• Authors:
    • Young, D. L.
    • Schillinger, W. F.
    • Kennedy, A. C.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 120
  • Issue: 2-4
  • Year: 2007
  • Summary: The tillage-based winter wheat (Triticum aestivum L.)-summer fallow (WW-SF) cropping system has dominated dryland farming in the Pacific Northwest USA for 125 years. We conducted a large-scale multidisciplinary 8-year study of annual (i.e., no summer fallow) no-till cropping systems as an alternative to WW-SF. Soft white and hard white classes of winter and spring wheat, spring barley (Hordeum vulgare L.), yellow mustard (Brassica hirta Moench), and safflower (Carthamus tinctorius L.) were grown in various rotation combinations. Annual precipitation was less than the long-term average of 301 mm in 7 out of 8 years. Rhizoctonia bare patch disease caused by the fungus Rhizoctonia solani AG-8 appeared in year 3 and continued through year 8 in all no-till plots. All crops were susceptible to rhizoctonia, but bare patch area in wheat was reduced, and grain yield increased, when wheat was grown in rotation with barley every other year. Remnant downy brome (Bromus tectorum L.) weed seeds remained dormant for 6 years and longer to heavily infest recrop winter wheat. There were few quantifiable changes in soil quality due to crop rotation, but soil organic carbon (SOC) increased in the surface 0-5 cm depth with no-till during the 8 years to approach that found in undisturbed native soil. Annual no-till crop rotations experienced lower average profitability and greater income variability compared to WW-SF. Yellow mustard and safflower were not economically viable. Continuous annual cropping using no-till provides excellent protection against wind erosion and shows potential to increase soil quality, but the practice involves high economic risk compared to WW-SF. This paper provides the first comprehensive multidisciplinary report of long-term alternative annual no-till cropping systems research in the low-precipitation region of the Pacific Northwest.
  • Authors:
    • Babu, K. S.
    • Sharma, R. K.
    • Kumar, K.
    • Sharma, A. K.
  • Source: Crop Protection
  • Volume: 26
  • Issue: 6
  • Year: 2007
  • Summary: A study was conducted to evaluate the influence of tillage systems on the incidence of Tilletia indica (Karnal bunt) in a rice-wheat system that is the most popular and prevalent crop rotation in the Indo-Gangetic Plains of India. A total of 906 samples, were drawn from the farmers' fields during the month of April during the 3 years study period. The samples collected were 365, 171, and 370 from the zero tillage (ZT), furrow irrigated raise bed system (FIRBS), and conventional till (CT) sown fields, respectively. The disease incidence, incidence index and percent-infected samples were calculated and statistically analyzed. Results showed that ZT fields had the lowest mean incidence of Karnal bunt, i.e. 9.00% infected samples in comparison to 18.10% and 16.20% under FIRBS and CT, respectively. Similarly, the average infection in infected samples was equal in FIRBS and CT, but the samples from ZT were statistically lower. KB incidence index showed a similar trend. ZT has shown a reduced incidence of KB in comparison to the raised bed (FIRBS) and CT systems. If ZT is followed for a period of a few years, it may help in reducing the effective soil inoculum and reducing the disease incidence over time.
  • Authors:
    • Shah, Z.
    • Stromberger, M.
    • Westfall, D.
  • Source: Applied Soil Ecology
  • Volume: 35
  • Issue: 1
  • Year: 2007
  • Summary: In degraded agricultural soils, organic C levels can be increased and conserved by adopting alternative management strategies such as no-tillage and increased cropping intensity. However, soil microbial community responses to increased soil organic C (SOC) may be constrained due to water limitations in semi-arid dryland agroecosystems. The purpose of this study was to assess SOC, microbial biomass C (MBC) and community ester-linked fatty acid methyl ester (EL-FAME) composition under winter wheat ( Triticum aestivum L.) in no-till systems of wheat-corn ( Zea mays L.)-fallow (WCF), wheat-wheat-corn-millet ( Panicum miliaceum L.) (WWCM), wheat-corn-millet (WCM), opportunity cropping (OPP), and perennial grass across a potential evapotranspiration gradient in eastern Colorado. Rotations of WWCM and OPP, in which crops are chosen based on available soil water at the time of planting rather than according to a predetermined rotation schedule, increased levels of SOC to those measured under perennial grass. However, MBC under OPP cropping accounted for the smallest fraction (2.0-3.6%) of SOC compared to other systems, in which MBC ranged from 2.4 to 6.3% of SOC. Microbial community structure was most divergent between OPP-cropped and perennial grass soils, whereas few differences were observed among microbial communities of the WCF, WCM, and WWCM rotations. Compared to perennial grass and other cropping systems, microbial biomass in OPP-cropped soil was low and contained less of the arbuscular mycorrhizal fungal biomarker 16:1omega5 c. Microbial stress, as indicated by the ratio of 17:0 cy to 16:1omega7 c, was greatest under OPP and WCF cropping. In contrast, soils under perennial grass contained lower ratios of bacterial:fungal EL-FAMEs and higher levels of MBC, ratios of MBC:SOC, and relative abundances of 16:1omega5 c. Across locations, SOC and moisture content increased as soil texture became finer, whereas trends in MBC and community structure followed the potential evapotranspiration gradient. Soil from the high potential evapotranspiration site contained the lowest level of MBC but greater relative amounts of 16:1omega5 c and lower ratios of stress indicator and bacterial:fungal EL-FAMEs compared to soil located at the moderate and low potential evapotranspiration sites. Indistinct microbial communities under WCF, WCM, and WWCM could be explained by EL-FAME limitations to detecting slight differences in microbial community structure or to the overwhelming response of microbial communities to environmental rather than management conditions. Further research is needed to assess potential legacy effects of long-term agricultural management that may mask microbial responses to recent management change, as well as to identify conditions that lead to high microbial community resiliency in response to management so that communities are similar under a given crop despite different preceding crops.
  • Authors:
    • Qin, Y.
    • Li Fengmin
    • Li, Y.
    • Xiang, S.
    • Cao, X.
    • Wu, T.
  • Source: Dryland crop production: technology breakthroughs and study cases
  • Year: 2007
  • Summary: Fertilization according to soil hydraulic conditions, fertilization in balance of nutrition and fertilization with nutrient use efficiency and sustainability are reestablished as the principles of fertility management in dryland area on the Loess Plateau according to the natural conditions and soil properties. Corresponding techniques to the principles are reviewed and represented in the paper.
  • Authors:
    • Becher, R.
  • Source: Plant Breeding
  • Volume: 126
  • Issue: 3
  • Year: 2007
  • Summary: Polymerase chain reaction-based microsatellite markers are valuable tools for molecular breeding because of their co-dominant inheritance and their applicability for high-throughput analysis. Being still very limited for oats, their number has to be increased significantly to cover the entire genome. For these purposes, a set of 7031 recently published expressed sequence tags (ESTs) was screened for microsatellites with dinucleotide, trinucleotide and tetranucleotide repeat motifs. Subsequent in silico analysis resulted in the development of 216 primer pairs for Avena EST-derived microsatellite loci ( AME). Using a sample set of 12 oat lines, 107 of 195 functional primers could be assayed as polymorphic. The marker variability averaged out at three alleles per locus and a polymorphic information content (PIC) value of 0.42. This variability documents their suitability for molecular oat-breeding purposes. Finally, 51 of the AME loci could be placed within the known reference map of 'Kanota' * 'Ogle' that previously contained only 12 microsatellite loci. Thus, a remarkable enhancing of the number of mapped oat microsatellite loci could be achieved.
  • Authors:
    • Weiss, M. J.
    • Pike, K. S.
    • Buntin, G. D.
    • Webster, J. A.
  • Source: Handbook of small grain insects
  • Year: 2007
  • Summary: This handbook is designed primarily for the practitioners of integrated pest management programmes in small grains, growers, crop consultants, extension agents, and company agronomists and sales representatives. Its primary objective is to provide fundamental and useful information about managing (through cultural, plant resistance, biological and chemical methods) small grain insects throughout the United States and Canada. Although it focuses on insect pests of small grains, noninsect pests (e.g. mites) also are covered. Crops covered in this handbook are wheat, barley, oats, rye and triticale, with an emphasis on wheat. The first three sections provide information about small grains and their production, principles and practices of small grain insect management, and an overview of the pest injury to small grains by insects, weeds, and plant pathogens. The remainder of the handbook is devoted to discussions of insect and mite pests of small grains and to beneficial organisms, including insect pathogens, parasitoids and predators.
  • Authors:
    • Simon, M.
    • Monaco, C.
    • Cordo, C.
  • Source: Australasian Plant Pathology
  • Volume: 36
  • Issue: 3
  • Year: 2007
  • Summary: Two Septoria Monitoring Nursery sets were tested for resistance in the field during three consecutive years. Different concentrations of oat grains covered with mycelia of Septoria tritici were applied as inoculum. The position of the disease on the plants and the severity of the Septoria leaf blotch infection were recorded at two growth stages. A comparison between leaf pulverisation and grain application as a source of conidia was made in the last year. The percentages of necrotic lesions and pycnidial coverage were recorded on the upper three leaves of the plants at the same growth stages as for previous years. With grain inoculation, the infection reached the 7th leaf of the plants with the maximum concentration applied at tillering stage. The best concentration to obtain the highest discrimination among resistances is 120 g/m 2. In the comparison of inoculation techniques, the results showed a higher necrosis and pycnidial coverage following leaf pulverisation than with the grain application treatment.
  • Authors:
    • Puzynski, S.
    • Wrzesinska, E.
    • Dzienia, S.
  • Source: Folia Universitatis Agriculturae Stetinensis
  • Volume: 255
  • Issue: 2
  • Year: 2007
  • Summary: Drawski Landscape Park is located in the centre of Drawskie Lake District in the Zachodniopomorskie Voivodship, Poland. The park covers 41 430 ha with 10.5% of lakes belonging to the following communes: Barwice, Borne Sulinowo, Czaplinek, Ostrowice, Poczyn Zdroj and Zocieniec. The condition for agricultural production in these communes are mostly medium-favourable. Soils have predominately medium as well as poor and very poor properties. The land use in administrative boundaries of the communes is varied, the lowest share of agricultural area at 19.6% is in Borne Sulinowo commune whereas the highest at 50.2% is in Barwice. In agricultural land use structure, the share of arable land among communes ranged from 82.4% in Borne Sulinowo to 88.3% in Czaplinek, and grasslands from 11.6% in Czaplinek, to 17.5% in Borne Sulinowo. Relatively high share of afforestated areas (30.0-57.3%), as well as low population density (17-81 persons per km 2), favours development of tourism in these communes. Small farms (with less than 5 ha of agricultural land) are dominant and they operate on poor soils which causes problems. Areas sown with cereals have been recorded at 76.7-89.3%, potatoes at 1.6 to 6.8%, industrial crops at 2.8 to 12.1% and fodder crops at 0.4 to 8.7%. The major crops among cereals are rye- 24.1 to 49.2% and wheat- 17.7 to 35.2%. The biggest share (26.4%) of oat among cereals is in Barwice commune. The share of potato is in the range of 1.6-6.8%, whereas oilseed rape and agrimony is planted on 2.8 to 12.1% of sown area. The number of livestock unit per 100 ha of agricultural area is very low (12.0-29.0 LU), which do not provide the required amount of manure.
  • Authors:
    • Iwaniak, A.
    • Dziuba, J.
    • Dziuba, M.
  • Source: Polish Journal of Food and Nutrition Sciences
  • Volume: 57
  • Issue: 4
  • Year: 2007
  • Summary: A structural analysis was conducted of peptides responsible for inducing celiac disease, as well as of the structural fragments they are located in, i.e. the so-called "extended structural motifs". These motifs originated from wheat A-gliadin and constituted a standard for the analysis of the other proteins. Experiments were carried out based on in silico methods. Analyses covered a total of 403 sequences of selected cereal and seed proteins. Of all the analysed sequences, 155 were found to contain tetrapeptides (potentially known as toxic for celiac disease), namely: QQQP, QQPY, PSQQ, QPYP, including 29 proteins in which the tetrapeptides were constituents of a structural motif with a longer sequence. These were proteins of wheat, barley and oat. All the extended motifs occurred in a hydrophilic surrounding, attaining the structure of beta-turn and random coil. Computer-aided design of the proteolysis process of selected proteins was carried out as well in the aspect of celiac-toxic peptide release. Active fragments were released from twenty-eight proteins by thermolysin, K proteinase and prolyl oligopeptidase.
  • Authors:
    • Carvalho, P. C. de F.
    • Cassol, L. C.
    • Anghinoni, I.
    • Flores, J. P. C.
    • Leite, J. G. dal B.
    • Fraga, T. I.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 31
  • Issue: 4
  • Year: 2007
  • Summary: The integration of farming and cattle production activities in no-tillage system areas with winter cover crops can be an income supplement for summer grain farmers. However, many of them are afraid of adopting this integration system because of possible negative effects of animal treading on soil attributes, mainly of those related to soil compaction. This study was conducted: (1) to determine the alterations in the soil physical attributes promoted by animal treading; and (2) to verify if the alterations in soil attributes due to animal treading affect soyabean establishment and grain yield. The experiment was carried out with a Rhodic Hapludox (Oxisol), under black oat [ Avena nuda] + ryegrass [ Lolium] pasture grazed at different heights (10, 20, 30 and 40 cm) and an ungrazed area. After one cycle of animal treading, there were no significant modifications in soil bulk density, porosity and compressibility at different grazing heights. However, soil density and compressibility were higher and the porosity lower in the grazed plots. The soyabean population and grain yield were not affected by modifications in the soil physical attributes.