• Authors:
    • Alakukku, L.
    • Pietola, L.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 108
  • Issue: 2
  • Year: 2005
  • Summary: Roots are an important sink for photoassimilates and carbon input to soil. Here the root growth and biomass of different spring sown annuals was determined to estimate the shoot:root (S:R) ratios and carbon inputs in the typical Nordic agroecosystem. The data, collected in southern Finland, present evidence for large difference in root growth dynamics and biomass input between spring oilseed rape (Brassica rapa L) and annual ryegrass (Lolium multiflorum Lam. var. italicum) whereas the rooting of spring sown barley (Hordeum vulgare) and oats (Avena sativa) was related. The four crops were sown at the same time in a field with a fine sand soil (Eutric Cambisol) with good nutrient and water supply. During one growing season, root growth was determined 12 times to a soil depth of 50 cm by using a minirhizotron-micro-video camera technology. At anthesis, root biomass and morphological parameters were measured to 60 cm soil depth at 5 cm intervals, with destructive soil sampling and image analysis of washed roots. The root growth rate of oilseed rape was clearly faster and that of rye grass slower compared with the other crops. At anthesis, the average total root dry biomass (0-60 cm) was 160 g for barley, 260 g for oats, 340 g for ryegrass, and 110 g m(-3) for oilseed rape. Also, the root length density and surface area of oilseed rape was less than that of other crops. Most of the biomass (59-80%) was accumulated the upper 20 cm of the soil. Shoot to root ratios (at anthesis for the seed crops) of 7.1, 4.4, 4.2 and 2.5 for barley, oats, oilseed rape, and ryegrass respectively, could be used for an approximation to estimate the amount of root biomass left in the 0-60 cm soil layer under Nordic long day conditions. In contrast to the seed crops, the root growth rate and density of ryegrass was high in the late season. Thus, ryegrass would be an efficient catch crop after harvest of cereals. (c) 2005 Elsevier B.V. All rights reserved.
  • Authors:
    • Spiridon, C.
    • Rotarescu, M.
    • Raranciuc, S.
    • Guran, M.
    • Popov, C.
    • Vasilescu, S.
    • Gogu, F.
  • Source: Probleme de Protectia Plantelor
  • Volume: 33
  • Issue: 1/2
  • Year: 2005
  • Summary: The paper presents the harmful organisms which attacked the field crops in 2004. It is emphasized the occurrence and spreading of the most important pathogens and harmful insects in cereals, grain legumes, industrial and fodder crops as well as their role on yield quality and quantity. In Romania, the most important issues of plant protection in 2004, by the economic impact and applied chemical measures were those determined by the following pathogens and harmful insects. The soil and seed pathogens were: Tilletia spp., Fusarium spp. in wheat; Ustilago nuda [ U. segetum var. nuda], Pyrenophora graminea in barley; Pythium spp., Fusarium spp. in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Plasmopara helianthi [ Plasmopara halstedii], Orobanche cumana in sunflower; Fusarium spp., Pythium spp. in pea, beans and soyabean foliar and ear diseases were: Erysiphe spp., Septoria spp., Pyrenophora graminea, Puccinia spp., Fusarium spp. in wheat and barley; Ustilago maydis [ Ustilago zeae], Helminthosporium turcicum [ Setosphaeria turcica], Fusarium spp., Nigrospora oryzae [ Khuskia oryzae] in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Alternaria spp., Phomopsis spp. in sunflower; Erysiphe spp., Septoria spp. in rape. The soil pests were: Zabrus tenebrioides, Agriotes spp. in spiked cereals; Tanymecus dilaticollis, Agriotes spp. in maize and sunflower; Delia platura in beans; Phyllotreta atra in rape and mustard; Aphthona euphorbiae in linseed; Sitona spp., Agriotes spp. in lucerne and clover. The pests which attack aerial part of plants and seeds were: Eurygaster integriceps, Lema melanopa [ Oulema melanopus], Anisoplia spp. in wheat, barley and oats; Ostrinia nubilalis, Diabrotica virgifera virgifera in maize; Thrips linarius in linseed; Athalia rosae, Meligethes aeneus, Brevicoryne brassicae in rape and mustard; Hypera variabilis [ Hypera postica], Semiothisa clathrata [ Chiasmia clathrata], Bruchophagus roddi, Subcoccinella 24- punctata in lucerne and clover. Based on evaluation of the attack potential of these harmful organisms in 2004, the potential for the future manifestation was also estimated.
  • Authors:
    • Prado A., R. del
    • Diaz S., J.
    • Espinoza N., N.
  • Source: XVII Congreso de la Asociación Latinoamericana de Malezas (ALAM) I Congreso Iberoamericano de Ciencia de las Malezas, IV Congreso Nacional de Ciencia de Malezas, Matanzas, Cuba, 8 al 11 de noviembre del 2005, pp. 326
  • Year: 2005
  • Summary: Eight biotypes of herbicide-resistant weeds have been described in Chile. All belong to grass weeds, specifically wild oat ( Avena fatua), ryegrass ( Lolium rigidum), Italian ryegrass ( L. multiflorum) and crested dogtailgrass ( Cynosurus echinatus), which are the most common in the main wheat, barley, oats, lupin and canola producing area (36degreesS to 39degreesS). The biotypes have shown resistance to ACCasa, ALS and EPSP inhibitors. Most biotypes have appeared in farm fields subjected to intensive land use, with annual crops, with a trend to wheat monoculture in some cases, and with intense use of no-till and herbicides with similar mode of action. Herbicides most frequently used have been glyphosate (EPSP), diclofop-methyl and clodinafop-propargyl (ACCasa). Cross-resistance to ACCasa was found in some biotypes of wild oat and ryegrass, with greater resistance to aryloxyphenoxypropionates than to cyclohexanediones. All ACCasaresistant biotypes were susceptible to iodosulfuron and flucarbazone Na (ALS). These two herbicides are recommended for wheat and began to be used just recently in the country. Two biotypes of Italian ryegrass were found resistant to glyphosate. One of these biotypes showed, in addition, resistance to ALS; that is to say, showed multiple resistance. Also the crested dogtailgrass biotype showed multiple resistance to ACCasa and ALS.
  • Authors:
    • McRae, F. J.
    • Brooke, G.
    • Francis, R. J.
    • Dellow, J. J.
  • Source: Weed control in winter crops 2005
  • Year: 2005
  • Summary: This publication provides a guide to chemical weed control during different growth stages of fallow, wheat, barley, oats, rye, triticale, rape, safflower, lentil, linseed, lupin, chickpea, faba bean and field pea in New South Wales, Australia. Recommended timing of herbicide application is given. Sensitivity of winter crop cultivars to herbicides is outlined. Information is also included on crop rotation, use of surfactants and oils, water quality for herbicide application, spray equipment clean-up, herbicide spray drift, compatibility of winter crop herbicides and insecticides, and common retail prices of chemicals used on winter crops.
  • Authors:
    • Australia, Wagga Wagga Agricultural Institute
  • Source: Cultivar X herbicide screening: 2005 results
  • Year: 2005
  • Summary: The results are included on this CD-ROM for herbicide trials involving wheat, barley, oats, triticale, rape, lupin and field pea. Field trials were sprayed with the recommended application rate (1xR) and twice the rate (2xR). The high rate establishes the safety margin of the herbicide and confirms the differences in tolerances between the cultivars used. New varieties and advanced lines from various breeding programmes were tested at the x2 rate of only a subset of herbicides. Grain yield of sprayed versus unsprayed plots is used as a measure of crop tolerance of the herbicide. The results of not just 2005 trials are included but also those from 2002, 2003 and 2004 are also included on the CD-ROM together with photographs from the trials.
  • Authors:
    • NASDA
  • Year: 2004
  • Authors:
    • Harveson, R. M.
    • Burgener, P. A.
    • Blumenthal, J. M.
    • Baltensperger, D. D.
    • Lyon, D. J.
  • Source: Crop Science
  • Volume: 44
  • Issue: 3
  • Year: 2004
  • Summary: ummer fallow is commonly used to stabilize winter wheat (Triticum aestivum L.) production in the Central Great Plains, but summer fallow results in soil degradation, limits farm productivity and profitability, and stores soil water inefficiently. The objectives of this study were to quantify the production and economic consequences of replacing summer fallow with spring-planted crops on the subsequent winter wheat crop. A summer fallow treatment and five spring crop treatments [spring canola (Brassica napus L.), oat (Avena sativa L.) + pea (Pisum sativum L.) for forage, proso millet (Panicum miliaceum L.), dry bean (Phaseolus vulgaris L.), and corn (Zea mays L.)] were no-till seeded into sunflower (Helianthus annuus L.) residue in a randomized complete block design with five replications during 1999, 2000, and 2001. Winter wheat was planted in the fall following the spring crops. Five N fertilizer treatments (0, 22, 45, 67, and 90 kg N ha-1) were randomly assigned to each previous spring crop treatment in a split-plot treatment arrangement. The 3-yr mean wheat grain yield after summer fallow was 29% greater than following oat + pea for forage and 86% greater than following corn. The 3-yr mean annualized net return for the spring crop and subsequent winter wheat crop was $4.20, -$6.91, -$7.55, -$29.66, -$81.17, and -$94.88 ha-1 for oat + pea for forage, proso millet, summer fallow, dry bean, corn, and spring canola, respectively. Systems involving oat + pea for forage and proso millet are economically competitive with systems using summer fallow.
  • Authors:
    • Correa, R.
    • Wilkins, D.
    • Siemens, M.
  • Source: Transactions of the ASAE
  • Volume: 47
  • Issue: 2
  • Year: 2004
  • Summary: Adoption of conservation tillage in the Pacific Northwest lags that of the U.S. in part due to the lack of reliable seeding equipment for planting into the high residue densities encountered in this region. To overcome this problem, a drill attachment was developed to manage heavy residue next to the furrow opening tines of hoe-type no-till drills. The U.S. patented device consists of a fingered rubber wheel, a rubber inner ring, and a spring-loaded arm that pivots about vertical and horizontal axes. The performance of the device was evaluated in terms of stand establishment and yield in Oregon and Washington. Test site locations varied significantly in the amount and condition of crop residue and were planted to a variety of different crops. As compared to the standard no-till drill without the attachment, use of the residue management wheel was found to increase the stand establishment of small seeded crops such as canola and mustard by over 40% and large seeded crops such as wheat and barley by approximately 17%. Increases in stand establishment were attributed to fewer piles of residue covering the seed row. Use of the device also significantly increased crop yield by up to 12% in 8 of the 20 trials conducted (P≤0.10). Although the residue management wheel costs $300 per unit to fabricate, using the device may be economically feasible if it results in significant improvements in both stand establishment and yield.
  • Authors:
    • Arshad, M.
    • Soon, Y.
  • Source: Canadian Journal of Soil Science
  • Volume: 84
  • Issue: 4
  • Year: 2004
  • Summary: A field study was conducted to determine the effects and interactions of crop sequence, tillage and residue management on labile N pools and their availability because such information is sparse. Experimental treatments were no-till (NT) vs. conventional tillage (CT), and removal vs. retention of straw, imposed on a barley ( Hordeum vulgare L.)-canola ( Brassica rapa L.)-field pea ( Pisum sativum L.) rotation. 15N-labelling was used to quantify N uptake from straw, below-ground N (BGN), and fertilizer N. Straw retention increased soil microbial biomass N (MBN) in 2 of 3 yr at the four-leaf growth stage of barley, consistent with observed decreases in extractable soil inorganic N at seeding. However, crop yield and N uptake at maturity were not different between straw treatments. No tillage increased soil MBN, crop yield and N uptake compared to CT, but had no effect on extractable soil inorganic N. The greater availability of N under NT was probably related to soil moisture conservation. Tillage effects on soil and plant N were mostly independent of straw treatment. Straw and tillage treatments did not influence the uptake of N from its various sources. However, barley following pea (legume/non-legume sequence) derived a greater proportion of its N from BGN (13 to 23% or 9 to 23 kg N ha -1) than canola following barley (non-legumes) (6 to 16% or 3 to 9 kg N ha -1). Fertilizer N constituted 8 to 11% of barley N uptake and 23 to 32% of canola N uptake. Straw N contributed only 1 to 3% of plant N uptake. This study showed the dominant influence of tillage on N availability, and of the preceding crop or cropping sequence on N uptake partitioning among available N sources.
  • Authors:
    • Andren, O.
    • Katterer, T.
    • Persson, J.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 70
  • Issue: 2
  • Year: 2004
  • Summary: Land use in general and particularly agricultural practices can significantly influence soil carbon storage. In this paper, we investigate the long-term effects of management changes on soil carbon stock dynamics on a Swedish farm where C concentrations were measured in 1956 at 124 points in a regular grid. The soil was re-sampled at 65 points in 1984 and at all grid points in 2001. Before 1956 most of the fodder for dairy cattle was produced on the farm and crop rotations were dominated by perennial grass leys and spring cereals with manure addition. In 1956 all animals were sold; crop rotations were thereafter dominated by wheat, barley and rapeseed. Spatial variation in topsoil C concentration decreased significantly between 1956 and 2001. C stocks declined in fields with initially large C stocks but did not change significantly in fields with moderate C stocks. In the latter fields, soil C concentrations declined from 1956 to 1984, but increased slightly thereafter according to both measurements and simulations. Thus, the decline in C input due to the altered management in 1956 was partly compensated for by increasing crop yields and management changes, resulting in increased C input during the last 20 years. A soil carbon balance model (ICBM) was used to describe carbon dynamics during 45 years. Yield records were transformed to soil carbon input using allometric functions. Topsoil C concentrations ranging between 1.8 and 2.4% (depending on individual field properties) seemed to be in dynamic equilibrium with C input under recent farming and climatic conditions. Subsoil C concentrations seemed to be unaffected by the management changes.