scholarly journals Dependence of pea root mass distribution on weather conditions under varying levels of phosphorus application

2018 ◽  
Vol 32 (3) ◽  
pp. 365-372 ◽  
Author(s):  
Agnieszka Klimek-Kopyra ◽  
Krzysztof Rębilas
Keyword(s):  
Mass Distribution ◽  
Water Availability ◽  
Soil Depth ◽  
Weather Conditions ◽  
Root Mass ◽  
Pea Root ◽  
Application Rates ◽  
Phosphorus Application ◽  
Very High ◽  
Different Levels

Abstract The aim of the study was to describe the distribution of pea root mass in the soil, over a three-year period, under varying weather conditions and at different levels of phosphorus application, by means of evaluating and comparing parameters of a mathematical model characterising cumulative root mass distribution. A two-factor experiment was conducted in Prusy, near Krakow: the first factor was the level of phosphorus application (0-70-140 kg P2O5 ha−1) and the second was the cultivars (six cultivars were tested). Experimental data produced using the model indicated that the root distribution was strongly differentiated by water availability in the years of the study. This appeared in some cases to be a more important factor than phosphorus application rates. The estimated soil depth at which 50% of the root mass was accumulated differed significantly for the dry and the wet year. In the wet year, only very high phosphorus application rates contributed to an increase in root mass distribution. The estimation of root mass distribution from the presented data can be used to improve phosphorus application depending on the amount of precipitation.

scholarly journals Soil typologies in the wine-growing areas of Mallorca, with special emphasis on available water content.

2018 ◽  
Vol 50 ◽  
pp. 01011
Author(s):  
Joan Rossello ◽  
José M. Escalona ◽  
Josep Cifre ◽  
Jaume Vadell ◽  
Hipólito Medrano
Keyword(s):  
Water Content ◽  
Water Availability ◽  
Soil Depth ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Available Water ◽  
Available Water Content ◽  
Water Classification ◽  
Grape Varieties ◽  
Very High

Under the conditions of the semi-arid Mediterranean climate, soil depth and water retention capacity are the most important characteristics of the soil related to the quality of the wines. The availability of water will mark the development of the vines and the development and maturity of the grape. The characterization and agronomic evaluation of the soil has been carried out from the excavation of 38 soil pits in the main wine growing areas of Mallorca. Cambisols are the most predominant soil typology followed by Cambisols, Regosols and Luvisols. The water classification of the soils has been made according to the maximum water availability (useful water) in 2 m of soil (mm water / 2 m soil). The proposed levels are: very low (<120 mm), low (120-180 mm), Medium (180-240 mm), High (240-300 mm) and Very high> 300 (mm). The most abundant soil type we find that 47% have high soil water availability, 27% very high, 14% normal and 14% low. Establishing an area based on available water content is a tool that allows us to adjust the selection of the most suitable grape varieties in each soil, thus taking advantage more efficiently of the potential of each type of grape.

High phosphorus supply increases persistence and growth of white clover in grazed dairy pastures during dry summer conditions

1999 ◽  
Vol 39 (5) ◽  
pp. 579 ◽  
Author(s):  
D. K. Singh ◽  
C. J. P. Gourley ◽  
P. W. G. Sale ◽  
C. Hasthorpe
Keyword(s):  
White Clover ◽  
Stocking Rate ◽  
High Phosphorus ◽  
Application Rates ◽  
Low Phosphorus ◽  
The Mean ◽  
Phosphorus Application ◽  
Different Levels ◽  
Clover Content ◽  
Made In

Measurements of pasture appearance, white clover leaf and stolon mass, stolon water potential, and percentage clover cover in the sward were made for grazed dairy pastures at Ellinbank, West Gippsland, Victoria, during the hot, dry month of February 1997. The perennial ryegrass–white clover-based pastures were in rotationally grazed paddocks from a large farmlet experiment and had received different levels of phosphorus fertiliser (0 or 280 kg P/ha over an 18-month period), and were being grazed with 2 or 3 cows/ha for the no-phosphorus, or 3 or 4 cows for the high-phosphorus paddocks. Further measurements of white clover composition in the pasture swards were made in April, following autumn rain. There were marked differences in white clover (i.e. more yellow, flaccid and desiccated plants with fewer leaves) and pasture appearance (higher frequency of patchy, weedy, poorly utilised areas) in the no-phosphorus, compared with the high-phosphorus treated pastures with the same stocking rate of 3 cows/ha. Also, the high-phosphorus paddocks had a greater white clover percentage than the low-phosphorus paddocks in February with mean percentages of 13.8 and 7.8% respectively. Following rains in March and April, the mean percentage clover cover in high-phosphorus paddocks had increased substantially by 30 April 1997 to 30.6% whereas there was a small improvement in mean clover content in the low-phosphorus paddocks (12.3%). The white clover plants in the high-phosphorus paddocks had heavier stolons, larger leaves and, for the medium stocking rate (3 cows/ha), they appeared to have more leaves per cm of stolon. The findings support previous studies which have highlighted how high-phosphorus application rates can improve the performance of repeatedly defoliated white clover plants during dry periods.

Attitudes toward the use of TELL tools in English language learning among Vietnamese Tertiary English majors

2019 ◽  
Vol 5 (5) ◽  
pp. 581-596
Keyword(s):  
Language Learning ◽  
Language Proficiency ◽  
English Language ◽  
English Language Learning ◽  
Guided Learning ◽  
Positive Attitudes ◽  
Significant Difference ◽  
English Majors ◽  
Very High ◽  
Different Levels

Technology plays a crucial role in the self-guided learning of a second language in general and English in particular. Nevertheless, many students in different contexts still ignore the application of technology-enhanced language learning (TELL) tools in enhancing their foreign language proficiency. Therefore, this study is conducted to investigate the attitudes towards the use of TELL tools in English-language learning (ELL) among English majors at one university in Vietnam. To collect data, 197 English majors participated in finishing the questionnaire, and 20 students were invited to join the interviews. The findings are that the majority of students have positive attitudes towards the use of TELL tools and the frequency of using these tools is very high. In addition, the results also reveal that there is no significant difference in attitudes towards and frequency of using TELL tools in learning English in terms of the year of study. However, students of different levels of academic achievements have different attitudes towards using TELL tools and use TELL tools to learn English differently. Received 2nd May 2019; Revised 16th July 2019, Accepted 20th October 2019

scholarly journals Effect of different soil and weather conditions on efficacy, selectivity and dissipation of herbicides in sunflower

2020 ◽  
Vol 66 (No. 9) ◽  
pp. 468-476
Author(s):  
Miroslav Jursík ◽  
Martin Kočárek ◽  
Michaela Kolářová ◽  
Lukáš Tichý
Keyword(s):  
Cation Exchange Capacity ◽  
Chenopodium Album ◽  
Soil Layer ◽  
Weather Conditions ◽  
Growing Season ◽  
Application Rate ◽  
Exchange Capacity ◽  
Vertical Transport ◽  
Application Rates ◽  
High Precipitation

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.  

scholarly journals Influence of Lime and Phosphorus Application Rates on Growth of Maize in an Acid Soil

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Peter Asbon Opala
Keyword(s):  
Dry Matter ◽  
Acid Soil ◽  
Interactive Effects ◽  
Available P ◽  
Dry Matter Yield ◽  
Exchangeable Acidity ◽  
Application Rates ◽  
Randomized Design ◽  
Lime Application ◽  
Phosphorus Application

The interactive effects of lime and phosphorus on maize growth in an acid soil were investigated in a greenhouse experiment. A completely randomized design with 12 treatments consisting of four lime levels, 0, 2, 10, and 20 t ha−1, in a factorial combination with three phosphorus rates, 0, 30, and 100 kg ha−1, was used. Maize was grown in pots for six weeks and its heights and dry matter yield were determined and soils were analyzed for available P and exchangeable acidity. Liming significantly reduced the exchangeable acidity in the soils. The effect of lime on available P was not significant but available P increased with increasing P rates. There was a significant effect of lime, P, and P by lime interactions on plant heights and dry matter. Without lime application, dry matter increased with increasing P rates but, with lime, dry mattes increased from 0 to 30 kg P ha−1but declined from 30 to 100 kg P ha−1. The highest dry matter yield (13.8 g pot−1) was obtained with a combined 2 t ha−1of lime with 30 kg P ha−1suggesting that lime application at low rates combined with moderate amounts of P would be appropriate in this soil.

scholarly journals Drought resistance of sugar-cane crop for different levels of water availability in the soil

2014 ◽  
Vol 34 (2) ◽  
pp. 203-210 ◽  
Author(s):  
Fernando da S. Barbosa ◽  
Rubens D. Coelho ◽  
Rafael Maschio ◽  
Carlos J. G. de S. Lima ◽  
Everaldo M. da Silva
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Deficit ◽  
Early Development ◽  
Drought Resistance ◽  
Sugar Cane ◽  
Water Availability ◽  
Sandy Loam ◽  
Final Population ◽  
Different Levels

Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250 during the early development using different levels of water deficit on four soil depths. The experiment was conducted at the Department of Biosystems at Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP) in a greenhouse in soil classified as Oxisol, sandy loam texture (Series "Sertãozinho"). Once exhausted the level of available water in the soil, the dry strength of the studied strains are relatively low. Water balance with values less than -13 mm cause a significant decrease in the final population of plants, regardless of the variety, and values below -35 mm, leads to the death of all plants.

scholarly journals Effects of repeated phosphorus fertilisation on field crops in Finland 2.Sufficient phosphorus application rates on silty and sandy soils

2008 ◽  
Vol 15 (4) ◽  
pp. 423 ◽  
Author(s):  
I. SAARELA ◽  
H. HUHTA ◽  
P. VIRKAJÄRVI
Keyword(s):  
Relative Yield ◽  
Sandy Soils ◽  
Application Rate ◽  
Application Rates ◽  
P Application ◽  
The Mean ◽  
Yield Responses ◽  
Phosphorus Application ◽  
Phosphorus Fertilisation ◽  
Annual Application

In order to update fertilisation recommendations for Finnish silty and sandy soils, the effects of repeated phosphorus (P) fertilisation on the yields of cereals, grasses and other crops were measured at ten sites for 9 to 18 years. Results of some earlier studies were also used in examining the relationships of the yield responses to applied P and to the soil test values measured by the Finnish ammonium acetate method (PAc). Significant effects of P fertilisation were observed at all sites that had low or medium PAc values; in the case of potatoes, even at sites with fairly high values. The mean relative yield without applied P divided by yield with 60 or 45 kg P ha-1 of the ten sites was 81% (mean PAc 11.6 mg dm-3) varying from 55% at the PAc value of 4.7 mg dm-3 to 100% at the highest PAc values. In order to achieve a relative yield of 97%, which is considered the optimum for cereals and leys, the required mean annual application of P in the later parts of the experiments was 25 kg ha-1 (variation 0-42 kg ha-1). On the six soils that had low or medium PAc values (4.5-9.1 mg dm-3, mean 8.0 mg dm-3), relative yield was 97% at the P application rate of 35 kg ha-1 (variation 22-42 kg ha-1), while 11 kg P ha-1 (variation 0-25 kg ha-1) sufficed on the four soils that had higher PAc values (mean 20.8 mg dm-3, variation 11.7-35.2 mg dm-3). Reasons for the poor availability of P in silty and sandy soils were discussed.;

Infidélité paléomagnétique observée dans une formation lacustre varvée quaternaire dite: "argiles d'Eybens" (Grenoble, France)

1982 ◽  
Vol 19 (6) ◽  
pp. 1196-1217 ◽  
Author(s):  
Daniel Biquand
Keyword(s):  
Remanent Magnetization ◽  
Axial Direction ◽  
Field Studies ◽  
Particle Orientation ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
Continuous Field ◽  
Very High ◽  
Different Levels ◽  
Thermal Remanent Magnetization

We have investigated the properties of natural magnetization of a lacustrine interglacial Riss–Würm deposit near Grenoble (France). Made up of accumulated argillite 250 m thick, this deposit comprises annual varves with an average thickness of 0.5 cm.The magnetic viscosity of this sediment is not very high, and we have demonstrated that the characteristic magnetization, measured after a moderate thermal treatment (between 160 and 220 °C) followed by alternating field demagnetization with maximum intensity at 200 Oe (15.9 × 103 A/m), is possibly a detrital magnetization carried by the magnetite (thermomagnetic and strong continuous field studies).On a local scale (area of about 100 m2), the direction of this magnetization remains very homogeneous within each horizon; sampling restricted to about 10 sites 1 m apart indicates for each level a mean direction of magnetization with a high accuracy: α95 = 1–2°, k = 500–2500. The aveage direction calculated by this method for different levels indicates significant stratigraphic variations (attaining an inclination of 20° and a declination of 50°), which are reached rapidly (from 1 to few degrees per year). Such variations cannot be reasonably attributed to changes in the directions of the Earth's magnetic field.A study of the acquired anisotropy of the thermal remanent magnetization indicates a magnetic anisotropy that is related to the lithological structure of the sediment and shows a strong intensity: the maximum divergence between the field direction and the acquired thermal remanent magnetization direction in this field varies, with individual samples, between 9 and 50°. The study of the properties of this anistotropy demonstrates the "infidelity" of the detrital magnetization: for one of the small vertical sequences studied for anisotropy the characteristic magnetization of a specified level has a direction nearer the axial direction of easy magnetization when the anisotropic intensity is large. This infidelity may be caused by different factors influencing the deposition of the sediment, particularly the variable directions of water flows determining the particle orientation. [Journal Translation]

Influence of intra-row plant spacing, phosphorus application and growth stage on the forage, seed yields and quality of phasey bean (Macroptilium lathyroides) in subhumid area of Nigeria

2021 ◽  
Vol 31 (1) ◽  
pp. 45-50
Author(s):  
A. T. Omokanye ◽  
J. T. Amodu ◽  
S. O. Onifade
Keyword(s):  
Production Systems ◽  
Fertilizer Application ◽  
Plant Spacing ◽  
Growing Seasons ◽  
Application Rates ◽  
P Fertilizer ◽  
P Application ◽  
Macroptilium Lathyroides ◽  
Seed Yields ◽  
Phosphorus Application

Forage, seed yields and herbage chemical composition of phasey bean Macroptilium lathyroides) were investigated at 3 intra-row plant spacings (15, 30 and 45cm between plants; 50 cm between roms), 4 phosphorus (P) fertilizer application rates (O), 50, 100 and 750 kg/ha P) and 5 harvest stages (uncut control, 6, 9, 12 and 15 weeks post sowing) in two growing seasons at Shika in northern Nigeria. The least intra-row plant spacing (15cm) produced higher (p<0.01) total DM vield (1.50 t/ha) than wider spacings. The proportion of leaf was least (40 %) in the widest spacing compared with other spacings (59-62 %). The P-fertilized plots produced 58-60% more total DM vields than the unfertilized plots and total DM yields increased with advanced plant growth. The highest percentage (61-63) of leaf was recorded from 6 to 12 weeks post sowing. Nitrogen level in herbage increased (p<0.05) with increased intra-row plant spacing and P application. Phosphorus and Calcium. Levels in herbage did not respond to intra-row plant spacing but increased with P application. The Ca:P ratios at the harvest stages were between 1:1 and 6:1. The highest seed yields (198 and 188 kg/ha) were recorded respectiely in the least intra-row plant spacing and the application of 100 kg Piha. Supplementation of calves on grasses/cereal stovers with phasey bean hay in a sustainable crop livestock production systems is suggested.

Handling Quantity in Variability Models for System-of-Systems

2021 ◽  
Vol 31 (05) ◽  
pp. 693-724
Author(s):  
Daisuke Shimbara ◽  
Motoshi Saeki ◽  
Shinpei Hayashi ◽  
Øystein Haugen
Keyword(s):  
System Of Systems ◽  
Tree Structure ◽  
Entire System ◽  
Simple Experiment ◽  
Domain Specific ◽  
High Degree ◽  
Variability Model ◽  
Very High ◽  
Different Levels ◽  
Parent Node

Problem: Modern systems contain parts that are themselves systems. Such complex systems thus have sets of subsystems that have their own variability. These subsystems contribute to the functionality of a whole system-of-systems (SoS). Such systems have a very high degree of variability. Therefore, a modeling technique for the variability of an entire SoS is required to express two different levels of variability: variability of the SoS as a whole and variability of subsystems. If these levels are described together, the model becomes hard to understand. When the variability model of the SoS is described separately, each variability model is represented by a tree structure and these models are combined in a further tree structure. For each node in a variability model, a quantity is assigned to express the multiplicity of its instances per one instance of its parent node. Quantities of the whole system may refer to the number of subsystem instances in the system. From the viewpoint of the entire system, constraints and requirements written in natural language are often ambiguous regarding the quantities of subsystems. Such ambiguous constraints and requirements may lead to misunderstandings or conflicts in an SoS configuration. Approach: A separate notion is proposed for variability of an SoS; one model considers the SoS as an undivided entity, while the other considers it as a combination of subsystems. Moreover, a domain-specific notation is proposed to express relationships among the variability properties of systems, to solve the ambiguity of quantities and establish the total validity. This notation adapts an approach, named Pincer Movement, which can then be used to automatically deduce the quantities for the constraints and requirements. Validation: The descriptive capability of the proposed notation was validated with four examples of cloud providers. In addition, the proposed method and description tool were validated through a simple experiment on describing variability models with real practitioners.

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