• Authors:
    • Lezaún, J. A.
    • Lacasta, C.
    • Ciria, P.
    • Aibar, J.
    • Pardo, G.
    • Zaragoza, C.
  • Source: Chilean Journal of Agricultural Research
  • Volume: 71
  • Issue: 2
  • Year: 2011
  • Summary: Under semiarid conditions the response of cereal crops to chemical fertilizers and weed control practices with herbicides is often reduced. In fact, the economic profitability of agricultural production in many dryland regions is critically affected by high costs of inputs and low crop yields. As a solution, cropping systems like organic farming, obtaining similar yields and promoting environmental sustainability by reducing fertilizer and herbicides, could be an alternative to conventional systems. In this study, 23 trials were performed in five semiarid regions of Spain during 5 yr to compare different fertilizers and weed control methods on durum wheat ( Triticum durum Desf.) and barley ( Hordeum vulgare L.) yields. The following rotation pattern was developed on the experimental plots: fallow-barley-ground ploughed vetch ( Vicia sativa L.)-durum wheat. Plots either received organic fertilizer, chemical fertilizer, or no fertilizer. In addition, three levels of weed control were applied in cereal plots: flex-tine harrow tillage, conventional herbicide, and no weeding. The results indicated that neither the fertilization nor the weed control have effect on the yield crop.
  • Authors:
    • Alonso, J. C.
    • Magana, M.
    • Garcia de Leon, D.
    • Bravo, C.
    • Ponce, C.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 141
  • Issue: 1/2
  • Year: 2011
  • Summary: Organic farming is considered an important way to preserve biodiversity in agricultural landscapes. However, more work is still necessary to enable a full appraisal of the potential benefits of this way of farming, since studies differ in the evaluation of its effectiveness. Studies are particularly scarce in the Mediterranean region, where different climatic and ecological conditions prevent simple extrapolations from work carried out at northern latitudes. In the present study, an analysis of weed and arthropod communities was conducted in 28 pairs of organic and conventional fields in a dry cereal farmland in central Spain. Plants were identified to the species level, and arthropods to the family level. Pitfalls and sweep nets were used to sample respectively, ground-dwelling and plant-visiting arthropods. Abundance (total numbers of individuals), richness (total numbers of plant species or arthropod families), diversity (Shannon-Wiener index) and biomass (milligrams per pitfall/sweep-net) were calculated for each field and compared between organic and conventional fields using Generalized Linear Mixed Models (GLMMs). To explore the effect of predictor variables on weed richness and arthropod biomass, GLMMs were used. Organic fields showed higher abundance of weeds and arthropods (3.01 and 1.43 times, respectively), higher weed richness and diversity (2.76 and 2.33 times, respectively), and a 24% reduction in cereal plants. Arthropod diversity was lower in organic fields due to the presence of three dominant groups: Collembola, Chloropidae (Diptera), and Aphididae (Hemiptera). Weed richness increased as cereal cover decreased in organic fields. Total arthropod biomass was slightly higher in organic fields, and was affected by weed abundance and diversity. The differences between organic and conventional fields found in this study were higher than those reported for northern latitudes. This could be explained by the richer weed flora in the Mediterranean region, and a higher weed seed availability favored by the two-year rotation system typical of Iberian dry cereal farmland. We conclude that organic farming may contribute to preserve biodiversity in dryland cereal agroecosystems in the Mediterranean region.
  • Authors:
    • Zhang, T. Z.
    • Yusuf, Z.
    • Nabila, T.
    • Ihsan, U.
    • Guo, W. Z.
    • Mehboob-ur-Rahman
    • Saeed, M.
  • Source: Electronic Journal of Biotechnology
  • Volume: 14
  • Issue: 3
  • Year: 2011
  • Summary: Increasing scarcity of irrigation water is a major threat to sustainable production of cotton ( Gossypium hirsutum L.). Identifying genomic regions contributing to abiotic stress tolerance will help develop cotton cultivars suitable for water-limited regions through molecular marker-assisted breeding. A molecular mapping F 2 population was derived from an intraspecific cross of the drought sensitive G. hirsutum cv. FH-901 and drought tolerant G. hirsutum cv. RH-510. Field data were recorded on physiological traits (osmotic potential and osmotic adjustment); yield and its component traits (seedcotton yield, number of bolls/plant and boll weight); and plant architecture traits (plant height and number of nodes per plant) for F 2, F 2:3 and F 2:4 generations under well-watered versus water-limited growth conditions. The two parents were surveyed for polymorphism using 6500 SSR primer pairs. Joinmap3.0 software was used to construct linkage map with 64 polymorphic markers and it resulted into 35 markers mapped on 12 linkage groups. QTL analysis was performed by composite interval mapping (CIM) using QTL Cartographer2.5 software. In total, 7 QTLs (osmotic potential 2, osmotic adjustment 1, seedcotton yield 1, number of bolls/plant 1, boll weight 1 and plant height 1) were identified. There were three QTLs ( qtlOP-2, qtlOA-1, and qtlPH-1) detected only in water-limited conditions. Two QTLs ( qtlSC-1 and qtlBW-1) were detected for relative values. Two QTLs ( qtlOP-1 and qtlBN-1) were detected for well-watered treatment. Significant QTLs detected in this study can be employed in MAS for molecular breeding programs aiming at developing drought tolerant cotton cultivars.
  • Authors:
    • Lenssen, A. W.
    • Sainju, U. M.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 2
  • Year: 2011
  • Summary: Forages grown in rotation with or without cereals to sustain dryland soil water content and crop production may influence N dynamics. We evaluated the effect of alfalfa ( Medicago sativa L.) and durum ( Triticum turgidum L.)-annual forage cropping sequences on above-(stems+leaves) and belowground (roots) biomass N, dryland soil total N (STN), particulate organic N (PON), microbial biomass N (MBN), potential N mineralization (PNM), NH 4-N, and NO 3-N contents at the 0- to 120-cm depth in northeastern Montana from 2002 to 2005. Cropping sequences were continuous alfalfa (CA), durum-barley ( Hordeum vulgare L.) hay (D-B), durum-foxtail millet ( Setaria italica L.) hay (D-M), durum-Austrian winter pea ( Pisum sativum L.)/barley mixture hay (D-P/B), and durum-fallow (D-F). From 2002 to 2005, total above- and belowground biomass N was 20 to 97 kg N ha -1 greater under CA than other treatments. In 2005, STN, PON, and PNM were 7 to 490 kg N ha -1 greater under CA than D-M, D-B, and D-P/B at 0 to 30 cm but varied by treatment at other depths. In contrast, MBN at 0 to 15 cm and NH 4-N content at 30 to 90 cm were 23 to 37 kg N ha -1 greater under D-B than D-M and D-F. The NO 3-N content at 0 to 120 cm was 65 to 107 kg N ha -1 greater under D-P/B than other treatments. Even though haying removed a greater amount of N, alfalfa increased surface soil N storage and mineralization and reduced the potential for N leaching compared with durum-annual forages, probably due to increased root growth or N 2 fixation. Durum-pea/barley hay, however, increased N mineralization and availability in subsoil layers, probably due to greater root N concentration or downward movement of water-soluble N.
  • Authors:
    • Amanullah
    • Khalid, N.
    • Khan, A.
    • Amanullah, J.
    • Khalil, S.
    • Shitab, K.
  • Source: Pakistan Journal of Botany
  • Volume: 43
  • Issue: 4
  • Year: 2011
  • Summary: The performance of six high yielding wheat ( Triticum aestivum L.) and two barley ( Hordeum vulgare) cultivars was studied under moisture stress. The experiment was undertaken at the Agricultural Research Farm of Agricultural University Peshawar, during winter 2003-04 on six wheat cultivars: BARS-II, Saleem-2000, Haider-2000, Kohat-2002, Suleman-96 and Takbeer and two barley cultivars: Sorab-96 and Awaran-2002. Sorab-96 produced the highest (296 m -2) number of tillers while Haider-2000 and BARS-II each produced the lowest (185 m -2) number of tillers. Plant height ranged between 77 (Sorab-96) to 117 cm (Sulaman-96). Takbeer produced the highest (73) number of grains spike -1 in comparison with Awaran-2002 which produced only 45 grains spike -1. The 1000-seed weight was highest (43.13 g) in Awaran-2002 and lowest in Kohat-2002 (23.21 g/1000-seeds). Saleem-2000 produced the highest grain yield (3875 kg ha -1) as well as biological yield (8833 kg ha -1). Both barely cultivars performed better, though Awaran-2002 displayed slightly superior results than Sorab-96. The harvest-index was maximum (53.7%) for Kohat-2002 and lowest for Sorab-96 (20.9%). The average grain yield of six wheat cultivars was higher than the average grain yield of the two barley cultivars. In this investigation, wheat cultivars: Saleem-2000, Haider-2000 and Kohat-2002, produced higher (3875, 3525, 3225 kg ha -1) grain yields, respectively and are therefore, recommended for cultivation in dryland areas.
  • Authors:
    • Kahrizi, D.
    • Dehaghi, M.
    • Heidari, S.
    • Mofrad, A.
    • Azizi, K.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 1
  • Year: 2011
  • Summary: In order to investigate the effect of intercropping and sole cropping of barley and narbon vetch with weed control and interference conditions on their qualitative and quantitative traits, this experiment was conducted with 5 levels of intercropping (seed contribution): sole cropping of narbon vetch, 75:25 (narbon vetch : barley), 50:50, 25:75 and sole cropping of barley. Two levels of weed control and weed interference in row replacement series system in the form of factorial was designed with Randomized Complete Blocked Design (RCBD) in 3 replications in the College of Agriculture, Lorestan University, from 2006-2007. Results showed that the interaction of weed and the contribution of complementary components of intercropping has significant effect on crude protein (CP) and neutral detergent fibers (NDF) content in barley. Maximum CP and NDF were related to sole cropping of barley (infected by weeds), and maximum CP with minimum NDF were related to (narbon vetch: barley) 75:25 treatment, so that 31% of CP decreased in sole cropping of barley (infected by weeds) when compared with 75:25 combination. NDF percentage in sole cropping increased to 16.6%, therefore 25:75 (narbon vetch: barley) combination was better than the others. So, in order to get proper percentage of protein and digestibility of forage for livestock, 75:25 (infected by weeds) combination is better, especially the combination of 25:75 (infected by weeds), due to its high protein content. The highest and lowest dry forage production of barley were related to its sole cropping (a control which is equal to 3.75 t/ha) and 75:25 barley (infected by weeds that are equal to 1.59 t/ha), respectively.
  • Authors:
    • Han, T.
    • Huang, Z.
  • Source: Guizhou Agricultural Sciences
  • Issue: 9
  • Year: 2011
  • Summary: Beiqing 7, a new hulles barley variety with characteristics of early maturity, high yield, 13% crude protein content, good agronomic characters, strong resistance to lodging and disease and wide adaptability, was bred from MDYT (female parent) * 245 (male parent) combination by systematic breeding method for 13 years and approved by Qinghai Crops Variety Examination Committee to improve breeding level of hulless barley, culture new hulless barley varieties with quality and high yield for promoting development of hulless barley industrialization in Qinghai province. The yield of Beiqing 7 in the production tests was 10% higher than Beiqing 6 (a current commercial variety). Beiqing 7 can be cultivated in dryland areas with 0degreesC in Tibet plateau.
  • Authors:
    • Ward, G.
    • Jacobs, J.
  • Source: Animal Production Science
  • Volume: 51
  • Issue: 12
  • Year: 2011
  • Summary: Limitations to the current perennial ryegrass-based pasture system on dryland dairy farms in southern Australia has led to research into alternatives that can produce either additional DM, out of season feed or can improve nutritive characteristics. The use of winter annual crops followed by a summer crop have the potential to achieve these goals but often result in considerable periods where new crops are establishing and feed is not available for consumption. Companion cropping offers an option to overcome these limitations. The experiment reported in this paper examines the DM yields, nutritive characteristics and mineral content of companion cropping wheat or triticale at different sowing rates into an existing chicory monoculture over a 2-year period. We hypothesised that oversowing cereal crops in autumn into an existing stand of chicory would result in improvements in nutritive characteristics at ensiling, without adversely affecting DM yield or subsequent chicory DM yields following harvesting, thus negating the need to sow a new summer forage crop each year. Total DM yields for the chicory and cereal monocultures were similar over the experimental period, while DM yields for all triticale mixtures were higher than the chicory only treatment. Chicory produced lower DM yields for silage but higher DM yields at most grazing events. The crude protein and estimated metabolisable energy content of the chicory only treatment was higher than the cereal monocultures and all triticale/chicory mixtures at both silage harvests with wheat/chicory mixes being intermediate. The proportion of chicory in the mixed swards declined over the course of the experiment. The use of chicory with cereals resulted in no adverse effects on total DM yields, some improvements in nutritive characteristics and mineral content and a more continuous supply of DM compared with double cropping with annual species in winter and summer. This experiment has highlighted the potential of oversowing cereal forages into an existing chicory sward to contribute to DM production on dairy farms in southern Australia. Such forage mixes can provide flexibility into forage systems through the provision of forage for grazing in early winter, the production of high DM yield silage harvests and then subsequent feed supply over summer and early autumn.
  • Authors:
    • Hontoria, C.
    • Lammerding, D.
    • Tenorio, J.
    • Walter, I.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 2
  • Year: 2011
  • Summary: It is widely accepted that conservation tillage management affords benefits to soil properties and reduces production costs; therefore these practices could be attractive to farmers from semiarid regions. The objective of this study was to assess the long-term effects of different tillage practices under semiarid conditions on macroaggregate stability (water stable aggregates, WSA), soil organic carbon (SOC), and particulate organic carbon (C-POM) content of an Alfisol from Spain. The experimental design involved a split plot and four randomized blocks in which tillage was the main factor and crop rotation (fallow-wheat-pea-barley) the secondary factor. Three tillage systems were compared: no tillage (NT), minimum tillage (MT), and conventional tillage (CT). Soil samples were collected on November 2006 and October 2007. In November 2006 no significant differences in WSA were found among the tillage treatments. In October 2007, however, the mean WSA in the upper soil layer for the NT was significantly higher, 24%, that in the CT. No significant differences were seen for the subsurface layer. Under NT, the SOC and C-POM values for the surface soil layer were significantly higher than those for the other treatments on both sampling dates. At the subsurface depth, no significant differences were seen in either of these variables. The SOC and C-POM values were more homogeneous throughout the soil profile in the plowed soil than in the NT for which the corresponding values were more stratified. The results show that NT will help improve soil structure and soil fertility, which is particularly relevant to semiarid conditions like the area studied.
  • Authors:
    • Olson, B.
    • Curtis, T.
    • Chanasyk, D.
    • Miller, J.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 3
  • Year: 2011
  • Summary: Application of beef cattle ( Bos taurus) manure based on nitrogen (N) requirements of crops has resulted in elevated concentrations of soil test phosphorus (P) in surface soils, and runoff from this cropland can contribute to eutrophication of surface waters. We conducted a 3-yr field study (2005-2007) on a Lethbridge loam soil cropped to dryland barley ( Hordeum vulgare) in southern Alberta, Canada to evaluate the effect of annual and triennial P-based and annual N-based feedlot manure on P and N in runoff. The manure was spring applied and incorporated. There was one unamended control plot. A portable rainfall simulator was used to generate runoff in the spring of each year after recent manure incorporation, and the runoff was analyzed for total P, total dissolved P, total particulate P, dissolved reactive P, total N, total dissolved N, total particulate N, NO 3-N, and NH 4-N. Annual or triennial P-based application resulted in significantly ( p≤0.05) lower (by 50 to 94%) concentrations or loads of mainly dissolved P fractions in runoff for some years compared with annual N-based application, and this was related to lower rates of annual manure P applied. For example, mean dissolved reactive P concentrations in 2006 and 2007 were significantly lower for the annual P-based (0.12-0.20 mg L -1) than for the annual N-based application (0.24-0.48 mg L -1), and mean values were significantly lower for the triennial P-based (0.06-0.13 mg L -1) than for the annual N-based application. In contrast, other P fractions in runoff were unaffected by annual P-based application. Our findings suggested no environmental benefit of annual P-based application over triennial P-based application with respect to P and N in runoff. Similar concentrations and loads of N fractions in runoff for the P- and N-based applications indicated that shifting to a P-based application would not significantly influence N in runoff.