A rotation design to reduce weed density in organic farming

2010 ◽  
Vol 25 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Randy L. Anderson

AbstractWeeds are a major obstacle to successful crop production in organic farming. Producers may be able to reduce inputs for weed management by designing rotations to disrupt population dynamics of weeds. Population-based management in conventional farming has reduced herbicide use by 50% because weed density declines in cropland across time. In this paper, we suggest a 9-year rotation comprised of perennial forages and annual crops that will disrupt weed population growth and reduce weed density in organic systems. Lower weed density will also improve effectiveness of weed control tactics used for an individual crop. The rotation includes 3-year intervals of no-till, which will improve both weed population management and soil health. Even though this rotation has not been field tested, it provides an example of designing rotations to disrupt population dynamics of weeds. Also, producers may gain additional benefits of higher crop yield and increased nitrogen supply with this rotation design.

2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  

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.


Weed Science ◽  
1995 ◽  
Vol 43 (2) ◽  
pp. 269-275 ◽  
Author(s):  
John L. Lindquist ◽  
Bruce D. Maxwell ◽  
Douglas D. Buhler ◽  
Jeffrey L. Gunsolus

A simulation model was developed to predict the population dynamics and economics of velvetleaf control in a corn-soybean rotation. Data compiled from the literature were used to parameterize the model for two situations, one in which velvetleaf was infected by aVerticilliumspp. wilt and one without infection.Verticilliumwas assumed to have no effect on corn or soybean yield. In the absence of control, simulated seedbank densities of aVerticillium-infected velvetleaf population were 5 to 50 times lower than for an uninfected velvetleaf population. The model was used to evaluate a threshold weed management strategy under the assumption that velvetleaf was the only weed and bentazon the only herbicide available for its control. In the absence ofVerticillium, an economic optimum threshold of 2.5 seedlings 100 m−2afforded the highest economic returns after 20 yr of simulation. Simulations in which velvetleaf was infected in 8 out of 20 randomly assigned years indicated a 6% increase in annualized net return and an 11 % reduction in the number of years that control was necessary. Sensitivity analysis indicated the parameter estimates having the greatest impact on economic optimum threshold were seedling emergence and survival, maximum seed production, and herbicide efficacy. Under an economic optimum threshold of 2.5 seedlings 100 m−2, management practices that manipulate the most sensitive demographic processes increased annualized net return by up to 13% and reduced long-term herbicide use by up to 26%. Results demonstrate that combining an economic optimum threshold with alternative weed management strategies may increase economic return and reduce herbicide use.


2006 ◽  
Vol 20 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Bryan G. Young

Recent shifts in herbicide use patterns can be attributed to rapid, large-scale adoption of glyphosate-resistant soybean and cotton. A dramatic increase in glyphosate use is the most obvious change associated with the adoption of glyphosate-resistant crops. Consequently, the diversity of herbicides used for weed management in these crops has declined, particularly in soybean. To date, the availability of glyphosate-resistant corn has limited the use of glyphosate in corn. While exploiting the benefits of glyphosate-resistant crops, many growers have abandoned the principles of sound weed and herbicide-resistance management. Instead of incorporating glyphosate into a resistance management strategy utilizing multiple herbicide sites of action, many growers rely exclusively upon glyphosate for weed control. Although it is difficult to establish a clear relationship between the adoption of glyphosate-resistant crops and changes in other crop production practices, the increase in no-till and strip-till production of cotton and soybean between 1995 and 2002 may have been facilitated by glyphosate-resistant crops.


Author(s):  
M. D. Ojha ◽  
Vijay Kumar ◽  
Divya Tiwari ◽  
Vinod Kumar ◽  
Manish Kumar ◽  
...  

Organic agriculture seeks to augment ecological process that foster plant nutrition while conserving soil and water resources. Organic systems eliminate agrichemicals and reduce other external inputs to improve the environment as well as farm economics. It is a production system which favours maximum use of organic materials like crop residues, FYM, compost, green manures, oil cakes, biodynamic preparations and bio fertilizers etc. to enhance crop production, carbon sequestration and improve soil health. Organic production system is based on specific and precise standards of production which aim to achieving agro-ecosystems which are socially and ecologically sustainable. As demand for organically grown food has been growing rapidly and significant proportion of consumers believe that organic food is qualitatively better than non organic, the present study showed not only the quality of the produce but also quantitatively higher yield that touched the world record production (660 q/ha) in Nalanda Bihar.


2020 ◽  
Vol 12 (12) ◽  
pp. 4859 ◽  
Author(s):  
Monther M. Tahat ◽  
Kholoud M. Alananbeh ◽  
Yahia A. Othman ◽  
Daniel I. Leskovar

A healthy soil acts as a dynamic living system that delivers multiple ecosystem services, such as sustaining water quality and plant productivity, controlling soil nutrient recycling decomposition, and removing greenhouse gases from the atmosphere. Soil health is closely associated with sustainable agriculture, because soil microorganism diversity and activity are the main components of soil health. Agricultural sustainability is defined as the ability of a crop production system to continuously produce food without environmental degradation. Arbuscular mycorrhizal fungi (AMF), cyanobacteria, and beneficial nematodes enhance water use efficiency and nutrient availability to plants, phytohormones production, soil nutrient cycling, and plant resistance to environmental stresses. Farming practices have shown that organic farming and tillage improve soil health by increasing the abundance, diversity, and activity of microorganisms. Conservation tillage can potentially increase grower’s profitability by reducing inputs and labor costs as compared to conventional tillage while organic farming might add extra management costs due to high labor demands for weeding and pest control, and for fertilizer inputs (particularly N-based), which typically have less consistent uniformity and stability than synthetic fertilizers. This review will discuss the external factors controlling the abundance of rhizosphere microbiota and the impact of crop management practices on soil health and their role in sustainable crop production.


2013 ◽  
Vol 27 (2) ◽  
pp. 352-361
Author(s):  
Mohammad Ghorbani ◽  
Surendra Kulshreshtha

Inputs, including herbicides, used in crop production may create negative environmental impacts. One solution to minimize these adverse effects is the adoption of integrated weed management (IWM) with the intention of reducing herbicide use. This study, conducted in 2010, estimates the willingness of farmers to pay for the adoption of more effective weed management methods. Results suggest that the willingness to pay (WTP) for IWM is greater than the WTP for other weed management methods, including chemical weed management and chemical and mechanical weed management. This study also identified a number of factors that influence the adoption of IWM on wheat farms in Iran using a multinomial logit model. Total annual income, area under irrigated wheat, wheat yield loss due to weeds, perennial nature of the weeds, and having awareness of weed resistance to herbicides had a positive effect on the adoption of IWM practices. However, having rain-fed (dryland) wheat cultivation and a larger number of plots on the farm had a negative influence on the choice of IWM.


Agronomy ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Donato Loddo ◽  
Laura Scarabel ◽  
Maurizio Sattin ◽  
Antonio Pederzoli ◽  
Chiara Morsiani ◽  
...  

Herbicides have facilitated weed management but their incorrect use can lead to environmental contamination. Reducing herbicide use by limiting their application to a band along the crop row can decrease their environmental impact. Three field experiments were conducted in North-eastern Italy to evaluate herbicide band application systems integrated with inter-row hoeing for silage maize. Post-emergence herbicide band application (sprayed area 50% of total field; herbicide dose 50% of that recommended, application with an inter-row cultivator prototype) was compared with pre-emergence band application (sprayed area 33% of total field; herbicide dose 33% of that recommended, application with a seeder) and pre-emergence broadcast application (sprayed area 100% of total field; full recommended herbicide dose, application with a boom sprayer) that is standard management for maize. Weed density and composition were evaluated before and after post-emergence herbicide application and at crop harvest. Crop yield was also recorded. Weed density in untreated areas ranged between 5 and 15 plants m−2 in the different experiments. Optimal weed control and good yields were achieved without significant differences between all treatments. Herbicide band application can provide optimal weed control in silage maize, at the same time allowing a relevant reduction of herbicide input.


2019 ◽  
Vol 5 (2) ◽  
pp. 54-61
Author(s):  
Zahir Muhammad ◽  
Naila Inayat ◽  
Abdul Majeed ◽  
Hazrat Ali ◽  
Kaleem Ullah ◽  
...  

Abstract Crop plants have defined roles in agricultural production and feeding the world. They are affected by several environmental and biological stresses, which range from soil salinity, drought, and climate change to exposure to diverse plant pathogens. These stresses pose risk to agricultural sustainability. To avoid the increasing biotic and abiotic pressure on crop plants, agrochemicals are extensively used in agriculture for attaining desirable yield and production of crops. However, the use of agrochemicals is also challenging the integrity of ecosystems. Thus, to maintain the integrity of ecosystem, sustainable measures for elevated crop production are required. Allelopathy, a process of chemical interactions between plants and other organisms, could be used in the management of several biotic and abiotic stresses if the basic mechanisms of the phenomena and plants with allelopathic potentials are known. Allelopathy has a promising future for its application in agriculture for natural weed management, improving soil health and suppressing plant diseases. The aim of this review is to discuss the importance of allelopathy in agriculture and its role in sustainability with a specific focus on weed management and crop protection.


2020 ◽  
Vol 71 (5) ◽  
pp. 491 ◽  
Author(s):  
Martin Harries ◽  
Ken C. Flower ◽  
Craig A. Scanlan ◽  
Michael T. Rose ◽  
Michael Renton

Six years of survey data taken from 184 paddocks spanning 14 million ha of land used for crop and pasture production in south-west Western Australia were used to assess weed populations, herbicide resistance, integrated weed management (IWM) actions and herbicide use patterns in a dryland agricultural system. Key findings were that weed density within crops was low, with 72% of cropping paddocks containing fewer than 10 grass weeds/m2 at anthesis. Weed density and herbicide resistance were not correlated, despite the most abundant grass weed species (annual ryegrass, Lolium rigidum Gaudin) testing positive for resistance to at least one herbicide chemistry in 92% of monitored paddocks. A wide range of herbicides were used (369 unique combinations) suggesting that the diversity of herbicide modes of action may be beneficial for reducing further development of herbicide resistance. However, there was a heavy reliance on glyphosate, the most commonly applied active ingredient. Of concern, in respect to the evolution of glyphosate resistant weeds, was that 45% of glyphosate applications to canola were applied as a single active ingredient and area sown to canola in Western Australia expanded from 0.4 to 1.4 million hectares from 2005 to 2015. In order to minimise the weed seed bank within crops, pastures were used infrequently in some regions and in 50% of cases pastures were actively managed to reduce weed seed set, by applying a non-selective herbicide in spring. The use of non-selective herbicides in this manner also kills pasture plants, consequently self-regenerating pastures were sparse and contained few legumes where cropping intensity was high. Overall, the study indicated that land use selection and utilisation of associated weed management actions were being used successfully to control weeds within the survey area. However, to successfully manage herbicide resistant weeds land use has become less diverse, with pastures utilised less and crops with efficacious weed control options utilised more. Further consideration needs to be given to the impacts of these changes in land use on other production factors, such as soil nutrient status and plant pathogens to assess sustainability of these weed management practices in a wider context.


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