10 research outputs found
The use of the growth regulator triapenthenol in seed crops of Lolium perenne L
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SAFFIE - research into research and practice
The Sustainable Arable Farming For an Improved Environment (SAFFIE) project
started in 2002 and experimental work continued until the end of 2006. When the
project was conceived, arable farmers needed to optimise inputs and improve
efficiency, and the UK was committed to increase biodiversity, especially for farmland
birds. The SAFFIE project aimed to reconcile these pressures by developing new
crop and margin management techniques for winter cereals and quantifying the
associated costs and environmental benefits.
The SAFFIE project developed Skylark Plots, confirmed the benefits of adding
wildflowers to grass margins, evaluated a range of in crop weed control programmes
and tested two margin management techniques (graminicides and scarification) that
had potential to create new habitats. The studies quantified: (a) the impact of these
techniques on key species of grasses and flowering plants, beetles, bugs, flies,
grasshoppers, soil invertebrates, spiders, bees, butterflies and birds; and (b) the
costs of the techniques. Key findings included the following.
Plants
• Weed cover was increased by the use of selective herbicides and this benefited
wider biodiversity. Selective herbicide applications in spring left more plant cover
than application sequences, benefiting arthropod abundance. However, weed
management must be site-specific and this approach is not appropriate where
pernicious weeds are common or where there are herbicide resistant weeds.
• Plant species diversity in margins decreased over the five years, regardless of
seed mix and treatment.
• Plots sown with a seed mix of fine grasses and wild flowers generally had the
greatest abundance of reproductive resources (buds, flowers, seed/fruit) and
plots sown with a grass seed mix generally had the lowest values.
• Compared with other margin management treatments, margins scarified in
March/April had:
• the greatest percentages of bare ground (21%, compared to 3% with cutting
and 4% with graminicide),
• enhanced plant species diversity at some sites,
• plant diversities converging between margins sown with different seed mixes,
• lower values of architectural complexity (especially of the dead litter, fine
grass and legume components), and
• reduced values of reproductive resources.
• In margins that had an application of a graminicide, plant communities included
more sown wildflower species than margins that were scarified or cut.
Invertebrates
• The grass seed mix provided a good resource for those invertebrate species that
are dependent on sward architectural complexity; however, it is a poor resource
for phytophagous species, particularly where their host plants are wildflowers.
• A seed mix of tussocky grasses and wild flowers provided an architecturally
complex sward and host plants vital for many invertebrate species.
• For a variety of invertebrate taxa there was evidence that abundance and species
richness will reach a maximum 2–3 years after margin establishment.
• Sowing a diverse seed mixture of perennial wildflowers was the most effective
means of creating foraging habitat for bees and butterflies on arable field
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margins. Inclusion of forbs in the seed mixture resulted in increases in abundance
and diversity of pollen and nectar resources, bumblebees and butterflies.
• Invertebrate species that required either an architecturally complex sward or
dense grass responded poorly to scarification, e.g. planthoppers, spiders and
Symphyta/ Lepidoptera larvae. In contrast, improved establishment of some
wildflower species in response to scarification benefited some phytophagous
invertebrates, e.g. weevils and leaf beetles.
• In scarified margins there were fewer species and lower abundances of isopods
than in other margins. Species assemblages in the scarified plots consisted of
species commonly associated with cropped or exposed habitats.
• Graminicide application is a practical option for enhancing the value of the large
area of species-poor grass margins for pollinators.
Birds
• Creating bare ground and foraging access in wheat crops and field margins were
the most important management treatments, and gave a significant (up to 4 fold)
increase in bird densities and breeding territories for both field and boundary
nesting species. Open ground can be achieved at relatively low cost by
scarification in margins, and by creating undrilled patches in winter cereal crops.
• In wheat fields with undrilled patches, skylark territory densities were higher
(particularly in the crucial late-season breeding period) and the number of skylark
chicks reared was nearly 50% greater than in fields without undrilled patches.
• Wheat sown with wide-spaced rows provided some wildlife benefits (particularly
for skylarks) but effects were smaller and less consistent than for crops with
undrilled patches.
• For all species and species groups, bird densities and territories were
consistently higher (1.3 - 2.8 times) in fields with margins and undrilled patches,
than in fields with a conventional crop. This response was consistent also for
Farmland Bird Index species and Biodiversity Action Plan species.
• In fields with undrilled patches and un-cropped field margins there were
indications that skylarks experienced reduced breeding success and productivity
compared with conventionally managed wheat. This was attributed to increased
mammalian predator activity. It is recommended that wherever practical undrilled
patches should not be situated within 50 m of a margin.
• For birds, margin sward content in terms of the grass/flower mix, was best
managed to encourage beetles (especially Carabidae) and spiders (Arachnidae).
Costs
• Undrilled patches receiving Defra Entry Level Scheme (ELS) payments had a net
benefit to farmers of £7.00 to £8.50 /ha, if made by lifting the drill and there was
no additional weed control. If undrilled patches were made using an herbicide
after crop emergence, and there was the unlikely need for additional weed
control, the net cost to farmers would be £3.50 to £5.00 /ha.
• Field margins established with wild flowers in the seed mixes were ten times
more expensive than grass-only seed mixes, and these costs are unlikely to be
met by current agri-environment schemes. Higher wheat prices increase costs to
the farmer because of greater production loss. Additional agri-environment
scheme payments for floristic enhancement of margins are likely to be required if
take-up is to be substantially improved
Fluxo de seiva pelo método do balanço de calor: base teórica, qualidade das medidas e aspectos práticos Sap flow by heat balance method: theoretical basis, data quality and practical aspects
O método do balanço de calor representa uma técnica importante para estudos sobre fisiologia vegetal, agrometeorologia e irrigação. Sua aplicação tem aumentado nos últimos anos em decorrência da maior facilidade de importação de material e equipamentos e do uso mais disseminado dos sistemas automáticos de aquisição de dados. Avanços importantes em diversas áreas de pesquisa têm sido alcançados com a possibilidade de se quantificar o consumo hÃdrico em plantas isoladas em diferentes escalas de tempo. Com base na teoria do método, esta revisão tem como objetivo apresentar e discutir os procedimentos de instalação, manutenção e de análise e processamento dos dados com vistas ao uso mais adequado da técnica e à obtenção de dados mais confiáveis e coerentes. Aspectos relacionados à influência das condições ambientais no funcionamento do sensor são abordados; são também discutidas diversas recomendações práticas observadas na literatura disponÃvel. O grande número e a diversidade de procedimentos que envolvem a instalação dos sensores, sua manutenção em condições de campo e a análise dos dados conferem ao método grande aplicação na experimentação cientÃfica. Entretanto, o uso do método de balanço de calor em larga escala parece inadequado devido à dificuldade de correta operação, o que facilmente compromete a qualidade das medidas.<br>The stem heat balance method has become an important technique in plant physiology, agrometeorology and irrigation science. Its application has increased in the last years due to the development of less expensive automatic data acquisition systems that are widespread. Important advances in several research areas have been reached by quantifying the water consumption by isolated plants in different temporal scales. Based on the theory of the method, this review aims to present and discuss the procedures of installation and maintenance, and data analysis and processing, giving elements to improve the user's criticism about data quality. Aspects related to the impact of environmental conditions on sensor performance are presented, as well as the practical recommendations found in literature are critically discussed. The method is a useful tool for research and experimentation, but it seems to be inadequate for use in practical conditions. Difficulties involving its operational and practical aspects - installation and maintenance in field conditions - in addition to data analysis and processing are the main obstacles to the users of this technique