DIFFERENTIAL FERTILIZER N IMMOBILIZATION IN TWO TILLAGE SYSTEMS INFLUENCES GRAIN N CONCENTRATION

1990 ◽  
Vol 70 (2) ◽  
pp. 215-225 ◽  
Author(s):  
J. M. CAREFOOT ◽  
C. W. LINDWALL ◽  
M. NYBORG

Differential N immobilization between conventional tillage (CT) and no-till (NT) systems has been suggested as a possible mechanism for differences in crop response to N. To examine this effect, immobilization of N fertilizer was compared in NT and CT cereal production systems at two sites in southern Alberta (Lethbridge and Vauxhall) from 1983 to 1985. Fertilizer N, labelled with 15N, was applied at rates ranging from 25 to 50 kg N ha−1 to winter wheat (Triticum aestivum L. 'Norstar'), barley (Hordeum vulgare L. 'Galt'), or spring wheat (Triticum aestivum L. 'Chester') in various rotations. Nitrogen immobilization was subsequently quantified by 15N analysis of crop tissues and soil N fractions. The amount of N immobilized was strongly influenced by climatic variables. In 1984, characterized by drought in the spring but significant precipitation during June, mean N immobilization losses for winter wheat and barley in the CT treatments averaged much less than those in NT treatments (20 vs. 34% of N applied). Conversely, in 1985, which was characterized by a wet spring and a very dry summer, N immobilization losses were comparable in the two barley tillage treatments (mean = 29% of N applied). Lack of precipitation early in the season appears to restrict immobilization less in CT than in NT treatments because of greater fertilizer-residue contact in the latter. Despite the trends in immobilized N, grain yields were often higher in the NT than in the CT treatments, indicating that yield differences were likely related to the availability of moisture rather than to N fertility. Restricted N availability resulting from immobilization losses, however, reduced grain N concentration in NT relative to CT treatments. Key words: No-till, conventional till, N immobilization, N response, residual N

1992 ◽  
Vol 72 (3) ◽  
pp. 965-972 ◽  
Author(s):  
D. K. Tompkins ◽  
D. B. Fowler ◽  
A. T. Wright

Agronomic practices must be modified to maximize winter wheat (Triticum aestivum L.) yield in different environments. Changes in crop management may modify the microclimate within the crop canopy thereby influencing the development of foliar pathogens. This study was initiated to determine the effect of cultivar, nitrogen (N) fertility, seed rate (SR) and row spacing (RS) on the severity of powdery mildew (Erysiphe graminis DC f.sp. tritici E. Marchal) on the upper leaves of no-till winter wheat grown in the Saskatchewan Parkland region. Average powdery mildew (PM) severity was greater on the upper leaves of the semi-dwarf cultivar Norwin than on the tall cultivar Norstar and increased under conditions of high N fertility. The use of 36 cm RS and 140 kg ha−1 SR compared to 9 cm RS and 35 kg ha−1 SR also resulted in increased PM severity. In general, wide RS enhanced spore dispersal and disease progress up the plant while high SR created a more favourable crop canopy microclimate for PM development once the pathogen was established on a leaf.Key words: Wheat (winter). Triticum aestivum L., no-till, powdery mildew, Erysiphe graminis, row spacing, seed rate, nitrogen fertilizer


2019 ◽  
Vol 23 (1) ◽  
pp. 39-46
Author(s):  
Hazzar Habbib ◽  
Bertrand Hirel ◽  
Fabien Spicher ◽  
Frédéric Dubois ◽  
Thierry Tétu

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2047
Author(s):  
Matthew R. Ryan ◽  
Sandra Wayman ◽  
Christopher J. Pelzer ◽  
Caitlin A. Peterson ◽  
Uriel D. Menalled ◽  
...  

Mulch from cover crops can effectively suppress weeds in organic corn (Zea mays L.) and soybean (Glycine max L.) as part of cover crop-based rotational no-till systems, but little is known about the feasibility of using mulch to suppress weeds in organic winter small grain crops. A field experiment was conducted in central NY, USA, to quantify winter wheat (Triticum aestivum L.) seedling emergence, weed and crop biomass production, and wheat grain yield across a gradient of mulch biomass. Winter wheat seedling density showed an asymptotic relationship with mulch biomass, with no effect at low rates and a gradual decrease from moderate to high rates of mulch. Selective suppression of weed biomass but not wheat biomass was observed, and wheat grain yield was not reduced at the highest level of mulch (9000 kg ha−1). Results indicate that organic winter wheat can be no-till planted in systems that use mulch for weed suppression. Future research should explore wheat tolerance to mulch under different conditions, and the potential of no-till planting wheat directly into rolled-crimped cover crops.


Author(s):  
A. Yu. Egovtseva ◽  
T. N. Melnichuk ◽  
S. F. Abdurashitov

The use of microbial preparations contributed to a change in the taxonomic structure of winter wheat rhizosphere microbiome was established. A more significant effect of microbial preparations was noted under no-till technology on the structure of the microbiome than with the traditional farming system.


2010 ◽  
Vol 29 (1) ◽  
pp. 1-6 ◽  
Author(s):  
José M.G. Calado ◽  
Gottlieb Basch ◽  
Mário de Carvalho

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 813-818 ◽  
Author(s):  
Charles L. Cleary ◽  
Thomas F. Peeper

Experiments were conducted from 1979 to 1982 to determine whether selected herbicide treatments applied before or after harvest would provide adequate weed control without the use of tillage between crops in continuous winter wheat (Triticum aestivumL.) production systems. of the herbicide treatments evaluated, only oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) at 2.2 kg ai/ha applied prior to wheat maturity adequately controlled summer annual weeds each year. Populations of yellow nutsedge (Cyperus esculentusL. # CYPES) and/or clammy groundcherry (Physalis heterophyllaNees) increased from continued preharvest use of oryzalin in no-till treatments and were greater than those resulting from conventional tillage or various postharvest no-till treatments containing glyphosate [N-(phosphonomethyl)glycine]. After 4 yr, populations of winter annualCruciferaespp. at one location were lower in treatments that had poorer control of summer annual weeds or volunteer wheat. At a second location, winter annual broadleaf species were more numerous in conventionally tilled than in no-till treatments. Wheat yields obtained with no-till treatments were lower than yields obtained with conventional tillage in seasons favorable for high yields.


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