• Authors:
    • Zieminska-Smyk,M.
  • Source: Annales Universitatis Mariae Curie-Skodowska. Sectio E, Agricultura
  • Volume: 63
  • Issue: 3
  • Year: 2008
  • Summary: The characteristics of weeding in cereals were based on 68 phytosociological releves taken from ploughlands of traditional management. The main crops there were: rye, winter wheat, spring wheat, mixture of oat and barley, oat and triticale. Most of the records were taken from winter wheat (30). Cereal was the main crop of the area in Skierbieszowki Landscape Park. 26 samples were taken from spring cereals and 42 samples from winter cereal. Segetal weeds communities of the winter cereals were richer than spring cereals when the number of species is considered, which is shown with an average number of weed species in one single sample: 20.3 species in winter cereals and 17.7 species in spring cereals. Weed coverage varied from 20% to 70% but only occasionally reached 70%. Cereals fields were not very weeded because of good fertilization and crop protection chemicals. Most of the weeds in spring and winter cereals were short-lived rather than perennial, which can be a result of progress rhythm in arable crops. Spring cereals were less weeded than winter cereals. It can be noticed by covering coefficient which were 7.500 in spring cereals and 9.600 in winter cereals.
  • Authors:
    • Diekmann, J.
    • Ryan, J.
    • Pala, M.
    • Singh, M.
  • Source: Experimental Agriculture
  • Volume: 44
  • Issue: 4
  • Year: 2008
  • Summary: With increasing land-use pressure in semi-arid, dryland Middle Eastern agriculture, fallow-based cereal production has given way to cropping intensification, including legume-based rotations along with conservation tillage and on-farm straw disposal. Such agronomic developments can only be biologically and economically assessed in multi-year trials. Thus, this 10-year study examined the influence of tillage systems (conventional and shallow or conservation) and variable stubble management, including compost application, on yields of barley and vetch grown in rotation. Barley yielded higher with compost applied every two or four years than with burning or soil-incorporating the straw and stubble. Barley straw and grain yields were generally higher with the mouldboard plough. Similarly with vetch, treatments involving compost application yielded significantly higher than burning or incorporating the straw and stubble. Despite yearly differences between crop yields, the pattern of treatment differences was consistent. Thus, the cereal-vetch rotation system is sustainable, while excess straw could be used as compost with benefit to the crop. Though there was no clear advantage of the shallow conservation-type tillage, the energy costs are less, thus indicating its possible advantage over conventional deep tillage in such rotational cropping systems.
  • Authors:
    • Chamorro, L.
    • Romero, A.
    • Xavier Sans, F.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 124
  • Issue: 1/2
  • Year: 2008
  • Summary: A comparative survey of weed vegetation in organic and conventional dryland winter cereal fields was performed in central Catalonia (NE Spain) in order to assess the effects of agricultural intensification on the diversity, structure and composition of weed communities. A total of 36 cereal fields were surveyed in nine agricultural sites, where a pair of one long-established organic and one conventional farms were selected. Weed surveys were carried out before harvest in 2003 and 2004, taking into account the spatial pattern. Organic practices produced an increase in weed cover, species richness and Hill's first order diversity (but not in equitability), as well as a shift in weed vegetation composition, which favoured potentially rare arable, broad-leaved, insect-pollinated and legume weeds. Weed diversity was concentrated in the crop edges, especially in the weed communities of conventional cereal fields, which were found to be more spatially heterogeneous than the organic ones.
  • Authors:
    • Pala, M.
    • Rashid, A.
    • Masri, S.
    • Matar, A.
    • Singh, M.
    • Ibrikci, H.
    • Ryan, J.
  • Source: European Journal of Agronomy
  • Volume: 28
  • Issue: 2
  • Year: 2008
  • Summary: Given the complex nature of rainfed cropping systems in Mediterranean agriculture and the dynamic nature of phosphorus (P) in soils, agronomic assessment of P fertilization must be long term in order to consider residual effects. Thus, a 9-year study involved initial relatively large applications of P (0, 50, 100, 150, 200 kg P 2O 5 ha -1) and yearly smaller dressings (0, 15, 30, 45, 60 kg P 2O 5 ha -1) in a trial involving dryland cereals (wheat/barley) in rotation with legumes (chickpea, lentil, or vetch) at three locations with varying mean annual rainfall in northern Syria; Breda (270 mm), Tel Hadya (342 mm) and Jindiress (470 mm). Assessment was made of grain, straw and total biomass yield and crop P uptake and available P (Olsen). While crop responses varied due to seasonal rainfall fluctuations, they tended to decrease with increasing initial available soil P levels (2.7, 6.2, and 4.4 mg kg -1 for Breda, Tel Hadya and Jindiress, respectively). Residual P was not significant for cereals or legumes at any site, but direct P was significant for both crops at Breda and Jindiress, as well as for legumes at Tel Hadya. In contrast, residual and direct P significantly influenced Olsen-P and seasonal and total P uptake. With no P fertilizer, or where minimal amounts (15 kg P 2O 5 ha -1) were applied annually, the balance between applied P and crop P offtake became increasingly negative; after 8 years without applied P, the P balance was -54, -38, -27, -17, and +7 kg ha -1 for the initial (residual) P application of 0, 50, 100, 150, and 200 kg P 20 5, respectively. This was counterbalanced by the higher annual application rates and to a lesser extent the amounts of P applied initially. The study demonstrated the highly variable nature of crop responses to fertilizer P under semi-arid field conditions over several years, with soil moisture from seasonal rainfall being the dominant influence on overall yields. While crop responses may not occur in any given year, especially if available P is near or above critical threshold levels, dryland cropping without P fertilizer is unsustainable in the long run.
  • Authors:
    • Ibrikci, H.
    • Grando, S.
    • Ceccarelli, S.
    • Masri, S.
    • Ryan, J.
  • Source: Journal of Plant Nutrition
  • Volume: 31
  • Issue: 2
  • Year: 2008
  • Summary: Barley is traditionally grown in the Mediterranean region as a dryland crop, invariably under drought-stressed conditions and often without inputs such as fertilizer. Following research that demonstrated the benefits of fertilization, even under less-than-favourable rainfall condition, fertilizer use on cereals has increased dramatically in the past few decades in countries of West Asia-North Africa. With developments in breeding new barley cultivars for higher yield, combined with disease resistance and environmental adaptability, it is crucial to assess the extent to which such cultivars respond to fertilizer inputs as this may affect aspects of a breeding strategy, particularly the choice of germplasm for adaptation in any particular environment. Thus, we assessed the yield potential of 30 barley cultivars with a range of germplasm types, including new cultivars and landraces, in a greenhouse in two soil types with and without adequate nitrogen and phosphorus fertilizer, i.e., low and high fertility. By comparison with the unfertilized low fertility soils, the fertilizer treatment increased yield parameters by about 10-fold. However, the rankings of some cultivars changed markedly with fertilization; some increased, others showed poor responses and decreased relatively, and two performed well with and without fertilizer. Based on the differential responses at the initial screening stage in the greenhouse, it is possible to identify lines or cultivars that are highly responsive to fertilizers and to incorporate such germplasm for further development to produce high-yielding cultivars for commercial adoption by farmers.
  • Authors:
    • Stevens, W.
    • Jabro, J.
    • Sainju, U.
  • Source: Journal of Environmental Quality
  • Volume: 37
  • Issue: 1
  • Year: 2008
  • Summary: Management practices can influence soil CO 2 emission and C content in cropland, which can effect global warming. We examined the effects of combinations of irrigation, tillage, cropping systems, and N fertilization on soil CO 2 flux, temperature, water, and C content at the 0- to 20-cm depth from May to November 2005 at two sites in the northern Great Plains. Treatments were two irrigation systems (irrigated vs. non-irrigated) and six management practices that contained tilled and no-tilled malt barley ( Hordeum vulgaris L.) with 0 to 134 kg N ha -1, no-tilled pea ( Pisum sativum L.), and a conservation reserve program (CRP) planting applied in Lihen sandy loam (sandy, mixed, frigid, Entic Haplustolls) in western North Dakota. In eastern Montana, treatments were no-tilled malt barley with 78 kg N ha -1, no-tilled rye ( Secale cereale L.), no-tilled Austrian winter pea, no-tilled fallow, and tilled fallow applied in dryland Williams loam (fine-loamy, mixed Typic Argiborolls). Irrigation increased CO 2 flux by 13% compared with non-irrigation by increasing soil water content in North Dakota. Tillage increased CO 2 flux by 62 to 118% compared with no-tillage at both places. The flux was 1.5- to 2.5-fold greater with tilled than with non-tilled treatments following heavy rain or irrigation in North Dakota and 1.5- to 2.0-fold greater with crops than with fallow following substantial rain in Montana. Nitrogen fertilization increased CO 2 flux by 14% compared with no N fertilization in North Dakota and cropping increased the flux by 79% compared with fallow in no-till and 0 kg N ha -1 in Montana. The CO 2 flux in undisturbed CRP was similar to that in no-tilled crops. Although soil C content was not altered, management practices influenced CO 2 flux within a short period due to changes in soil temperature, water, and nutrient contents. Regardless of irrigation, CO 2 flux can be reduced from croplands to a level similar to that in CRP planting using no-tilled crops with or without N fertilization compared with other management practices.
  • Authors:
    • Lawrence, R.
    • Jones, C.
    • Weist, D.
    • Schulthess, U.
    • Christensen, N.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture, Denver, Colorado, USA, 20-23 July, 2008
  • Year: 2008
  • Summary: RapidEye's five satellites to be launched in the summer of 2008 will make it possible to regularly monitor the N-status of crops from space. The sensors on board of each satellite are equipped with five broad bands: blue, green, red, rededge, and NIR. This opens new avenues for red-edge based algorithms to predict the N-status of cereals. In a study conducted in Montana in 2007, we obtained the best results to predict tissue N content (TNC) of irrigated spring wheat and barley, as well as dryland barley from the following algorithm, based on light reflectance (R) of the canopy in the red, red-edge, and NIR bands: ( TNC= RNIR - Rred-edge )/( RNIR -s* Rred ) where s stands for slope of the soil line, i.e. the separately measured bare soil reflectance of the NIR band divided by the red band. Red-edge band based algorithms will open new avenues to optimize in-season N management of cereals, and for monitoring and verifying the efficacy of N fertilization.
  • Authors:
    • Basnyat, P.
    • Huber, D.
    • Fernandez, M. R.
    • Zentner, R. P.
  • Source: Soil & Tillage Research
  • Volume: 100
  • Issue: 1-2
  • Year: 2008
  • Summary: Fusarium head blight (FHB) is an important disease which has been causing damage to wheat and barley crops in western Canada. Because crop residues are an important source of inoculum, it is important to know the ability of Fusarium spp. to colonize and survive in different residue types, and how their populations might be affected by agronomic practices. Sampling of residue types on producers' fields for quantification of Fusarium and other fungi was conducted in 2000-2001 in eastern Saskatchewan. Fusarium spp. were isolated from most fields, whereas their mean percentage isolation (MPI) was over 50% for cereal and pulse residues, and under 30% for oilseed residues. The most common Fusarium, F. avenaceum, had a higher MPI in pulse and flax (45-48%) than in cereal or canola (10-22%) residues. This was followed by F. equiseti, F. acuminatum, F. graminearum, F. culmorum and F. poae which were isolated from all, or most, residue types. Factors affecting Fusarium abundance in residues included the current crop, cropping history, and tillage system. In cereal residues, the MPI of F. avenaceum was higher when the current crop was another cereal (24%) versus a noncereal (4-8%). When the current crop was another cereal, the lowest MPI of F. avenaceum and F. culmorum occurred when the field had been in summerfallow (SF) two years previous (F. avenaceum: 17% for SF, 28% for a crop; F. culmorum: 1% for SF, 4% for a crop); in contrast, F. equiseti and Cochliobolus sativus were most common in residues of cereal crops preceded by SF (F. equiseti: 16% for SF, 10% for a crop; C. sativus: 22% for SF, 13% for a crop). The MPI of F graminearum was higher when the crop two years previous was an oilseed (7%) versus a cereal (4%). In regards to tillage effects, when the current crop was a cereal, the MPI of F. avenaceum was higher under minimum (MT) and zero tillage (ZT) (22-37%) than conventional tillage (CT) (15%), that of F. graminearum was lowest under ZT (3% for ZT, 7-11% for CT-MT), whereas that of C. sativus was highest under CT (27% for CT, 6-11% for MT-ZT). Under ZT, previous glyphosate applications were correlated positively with F. avenaceum and negatively with F. equiseti and C. sativus. These observations generally agreed with results from previous FHB and root rot studies of wheat and barley in the same region. Percentage isolation of F avenaceum from noncereal and of F. graminearum from cereal residues were positively correlated with FHB severity and percentage Fusarium-damaged kernels of barley and wheat caused by the same fungi. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
  • Authors:
    • Brenzil, C. A.
    • Hall, L. M.
    • Thomas, A. G.
    • Leeson,J. Y.
    • Beckie, H. J.
  • Source: Weed Technology
  • Volume: 22
  • Issue: 4
  • Year: 2008
  • Summary: Agricultural practices, other than herbicide use, can affect the rate of evolution of herbicide resistance in weeds. This study examined associations of farm management practices with the occurrence of herbicide (acetyl-CoA carboxylase or acetolactate synthase inhibitor)-resistant weeds, based upon a multi-year (2001 to 2003) random Survey of 370 fields/growers from the Canadian Prairies. Herbicide-resistant weeds Occurred in one-quarter of the surveyed fields. The primary herbicide-resistant weed species was wild oat, with lesser occurrence of green foxtail, kochia, common chickweed, spiny sowthistle, and redroot pigweed. The risk of weed resistance was greatest in fields with cereal-based rotations and least in fields with forage crops, fallow, or where three or more crop types were grown. Weed resistance risk also was greatest in conservation-tillage systems and particularly low soil disturbance no-tillage, possibly due to greater herbicide use or weed seed bank turnover. Large farms (> 400 ha) had a greater risk of weed resistance than smaller farms, although the reason for this association Was unclear. The results of this study identify cropping system diversity as the foundation of proactive weed resistance management.
  • Authors:
    • Claupein, W.
    • Lewandowski, I.
    • Boehmel, C.
  • Source: Agricultural Systems
  • Volume: 96
  • Issue: 1/3
  • Year: 2008
  • Summary: Given the political targets, it can be expected that in Europe, energy production from agricultural land will increase and that improved systems for its production are needed. Therefore, a four year field trial was conducted on one site in south-western Germany to compare and evaluate the biomass and energy yield performance of important energy crops. Six energy cropping systems with the potential to produce biomass for first and second-generation biofuels were selected. The systems were short rotation willow coppice, miscanthus, switchgrass, energy maize and two different crop rotation systems including winter oilseed rape, winter wheat and winter triticale. The two crop rotation systems were managed in either conventional tillage or no-till soil cultivation systems. The second test parameter was three different crop-specific nitrogen application levels. The performance of the energy cropping systems was evaluated by measuring the biomass yields and calculating the energy yields, as well as through an energy balance and nitrogen budget. Results show the superiority of the annual energy crop maize in dry matter yield (DMY) and primary net energy yield (PNEY=difference between the primary energy yield (DMY * lower heating value) and the energy consumption) performance with peak values at the highest N-application level of 19.1 t DM ha -1 a -1 and 350 GJ ha -1 a -1, respectively. The highest yielding perennial crop was miscanthus with 18.1 t ha -1 a -1 DMY and a PNEY of 277 GJ ha -1 a -1, followed by willow with 15.2 t ha -1 a -1 and 258 GJ ha -1 a -1, at the highest N-application level. Switchgrass showed the lowest yields of the perennial crops with 14.1 t ha -1 a -1 DMY at the highest N-application level. The yields of the two crop rotation systems did not differ significantly and amounted to 14.6 t ha -1 a -1 DMY of both grain and straw at the highest N-application level. Willow showed the significantly highest energy use efficiency (output (PNEY):input (energy consumption)-ratio) with 99 GJ energy output per GJ fossil energy input at the lowest N-application level (no fertilizer). The two crop rotation systems had the lowest energy use efficiency with 20 GJ GJ -1 for the production of total aboveground biomass. Energy maize gave the best energy yield performance but at a relatively high energy input, whereas willow and miscanthus as perennial energy crops combine high yields with low inputs. Results suggest that no-till systems had no negative impact on biomass and energy yields, but that there was also no positive impact on energy saving.