scholarly journals Soil Photosynthetic Microbial Communities Mediate Aggregate Stability: Influence of Cropping Systems and Herbicide Use in an Agricultural Soil

2019 ◽  
Vol 10 ◽  
Author(s):  
Olivier Crouzet ◽  
Laurent Consentino ◽  
Jean-Pierre Pétraud ◽  
Christelle Marrauld ◽  
Jean-Pierre Aguer ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Agricultural Soil ◽  
Cropping Systems ◽  
Aggregate Stability ◽  
Herbicide Use

scholarly journals The Pitfalls of Relating Weeds, Herbicide Use, and Crop Yield: Don't Fall Into the Trap! A Critical Review

2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  
Keyword(s):  
Crop Yield ◽  
Weed Management ◽  
Crop Production ◽  
Yield Loss ◽  
Crop Yields ◽  
Cropping Systems ◽  
Crop Productivity ◽  
Arable Farming ◽  
Herbicide Use ◽  
The Impact

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.

scholarly journals Outcomes of Long-Term Conservation Tillage Research in Northern China

2020 ◽  
Vol 12 (3) ◽  
pp. 1062 ◽  
Author(s):  
Francis Azumah Chimsah ◽  
Liqun Cai ◽  
Jun Wu ◽  
Renzhi Zhang
Keyword(s):  
Crop Yields ◽  
Greenhouse Gas Emission ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Meta Analysis ◽  
Arable Land ◽  
Aggregate Stability ◽  
Northern China ◽  
Total N

Sustainable food production has long been a priority for mankind and this is being challenged by limited arable land, challenged landscapes, and higher human population growth. China started conservation farming around the 1950’s. However, main Conservation Tillage (CT) research started in 1992. Using a systematic meta-analysis approach, this review aims at examining China’s approach to CT and to characterize the main outcomes of long-term CT research across northern China. Data from organizations in charge of CT research in China showed an improvement in crop yield of at least 4% under double cropping systems and 6% under single cropping systems in dry areas of northern China. Furthermore, long-term CT practices were reported to have improved soil physical properties (soil structure, bulk density, pore size, and aggregate stability), soil nutrient levels, and reduction in greenhouse gas emission. Other benefits include significant increase in income levels and protection of the environment. Limitations to CT practice highlighted in this study include occasional reduction in crop yields during initial years of cropping, significant reduction in total N of soils, increase in N2O emission, and the need for customized machinery for its implementation. Outcomes of CT practice are ecologically and economically beneficial though its limitations are worth cogitating.

scholarly journals Continuous monocropping highly affect the composition and diversity of microbial communities in peanut (Arachis hypogaea L.)

2021 ◽  
Vol 49 (4) ◽  
pp. 12532
Author(s):  
Ali I. MALLANO ◽  
Xianli ZHAO ◽  
Yanling SUN ◽  
Guangpin JIANG ◽  
Huang CHAO
Keyword(s):  
Microbial Communities ◽  
Management Practices ◽  
Rhizosphere Soil ◽  
Diversity Index ◽  
Cropping Systems ◽  
Soil Microbial Communities ◽  
Pathogenic Fungi ◽  
Continuous Cropping ◽  
Bacterial Phyla ◽  
Soil Microbial

Continuous cropping systems are the leading cause of decreased soil biological environments in terms of unstable microbial population and diversity index. Nonetheless, their responses to consecutive peanut monocropping cycles have not been thoroughly investigated. In this study, the structure and abundance of microbial communities were characterized using pyrosequencing-based approach in peanut monocropping cycles for three consecutive years. The results showed that continuous peanut cultivation led to a substantial decrease in soil microbial abundance and diversity from initial cropping cycle (T1) to later cropping cycle (T3). Peanut rhizosphere soil had Actinobacteria, Protobacteria, and Gemmatimonadetes as the major bacterial phyla. Ascomycota, Basidiomycota were the major fungal phylum, while Crenarchaeota and Euryarchaeota were the most dominant phyla of archaea. Several bacterial, fungal and archaeal taxa were significantly changed in abundance under continuous peanut cultivation. Bacterial orders, Actinomycetales, Rhodospirillales and Sphingomonadales showed decreasing trends from T1>T2>T3. While, pathogenic fungi Phoma was increased and beneficial fungal taxa Glomeraceae decreased under continuous monocropping. Moreover, Archaeal order Nitrososphaerales observed less abundant in first two cycles (T1&T2), however, it increased in third cycle (T3), whereas, Thermoplasmata exhibit decreased trends throughout consecutive monocropping. Taken together, we have shown the taxonomic profiles of peanut rhizosphere communities that were affected by continuous peanut monocropping. The results obtained from this study pave ways towards a better understanding of the peanut rhizosphere soil microbial communities in response to continuous cropping cycles, which could be used as bioindicator to monitor soil quality, plant health and land management practices.

Merits of a weed-sensing sprayer to control weeds in conservation fallow and cropping systems

Weed Science ◽  
1998 ◽  
Vol 46 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Louis J. Molnar ◽  
C. Wayne Lindwall
Keyword(s):  
Crop Residues ◽  
Cropping Systems ◽  
Cost Savings ◽  
Field Studies ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Canada Thistle ◽  
Perennial Weeds ◽  
Crop Harvest ◽  
Herbicide Use

Field studies were conducted from 1993 through 1995 to determine potential reductions in herbicide use and associated cost savings by utilizing a weed-sensing sprayer, named Detectspray, to control weeds throughout the fallow season and to control perennial weeds after crop harvest. The Detectspray system gave comparable weed control to conventional broadcast spraying on 80% of the application dates and reduced glyphosate/dicamba use over the fallow season by 19 to 60%. This reduced herbicide use resulted in cost savings of $6 to $32 ha−1. A fallow treatment that combined two herbicide applications with the Detectsprayer plus one to two wide-blade tillage operations was less costly than conventional tillage at two of 11 sites and at all sites retained more surface crop residues to reduce the risk of erosion. Postharvest glyphosate use on quackgrass with the Detectsprayer was reduced 50 to 78% compared to broadcast applications and resulted in cost savings of $16 to $25 ha−1. Clopyralid use on Canada thistle with the Detectsprayer was reduced 71 to 80%, with cost savings of $44 to $50 ha−1. The Detectspray system is a useful tool to effectively manage weeds in conservation fallow and reduced tillage cropping systems.

scholarly journals Tillage Intensity Effects on Soil Structure Indicators—A US Meta-Analysis

2020 ◽  
Vol 12 (5) ◽  
pp. 2071 ◽  
Author(s):  
Márcio R. Nunes ◽  
Douglas L. Karlen ◽  
Thomas B. Moorman
Keyword(s):  
Crop Production ◽  
Soil Structure ◽  
Management Practices ◽  
Cropping Systems ◽  
Meta Analysis ◽  
Soil Health ◽  
Health Assessment ◽  
Aggregate Stability ◽  
Soil Penetration Resistance ◽  
Wet Aggregate Stability

Tillage intensity affects soil structure in many ways but the magnitude and type (+/−) of change depends on site-specific (e.g., soil type) and experimental details (crop rotation, study length, sampling depth, etc.). This meta-analysis examines published effects of chisel plowing (CP), no-tillage (NT) and perennial cropping systems (PER) relative to moldboard plowing (MP) on three soil structure indicators: wet aggregate stability (AS), bulk density (BD) and soil penetration resistance (PR). The data represents four depth increments (from 0 to >40-cm) in 295 studies from throughout the continental U.S. Overall, converting from MP to CP did not affect those soil structure indicators but reducing tillage intensity from MP to NT increased AS in the surface (<15-cm) and slightly decreased BD and PR below 25-cm. The largest positive effect of NT on AS was observed within Inceptisols and Entisols after a minimum of three years. Compared to MP, NT had a minimal effect on soil compaction indicators (BD and PR) but as expected, converting from MP to PER systems improved soil structure at all soil depths (0 to >40-cm). Among those three soil structure indicators, AS was the most sensitive to management practices; thus, it should be used as a physical indicator for overall soil health assessment. In addition, based on this national meta-analysis, we conclude that reducing tillage intensity improves soil structure, thus offering producers assurance those practices are feasible for crop production and that they will also help sustain soil resources.

scholarly journals Effects of Different 3-Year Cropping Systems on Soil Microbial Communities and Rhizoctonia Diseases of Potato

2006 ◽  
Vol 96 (1) ◽  
pp. 68-79 ◽  
Author(s):  
Robert P. Larkin ◽  
C. Wayne Honeycutt
Keyword(s):  
Fatty Acid ◽  
Microbial Communities ◽  
Sweet Corn ◽  
Cropping Systems ◽  
Soil Microbial Communities ◽  
Microbial Populations ◽  
Culturable Bacteria ◽  
Soil Microbial ◽  
Entry Points ◽  
Potato Crops

Eight different 3-year cropping systems, consisting of soybean-canola, soybean-barley, sweet corn-canola, sweet corn-soybean, green bean-sweet corn, canola-sweet corn, barley-clover, and continuous potato (non-rotation control) followed by potato as the third crop in all systems, were established in replicated field plots with two rotation entry points in Presque Isle, ME, in 1998. Cropping system effects on soil microbial community characteristics based on culturable soil microbial populations, single carbon source substrate utilization (SU) profiles, and whole-soil fatty acid methyl ester (FAME) profiles were evaluated in association with the development of soilborne diseases of potato in the 2000 and 2001 field seasons. Soil populations of culturable bacteria and overall microbial activity were highest following barley, canola, and sweet corn crops, and lowest following continuous potato. The SU profiles derived from BIOLOG ECO plates indicated higher substrate richness and diversity and greater utilization of certain carbohydrates, carboxylic acids, and amino acids associated with barley, canola, and some sweet corn rotations, indicating distinct differences in functional attributes of microbial communities among cropping systems. Soil FAME profiles also demonstrated distinct differences among cropping systems in their relative composition of fatty acid types and classes, representing structural attributes of microbial communities. Fatty acids most responsible for differentiation among cropping systems included 12:0, 16:1 ω5c, 16:1 ω7c, 18:1 ω9c, and 18:2ω6c. Based on FAME biomarkers, barley rotations resulted in higher fungi-to-bacteria ratios, sweet corn resulted in greater mycorrhizae populations, and continuous potato produced the lowest amounts of these and other biomarker traits. Incidence and severity of stem and stolon canker and black scurf of potato, caused by Rhizoctonia solani, were reduced for most rotations relative to the continuous potato control. Potato crops following canola, barley, or sweet corn provided the lowest levels of Rhizoctonia disease and best tuber quality, whereas potato crops following clover or soybean resulted in disease problems in some years. Both rotation crop and cropping sequence were important in shaping the microbial characteristics, soilborne disease, and tuber qualities. Several microbial parameters, including microbial populations and SU and FAME profile characteristics, were correlated with potato disease or yield measurements in one or both harvest years. In this study, we have demonstrated distinctive effects of specific rotation crops and cropping sequences on microbial communities and have begun to relate the implications of these changes to crop health and productivity.

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