scholarly journals Methane emission from soil under long-term no-till cropping systems

2012 ◽  
Vol 124 ◽  
pp. 1-7 ◽  
Author(s):  
Cimélio Bayer ◽  
Juliana Gomes ◽  
Frederico Costa Beber Vieira ◽  
Josiléia Accordi Zanatta ◽  
Marisa de Cássia Piccolo ◽  
...  
Weed Science ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Dilshan Benaragama ◽  
Julia L. Leeson ◽  
Steve J. Shirtliffe

AbstractWeeds have acquired evolutionary adaptations to the diverse crop and weed management strategies used in cropping systems. Therefore, changes in crop production practices such as conventional to organic systems, tillage-based to no-till systems, and diversity in crop rotations can result in differences in weed community composition that have management implications. A study was carried out to understand the weed community dynamics in a long-term alternative cropping systems study at Scott, SK, Canada. Long-term (18-yr) weed community composition data in wheat (Triticum aestivumL.) in ORG (organic), RED (reduced-input, no-till), and HIGH (high-input, conventional tillage) systems with three levels of crop rotation diversity, LOW (low diversity), DAG (diversified annual grains), and DAP (diversified annuals and perennials), were used to study the effect of different cropping systems and the effect of environment (random temporal effects) on residual weed community composition using the principal response curve (PRC) technique. The interaction between cropping systems and year-to-year random environmental changes was found to be the predominant factor causing fluctuations in weed community composition. Furthermore, the single most predominant factor influencing the weed composition was year-to-year random changes. Organic systems clearly differed from the two conventional systems in most years and had more diverse weed communities compared with the two conventional systems. The two conventional systems exhibited similar weed composition in most years. In this study, the use of the PRC method allowed capture of the real temporal dynamics reflected in the cropping systems by time interaction. This study further concludes that moving from a tillage-based, high-input conventional system to a no-till, reduced-input system did not cause significant changes in the weed community composition throughout the time period, but diversity in organic systems was high, probably due to increased occurrence of some difficult to control species.


Plant Disease ◽  
2014 ◽  
Vol 98 (3) ◽  
pp. 389-394 ◽  
Author(s):  
W. F. Schillinger ◽  
T. C. Paulitz

The soilborne fungus Rhizoctonia solani AG-8 is a major concern for farmers who practice no-till in the inland Pacific Northwest of the United States. Bare patches caused by Rhizoctonia spp. first appeared in 1999 during year 3 of a 15-year no-till cropping systems experiment near Ritzville, WA (269 mm of annual precipitation). The extent and pattern of patches were mapped each year from 1999 to 2012 at the 8-ha study site with a backpack-mounted global positioning system equipped with mapping software. Bare patches appeared in winter and spring wheat (SW; Triticum aestivum), spring barley (SB; Hordeum vulgare), yellow mustard (Brassica hirta), and safflower (Carthamus tinctorius). At its peak in years 5 to 7, bare patches occupied as much as 18% of total plot area in continuous annual monoculture SW. The area of bare patches began to decline in year 8 and reached near zero levels by year 11. No measurable patches were present in years 12 to 15. Patch area was significantly greater in continuous SW compared with SW grown in a 2-year rotation with SB. Additionally, the 15-year average grain yield for SW in rotation with SB was significantly greater than for continuous SW. Russian thistle (Salsola tragus), a troublesome broadleaf weed with a fast-growing tap root, was the only plant that grew within patches. This article reports the first direct evidence of natural suppression of Rhizoctonia bare patch with long-term no-till in North America. This suppression also developed in a rotation that contained broadleaf crops (yellow mustard and safflower) in all but 5 years of the study, and the suppression was maintained when safflower was added back to the rotation.


2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Daniel C. Schlatter ◽  
Chuntao Yin ◽  
Scot Hulbert ◽  
Ian Burke ◽  
Timothy Paulitz

ABSTRACT Glyphosate is the most widely used herbicide worldwide and a critical tool for weed control in no-till cropping systems. However, there are concerns about the nontarget impacts of long-term glyphosate use on soil microbial communities. We investigated the impacts of repeated glyphosate treatments on bacterial communities in the soil and rhizosphere of wheat in soils with and without long-term history of glyphosate use. We cycled wheat in the greenhouse using soils from 4 paired fields under no-till (20+-year history of glyphosate) or no history of use. At each cycle, we terminated plants with glyphosate (2× the field rate) or by removing the crowns, and soil and rhizosphere bacterial communities were characterized. Location, cropping history, year, and proximity to the roots had much stronger effects on bacterial communities than did glyphosate, which only explained 2 to 5% of the variation. Less than 1% of all taxa were impacted by glyphosate, more in soils with a long history of use, and more increased than decreased in relative abundance. Glyphosate had minimal impacts on soil and rhizosphere bacteria of wheat, although dying roots after glyphosate application may provide a “greenbridge” favoring some copiotrophic taxa. IMPORTANCE Glyphosate (Roundup) is the most widely used herbicide in the world and the foundation of Roundup Ready soybeans, corn, and the no-till cropping system. However, there have been recent concerns about nontarget impacts of glyphosate on soil microbes. Using next-generation sequencing methods and glyphosate treatments of wheat plants, we described the bacterial communities in the soil and rhizosphere of wheat grown in Pacific Northwest soils across multiple years, different locations, and soils with different histories of glyphosate use. The effects of glyphosate were subtle and much less than those of drivers such as location and cropping systems. Only a small percentage of the bacterial groups were influenced by glyphosate, and most of those were stimulated, probably because of the dying roots. This study provides important information for the future of this important tool for no-till systems and the environmental benefits of reducing soil erosion and fossil fuel inputs.


2015 ◽  
Vol 66 (6) ◽  
pp. 553 ◽  
Author(s):  
A. M. Whitbread ◽  
C. W. Davoren ◽  
V. V. S. R. Gupta ◽  
R. Llewellyn ◽  
the late D. Roget

Continuous-cropping systems based on no-till and crop residue retention have been widely adopted across the low-rainfall cereal belt in southern Australia in the last decade to manage climate risk and wind erosion. This paper reports on two long-term field experiments that were established in the late 1990s on texturally different soil types at a time of uncertainty about the profitability of continuous-cropping rotations in low-rainfall environments. Continuous-cereal systems significantly outyielded the traditional pasture–wheat systems in five of the 11 seasons at Waikerie (light-textured soil), resulting in a cumulative gross margin of AU$1600 ha–1 after the initial eight seasons, almost double that of the other treatments. All rotation systems at Kerribee (loam-textured soil) performed poorly, with only the 2003 season producing yields close to 3 t ha–1 and no profit achieved in the years 2004–08. For low-rainfall environments, the success of a higher input cropping system largely depends on the ability to offset the losses in poor seasons by capturing greater benefits from good seasons; therefore, strategies to manage climatic risk are paramount. Fallow efficiency, or the efficiency with which rainfall was stored during the period between crops, averaged 17% at Kerribee and 30% at Waikerie, also indicating that soil texture strongly influences soil evaporation. A ‘responsive’ strategy of continuous cereal with the occasional, high-value ‘break crop’ when seasonal conditions are optimal is considered superior to fixed or pasture–fallow rotations for controlling grass, disease or nutritional issues.


ISRN Ecology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Justin P. Ng ◽  
Emily B. Hollister ◽  
Ma. del Carmen A. González-Chávez ◽  
Frank M. Hons ◽  
David A. Zuberer ◽  
...  

Few studies have used molecular methods to correlate the abundance of specific microbial taxonomic groups with changes in soil properties impacted by long-term agriculture. Community qPCR with 16S rRNA gene sequencing to examine the effects of long-term crop-management practices (no-till vs. conventional tillage, and continuous wheat (Triticum aestivum L.) vs. sorghum-wheat-soybean rotation (Sorghum bicolor L. Moench-Triticum aestivum L.-Glycine max L. Merr) on bacterial and fungal relative abundances and identify the dominant members of the soil microbial community. The qPCR assays revealed that crop rotation decreased bacterial copy numbers, but no-till practices did not significantly alter bacteria or fungi relative to conventional tillage. Cyanobacteria were more abundant while Actinobacteria were less numerous under continuous wheat. Acidobacteria and Planctomycetes were positively correlated with soil microbial biomass C and N. This study highlights ways cropping systems affect microbial communities and aids the development of sustainable agriculture.


2005 ◽  
Vol 268 (1) ◽  
pp. 319-328 ◽  
Author(s):  
Jeferson Diekow ◽  
João Mielniczuk ◽  
Heike Knicker ◽  
Cimélio Bayer ◽  
Deborah P. Dick ◽  
...  

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184611 ◽  
Author(s):  
Dipak Sharma-Poudyal ◽  
Daniel Schlatter ◽  
Chuntao Yin ◽  
Scot Hulbert ◽  
Timothy Paulitz

2006 ◽  
Vol 35 (4) ◽  
pp. 1487-1495 ◽  
Author(s):  
A. Stuart Grandy ◽  
Terrance D. Loecke ◽  
Sara Parr ◽  
G. Philip Robertson

2017 ◽  
Vol 155 (7) ◽  
pp. 1093-1112 ◽  
Author(s):  
A. C. A. CARMEIS FILHO ◽  
C. A. C. CRUSCIOL ◽  
A. M. CASTILHOS

SUMMARYThe adequate management of soil acidity has long been a challenge in no-till (NT) cropping systems. Some studies conducted in sub-tropical conditions have demonstrated the feasibility of surface liming. However, for tropical regions with dry winters, little long-term information about adequate rates and frequencies of application is available. A 12-year field trial was performed under a tropical no-tillage system with an annual crop rotation scheme. The treatments were composed of four lime rates (0, 1000, 2000 and 4000 kg/ha), estimated via the base saturation (BS) method. Surface application of lime was found to be an effective method for improving the soil fertility profile under this long-term NT cropping system. All three acidity components (pH, hydrogen + aluminium (H + Al), exchangeable Al) and some fertility attributes (phosphorus, exchangeable calcium and magnesium, and BS) were adjusted to a linear function, and better soil chemical conditions were obtained in the 4000 kg/ha treatment, even 4 years after the final application. Due to soil chemical changes, the root length density of wheat and common bean was greater at depths <0·20 m, which led to a higher grain yield, even under unfavourable weather conditions. The results indicate that the application of lime at higher rates can be an acceptable criterion for a tropical Oxisol under a no-tillage system, reducing the frequency of lime application.


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