORATION DISTRIBUTION INSIDE A PLASTIC TUNNEL IN THE SPRING SEASON  2  ABSTRACT                 The main aim of this study was to verify the evaporation distribution inside a plastic tunnel, with pepper crop, oriented to north/south, through spatial variability and to compare Class A Pan evaporation to punctual evaporations of 40 equidistant microevaporimeters placed from 50cm the soil. The study was carried out at the College of Agricultural Sciences/UNESP, Botucatu – SP in the spring season.  The highest evaporation occurred next to north and to south sides of the tunnel, with tendency to west. Consequently, the lowest evaporations occurred at the center area. The microevaporimeter evaporations were 55% higher than those obtained from Class A Pan. KEYWORDS: evaporation distribution, microevaporimeter.

scholarly journals Annual Actual Evapotranspiration Estimation via GIS Models of Three Empirical Methods Employing Remotely Sensed Data for the Peloponnese, Greece, and Comparison with Annual MODIS ET and Pan Evaporation Measurements

2021 ◽  
Vol 10 (8) ◽  
pp. 522
Author(s):  
Stavroula Dimitriadou ◽  
Konstantinos G. Nikolakopoulos
Keyword(s):  
Time Scale ◽  
Gradual Decrease ◽  
Actual Evapotranspiration ◽  
Pan Evaporation ◽  
Empirical Methods ◽  
Remotely Sensed Data ◽  
Upward Trend ◽  
Class A ◽  
Evapotranspiration Estimation ◽  
Class A Pan

Actual evapotranspiration (ETa) has been insufficiently investigated in Greece. This study aimed to estimate annual ETa by empirical methods (Turc, modified Turc, and Coutagne) for the Peloponnese, Greece, a Mediterranean testbed, between 2016–2019, four of the warmest years since the preindustrial era, and compare them to MODIS ET. Furthermore, measurements of annual pan evaporation (Epan) were performed for two Class A pan stations in the Peloponnese with different reliefs and conditions. The empirical methods and statistical formulae (RMSD, MB, and NMB) were developed as models in ArcMap. The outcomes of the Turc method resembled MODIS ET ranges for all years, followed by those of Coutagne. The estimates by the modified Turc method were almost identical to MODIS ET. Therefore, the modified Turc method can be used as an alternative to MODIS ET (and vice versa) for the Peloponnese for 2016–2019. Moreover, the Epan at Patras University station (semiurban, low elevation) exhibited an upward trend resembling the trends of the empirical methods over the study years, whereas the Epan at Ladonas station (higher elevation, lakeside) required investigation on a monthly time scale. Additionally, the gradual decrease of pan-water icing at Ladonas in December (from 20 d in 2016 to 0 d in 2019) could imply an undergoing decrease in snowpack storage retention across the mountains of the Peloponnese.

In vitro rumen gas production kinetics, hydrocyanic acid concentration and fermentation characteristics of fresh cassava root and feed block sulfur concentration

2020 ◽  
Vol 60 (5) ◽  
pp. 659 ◽  
Author(s):  
Gamonmas Dagaew ◽  
Anusorn Cherdthong ◽  
Metha Wanapat ◽  
Pin Chanjula
Keyword(s):  
Nitrogen Concentration ◽  
Gas Production ◽  
Nutrient Digestibility ◽  
Hydrocyanic Acid ◽  
In Vitro Digestibility ◽  
High Concentration ◽  
Cassava Root ◽  
Fermentation Liquor ◽  
Kinetics Of

Context Feeding ruminants with fresh cassava roots (FCR) is limited because they have a high concentration of hydrocyanic acid (HCN). Thus, it was hypothesised that receiving a feed block containing high sulfur (FBS) would reduce hydrocyanic acid (HCN) in FCR and improve rumen fermentation and nutrient digestibility in animals. Aims The goal of the present work was to study the influence of the ratio of FCR to rice straw (RS) together with FBS on kinetics of gas production, HCN concentration, fermentation characteristics and nutrient digestibility, using in vitro technique. Methods The experimental design was a 4 × 2 factorial arrangement in a completely randomised design, with three replications per treatment. Factor A was the FCR to RS ratio, which was 100:0, 60:40, 40:60 or 0:100. Factor B was sulfur, which was provided as two concentrations in FBS (2% and 4% DM). Gas production was recorded after incubation, at 0, 0.5, 1, 2, 4, 6, 8, 12, 18, 24, 48, 72 and 96 h. Fermentation liquor was collected and determined for kinetics of gas production, HCN concentration, fermentation characteristics and nutrient digestibility. Key results Cassava root to RS ratio influenced the cumulative gas production after 96 h. Inclusion of sulfur in the FBS at 4% increased the cumulative gas production, when compared with inclusion at 2%. The gas production from degradable fraction (b) and the rate of gas production (c) were significantly different among the treatments with different FCR:RS ratios, whereas there was no difference between using 2% and 4% sulfur in the FBS. The HCN concentration in fermentation liquor increased with an increasing proportion of FCR. Furthermore, inclusion of sulfur in the feed block at 4% reduced HCN concentration by 42.8%, when compared with inclusion at 2% (P < 0.05). Ammonia-nitrogen concentration was significantly different among the FCR:RS-ratio treatments and was reduced when the proportion of FCR was decreased (P < 0.05). In vitro digestibility was significantly increased with an increasing proportion of FCR. Increasing the proportion of FCR with 4% of sulfur in the FBS significantly increased in vitro DM digestibility, compared with 2% sulfur. Increasing the FCR:RS ratio with 4% of sulfur in the FBS increased the proportion of propionic acid (P < 0.05). Conclusions Using a high FCR:RS ratio (100:0 or 60:40) with 4% sulfur in the FBS enhanced kinetics of gas production, propionic molar proportion, nutrient digestibility, and HCN detoxification by rumen microbes in an in vitro trial. Implications An in vivo study should be encouraged to verify the results and obtain more data.

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