Showing papers on "Organic farming published in 2014"

Land-use intensity and the effects of organic farming on biodiversity: a hierarchical meta-analysis

Abstract: Summary 1. The benefits of organic farming to biodiversity in agricultural landscapes continue to be hotly debated, emphasizing the importance of precisely quantifying the effect of organic vs. conventional farming. 2. We conducted an updated hierarchical meta-analysis of studies that compared biodiversity under organic and conventional farming methods, measured as species richness. We calculated effect sizes for 184 observations garnered from 94 studies, and for each study, we obtained three standardized measures reflecting land-use intensity. We investigated the stability of effect sizes through time, publication bias due to the ‘file drawer’ problem, and consider whether the current literature is representative of global organic farming patterns. 3. On average, organic farming increased species richness by about 30%. This result has been robust over the last 30 years of published studies and shows no sign of diminishing. 4. Organic farming had a greater effect on biodiversity as the percentage of the landscape consisting of arable fields increased, that is, it is higher in intensively farmed regions. The average effect size and the response to agricultural intensification depend on taxonomic group, functional group and crop type. 5. There is some evidence for publication bias in the literature; however, our results are robust to its impact. Current studies are heavily biased towards northern and western Europe and North America, while other regions with large areas of organic farming remain poorly investigated. 6. Synthesis and applications. Our analysis affirms that organic farming has large positive effects on biodiversity compared with conventional farming, but that the effect size varies with the organism group and crop studied, and is greater in landscapes with higher land-use intensity. Decisions about where to site organic farms to maximize biodiversity will, however, depend on the costs as well as the potential benefits. Current studies have been heavily biased towards agricultural systems in the developed world. We recommend that future studies pay greater attention to other regions, in particular, areas with tropical, subtropical and Mediterranean climates, in which very few studies have been conducted.

Biofertilizer, a way towards organic agriculture: A review

Abstract: Fertilizers supply essential plant nutrients, mainly nitrogen (N), potassium (K) and phosphorous (P). These fertilizers increase the yield of the crop but they cause several health hazard. Due to the several health hazard, consumer preferences shift towards the use of the organic food grown without use of any chemical. In recent years, biofertilizers have emerged as an important component for biological nitrogen fixation. They offer an economically attractive and ecologically sound route for providing nutrient to the plant. Biofertilizers are low-cost renewable source of nutrient that supplements the chemical fertilizer. Biofertilizers gained importance due to its low cost amongst small and marginal farmer. Key words: Biofertilizer, isolation, mass multiplication, N2 fixers, plant growth promoting rhizobacteria (PGPR), organic agriculture.

Reconciling pesticide reduction with economic and environmental sustainability in arable farming.

Abstract: Reducing pesticide use is one of the high-priority targets in the quest for a sustainable agriculture Until now, most studies dealing with pesticide use reduction have compared a limited number of experimental prototypes Here we assessed the sustainability of 48 arable cropping systems from two major agricultural regions of France, including conventional, integrated and organic systems, with a wide range of pesticide use intensities and management (crop rotation, soil tillage, cultivars, fertilization, etc) We assessed cropping system sustainability using a set of economic, environmental and social indicators We failed to detect any positive correlation between pesticide use intensity and both productivity (when organic farms were excluded) and profitability In addition, there was no relationship between pesticide use and workload We found that crop rotation diversity was higher in cropping systems with low pesticide use, which would support the important role of crop rotation diversity in integrated and organic strategies In comparison to conventional systems, integrated strategies showed a decrease in the use of both pesticides and nitrogen fertilizers, they consumed less energy and were frequently more energy efficient Integrated systems therefore appeared as the best compromise in sustainability trade-offs Our results could be used to re-design current cropping systems, by promoting diversified crop rotations and the combination of a wide range of available techniques contributing to pest management

Gains to species diversity in organically farmed fields are not propagated at the farm level

Abstract: Organic farming is promoted to reduce environmental impacts of agriculture, but surprisingly little is known about its effects at the farm level, the primary unit of decision making. Here we report the effects of organic farming on species diversity at the field, farm and regional levels by sampling plants, earthworms, spiders and bees in 1470 fields of 205 randomly selected organic and nonorganic farms in twelve European and African regions. Species richness is, on average, 10.5% higher in organic than nonorganic production fields, with highest gains in intensive arable fields (around +45%). Gains to species richness are partly caused by higher organism abundance and are common in plants and bees but intermittent in earthworms and spiders. Average gains are marginal +4.6% at the farm and +3.1% at the regional level, even in intensive arable regions. Additional, targeted measures are therefore needed to fulfil the commitment of organic farming to benefit farmland biodiversity.

Nitrate leaching from intensive organic farms to groundwater

Abstract: It is commonly presumed that organic agriculture causes only minimal environmental pollution. In this study, we measured the quality of percolating water in the vadose zone, underlying both organic and conventional intensive greenhouses. Our study was conducted in newly established farms where the subsurface underlying the greenhouses has been monitored continuously from their establishment. Surprisingly, intensive organic agriculture relying on solid organic matter, such as composted manure that is implemented in the soil prior to planting as the sole fertilizer, resulted in significant down-leaching of nitrate through the vadose zone to the groundwater. On the other hand, similar intensive agriculture that implemented liquid fertilizer through drip irrigation, as commonly practiced in conventional agriculture, resulted in much lower rates of pollution of the vadose zone and groundwater. It has been shown that accurate fertilization methods that distribute the fertilizers through the irrigation system, according to plant demand, during the growing season dramatically reduce the potential for groundwater contamination from both organic and conventional greenhouses.

Energy use and greenhouse gas emissions in organic and conventional farming systems in the Netherlands

Abstract: Organic agriculture is often considered to contribute to reducing energy use and greenhouse gas (GHG) emissions, also on a per unit product basis. For energy, this is supported by a large number of studies, but the body of evidence for GHGs is smaller. Dutch agriculture is characterized by relatively intensive land use in both organic and conventional farming, which may affect their performance in terms of energy use and GHG emissions. This paper presents results of a model study on energy use and GHG emissions in Dutch organic and conventional farming systems. Energy use per unit milk in organic dairy is approximately 25% lower than in conventional dairy, while GHG emissions are 5-10% lower. Contrary to dairy farming, energy use and GHG emissions in organic crop production are higher than in conventional crop production. Energy use in organic arable farming is 10-30% and in organic vegetable farming 40-50% higher than in their respective conventional counterparts. GHG emissions in organic arable and vegetable farming are 0-15% and 35-40% higher, respectively. Our results correspond with other studies for dairy farming, but not for crop production. The most likely cause for higher energy use and GHG emissions in Dutch organic crop production is its high intensity level, which is expressed in crop rotations with a large share of high-value crops, relatively high fertiliser inputs and frequent field operations related to weeding.

First evidence for a major cover crop effect on arbuscular mycorrhizal fungi and organic maize growth

Abstract: Arbuscular mycorrhizal fungi are increasingly used in organic cropping systems to increase yields. Although cover crops are largely used in organic farming, there is little knowledge on the impact of cover crops on native mycorrhizal fungi. Here, we studied the effect of cover crop diversity on mycorrhizal colonization in subsequent organic maize cultivars differing in the level of genetic diversity. Experiments were conducted from 2010 to 2012 in a Mediterranean environment. First Indian mustard (Brassica juncea L. Czern.), hairy vetch (Vicia villosa Roth), a mix of seven cover crop species (Mix), and natural vegetation (Control) were cultivated as winter cover crops. Then, an organically and a conventionally bred maize hybrid and three organically bred composite cross populations were cultivated. Mycorrhizal propagule dynamics were measured. Results at juvenile stage show a higher mycorrhizal colonization in maize plants grown after hairy vetch, of 35.0 %, and Mix cover crops, of 29.4 %, compared to Indian mustard, of 20.9 %, and Control, of 21.3 %. The potential of soil mycorrhization decreased of 56.5 % following Indian mustard, higher than that of other cover crops, of 34.1–47.3 %. This finding could be explained by the release of isothiocyanates in soils. Moreover, maize shoot biomass, nitrogen, and phosphorus content across all maize genotypes at juvenile stage increased with mycorrhizal colonization. These findings provide the first evidence of the greater role played by cover crop identity in the enhancement of early mycorrhizal colonization of the subsequent crop and of soil mycorrhizal activity.

Contribution of Organically Grown Crops to Human Health

Abstract: An increasing interest in organic agriculture for food production is seen throughout the world and one key reason for this interest is the assumption that organic food consumption is beneficial to public health The present paper focuses on the background of organic agriculture, important public health related compounds from crop food and variations in the amount of health related compounds in crops In addition, influence of organic farming on health related compounds, on pesticide residues and heavy metals in crops, and relations between organic food and health biomarkers as well as in vitro studies are also the focus of the present paper Nutritionally beneficial compounds of highest relevance for public health were micronutrients, especially Fe and Zn, and bioactive compounds such as carotenoids (including pro-vitamin A compounds), tocopherols (including vitamin E) and phenolic compounds Extremely large variations in the contents of these compounds were seen, depending on genotype, climate, environment, farming conditions, harvest time, and part of the crop Highest amounts seen were related to the choice of genotype and were also increased by genetic modification of the crop Organic cultivation did not influence the content of most of the nutritional beneficial compounds, except the phenolic compounds that were increased with the amounts of pathogens However, higher amounts of pesticide residues and in many cases also of heavy metals were seen in the conventionally produced crops compared to the organic ones Animal studies as well as in vitro studies showed a clear indication of a beneficial effect of organic food/extracts as compared to conventional ones Thus, consumption of organic food seems to be positive from a public health point of view, although the reasons are unclear, and synergistic effects between various constituents within the food are likely

Nitrate leaching from organic and conventional arable crop farms in the Seine Basin (France)

Abstract: In the Seine Basin, characterised by intensive arable crops, most of the surface and groundwater is contaminated by nitrate (NO3-). The goal of this study is to investigate nitrogen leaching on commercial arable crop farms in five organic and three conventional systems. In 2012-2013, a total of 37 fields are studied on eight arable crop rotations, for three different soil and climate conditions. Our results show a gradient of soil solution concentrations in function of crops, lower for alfalfa (mean 2.8 mg NO3-N l(-1)) and higher for crops fertilised after legumes (15 mg NO3-N l(-1)). Catch crops decrease nitrate soil solution concentrations, below 10 mg NO3-N l(-1). For a full rotation, the estimated mean concentrations is lower for organic farming, 12 +/- 5 mg NO3-N l(-1) than for conventional farming 24 +/- 11 mg NO3-N l(-1), with however a large range of variability. Overall, organic farming shows lower leaching rates (14-50 kg NO3-N ha(-1)) than conventional farms (32-77 kg NO3-N ha(-1)). Taking into account the slightly lower productivity of organic systems, we show that yield-scaled leaching values are also lower for organic (0.2 +/- 0.1 kg N kg(-1) N year(-1)) than for conventional systems (0.3 +/- 0.1 kg N kg(-1) N year(-1)). Overall, we show that organic farming systems have lower impact than conventional farming on N leaching, although there is still room for progress in both systems in commercial farms.

Soil properties in organic olive orchards following different weed management in a rolling landscape of Andalusia, Spain

Abstract: This study evaluated the most significant physical, chemical and biological soil properties from a group of organic olive farms located in a typical olive-growing area of Andalusia, Spain, after 5 or more years since the shift from conventional to organic farming, and compared soils with those in nearby undisturbed (U) natural areas. Two soil management systems implemented in these organic olive farms to control weeds, tillage (T), characterized by non-inverting-shallow tillage in spring, and mechanical mowing (M), were compared and evaluated against the U areas. Organic olive orchards showed similar productivity (average fruit yield of 3130 kg ha−1 yr−1) as the conventional, rain-fed olive groves in the same area, with no significant differences due to soil management systems. Soil properties in the olive orchards (i.e. texture, pH, organic carbon (C), organic nitrogen (N), C:N ratio, cation exchange capacity (CEC) and exchangeable potassium) were in the suitable range for olive farming in both soil managements, although organic C and N, saturated hydraulic conductivity and available water-holding capacity (AWC) of the soil were lower than in the U areas. A principal component analysis (PCA) for soil properties in topsoil (0–10 cm depth) distinguished the T from M olive orchards and U areas, and determined organic C and N as the most significant soil properties to characterize them. Average values of soil organic carbon (SOC) stocks for the surface layer (0–10 cm depth) were 18.6, 59.3 and 67.8 Mg ha−1, for T and M soil management systems and U areas, respectively. This indicates that the sustainability of organic olive orchards could be significantly improved by shifting to M soil management to decrease soil erosion and depletion of SOC.

GM Crops, Organic Agriculture and Breeding for Sustainability

Abstract: The ongoing debate about the use of genetically-modified (GM) crops in agriculture has largely focused on food safety and genetic contamination issues. Given that the majority of GM crops have been produced to respond to the problem of crop yield reductions caused by diseases, insects and weeds, the paper argues that in those cases, the currently used GM crops are an unstable solution to the problem, because they represent such a strong selection pressure, that pests rapidly evolve resistance. Organic agriculture practices provide a more sustainable way of producing healthy food; however, the lower yields often associated with those practices, making the resultant healthy food more expensive, open the criticism that such practices will not be able to feed human populations. Evolutionary plant breeding offers the possibility of using the evolutionary potential of crops to our advantage by producing a continuous flow of varieties better adapted to organic systems, to climate change and to the ever changing spectrum of pests, without depending on chemical control.

Mixed crop–livestock farming systems: a sustainable way to produce beef? Commercial farms results, questions and perspectives

Abstract: Mixed crop–livestock (MC–L) farming has gained broad consensus as an economically and environmentally sustainable farming system. Working on a Charolais-area suckler cattle farms network, we subdivided the 66 farms of a constant sample, for 2 years (2010 and 2011), into four groups: (i) ‘specialized conventional livestock farms’ (100% grassland-based farms (GF), n=7); (ii) ‘integrated conventional crop–livestock farms’ (specialized farms that only market animal products but that grow cereal crops on-farm for animal feed, n=31); (iii) ‘mixed conventional crop–livestock farms’ (farms that sell beef and cereal crops to market, n=21); and (iv) organic farms (n=7). We analyse the differences in structure and in drivers of technical, economic and environmental performances. The figures for all the farms over 2 years (2010 and 2011) were pooled into a single sample for each group. The farms that sell crops alongside beef miss out on potential economies of scale. These farms are bigger than specialized beef farms (with or without on-farm feed crops) and all types of farms show comparable economic performances. The big MC–L farms make heavier and consequently less efficient use of inputs. This use of less efficient inputs also weakens their environmental performances. This subpopulation of suckler cattle farms appears unable to translate a MC–L strategy into economies of scope. Organic farms most efficiently exploit the diversity of herd feed resources, thus positioning organic agriculture as a prototype MC–L system meeting the core principles of agroecology.

Integrating Weed and Vegetable Crop Management with Multifunctional Air-Propelled Abrasive Grits

Abstract: Abrasive weed control is a novel weed management tactic that has great potential to increase the profitability and sustainability of organic vegetable cropping systems. The objective of this study was to determine the effect of air-propelled organic abrasive grits (e.g., organic fertilizers) on weed seedling emergence and growth and vegetable crop growth. A series of thirteen greenhouse trials were conducted to determine the susceptibility of weeds to abrasive weed control with one of six organic materials including: corn cob grits, corn gluten meal, greensand fertilizer, walnut shell grits, soybean meal, and bone meal fertilizer. In addition, crop injury was quantified to determine the potential utility of each organic material as abrasive grits in tomato and pepper cropping systems. Of the six organic materials, corn gluten meal, greensand fertilizer, walnut shell grits, and soybean meal provided the broadest range of POST weed control. For example, one blast of corn gluten meal and greensand f...

Technical efficiency and conversion to organic farming: the case of France

Abstract: Using a panel of French crop farms, we test whether farmers’ technical efficiency under conventional practices is a significant driver of conversion to organic farming. An important issue is whether subsidies to organic farming could encourage inefficient farmers to convert. We find that the probability of conversion does depend on technical efficiency preceding the conversion, but that the direction of the effect depends on farm size. This result is found to be robust to the method of calculation of efficiency scores, either parametric or non-parametric. This study also confirms that farm’s characteristics impact the probability of conversion to organic farming.

Screening Five Fall-Sown Cover Crops for Use in Organic No-Till Crop Production in the Upper Midwest

Abstract: Organic no-till systems continue to draw interest from organic producers across the upper Midwest in the United States. Fall-planted cover crops, terminated in the spring through the use of a roller-crimper or a mower, are a key component of these systems. In this study, five different cover crops (hairy vetch, Austrian winter peas, winter rye, winter barley, and winter triticale) were planted in the fall and terminated in the spring in preparation for no-till organic row crop production. This study compared the cover crops through measurements of: a) the amount of biomass produced by the cover crops before termination; b) the weed suppression potential of the cover crops terminated with either a roller-crimper or sickle-bar mower; and c) volumetric soil water content throughout the row crop production season. Biomass production of each of the cover crops differed significantly by variety and by year, ranging from 3.67 to 14.56 Mg DM ha−1. Significant differences in weed densities and weed biomass were al...

Current State of Weed Management in Organic and Conventional Cropping Systems

Abstract: Crop losses due to weeds result in reduced yields and quality and increases in harvest costs. Weed management often requires major resource inputs to produce a successful crop. Herbicides are central to the conventional approach to weed management, and they have allowed the grower to reduce management priority, time, effort, and cost of managing weeds. Their use has at times come at a price such as herbicide-resistant weeds, environmental damage, reduced water quality, and loss of genetic diversity. Although growers use a combination of management practices to control weeds, differences between those used in conventional agriculture compared to organic production systems often vary widely in their implementation and relative importance. Approaches to weed management within an organic system revolve around implementing a range of techniques, often consecutively over the course of the cropping rotation. For both organic and conventional growers, weed management remains a significant impediment to optimizing crop yield, improving crop quality, and reducing the costs of production.