• Authors:
    • Asgharzade, A.
    • Tavassoli, A.
    • Esmaeilian, Y.
    • Babaeian, M.
    • Sadeghi, M.
  • Source: Scientific Research and Essays
  • Volume: 6
  • Issue: 17
  • Year: 2011
  • Summary: Barley is a cool-weather cereal grain primarily produced on dryland farms in Sistan region. In order to study the effect of different proportions of manure and chemical fertilizer and water stress on grain yield and grain nutrient content in barley an experiment was conducted as split plot randomized complete block design with three replications in research field of Zabol University, 2009. Water stress treatments consisted of: water stress in grain filling stage (S 1) and control (S 2) as the main factor and different proportions of manure and chemical fertilizer treatment consisted of: 100% manure (N 1), 100% chemical fertilizer (N 2), 50% manure+50% chemical fertilizer (N 3), 75% manure+25% chemical fertilizer (N 4) and control (N 5) as sub factor in this experiment. Results illustrated that the effect of drought stress in grain filling stage treatment on all grain yield and yield components with the exception of ear weight, were significant. Drought stress in grain filling stage strongly decreased grain yield but its effect was not very strong on another traits. With the exception of grain number/ear and ear weight, fertilizer treatments had significant effect on grain yields and yield components. Grain nutrient content not affected by water stress but among different proportions of fertilizer treatments, 100% manure (N 1) caused to increase of these elements in grain.
  • Authors:
    • Olesen, J.
    • Bindi, M.
  • Source: Regional Environmental Change
  • Volume: 11
  • Issue: Supplement 1
  • Year: 2011
  • Summary: Human activities are projected to lead to substantial increases in temperature that will impact northern Europe during winter and southern Europe during summer. Moreover, it is expected that these changes will cause increasing water shortages along the Mediterranean and in the south-west Balkans and in the south of European Russia. The consequences on the European agricultural ecosystems are likely to vary widely depending on the cropping system being investigated (i.e. cereals vs. forage crops vs. perennial horticulture), the region and the likely climate changes. In northern Europe, increases in yield and expansion of climatically suitable areas are expected to dominate, whereas disadvantages from increases in water shortage and extreme weather events (heat, drought, storms) will dominate in southern Europe. These effects may reinforce the current trends of intensification of agriculture in northern and western Europe and extensification and abandonment in the Mediterranean and south-eastern parts of Europe. Among the adaptation options (i.e. autonomous or planned adaptation strategies) that may be explored to minimize the negative impacts of climate changes and to take advantage of positive impacts, changes in crop species, cultivar, sowing date, fertilization, irrigation, drainage, land allocation and farming system seem to be the most appropriate. In adopting these options, however, it is necessary to consider the multifunctional role of agriculture and to strike a variable balance between economic, environmental and economic functions in different European regions.
  • Authors:
    • Lasram, A.
    • Akkari, T.
    • Dellagi, H.
  • Source: New Medit
  • Volume: 10
  • Issue: 4
  • Year: 2011
  • Summary: This work deals with the regional characteristics of the supplied irrigation effect on the cereal yield in Tunisia. It underlines the value of the knowledge how scientifically brought to farmers. This study analyses the results of an inquiry carried on over seven consecutive years at the level of two categories for farmers practising irrigated wheat farming. The first category of farmers is taking advantage of a set of the technological support actions which related both to the vulgarization of different forms of technological innovations and the miscellaneous forms of support in kind, while the second category of farmers is granted no form of support. The specification of the different regions studied in Tunisia and the comparison of the two farmers categories studied is brought out by the Principal Components Analysis technique and the PLS regression. The mastering of the irrigation waters use, the rationalization of the fertilization as well as the soil exploitation in the north of the country are better valorised by the supported farmers.
  • Authors:
    • Eryigit,T.
  • Source: Yuzuncu Yil Universitesi Journal of Agricultural Sciences
  • Volume: 21
  • Issue: 1
  • Year: 2011
  • Summary: The industrial crops with contribution to national income and industrial sector in terms of providing raw materials have a significant place in our crop production. Agricultural industry in our country has a large capacity, but due to lack of raw materials and financing a significant portion of the installed capacity can not be benefited. Especially in recent years, increasing of population and production decrease in some industrial plants due to the resulting vegetable oil deficit. Our country pays the highest foreign currency to imports of the oil and oil seed crops for closure of this gap after the oil imports. Therefore, the priority should be given to the oil plants within the groups of industrial plants. Igdr has its own microclimate characteristics. The diversity of product design is greater due to the climate and irrigation conditions in the plain. Grains constitute the main products of the region. All kinds of vegetables, olives and citrus fruit except that all the fruits can be grown. Sugar beet and cotton plants of industrial crop and the alfalfa plants of the forage crops have great importance in the development of animal husbandry. However, in recent years, changes in the climate regime, increases in the cultivation of sugar beet, sunflower and rapeseed gave rise to a decrease in the number of the small farmers who planted cotton. Igdr has high agricultural potential, so the alternative species of industrial crops and their varieties will be integrated to the present cultivation of plain by the scientific studies which will be held on industrial crops in the province.
  • Authors:
    • Navarrete, L.
    • Kozak, M.
    • Hernandez Plaza, E.
    • Gonzalez-Andujar, J. L.
  • Source: Agriculture, Ecosystems and Environment
  • Volume: 140
  • Issue: 1-2
  • Year: 2011
  • Summary: This study investigated whether the choice of a tillage system (no-tillage, minimum tillage or traditional tillage) affected weed diversity in a 23 years cereal-leguminous rotation system in Spain. Weed diversity was assessed using common diversity indices: species richness, Shannon's index and Pielouis evenness. Linear mixed-effects models were employed to compare the tillage systems. It was found that after 23 years no large differences between tillage systems have arisen related to weed diversity. Only minimum tillage appeared to support, on average, more species than the two other tillage systems. Richness, Shannon diversity index and evenness varied largely through the years in all tillage systems but this variation was not related to type of crop sown (cereal or leguminous). Our results highlight that conservation tillage practices did not represent any concern for weed diversity conservation in cereal-leguminous rotations in the conditions of central Spain.
  • Authors:
    • Armengot, L.
    • Blanco-Moreno, J. M.
    • Jose-Maria, L.
    • Xavier Sans, F.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 145
  • Issue: 1
  • Year: 2011
  • Summary: Agricultural intensification, at local and landscape scales, has caused a decrease in plant diversity and changes in species composition in cereal fields. To better understand the role of landscape complexity and farming systems in shaping plant assemblages, it is of interest to focus on functional traits rather than on floristic composition, which may help to highlight trends in vegetation patterns. We analysed the relative abundance of various functional attributes (different life forms, growth forms, wind-pollinated species and wind-dispersed species) at three contrasted field positions (boundary, edge and centre) of 29 organic and 29 conventional cereal fields distributed in 15 agrarian localities of NE Spain. Agricultural intensification affected the biological attributes of the vegetation in dryland Mediterranean cereal fields; local factors (farming system and position) had a more prominent role in affecting plant functional composition than the surrounding landscape. Local factors were important for life form distribution, growth form and pollination type, whereas landscape complexity mainly affected the proportion of wind-dispersed species. Therefore, depending on the objective of the study, it is important to select functional attributes sensitive to the different scales of agricultural intensification, especially because landscape complexity and land-use intensity are commonly related.
  • Authors:
    • José-María, L.
    • Sans, F. X.
  • Source: Weed Research
  • Volume: 51
  • Issue: 6
  • Year: 2011
  • Summary: Weed seedbanks are a reserve of weed diversity and can contribute to the prediction of future weed problems in arable fields. Managing seedbanks should therefore help in optimising biodiversity and controlling weed infestations. This study assessed the effects of management system (organic vs. conventional) and landscape complexity on seedbank size and species richness at the edges and centres of Mediterranean dryland cereal fields and examines the relationship between specific management practices and seedbanks. Field edges and organic fields had more species-rich, denser seedbanks than field centres and conventional fields, and landscape complexity had a limited effect on arable seedbanks. Accordingly, the promotion of low-intensity farming practices regardless of landscape complexity, especially at field edges, would be an effective measure for conservation purposes in Mediterranean agroecosystems. Nevertheless, the high seed density of organic seedbanks reveals the need for more effective seedbank management. The analysis of the effects of specific management practices highlights the importance of cleaning crop seeds properly to reduce seedbank size and using complex rotations, especially as this tends to conserve species richness while reducing seed abundance.
  • Authors:
    • Stevenson, F. C.
    • Legere, A.
    • Benoit, D. L.
  • Source: Weed Science
  • Volume: 59
  • Issue: 1
  • Year: 2011
  • Summary: A conservation tillage study provided the opportunity to test whether tillage effects on the germinable weed seedbank would be consistent across different crop rotations and to investigate the potential residual effects of herbicide treatments terminated 12 yr earlier. Our objective was to measure the effects of tillage (moldboard plow [MP] vs. chisel plow [CP] vs. no-till [NT]), crop rotation (2-yr barley-red clover followed by 4-yr barley-canola-wheat-soybean rotation, compared to a cereal monoculture), and of a prior weed management factor (three intensity levels of herbicide use) on the density, diversity, and community structure of weed seedbanks. Species richness, evenness (Shannon's E), and diversity (Shannon's H′) of spring seedbanks varied little across treatments and over time. Total seedbank density generally increased as tillage was reduced, with some variations due to weed management in 1993 and crop rotation in 2006. Crop rotations generally had smaller seedbanks with fewer species than the monoculture. In 1993, seedbanks with minimum weed management were twice as dense as those with intensive or moderate weed management (approximately 6,000 vs. 3,000 seed m -2). By 2006, seed density averaged 6,838 seed m -2 across intensive and moderate weed management regardless of tillage, but was nearly twice as large in NT (12,188 seed m -2) compared to MP (4,770 seed m -2) and CP (7,117 seed m -2) with minimum weed management (LSD 0.005=4488). Species with abundant seedbanks responded differently to treatments. Barnyardgrass and green foxtail had larger seedbanks in the monoculture than in the rotation. Common lambsquarters and pigweed species had large seedbanks in tilled treatments in the rotation, whereas yellow foxtail and field pennycress contributed to the large seedbanks observed in NT treatments. The latter two species were also associated with residual effects of weed management treatments (terminated 12 yr earlier) in NT. The differential seedbank response of weed species, attributed in part to contrasting weed emergence patterns and agronomic practice effects on seed rain, explained some of the weak treatment effects observed for total seedbank density and diversity. The large weed seedbanks observed in NT plots after 18 yr confirms the importance of seed rain and seedbank management for the sustainability of NT systems.
  • Authors:
    • Murari, L.
  • Source: Regional Environmental Change
  • Volume: 11
  • Issue: Supplement 1
  • Year: 2011
  • Summary: One of the targets of the United Nations 'Millennium Development Goals' adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (
  • Authors:
    • Barton, L.
    • Butterbach-Bahl, K.
    • Kiese, R.
    • Murphy, D. V.
  • Source: Global Change Biology
  • Volume: 17
  • Issue: 2
  • Year: 2011