Yantai Gan

Dalhousie University, Halifax, Nova Scotia, Canada

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Publications (30)52.45 Total impact

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    ABSTRACT: The influence of land use on soil bio-resources is largely unknown. We examined the communities of arbuscular mycorrhizal (AM) fungi in wheat-growing cropland, natural areas and semi-natural roadsides. We sampled the Canadian Prairie extensively (317 sites), and sampled 20 sites in the Atlantic maritime ecozone for comparison. The proportion of the different AM fungal tasa in the communities found at these sites varied with land use type and ecozones, based on pyrosequencing of 18S rDNA amplicons, but the lists of AM fungal taxa obtained from the different land use types and ecozones were very similar. In the Prairie, Glomeraceae was the most abundant and diverse family of Glomeromycota, followed by Claroideoglomeraceae, but in the Atlantic maritime Claroideoglomeraceae was most abundant. In the Prairie, species richness and Shannon's diversity were highest in roadsides, whereas cropland had a higher degree of species richness than roadsides in the Atlantic maritime. The frequency of occurrence of the different AM fungal taxa in croplands in the Prairie and Atlantic maritime ecozones was highly correlated, but the AM fungal communities in these ecozones had different structures. We conclude that the AM fungal resources of soils are resilient to disturbance and that the richness of AM fungi under cropland management has been maintained, despite evidence of a structural shift imposed by this type of land use. Roadsides in the Canadian Prairie are a good repository for the conservation of AM fungal diversity.
    Applied and environmental microbiology 08/2013; · 3.69 Impact Factor
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    ABSTRACT: Accumulating evidence supports the feasibility of creating biotic soil environments that promote root health using selected plant genotypes. Five years of field experimentation conducted in the semiarid grasslands of North America revealed genotypic variation in the influence of chickpea on the composition of the soil microbial community and on the establishment of the subsequent crop. A 2-year experiment documented the effects of four chickpea cultivars on the arable soil microbiome using cultural methods, the cloning and sequencing of soil-extracted DNA, and fatty acid methyl ester profiling. Cultivar CDC Frontier was characterized by low bacterial biomass, whereas Amit and CDC Anna selected similarly structured bacterial communities but contrasting soil fungal communities. Amit and CDC Anna became colonized by arbuscular mycorrhizal (AM) fungi to the same extent, but the arable soil planted with CDC Anna hosted the highest level of culturable fungal diversity, whereas the soil planted with Amit hosted the lowest. The highest diversity of culturable fungi and the richness of AM fungal ribotypes (11) were also associated with CDC Anna. Amit was preferentially associated with the antagonist species Penicillium canescens. Higher durum wheat stand density was found after CDC Anna than after Amit, indicating that microbial diversity is an important feature of productive soils. The influence of chickpea genotype on the arable soil microbiome and on the establishment of the subsequent durum wheat crop was related to the soil water reserve at depths of 30–120 cm and was eliminated when the chickpea crops experienced drought. Genetic variation in the influence of chickpea on the soil microbiome suggests the possibility of selecting genotypes to engineer beneficial soil biotic environments. Inadequate levels of soil water could limit the success of this strategy, however, in rainfed cropping systems of the semiarid grasslands of North America.
    Soil Biology and Biochemistry 01/2013; 63:129-141. · 3.65 Impact Factor
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    ABSTRACT: Field crops influence the biotic properties of the soil, impacting the health and productivity of subsequent crops. Polymerase chain reaction and 454 GS FLX pyrosequencing of amplicons were used to clarify the legacy of chickpea and pea crops on the quality of the bacterial community colonizing the root endosphere of subsequent crops of wheat, in a replicated field study. Similar communities of root endosphere bacteria were formed in durum wheat grown after pea and chickpea crops when chickpea crops were terminated as early as pea (July). Termination of the chickpea crops in September led to the domination of Firmicutes in wheat root endosphere; Actinobacteria dominated the wheat root endosphere following early pulse crop termination. The architecture of wheat plants was correlated with the composition of its root endosphere community. High grain yield was associated with the production of fewer but larger wheat heads, the abundance of endospheric Actinobacteria and Acidobacteria, and the scarcity of endospheric Firmicutes. Pulse termination time affected wheat root endosphere colonization strongly in 2009 but weakly in 2010, an abnormally wet year. This study improved our understanding of the so-called "crop rotation effect" in pulse-wheat systems and showed how this system can be manipulated through agronomic decisions.
    Canadian Journal of Microbiology 12/2012; 58(12):1368-77. · 1.20 Impact Factor
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    ABSTRACT: Fusarium diseases cause major economic losses in wheat-based crop rotations. Volatile organic compounds (VOC) in wheat and rotation crops, such as chickpea, may negatively impact pathogenic Fusarium. Using the headspace GC-MS method, 16 VOC were found in greenhouse-grown wheat leaves: dimethylamine, 2-methyl-1-propanol, octanoic acid-ethyl ester, acetic acid, 2-ethyl-1-hexanol, nonanoic acid-ethyl ester, nonanol, N-ethyl-benzenamine, naphthalene, butylated hydroxytoluene, dimethoxy methane, phenol, 3-methyl-phenol, 3,4-dimethoxy-phenol, 2,4-bis (1,1-dimethyethyl)-phenol, and 1,4,7,10,13,16-hexaoxacyclooctadecane; and 10 VOC in field-grown chickpea leaves: ethanol, 1-penten-3-ol, 1-hexanol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, trans-2-hexenal, 3-methyl-1-butanol, 3-hydroxy-2-butanone, 3-methyl-benzaldehyde and naphthalene. Also found was 1-penten-3-ol in chickpea roots and in the root nodules of two of the three cultivars tested. Chickpea VOC production pattern was related (P=0.023) to Ascochyta blight severity, suggesting that 1-penten-3-ol and cis-3-hexen-1-ol were induced by Ascochyta rabiei. Bioassays conducted in Petri plates established that chickpea-produced VOC used in isolation were generally more potent against Fusarium graminearum and Fusarium avenaceum than wheat-produced VOC, except for 2-ethyl-1-hexanol, which was rare in wheat and toxic to both Fusarium and tetraploid wheat. Whereas exposure to 1-penten-3-ol and 2-methyl-1-propanol could suppress radial growth by over 50% and octanoic acid-ethyl ester, nonanol, and nonanoic acid-ethyl ester had only weak effects, F. graminearum and F. avenaceum growth was completely inhibited by exposure to trans-2-hexenal, trans-2-hexen-1-ol, cis-3-hexen-1-ol, and 1-hexanol. Among these VOC, trans-2-hexenal and 1-hexanol protected wheat seedlings against F. avenaceum and F. graminearum, respectively, in a controlled condition experiment. Genetic variation in the production of 2-ethyl-1-hexanol, a potent VOC produced in low amount by wheat, suggests the possibility of selecting Fusarium resistance in wheat on the basis of leaf VOC concentration. Results also suggests that the level of Fusarium inoculum in chickpea-wheat rotation systems may be reduced by growing chickpea genotypes with high root and shoot levels of trans-2-hexen-1-ol and 1-hexanol.
    Phytochemistry 04/2012; 78:72-80. · 3.05 Impact Factor
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    ABSTRACT: Plants trigger various responses in the organisms living around them using a wide array of phytochemicals, which are components of their adaptation to a biological environment. The roots of five varieties of chickpea inoculated with Glomus intraradices were extracted, and extracts were fractionated, first based on solubility in methanol and further by HPLC. We found a relationship between chickpea genotype and root phytochemical composition. Several HPLC fractions repressed the germination of AM fungal spores in bioassays conducted in multi-well plates with extracts from the variety CDC Anna. This repression may be an expression of the control of the plant on the AM fungal symbionts. Glomus etunicatum and Gigaspora rosea spore germination responded differently to exposure to the HPLC fractions soluble in 25% methanol. A differential response of AM fungal species to plant phytochemicals could be involved in the so called “host preference” of AM fungi. Whereas extensin and other proteins were identified in a bioactive root extract fraction, other proteins undetected by LC–MS/MS analysis and non-peptidic compounds may be involved in AMF spore germination suppression.
    Applied Soil Ecology 01/2012; 60:98-104. · 2.11 Impact Factor
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    Canadian Journal of Microbiology 01/2012; 68. · 1.20 Impact Factor
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    ABSTRACT: Plants trigger various responses in the organisms living around them using a wide array of phytochemicals, which are components of their adaptation to a biological environment. The roots of five varieties of chickpea inoculated with Glomus intraradices were extracted, and extracts were fractionated, first based on solubility in methanol and further by HPLC. We found a relationship between chickpea genotype and root phytochemical composition. Several HPLC fractions repressed the germination of AM fungal spores in bioassays conducted in multi-well plates with extracts from the variety CDC Anna. This repression may be an expression of the control of the plant on the AM fungal symbionts. Glomus etunicatum and Gigaspora rosea spore germination responded differently to exposure to the HPLC fractions soluble in 25% methanol. A differential response of AM fungal species to plant phytochemicals could be involved in the so called “host preference” of AM fungi. Whereas extensin and other proteins were identified in a bioactive root extract fraction, other proteins undetected by LC–MS/MS analysis and non-peptidic compounds may be involved in AMF spore germination suppression.
    Applied Soil Ecology 01/2012; 60:98-104. · 2.11 Impact Factor
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    ABSTRACT: Root distribution patterns in the soil profile are the important determinant of the ability of a crop to acquire water and nutrients for growth. This study was to determine the root distribution patterns of selected oilseeds and pulses that are widely adapted in semiarid northern Great Plains. We hypothesized that root distribution patterns differed between oilseed, pulse, and cereal crops, and that the magnitude of the difference was influenced by water availability. A field experiment was conducted in 2006 and 2007 near Swift Current (50°15′N, 107°44′W), Saskatchewan, Canada. Three oilseeds [canola (Brassica napus L.), flax (Linum usitatissimum L.), mustard (Brassica juncea L.)], three pulses [chickpea (Cicer arietinum L.), field pea (Pisum sativum L.), lentil (Lens culinaris)], and spring wheat (Triticum aestivum L.) were hand-planted in lysimeters of 15cm in diameter and 100cm in length which were pushed into soil with a hydraulic system. Crops were evaluated under low- (natural rainfall) and high- (rainfall+irrigation) water conditions. Vertical distribution of root systems was determined at the late-flowering stage. A large portion (>90%) of crop roots was mainly distributed in the 0–60cm soil profile and the largest amount of crop rooting took place in the top 20cm soil increment. Pulses had larger diameter roots across the entire soil profile than oilseeds and wheat. Canola had 28% greater root length and 110% more root tips in the top 10cm soil and 101% larger root surface area in the 40cm soil under high-water than under low-water conditions. In 2007, drier weather stimulated greater root growth for oilseeds in the 20–40cm soil and for wheat in the 0–20cm soil, but reduced root growth of pulses in the 0–50cm soil profile. In semiarid environments, water availability did not affect the vertical distribution patterns of crop roots with a few exceptions. Pulses are excellent “digging” crops with a strong “tillage” function to the soil due to their larger diameter roots, whereas canola is more suitable to the environment with high availability of soil water that promotes canola root development.
    Fuel and Energy Abstracts 01/2011; 122(3):248-255.
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    ABSTRACT: Oilseed and pulse crops have been increasingly used to diversify cereal-based cropping systems in semiarid environments, but little is known about the root characteristics of these broadleaf crops. This study was to characterize the temporal growth patterns of the roots of selected oilseed and pulse crops, and determine the response of root growth patterns to water availability in semiarid environments. Canola (Brassica napus L.), flax (Linum usitatissimum L.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), field pea (Pisum sativum L.), lentil (Lens culinaris), and spring wheat (Triticum aestivum L.) were tested under high- (rainfall + irrigation) and low- (rainfall only) water availability conditions in southwest Saskatchewan, in 2006 and 2007. Crops were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length that were installed in the field prior to seeding. Roots were sampled at the crop stages of seedling, early-flower, late-flower, late-pod, and physiological maturity. On average, root length density, surface area, diameter, and the number of tips at the seedling stage were, respectively, 41, 25, 14, and 110% greater in the drier 2007 than the corresponding values in 2006. Root growth in all crops progressed rapidly from seedling, reached a maximum at late-flower or late-pod stages, and then declined to maturity; this pattern was consistent under both high- and low-water conditions. At the late-flower stage, root growth was most sensitive to water availability, and the magnitude of the response differed between crop species. Increased water availability increased canola root length density by 70%, root surface area by 67%, and root tips by 79% compared with canola grown under low-water conditions. Water availability had a marginal influence on the root growth of flax and mustard, and had no effect on pulse crops. Wheat and two Brassica oilseeds had greater root length density, surface area and root tips throughout the entire growth period than flax and three pulses, while pulse crops had thicker roots with larger diameters than the other species. Sampling roots at the late-flower stage will allow researchers to capture best information on root morphology in oilseed and pulse crops. The different root morphological characteristics of oilseeds, pulses, and wheat may serve as a science basis upon which diversified cropping systems are developed for semiarid environments.Highlights► Root growth progressed aggressively from seedling to the late-flower and then declined to maturity; this trend was consistent for all oilseeds and pulses tested. ► Responses of root growth patterns to water availability varied substantially among crop species; canola was the most sensitive to water availability. ► Differences in root morphology were small among three pulse crops, but field pea typically had greater number of root tips than lentil and chickpea. ► Canola and mustard had similar root length and surface areas as spring wheat, and they were all greater than pulses and flax.
    Field Crops Research 01/2011; 122(3):256-263. · 2.47 Impact Factor
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    ABSTRACT: Improving cropping systems may help mitigate greenhouse gas emissions. This study determined the carbon footprint of durum wheat (Triticum turgidum L.) produced in diverse cropping systems. Durum was grown in rotation systems which had different combinations of oilseed, pulse, and cereal crops at five site-years in Saskatchewan, Canada. Total greenhouse gas emissions from the decomposition of crop residues along with various production inputs were used for the estimation of carbon footprint. On average, emissions from the decomposition of crop straw and roots accounted for 25% of the total emissions, those from the production, transportation, storage, and delivery of fertilizers and pesticides to farm gates and their applications 43%, and emissions from farming operations 32%. Durum wheat preceded by an oilseed crop (Brassica napus or Brassica juncea) the previous year had carbon footprint of 0.33 kg CO2e kg−1 of grain, or 7% lower than durum in cereal–cereal–durum system. Durum preceded by a biological N-fixing crop (Cicer arietinum chickpea, Lens culinaris lentil, or Pisum sativum pea) the previous year lowered its carbon footprint by 17% compared with durum preceded by a cereal crop. Durum produced in a pulse–pulse–durum system had carbon footprint 0.27 kg CO2e kg−1 of grain, 34% lower than durum grown in cereal–cereal–durum systems. Diversifying cropping systems with oilseeds and biological N-fixers significantly lowered carbon footprint of durum wheat.Highlights► Strategies are needed to reduce the carbon footprint of grain products in agriculture. ► Diversifying cropping systems with oilseeds, cereals, and biological N-fixing crops significantly lowered carbon footprint of durum wheat compared with cereal-based monoculture systems. ► Durum wheat preceded by an oilseed crop (Brassica napus or Brassica juncea) the previous year had carbon footprint of 0.30 kg CO2e kg−1 of grain, or 18% lower than durum in cereal-cereal-durum system. ► Durum preceded by a biological N-fixing crop (Cicer arietinum chickpea, Lens culinaris lentil, or Pisum sativum pea) the previous year lowered its carbon footprint by 28% compared with durum preceded by a cereal crop. ► Durum produced in a pulse-based system had carbon footprint 0.24 kg CO2e kg−1 of grain, 34% lower than durum produced in cereal-cereal-durum systems.
    Field Crops Research 01/2011; 122(3):199-206. · 2.47 Impact Factor
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    ABSTRACT: The Earth’s climate is rapidly changing largely due to increasing anthropogenic greenhouse gas (GHG) emissions. Agricultural practices during crop production, food processing, and product marketing all generate GHG, contributing to the global climate change. The general public and farmers are urging the development and adoption of effective measures to reduce GHG emissions from all agricultural activities and sectors. However, quantitative information is not available in regard to what strategies and practices should be adopted to reduce emission from agriculture and how crop productivity would affect the intensity of GHG emission. To provide the potential solution, we estimated the carbon footprint [i.e., the total amount of GHG associated with the production and distribution of a given food product expressed in carbon dioxide equivalence (CO2e)] for some of the major field crops grown on the Canadian prairie and assessed the effect of crop sequences on the carbon footprint of durum wheat. Key strategies for reducing the carbon footprint of various field crops grown in semiarid areas were identified. Carbon footprints were estimated using emissions from (1) the decomposition of crop straw and roots; (2) the manufacture of N and P fertilizers and their rates of application; (3) the production of herbicides and fungicides; and (4) miscellaneous farm field operations. Production and application of N fertilizers accounted for 57% to 65% of the total footprint, those from crop residue decomposition 16% to 30%, and the remaining portion of the footprint included CO2e from the production of P fertilizer and pesticides, and from miscellaneous field operations. Crops grown in the Brown soil zone had the lowest carbon footprint, averaging 0.46kg CO2e kg−1 of grain, whereas crops grown in the Black soil zone had a larger average carbon footprint of 0.83kg CO2e kg−1 of grain. The average carbon footprint for crops grown in the Dark Brown soil zone was intermediate to the other two at 0.61kg CO2e kg−1 of grain. One kilogram of grain product emitted 0.80kg CO2e for canola (Brassica napus L.), 0.59 for mustard (Brassica juncea L.) and flaxseed (Linum usitatissimum L.), 0.46 for spring wheat (Triticum aestivum L.), and 0.20 to 0.33kg CO2e for chickpea (Cicer arietinum L.), dry pea (Pisum sativum L.), and lentil (Lens culinaris Medik.). Durum wheat (T. aestivum L.) preceded by an N-fixing crop (i.e., pulses) emitted total greenhouse gases of 673kg CO2e, 20% lower than when the crop was preceded by a cereal crop. Similarly, durum wheat preceded by an oilseed emitted 744kg CO2e, 11% lower than when preceded by a cereal. The carbon footprint for durum grown after a pulse was 0.25kg CO2e per kg of the grain and 0.28kg CO2e per kg of the grain when grown after an oilseed: a reduction in the carbon footprint of 24% to 32% than when grown after a cereal. The average carbon footprint can be lowered by as much as 24% for crops grown in the Black, 28% in the Dark Brown, and 37% in the Brown soil zones, through improved agronomic practices, increased N use efficiency, use of diversified cropping systems, adoption of crop cultivars with high harvest index, and the use of soil bioresources such as P-solublizers and arbuscular mycorrhizal fungi in crop production. KeywordsCarbon footprint–Legumes–Oilseeds–Broadleaf crops–Biochar–Crop diversification–Carbon sequestration–Straw management–Input–N-fixation
    Agronomy for Sustainable Development 01/2011; 31(4):643-656. · 3.57 Impact Factor
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    ABSTRACT: Fungicides have been used widely in order to control fungal diseases and increase crop production. However, the effects of fungicides on microorganisms other than fungi remain unclear. The modes of action of fungicides were never well classified and presented, making difficult to estimate their possible nontarget effects. In this paper, the action modes and effects of fungicides targeting cell membrane components, protein synthesis, signal transduction, respiration, cell mitosis, and nucleic acid synthesis were classified, and their effects on nontarget microorganisms were reviewed. Modes of action and potential non-target effects on soil microorganisms should be considered in the selection of fungicide in order to protect the biological functions of soil and optimize the benefits derived from fungicide use in agricultural systems.
    ISRN Ecology. 01/2011; 2011.
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    ABSTRACT: Fusarium redolens [syn: F. oxysporum var. redolens] is pathogenic on a wide range of plant species. Fusarium redolens was frequently isolated from necrotic and discolored root and crown tissues of chickpea, pea, lentil, and durum wheat in Saskatchewan. The fungus was identified using distance analysis of the translation elongation factor-1 alpha sequences. Comparative pathogenicity tests showed that F. redolens, like Fusarium graminearum and Cochliobolus sativus, caused lesions and/or discolorations on the root, crown and shoot of durum wheat, pea and chickpea, although it had a different host preference. While F. redolens was most virulent on pea, the other two fungi were more virulent on durum wheat. It appears that F. redolens is common in the Prairie Ecozone of Saskatchewan and it may cause yield reduction in pea, chickpea and durum crops. This warrants a closer look at the biology and ecology of F. redolens in the Canadian Prairies.
    Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie - CAN J PLANT PATHOL. 01/2011;
  • Crop Science - CROP SCI. 01/2010; 50(1).
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    ABSTRACT: Glyphosate-resistant (GR) crops are produced over large areas in North America. A study was conducted at six western Canada research sites to determine seed date and tillage system effects on weed populations in GR spring wheat and canola cropping systems from 2000 to 2003. Four-year wheat–canola–wheat–pea rotations were devised with varying levels of GR crops in the rotation. Weed populations were determined at pre– and post–in-crop herbicide application intervals in 2000 and 2003. Early seeding led to higher and more variable in-crop wild oat and wild buckwheat populations. High frequencies of in-crop glyphosate wheat in the rotation usually improved weed management and reduced weed density and variability. Canonical discriminant analysis (CDA) across all locations revealed that by 2003, green foxtail, redroot pigweed, sowthistle spp., wild buckwheat, and wild oat, all associated with the rotation lacking in-crop glyphosate. Similar CDA analyses for individual locations indicated specific weeds were associated with 3 yr of in-crop glyphosate (Canada thistle at Brandon, henbit at Lacombe, and volunteer wheat, volunteer canola, and round-leaved mallow at Lethbridge). However, only henbit at Lacombe and volunteer wheat at Lethbridge occurred at significant densities. Although excellent weed control was attained in rotations containing a high frequency of GR crops, the merits of more integrated approaches to weed management and crop production should also be considered. Overall, rotations including GR spring wheat did not significantly increase short-term weed management risks in conventional tillage or low soil-disturbance direct-seeding systems. Nomenclature: Glyphosate; annual sowthistle, Sonchus oleraceus L. SONOL; Canada thistle, Cirsium arvense (L.) Scop. CIRAR; green foxtail, Setaria viridis (L.) Beauv. SETVI; henbit, Lamium amplexicaule L. LAMAM; perennial sowthistle, Sonchus arvensis L. SONAR; redroot pigweed, Amaranthus retroflexus L. AMARE; round-leaved mallow, Malva pusilla Sm.; spiny sowthistle, Sonchus asper (L.) Hill SONAS; wild buckwheat, Polygonum convolvulous L. POLCO; wild oat, Avena fatua L. AVEFA; canola, Brassica napus L.; pea, Pisum sativum L.; wheat, Triticum aestivum L.
    Weed Science 09/2009; · 1.76 Impact Factor
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    Weed Technology 09/2009; · 1.11 Impact Factor
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    ABSTRACT: In areas where two crops are grown per year or three crops every 2 years, the status of residual soil nutrients after the harvest of the first crop is critical to the crop to be grown immediately after, while the postharvest soil nutrient status can be influenced by irrigation applied to the test crop. This study determined the effect of various soil water treatments applied to the test crop on the status of postharvest residual soil nutrient pools in an arid environment. Spring wheat (Triticum aestivum L.) was grown as test crop under conditions of full- (as control), high-, moderate-, and low-water conditions during jointing, booting-heading, and grain filling stages, in 2003 and 2004. Compared to the control, grain yield and water use efficiency (WUE) were significantly increased by subjecting the wheat crop to moderate-water conditions during various growth stages, and low-water conditions at jointing stage in both years. Soil C at harvest decreased linearly with increased grain yield of the test crop. Moderate- to high-water conditions during jointing stage resulted in 12-24% greater soil C in the top 40cm depth in 2003, with a marginal difference in 2004. Water treatments impacted the status of residual soil nutrients in 2003; soil total N and available soil P in the top 40cm depth were significantly higher in low- to moderate-water treatments compared to the control, while in 2004 significantly higher total N and P, available N, P and K were found only in the top 20cm depth. Increased yield of wheat test crop with moderate-water resulted in increased postharvest residual soil nutrients, whereas the ratios of C/N, C/P, and C/K were largely influenced by years and were less related to water treatments. We conclude that the determination of postharvest soil C and nutrient elements may provide useful information in monitoring potential changes of soil nutrient status over time in the intensified cropping systems, and that the recommendation of fertilization for the crop to be grown immediately following the first crop can be established by simply analyzing the productivity of the first crop without intensive measurements of soil nutrients.
    Agricultural Water Management 01/2009; 96(6):1045-1051. · 2.20 Impact Factor
  • Agronomy Journal - AGRON J. 01/2008; 100(2).
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    ABSTRACT: Brassica juncea var. juncea canola is a new oilseed species that is developed from B. juncea (L.) Czern. mustard with its oil and meal quality equivalent to conventional canola species. Understanding of the phenological characteristics and yield responses to diverse envi- ronments will allow the crop to be better adapted to target production areas. This study determined the responses of the juncea canola to various soil-climatic conditions and was compared with B. napus L. canola, B. rapa L. canola, juncea mustard, and Sinapis alba L. mus- tard. The five oilseed species/cultivars were grown under various N fertilizer rates (0, 25, 50, 100, 150, 200, and 250 kg N ha21), at four Saskatchewan locations from 2003 to 2005. On average, flowering began 40 d after seeding (DAS) for alba mustard and rapa canola (earliest), 49 DAS for napus canola (latest), and 44 DAS for juncea canola (intermediate). Flowering duration was longest for juncea canola (30 d) and shortest for napus canola (22 d). The napus canola and juncea mustard produced higher (1684 kg ha21) seed yields than the three other oilseeds (1303 kg ha21 on average). For all oilseed species, the seed yield was highly responsive to N fertilizer rates from zero to about 100 kg N ha21, and thereafter, the rate of yield responses declined. The amount of N fertilizer required to achieve the maximum seed yield was 106 kg N ha21 for rapa canola, 135 kg N ha21 for alba mustard and napus canola, and 162 kg N ha21 for the two juncea spp. Overall, juncea canola had lower seed yield than more popular hy- brid napus canola, and the yield stability of juncea canola was lowest among the five oilseed species when examined across diverse environ- ments. Earlier flowering, longer flowering duration, and greater toler- ance to drought stress exhibited by juncea canola make the crop best adapted to the drier areas of the northern Great Plains. The improve- ment of seed yield and yield stability is the key to potentially adapt this new oilseed species to a wider range of environmental conditions.
    Agronomy Journal - AGRON J. 01/2007; 99(5).
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    ABSTRACT: Field experiments were conducted in 2003, 2004, and 2005 on a S-deficient Gray Luvisol (Boralf) soil near Star City, in northeastern Saskatchewan, to determine yield, seed quality and S uptake response of different Brassica (B.) oilseed species/cultivars to S deficiency and S fertilization. A total of 20 treatments were tested in a factorial com- bination of four oilseed crops (B. juncea canola cv. Arid, B. juncea canola cv. Amulet, B. juncea mustard cv. Cutlass, and B. napus cv. InVigor 2663 hybrid canola) and five rates of potassium sulfate fer- tilizer (0, 10, 20, 30, and 40 kg S ha21). All B. species/cultivars re- sponded positively for seed yield and most other parameters to S fertilizer in all 3 yr, but the magnitude of response varied with species/ cultivar and year. Seed yield was highest with Cutlass juncea mustard in a dry year (2003), but was highest with InVigor 2663 hybrid canola in years with above-average precipitation (2004 and 2005). Seed yield was usually maximized at the rate of 30 kg S ha21 for all B. species/ cultivars. Oil concentration in seed increased with S fertilization for all B. species/cultivars. There was a significant (albeit small) increase of protein concentration in seed due to S fertilization. Cutlass juncea mustard accumulated considerably high concentrations of glucosino- lates in seed, but glucosinolate concentrations were low in other B. species/cultivars. Sulfur uptake in seed was highest with Cutlass juncea mustard in all years. The effects of S deficiency and applied S were more pronounced on seed than straw. In conclusion, S fertilizer re- quirements for optimum seed yield were similar for all the B. species/ cultivars used in this study on S-deficient soil, but higher yielding types of B. would produce greater seed yield by using S more efficiently.
    Agronomy Journal - AGRON J. 01/2007; 99(2).