Effects of annual pasture composition on subsequent wheat yields in the Waite Permanent Rotation Trial, South Australia

1998 ◽  
Vol 38 (1) ◽  
pp. 55 ◽  
Author(s):  
A. D. Moore ◽  
P. R. Grace

Summary. Legume-based annual pastures are commonplace in southern Australian dryland farming systems. By using the long-term wheat and pasture yield records from the Waite Permanent Rotation Trial (established in 1925), we have quantified how changes in the production and composition of a ley pasture will affect subsequent cereal yields and profitability. An analysis of the 1965–89 record reveals that 43% of the variance in wheat yield can be accounted for by the equation: WY = 3.42 + 0.0165AOR – 0.0000165AOR2 + 0.12PL – 2.64PG + 0.39PG2 – 0.019PG3 where WY is wheat yield (t/ha), AOR is April –October rainfall in the wheat year (mm), PL is pasture legume yield in the preceding year (t/ha) and PG is pasture grass yield in the preceding year (t/ha). By comparison with other published data, our results support the claim that nitrogen from legume sources is economically more efficient than fertiliser nitrogen, but the largest effect of increasing legume content comes from avoiding yield loss associated with grassy pastures.

1997 ◽  
Vol 33 (4) ◽  
pp. 469-475 ◽  
Author(s):  
M. SINGH ◽  
S. CHRISTIANSEN ◽  
B. K. CHAKRABORY

The introduction of appropriate crop rotations is known to be beneficial in many farming systems. One feature of rotations is that it takes a valuable length of time for the advantage of the rotation to take effect. In long-term rotation trials, the observations from the same plot over years are correlated; ignoring such correlations may affect the precision of the estimates of rotation effects. We examined five covariance structures between the plot errors over time to assess the effect of correlations on the standard errors of rotation means and rotation x cycle combination (interaction) means on wheat yields using eight years of data from six two-phase rotations with wheat. Based on wheat yield data from the four cycles of the rotations considered, the compound symmetry covariance structure (constant correlation) between plot errors arising over alternate years gave more efficient estimates of rotation means compared with the other four covariance structures.


1995 ◽  
Vol 35 (7) ◽  
pp. 835 ◽  
Author(s):  
JA Kirkegaard

Trends in wheat yield responses to conservation cropping in Australia were analysed using data from 33 medium-term (3-5 year) and long-term (>5 year) agronomic experiments. The overall effect of tillage (direct drilled v. cultivated) was small in all regions (-0.18 to +0.06 t/ha), while stubble retention (stubble retained v. stubble burnt) reduced yield in all regions (-0.31 to -0.02 t/ha). There was large year-to-year variation in the yield response to both tillage and stubble retention at all sites, but no consistent relationship between yield variation and amount or pattern of seasonal rainfall based on monthly totals. There was also little evidence that the yield of direct-drilled and stubble-retained treatments increased relative to cultivated or stubble-burnt treatments with the duration of the experiments, despite the improvement in soil conditions reported at many sites. The factors thought responsible for the year-toyear variation in yield response varied within and between regions, although some consistent effects emerged. Reduced early seedling growth of directdrilled crops was considered a major factor underlying the yield response at most sites, and this was rarely associated with the availability of water or nitrogen. High soil strength and increased severity of rhizoctonia root rot were responsible for these effects at some sites, but at others the cause remains unclear. Stubble retention influenced yield in many ways but the significance of the allelopathic effects of stubble, suspected by many authors to influence crop growth, is poorly understood. Adoption of direct drilling and stubble retention is likely to remain low in areas where no long-term yield benefit can be demonstrated and where greater management flexibility is offered by systems of reduced cultivation and late stubble burning-incorporation. Further research should identify and develop strategies to overcome the constraints to yield in conservation farming systems, particularly stubble retention, and assess the sustainability of recent innovations incorporating minimum disturbance and partial stubble retention. The more rapid adoption of such intermediate strategies will hasten the move of the grains industry toward sustainable production.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xuan Li ◽  
Shibo Fang ◽  
Yongchao Zhu ◽  
Dong Wu

There have been few pieces of research focused on quantifying wheat yield loss risk based on high-resolution long-term historical data. What is more, the existence of the area scale effect reduces the certainty and spatial comparability of results. In this study, long-term wheat yield and planting area data at the county level from 1981 to 2010 were used. The spatial distribution of wheat yield loss risks was analyzed in the mainland of the People’s Republic of China (China for short). An improved comprehensive risk index of yield loss risk was established by integrating the reduction rate, coefficient of variation, and the probability of occurrence for different yield reduction rates after removing the effect of area scale. 874 main wheat-growing counties in the mainland of China were divided into lowest, lower, moderate, higher, and highest risk areas based on it. The high-risk areas are located in Yellow-Huai-Hai Plain, including Shandong, Henan, northern Anhui, and parts of Jiangsu Province.


1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)


Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.


2016 ◽  
Vol 40 (4) ◽  
pp. 481-489
Author(s):  
Shu-Tsung Hsu ◽  
Yean-San Long ◽  
Teng-Chun Wu

The photovoltaic (PV) industry is expanding rapidly to meet the growing renewable-energy demands globally. The failure-rate analysis indicated that a large portion of the accelerated PV module qualification failures were related to the failure of PV cell itself, which was leading to the yield loss of PV products during shipping or transportation. Therefore, the damaged cell (or module) caused by shipping is always one of the serious problems to impact the long-term reliability of PV product. This paper aims to propose a new test method of reliability evaluation for shipping pallet of solar product. The first scenario is the test pallet shipped in fab (e.g., fork-lift truck or hand-pallet truck). The second scenario is the test pallet transported from fab to fab by different vehicle (e.g., truck, train, aircraft, and shipboard). Consequently, detailed results were applied to SEMI Doc. 5431 and released as SEMI PV56-1214 by voting in December 2014. The solar cell/module/system makers and buyers, or any other party interested like package design, can thus have a common document to refer to when desired.


Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2631
Author(s):  
Kandeepan Karthigesu ◽  
Robert F. Bertolo ◽  
Robert J. Brown

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.


2021 ◽  
Vol 41 (1) ◽  
Author(s):  
João Vasco Silva ◽  
Pytrik Reidsma ◽  
Frédéric Baudron ◽  
Moti Jaleta ◽  
Kindie Tesfaye ◽  
...  

AbstractWheat yields in Ethiopia need to increase considerably to reduce import dependency and keep up with the expected increase in population and dietary changes. Despite the yield progress observed in recent years, wheat yield gaps remain large. Here, we decompose wheat yield gaps in Ethiopia into efficiency, resource, and technology yield gaps and relate those yield gaps to broader farm(ing) systems aspects. To do so, stochastic frontier analysis was applied to a nationally representative panel dataset covering the Meher seasons of 2009 and 2013 and crop modelling was used to simulate the water-limited yield (Yw) in the same years. Farming systems analysis was conducted to describe crop area shares and the availability of land, labour, and capital in contrasting administrative zones. Wheat yield in farmers’ fields averaged 1.9 t ha− 1 corresponding to ca. 20% of Yw. Most of the yield gap was attributed to the technology yield gap (> 50% of Yw) but narrowing efficiency (ca. 10% of Yw) and resource yield gaps (ca. 15% of Yw) with current technologies can nearly double actual yields and contribute to achieve wheat self-sufficiency in Ethiopia. There were small differences in the relative contribution of the intermediate yield gaps to the overall yield gap across agro-ecological zones, administrative zones, and farming systems. At farm level, oxen ownership was positively associated with the wheat cultivated area in zones with relatively large cultivated areas per household (West Arsi and North Showa) while no relationship was found between oxen ownership and the amount of inputs used per hectare of wheat in the zones studied. This is the first thorough yield gap decomposition for wheat in Ethiopia and our results suggest government policies aiming to increase wheat production should prioritise accessibility and affordability of inputs and dissemination of technologies that allow for precise use of these inputs.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1735
Author(s):  
Marcello Franchini ◽  
Mirco Corazzin ◽  
Stefano Bovolenta ◽  
Stefano Filacorda

Conflicts between large carnivores and human activities undermine both the maintenance of livestock practices as well as the conservation of carnivores across Europe. Because large carnivore management is driven by a common EU policy, the purpose of this research was to assess stakeholders’ perception towards bears and wolves at an EU level. We conducted a systematic search and subsequent analysis of 40 peer-reviewed studies collected from 1990 to September 2020 within Member States of the EU. Rural inhabitants and hunters exhibited the most negative attitude compared to urban inhabitants and conservationists, whose attitude was more positive. We showed that direct experience with predators as a consequence of ongoing re-colonization may have affected the degree of acceptance of certain categories and that the long-term coexistence between humans and carnivores does not necessarily imply increased tolerance. To encourage coexistence, we recommend monitoring changes in attitudes over time relative to carnivore population dynamics.


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