The methodology of measurement of N2 fixation by nonlegumes as inferred from field experiments with legumes

1983 ◽  
Vol 29 (8) ◽  
pp. 1053-1062 ◽  
Author(s):  
M. Fried ◽  
S. K. A. Danso ◽  
F. Zapata
Keyword(s):  
Field Experiments ◽  
Growth Period ◽  
Relative Effect ◽  
Cropping Pattern ◽  
Rooting Pattern ◽  
Previous Crop ◽  
Faba Beans ◽  
Experimental Variability ◽  
Reference Crop ◽  
Selection Of

Results of field experiments using partial substratum labelling techniques are presented. These show that inorganic 15N application to soil just prior to sowing, the addition of 15N together with sucrose, incorporation of a 15N-labelled plant material into soil, as well as the 15N remaining in soil following the application of inorganic fertilizer to a previous crop provided adequate levels of 15N for field experiments to estimate N2 fixation in soybean and faba beans. These methods may be suitable for quantifying associative N2 fixation, especially if the experimental variability is low, or where N2 fixation is high. Proper site selection is therefore important. Under the conditions of the experiments reported in this paper, however, the sensitivity of detection of N2 fixation was low and could not estimate N2 fixed in plants in which the percentage of N derived from fixation was below 10–15%. The selection of the appropriate reference on standard, i.e., non-N2-fixing, crop and its judicious use in field experiments is crucial to the methodology for quantitatively measuring the amount of N2 fixed by the above methods. The most important factors in the selection of reference crops are absence of N2-fixing activity, similarity in feeding or rooting pattern of the non-N2-fixing and fixing crop, comparable growth period for reference and fixing crop, relative effect of environment on the two crops, and cropping pattern employed. In associative N2 fixation studies, an uninoculated plant in soil devoid of associative N2-fixing microorganisms would provide an ideal reference crop for an inoculated plant.

scholarly journals The research of dynamic impacts on the hydraulic structure foundation base, transformed in the process of accident recovery

2018 ◽  
Vol 251 ◽  
pp. 04040
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Field Experiments ◽  
Dynamic Properties ◽  
Soil Parameters ◽  
Experimental Site ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Foundation Base ◽  
Dynamic Impacts ◽  
Scale Experiment ◽  
Selection Of

The article presents the results of a comprehensive research of the dynamic impacts on a modified base. The modified base was obtained as a result of compensatory injection at the experimental site for the accident recovery at the hydraulic engineering structure. The complex study of the dynamic impacts includes special laboratory tests to determine the soil parameters, the finite element analysis of the experimental site, taking into account the dynamic properties, the selection of the necessary equipment for field experiments based on the numerical solution results, a full-scale experiment with the measurement of the foundation sediments of the experimental site.

scholarly journals Effects of Ridge Tillage and Straw Mulching on Cultivation the Fresh Faba Beans

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1054
Author(s):  
Bo Li ◽  
Xinyu Chen ◽  
Xiaoxu Shi ◽  
Jian Liu ◽  
Yafeng Wei ◽  
...  
Keyword(s):  
Rice Straw ◽  
Precision Agriculture ◽  
Field Experiments ◽  
Root Length Density ◽  
Root Surface ◽  
High Yield ◽  
Root Surface Area ◽  
Straw Mulching ◽  
Faba Beans ◽  
Ridge Tillage

Ridge tillage is an effective agronomic practice and a miniature precision agriculture; however, its effects on the growth of faba beans (Vicia faba L.) are poorly understood. This study aimed to determine the effect of ridge tillage and straw mulching on the root growth, nutrient accumulation and yield of faba beans. Field experiments were conducted during 2016 and 2017 cropping seasons and comprised four treatments: ridge tillage without any mulching (RT), flat tillage without any mulch (FT), flat tillage with rice straw mulched on the ridge tillage (FTRSM) and ridge tillage with rice straw mulched on the ridge tillage (RTRSM). The RT and RTRSM increased soil temperature and decreased soil humidity and improved soil total nitrogen, total phosphorus, available potassium and organic matter. RT and RTRSM increased the root length density, root surface area, root diameter and root activity of faba beans at flowering and harvest periods. The RT and RTRSM also increased the nitrogen, phosphorus, potassium absorption and the yield of faba beans. These results indicated that ridge tillage and straw mulching affect faba bean growth by improving soil moisture conditions and providing good air permeability and effective soil nutrition supply. This study provides a theoretical basis for the high yield cultivation improvement of faba beans.

Improved growth and yield of Faba beans (Vicia faba cv. Fiord) by inoculation with strains of Rhizobium leguminosarum biovar. viciae in acid soils in south west Victoria

1994 ◽  
Vol 45 (3) ◽  
pp. 613 ◽  
Author(s):  
JM Carter ◽  
WK Gardner ◽  
AH Gibson
Keyword(s):  
Vicia Faba ◽  
Rhizobium Leguminosarum ◽  
Field Experiments ◽  
Natural Populations ◽  
Acid Soils ◽  
Growth And Yield ◽  
Nitrogen Accumulation ◽  
Commercial Strain ◽  
South West ◽  
Faba Beans

The response of faba beans (Vicia faba L. cv. Fiord) to seed inoculation with eight strains of Rhizobium leguminosarum biovar. viciae was examined in field experiments at six sites on acid soils in south-west Victoria. At two of the sites, two additional strains were examined, and in 1988, 14 strains were examined at one site. Very low natural populations of R. leguminosarum bv. viciae were found at the experimental sites. Most strains resulted in improved early nodulation and increased grain yield at all sites, when compared to inoculation with the commercial strain of rhizobia (SU391). Plant dry matter production and nitrogen accumulation in the plant shoot tissue was also increased at one site during the flowering period by some strains. Large visual differences between plots inoculated with SU391 and other strains were evident at most sites. Most uninoculated treatments were not nodulated and yielded very poorly. Treatments inoculated with the strain SU391 performed similarly to the uninoculated treatments.

A fully automated method for late ventricular diastole frame selection in post-dive echocardiography without ECG gating

2021 ◽  
pp. 73-80
Author(s):  
Eric Markley ◽  
◽  
David Q. Le ◽  
Peter Germonpré ◽  
Costantino Balestra ◽  
...  
Keyword(s):  
Field Experiments ◽  
High Reliability ◽  
Rater Bias ◽  
Algorithm Performance ◽  
Frame Selection ◽  
Automated Method ◽  
Significant Difference ◽  
Computer Automation ◽  
Decompression Stress ◽  
Selection Of

Venous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubble-counting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this automation relies on the selection of a frame during late ventricular diastole (LVD) for each cardiac cycle of the recording. Since electrocardiograms (ECG) are not always recorded in field experiments, here we propose a fully automated method for LVD frame selection based on regional intensity minimization. The algorithm is tested on 20 previously acquired echocardiography recordings (from the original bubble-counting publication), half of which were acquired at rest (Rest) and the other half after leg flexions (Flex). From the 7,140 frames analyzed, sensitivity was found to be 0.913 [95% CI: 0.875-0.940] and specificity 0.997 [95% CI: 0.996-0.998]. The method’s performance is also compared to that of random chance selection and found to perform significantly better (p<0.0001). No trend in algorithm performance was found with respect to VGE counts, and no significant difference was found between Flex and Rest (p>0.05). In conclusion, full automation of LVD frame selection for the purpose of bubble counting in post-dive echocardiography has been established with excellent accuracy, although we caution that high quality acquisitions remain paramount in retaining high reliability.

Conservatism Gets Funded? A Field Experiment on the Role of Negative Information in Novel Project Evaluation

2021 ◽  
Author(s):  
Jacqueline N. Lanei ◽  
Misha Teplitskiy ◽  
Gary Gray ◽  
Hardeep Ranu ◽  
Michael Menietti ◽  
...  
Keyword(s):  
Information Sharing ◽  
Business Strategy ◽  
Research University ◽  
Field Experiments ◽  
Negative Information ◽  
Initial Score ◽  
Funding Opportunities ◽  
Allocation Decisions ◽  
Selection Of

The evaluation and selection of novel projects lies at the heart of scientific and technological innovation, and yet there are persistent concerns about bias, such as conservatism. This paper investigates the role that the format of evaluation, specifically information sharing among expert evaluators, plays in generating conservative decisions. We executed two field experiments in two separate grant-funding opportunities at a leading research university, mobilizing 369 evaluators from seven universities to evaluate 97 projects, resulting in 761 proposal-evaluation pairs and more than $250,000 in awards. We exogenously varied the relative valence (positive and negative) of others’ scores and measured how exposures to higher and lower scores affect the focal evaluator’s propensity to change their initial score. We found causal evidence of a negativity bias, where evaluators lower their scores by more points after seeing scores more critical than their own rather than raise them after seeing more favorable scores. Qualitative coding of the evaluators’ justifications for score changes reveals that exposures to lower scores were associated with greater attention to uncovering weaknesses, whereas exposures to neutral or higher scores were associated with increased emphasis on nonevaluation criteria, such as confidence in one’s judgment. The greater power of negative information suggests that information sharing among expert evaluators can lead to more conservative allocation decisions that favor protecting against failure rather than maximizing success. This paper was accepted by Alfonso Gambardella, business strategy.

Crossability Barriers in Interspecific Hybridization of Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] with Other Vigna Species

2021 ◽  
Author(s):  
Neelam Bhardwaj ◽  
Tanuja Kapoor ◽  
Parveen Sharma
Keyword(s):  
Growth Habit ◽  
Growth Period ◽  
Early Embryo ◽  
Grain Legume ◽  
Cropping Pattern ◽  
Storage Pests ◽  
Embryo Abortion ◽  
Vigna Species ◽  
Vigna Umbellata ◽  
Specific Hybridization

Background: Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] is a multipurpose grain legume of Mid-Himalayan region mainly cultivated for food, fodder, green manure and has emerged as a good alternative to other pulse crops such as blackgram and greengram which do not flourish in this region due to their susceptibility to cold temperature stress. It is well reported that the nutritional value of ricebean is higher as compared to many other legumes of the Vigna family and has some superior qualities greater than greengram, blackgram and cowpea. It is also resistance to drought, diseases and pests specially the storage pests during growth period and possesses high percentage of seed viability. Despite having all the favourable traits, it is not much popular among the farmers due to the late maturity and indeterminate growth habit. Instead, farmers prefer other crops which fit easily into their cropping pattern and are easy to harvest. A little genetic improvement with respect to maturity and growth habit can revive its cultivation and show great results in its production as a valuable crop. Thus, the present investigation was formulated to introgress desired traits from mash and adzukibean into otherwise high yielding ricebean genotypes using inter-specific hybridization. Methods: The present investigation involves the inter-specific hybridization among three Vigna species viz, ricebean (Vigna umbellata), blackgram (Vigna mungo) and adzukibean (Vigna angularis). In the year 2017, six genotypes of ricebean (RBHP-36, RBHP-38, RBHP-43, RBHP-61, RBHP-107 and RBHP-108) were crossed with two genotypes of blackgram (HimMash-1 and Palampur-93) and one genotype of adzukibean (HPU-51) in glasshouse conditions. Result: The study revealed that successful crosses were possible only between ricebean and blackgram. All the Inter-specific crosses showed very low pod set percentage ranging from 0 -4% and F1 germination percentage ranging from 20-42%. Pod set percentage and pods harvested varied with combinations of two parental cultivars of each species for most of the inter-specific hybrids. The successful pod set was observed in 16 out of 36 inter-specific crosses. Highest crossability was observed in blackgram and ricebean crosses. Crossing of adzukibean with ricebean showed poor or no pod set among the entire cross combinations which are attributed to early embryo abortion and degeneration during embryogenesis.

scholarly journals A Novel Water-Shore-Line Detection Method for USV Autonomous Navigation

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1682 ◽  
Author(s):  
Xiong Zou ◽  
Changshi Xiao ◽  
Wenqiang Zhan ◽  
Chunhui Zhou ◽  
Supu Xiu ◽  
...  
Keyword(s):  
Line Segment ◽  
Autonomous Navigation ◽  
Field Experiments ◽  
Lower Boundary ◽  
Water Area ◽  
Epipolar Constraint ◽  
Shore Line ◽  
Inland River ◽  
Straight Line ◽  
Selection Of

For the navigation of an unmanned surface vehicle (USV), detection and recognition of the water-shore-line (WSL) is an important part of its intellectualization. Current research on this issue mainly focuses on the straight WSL obtained by straight line fitting. However, the WSL in the image acquired by boat-borne vision is not always in a straight line, especially in an inland river waterway. In this paper, a novel three-step approach for WSL detection is therefore proposed to solve this problem through the information of an image sequence. Firstly, the initial line segment pool is built by the line segment detector (LSD) algorithm. Then, the coarse-to-fine strategy is used to obtain the onshore line segment pool, including the rough selection of water area instability and the fine selection of the epipolar constraint between image frames, both of which are demonstrated in detail in the text. Finally, the complete shore area is generated by an onshore line segment pool of multi-frame images, and the lower boundary of the area is the desired WSL. In order to verify the accuracy and robustness of the proposed method, field experiments were carried out in the inland river scene. Compared with other detection algorithms based on image processing, the results demonstrate that this method is more adaptable, and can detect not only the straight WSL, but also the curved WSL.

Advances in Measurement of Indoor 222Rn and 220Rn Gas Concentrations Using Solid State Nuclear Track Detectors

2015 ◽  
Vol 238 ◽  
pp. 116-126 ◽  
Author(s):  
B.K. Sahoo ◽  
B.K. Sapra
Keyword(s):  
Cost Effectiveness ◽  
Solid State ◽  
Field Experiments ◽  
Performance Comparison ◽  
Mode Ii ◽  
New Device ◽  
Nuclear Track Detectors ◽  
Radon Measurements ◽  
Selection Of ◽  
Radon Monitoring

Solid State Nuclear Track Detectors (SSNTDs) have been widely used for time integrated radon measurements due to their cost effectiveness, portability and easy-to-use feature. In order to obtain a proper measurement of radon using SSNTDs, it is necessary to select a proper exposure mode. The various modes in which the SSNTDs can be exposed are: (i) bare mode, (ii) single cup mode, and (iii) twin cup mode. This paper addresses the merits and demerits of SSNTDs used in each type of mode of exposure for radon monitoring. The paper analyses the results of the conventional bare mode as well as the latest twin cup mode of SSNTDs. The paper also analyses the performance comparison of single entrance vis a vis double entrance type twin cup dosimeter. Design and features of the newly developed pinhole based single entrance twin cup dosimeter have been discussed. A protocol has been proposed for the selection of houses and deployment of the dosimeter. Some of the important findings from laboratory and field experiments of the new device have been presented.

SENSITIVITY OF CROP PLANTS TO WATER STRESS AT SPECIFIC DEVELOPMENTAL STAGES: REEVALUATION OF EXPERIMENTAL FINDINGS

1995 ◽  
Vol 43 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Zvi Plaut
Keyword(s):  
Water Stress ◽  
Irrigation Water ◽  
Field Experiments ◽  
Developmental Stages ◽  
Growth Period ◽  
Soluble Solids ◽  
Growth Stages ◽  
Mild Stress ◽  
Uniform Reduction ◽  
Different Growth Stages

It has been suggested that in many crops differences in sensitivity to water stress occur at different growth stages. Since identical amounts of water may be applied, irrespective of whether a crop is exposed to relatively severe and short periods of stress or to extended periods of mild stress, the responses to such differing conditions should be compared. Unfortunately, such a comparison has not been conducted in most studies on sensitivity to water stress at different growth stages. In the present study, based on three field experiments conducted for different purposes, such a comparison was made for three crops: corn, sunflower, and tomato. In corn, distinct responses of ear and kernel yields to the timing of water stress were found. Withdrawal of irrigation water during flowering and cob formation resulted in greater yield losses than during other stages, indicating that this is a critical growth stage. However, slight and uniform reduction of water during the entire growth period resulted in significantly less damage to kernel or ear production, although the total amount of water applied was similar to that under staged withdrawal. In sunflowers, the withdrawal of irrigation water even at noncritical growth stages caused a more marked reduction in grain yield than did a uniform reduction throughout the entire season. In tomatoes, on the other hand, the withdrawal of irrigation water during specific growth stages caused minimal damage to fruit and total soluble solids yield as compared with fully irrigated control; reduction of irrigation water throughout the season brought about a significant decrease in yield. The difference between these crops is interpreted on the basis of the determinance of their floral meristems.

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