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

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.

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Effect of Cropping System and Rice Residue Retention on Crop Productivity and Soil Physical Properties in Rice Based Cropping System of Bangladesh

The Agriculturists ◽

10.3329/agric.v17i1-2.44693 ◽

2019 ◽

Vol 17 (1-2) ◽

pp. 14-30

Author(s):

M Jahangir Alam ◽

S Ahmed ◽

MK Islam ◽

R Islam ◽

M Islam

Keyword(s):

Crop Production ◽

Crop Yields ◽

Cropping Systems ◽

Wheat Yield ◽

Cropping System ◽

Physical Property ◽

Crop Productivity ◽

System Productivity ◽

Transplanted Rice ◽

Residue Retention

Cropping systems of Bangladesh are highly diverse and cultivation costs of puddled transplanted rice (PTR) are high. Therefore, an improved system is needed to address the issues, a field experiment was conducted during 2011-2013 to evaluate system intensification with varying degrees of cropping systems and residue retention. Four cropping systems (CSE) namely CSE1: T. boro rice-T. aman rice (control), CSE2: wheat-mungbean-T. aman rice (wheat and mungbean sown using a power tiller-operated seeder (PTOS) with full tillage in a single pass; puddled transplanted aman), CSE3: wheat-mungbean-dry seeded DS aman rice (DSR), and CSE4: wheat-mungbean-DS aman rice (all sown by PTOS with strip tillage) were compared. Two levels of aman rice residue retention (removed; partial retention i.e. 40 cm of standing stubble) were compared in sub plots. Grain yield was significantly higher (by 11%) when wheat was grown after DSR than PTR. Similarly, PTR and DSR (aman rice) produced statistically similar crop yields. Rice residue retention resulted a significantly higher (by 10%) wheat yield and a slightly increased (by 6%) mungbean yield than that of residues removed. The system productivity of CSE4 was significantly higher (by 10%) than CSE1 when averaged of the two years data. Partial aman residue retention gave significantly higher system yield than residue removal (by 0.6 t ha-1). After two years, no effect of CSE or partial aman residue retention was found on soil physical property (bulk density) of the top soil. Therefore, CSE4 along with residue retention would be more effective for sustainable crop production. The Agriculturists 2019; 17(1-2) 14-30

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Spatial distribution of cereal yields related to the application of soil-improving cropping systems (SICS)

10.5194/egusphere-egu21-2109 ◽

2021 ◽

Author(s):

Jerzy Lipiec ◽

Boguslaw Usowicz

Keyword(s):

Soil Properties ◽

Cover Crops ◽

Crop Production ◽

Crop Yields ◽

Cropping Systems ◽

Crop Productivity ◽

Organic Carbon Content ◽

Classical Statistics ◽

Normal Rainfall ◽

Cereal Yields

Research indicates that spatial differentiation of crop yields and soil properties are largely influenced by agricultural practices and the nature of the soil itself. The aim of this study was to examine the spatial relationship between cereal (wheat and oats ) yields and soil properties related to the application of soil-improving cropping systems (SICS). Four-year experiment (2017-2020) was carried out on low productive sandy soil with application of following SICS: S1 &#8211; control; S2 &#8211; liming; S3 &#8211; green manure/cover crops including lupine, phacelia, serradella; S4 &#8211; manure and S5 &#8211; manure, liming and cover crops together. Effect of the SICS was evaluated using classical statistics, Bland-Altman analysis and geostatistical methods. Mathematical functions, fitted to the experimental cross- and semivariograms were used for mapping the yields (grain and straw) by ordinary cokriging. The grain yields in years with normal rainfall increased by 2% for S2, 10% for S3, 46% for S4, 47% for S5 compared to control (S1) 2789 kg/ha and in dry years were lower (respectively for S2-S5 by 16.3, 10.6, 2.8, 9.9% compared to control 1567 kg/ha. The range of spatial dependence for the yields in direct semi-variograms varied was 50&#8211;100 m and > 100 m in cross-semivariograms using textural fractions as secondary variables. The spatial relationships were stronger between yield and soil texture and properties were much stronger with texture and cation exchange capacity than with pH and organic carbon content. Using cokriging for interpolation (mapping) allowed the delineation of zones of lower and higher cereal yields including areas of the SICS application. Higher cereal yield and lower spatial variability in the areas of SICS compared to control soil were observed in the years with normal rainfall. Analysis of the Bland-Altman including limits of agreement enabled to quantify the effect of particular SICS on cereal yield vs. control reference. Different effect of particular SICS on the cereal yield was observed in the years with scarce and good rainfall amount and distribution during growing season. The greatest variation of the cereal yield was observed in manure amended soil (S4) and it was lower and similar in the areas of remaining SICS (S2-S5). The results will help to to select most effective SICS for localized improving crop productivity and adaptation to global warming.Acknowledgements.The study was funded by HORIZON 2020, European Commission, Programme H2020-SFS-2015-2: SoilCare for profitable and sustainable crop production in Europe, project No. 677407 (SoilCare, 2016-2021).

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The hidden signature of temperature-moisture couplings in the heat sensitivity of global crops

10.5194/egusphere-egu21-1419 ◽

2021 ◽

Author(s):

Corey Lesk ◽

Ethan Coffel ◽

Jonathan Winter ◽

Deepak Ray ◽

Jakob Zscheischler ◽

...

Keyword(s):

Climate Change ◽

Crop Production ◽

Climate Model ◽

Crop Yields ◽

Cropping Systems ◽

Critical Role ◽

Heat Sensitivity ◽

Local Strength ◽

Dry Conditions ◽

The Impact

Rising air temperatures are a leading risk to global crop production and food security under climate change. Recent research has emphasized the critical role of moisture availability in regulating crop responses to heat&#160;and the importance of temperature-moisture couplings in the genesis of concurrent hot and dry conditions. Here, we demonstrate that the heat sensitivity of key global crops is dependent on the local strength of couplings between temperature and moisture in the climate system (namely, the interannual correlations of growing season temperature with evapotransipration and precipitation). Over 1970-2013, maize and soy yields declined more during hotter growing seasons where decreased precipitation and evapotranspiration more strongly accompanied higher temperatures. Based on this historical pattern and a suite of CMIP6 climate model projections, we show that changes in temperature-moisture couplings in response to warming could enhance the heat sensitivity of these crops as temperatures rise, worsening the impact of warming by ~5% on global average. However, these changes will benefit crops in some areas where couplings weaken, and are highly uncertain in others. Our results demonstrate that climate change will impact crops not only through warming, but also through changes in temperature-moisture couplings, which may alter the sensitivity of crop yields to heat as warming proceeds. Robust adaptation of cropping systems will need to consider this underappreciated risk to food production from climate change.

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A Review of Soil-Improving Cropping Systems for Soil Salinization

Agronomy ◽

10.3390/agronomy9060295 ◽

2019 ◽

Vol 9 (6) ◽

pp. 295 ◽

Cited By ~ 20

Author(s):

Julián Cuevas ◽

Ioannis N. Daliakopoulos ◽

Fernando del Moral ◽

Juan J. Hueso ◽

Ioannis K. Tsanis

Keyword(s):

Crop Production ◽

Crop Yields ◽

Cropping Systems ◽

Meta Analysis ◽

Conservation Agriculture ◽

Crop Productivity ◽

Soil Salinization ◽

Review Literature ◽

Residue Management ◽

Negative Effect

A major challenge of the Sustainable Development Goals linked to Agriculture, Food Security, and Nutrition, under the current global crop production paradigm, is that increasing crop yields often have negative environmental impacts. It is therefore urgent to develop and adopt optimal soil-improving cropping systems (SICS) that can allow us to decouple these system parameters. Soil salinization is a major environmental hazard that limits agricultural potential and is closely linked to agricultural mismanagement and water resources overexploitation, especially in arid climates. Here we review literature seeking to ameliorate the negative effect of soil salinization on crop productivity and conduct a global meta-analysis of 128 paired soil quality and yield observations from 30 studies. In this regard, we compared the effectivity of different SICS that aim to cope with soil salinization across 11 countries, in order to reveal those that are the most promising. The analysis shows that besides case-specific optimization of irrigation and drainage management, combinations of soil amendments, conditioners, and residue management can contribute to significant reductions of soil salinity while significantly increasing crop yields. These results highlight that conservation agriculture can also achieve the higher yields required for upscaling and sustaining crop production.

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Winter Wheat Row Spacing and Alternative Crop Effects on Relay-Intercrop, Double-Crop, and Wheat Yields

International Journal of Agronomy ◽

10.1155/2015/369243 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Leah Sandler ◽

Kelly A. Nelson ◽

Christopher Dudenhoeffer

Keyword(s):

Winter Wheat ◽

Crop Production ◽

Cropping Systems ◽

Cropping System ◽

Crop Productivity ◽

Yield Potential ◽

Row Spacing ◽

Severe Drought ◽

Alternative Crops ◽

The Impact

In Missouri as well as much of the Midwest, the most popular double-cropping system was winter wheat (Triticum aestivumL.) followed by soybean (Glycine max(L.) Merr). These two crops can also be used in an intercrop system, but optimal row spacing was important to increase crop productivity. Research was conducted to evaluate (1) winter wheat inter- and double-crop production systems, using a variety of alternative crops, and (2) the impact of different wheat row spacings on intercrop establishment and yields within the various cropping systems. Field research was conducted during droughts in 2012 and 2013. Spacing of wheat rows impacted wheat yields by 150 kg ha−1, as well as yields of the alternative crops. Narrower row spacings (150 kg ha−1) and the double-crop system (575 kg ha−1) increased yield due to the lack of interference for resources with wheat in 2013. Land equivalent ratio (LER) values determining productivity of intercrop systems of 19 and 38 cm row showed an advantage for alternative crops in 2013, but not 2012. This signified that farmers in Northeast Missouri could potentially boost yield potential for a given field and produce additional forage or green manure yields in a year with less severe drought.

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Spring Wheat, Canola, and Sunflower Response to Persian Darnel (Lolium persicum) Interference

Weed Technology ◽

10.1614/wt-03-056r ◽

2004 ◽

Vol 18 (3) ◽

pp. 509-520 ◽

Cited By ~ 12

Author(s):

Johnathon D. Holman ◽

Alvin J. Bussan ◽

Bruce D. Maxwell ◽

Perry R. Miller ◽

James A. Mickelson

Keyword(s):

Crop Yield ◽

Spring Wheat ◽

Weed Management ◽

Management Practices ◽

Yield Loss ◽

Wheat Yield ◽

Integrated Weed Management ◽

Crop Density ◽

The Impact ◽

Number Of Branches

Integrated weed management practices, such as crop rotation and increased seeding rates, potentially improve weed management. Yet, few studies compare competitive interactions of weeds with different crops. This research quantified the impact of Persian darnel on spring wheat, canola, and sunflower yield across different seeding rates. Increasing crop density increased yield when Persian darnel affected crop yield early in physiological development. Crop yield loss was estimated to reach 83, 70, and 57% for spring wheat, canola, and sunflower, respectively, at high Persian darnel densities. Persian darnel reduced spring wheat yield by limiting the number of tillers per plant and seed per tiller; reduced canola yield by limiting the number of branches per plant, pods per branch, and seed per pod; and reduced sunflower yield by limiting the number of seed per plant. Persian darnel affected crop growth early in physiological development, indicating that interspecific interference occurred early in the growing season. Cultural and resource management aimed at reducing Persian darnel impact on resource availability and crop yield components will reduce Persian darnel impact on crop yield.

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Strategies and tactics for herbicide use reduction in field crops in Canada: A review

Canadian Journal of Plant Science ◽

10.4141/p04-158 ◽

2005 ◽

Vol 85 (2) ◽

pp. 457-479 ◽

Cited By ~ 36

Author(s):

Orla M. Nazarko ◽

Rene C. Van Acker ◽

Martin H. Entz

Keyword(s):

Weed Management ◽

Crop Production ◽

Cropping Systems ◽

Cropping System ◽

Integrated Weed Management ◽

Pesticide Use ◽

Factors Affecting ◽

Field Crops ◽

Low Input Agriculture ◽

Herbicide Use

There are many economic and health reasons for reducing pesticide use in Canada. Herbicide use on field crops is by far the most common pesticide use in Canada. This paper is a review of four topics related to herbicide use reduction on field crops in Canada: (1) broad strategies and (2) specific tactics for herbicide use reduction; (3) factors affecting adoption; and 4) research approaches for improving the implementation of herbicide use reduction. Numerous tactics exist to use herbicides more efficiently and herbicides can sometimes be replaced by non-chemical weed control methods. Many of these tactics and methods have been investigated and demonstrated for use on field crops in Canada. However, herbicide use reduction is fundamentally dependent upon preventative strategies designed to create robust cropping systems that maintain low weed densities. Diverse crop rotation forms the basis of preventative strategies as it inherently varies cropping system conditions to avoid weed adaptation. There is evidence that residual weed densities resulting from herbicide use reduction are manageable within competitive cropping systems. A great deal of research has been done on herbicide use reduction on field crops in Canada, and most projects report definite possibilities for herbicide use reduction in field crop production in Canada. Synthesizing and extending this information and customizing it for use on individual farms remain challenges. Collaboration between researchers and farmers can help to build successful strategies for herbicide use reduction which reflect the context of modern farming, the will of farmers and the culture of technology adoption among farmers. Key words: Pesticide use reduction, low-input agriculture, integrated pest management, integrated weed management

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Slowing weed evolution with integrated weed management

Canadian Journal of Plant Science ◽

10.4141/cjps2013-049 ◽

2013 ◽

Vol 93 (5) ◽

pp. 759-764 ◽

Cited By ~ 22

Author(s):

K. N. Harker

Keyword(s):

Weed Management ◽

Crop Production ◽

Crop Yields ◽

Cropping Systems ◽

Cropping System ◽

Integrated Weed Management ◽

Research Knowledge ◽

Weed Evolution ◽

System Sustainability ◽

Weed Resistance

Harker, K. N. 2013. Slowing weed evolution with integrated weed management. Can. J. Plant Sci. 93: 759–764. For millennia, weeds have slowly evolved in response to ever-changing environments and crop production practices. Weeds are now evolving much more quickly due to consistently repeated cropping systems and intense herbicide selection pressures. Weed resistance to herbicides now threatens cropping system sustainability in several industrialized nations. Integrated weed management (IWM) provides opportunities to reduce selection pressure for weed resistance while maintaining current crop yields. Combining optimal IWM tactics that discourage weeds by minimizing disturbance (no till, direct-seeding), adopting diverse crop rotations, and attempting to preclude resource acquisition by weeds are encouraged. New research knowledge on practical IWM systems is available, but despite current and looming threats of major weed resistance, most crop producers will require greater incentives than those currently available to more-fully adopt IWM systems in the near future.

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Validation of a Management Program Based on A Weed Cover Threshold Model: Effects on Herbicide Use and Weed Populations

Weed Science ◽

10.1614/ws-08-090.1 ◽

2009 ◽

Vol 57 (2) ◽

pp. 187-193 ◽

Cited By ~ 11

Author(s):

Marie-Josée Simard ◽

Bernard Panneton ◽

Louis Longchamps ◽

Claudel Lemieux ◽

Anne Légère ◽

...

Keyword(s):

Seed Production ◽

Crop Yield ◽

Weed Management ◽

Crop Yields ◽

Threshold Model ◽

Management Program ◽

Weed Seed ◽

Weed Density ◽

Weed Cover ◽

Herbicide Use

Weed management decisions based on weed threshold models offer the opportunity to reduce herbicide use by allowing the possibility of forgoing treatment or lowering rates. Weed thresholds based on a relative leaf-cover model were tested during a 4-yr period at two locations. Two 1.62-ha fields, planted to conventional and glyphosate-resistant corn (2004, 2005, 2007) or soybean (2006), were divided in 900 m2sections. Herbicides were applied postemergence to each of these sections with either variable rates based on weed thresholds, or constant full rates. Variable herbicide rates included: no application, half rate, or full rate. Relative weed cover values of 0.2 and 0.4 (corn) or 0.1 and 0.3 (soybean) served as thresholds for incremental rates. Digital images were used to evaluate the relative weed cover. Weed density was assessed before and after herbicide application. Weed seed production was estimated for two species in 2004 and 2005. No difference in crop yield, relative weed cover, weed density, or weed seed production was observed between conventional and glyphosate-resistant cropping systems. During the first year, herbicide use reduction was obtained (−85.4%) with marginal crop yield loss (5 to 15%). In the subsequent 3 yr, preherbicide weed densities increased and concomitant increases in relative weed cover values did not allow more than a 10% overall reduction in herbicide use. This threshold model designed to maintain crop yields within a given year did not allow significant reduction in herbicide use during the following 3 yr. Residual weed populations most likely replenished the seed bank to levels that allowed weed densities to increase afterward. Increased weed density over time in plots treated with full rates of herbicide every year also indicated that a single postemergence herbicide treatment was not sufficient to contain weed populations at low levels every year in this corn–soybean rotation.

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Analysis of Crop Yield Prediction of Kharif & Rabi Jowar Crops Using Data Mining Techniques

International Journal of Advanced Research in Computer Science and Software Engineering ◽

10.23956/ijarcsse.v7i11.468 ◽

2017 ◽

Vol 7 (11) ◽

pp. 79

Author(s):

Sujata Mulik

Keyword(s):

Data Mining ◽

Crop Yield ◽

Crop Production ◽

Climatic Factors ◽

Crop Productivity ◽

Yield Prediction ◽

Data Mining Techniques ◽

Agriculture Sector ◽

Using Data ◽

Rabi Crops

Agriculture sector in India is facing rigorous problem to maximize crop productivity. More than 60 percent of the crop still depends on climatic factors like rainfall, temperature, humidity. This paper discusses the use of various Data Mining applications in agriculture sector. Data Mining is used to solve various problems in agriculture sector. It can be used it to solve yield prediction. The problem of yield prediction is a major problem that remains to be solved based on available data. Data mining techniques are the better choices for this purpose. Different Data Mining techniques are used and evaluated in agriculture for estimating the future year's crop production. In this paper we have focused on predicting crop yield productivity of kharif & Rabi Crops.

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