Organic Farming Provides Reliable Environmental Benefits but Increases Variability in Crop Yields: A Global Meta-Analysis

Canada, in 2009, will enact a regulatory regime to oversee certified organic agricultural productions systems, based on a management standard. The overreaching goal of that standard is to develop farm enterprises that are “sustainable and harmonious with the environment”. However, empirical evidence to shed light on claims of environmental benefits from organic agriculture is particularly scarce in Canada and North America generally, and has not been comprehensively summarized. This review examines the literature of Canadian and US studies which relate to environmental impacts of organic agriculture within the selected indicators of: (i) soil organic matter storage and soil quality/soil health; (ii) plant and wildlife biodiversity; (iii) energy use; (iv) nutrient loading and off-farm nutrient losses; and (v) climate change and greenhouse gas emissions. The empirical evidence presented suggests organic farming system attributes regarding cropping, floral, and habitat diversity, nutrient intensity, soil management, energy and pesticide use, etc., are sufficiently distinct as to impart potentially important environmental benefits across the indicator categories examined. However, on average, crop yields under organic management regimes continue to lag behind those obtained by conventional management systems. More research is needed to validate these results, for the benefit of producers, consumers and policy makers as they decide the relative importance and contribution of organic farming systems to the Canadian food marketplace and agrifood sector. Key words: Organic agriculture, farming system, soil, biodiversity, energy, greenhouse gases

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Shallow non-inversion tillage in organic farming maintains crop yields and increases soil C stocks: a meta-analysis

Agronomy for Sustainable Development ◽

10.1007/s13593-016-0354-1 ◽

2016 ◽

Vol 36 (1) ◽

Cited By ~ 61

Author(s):

Julia Cooper ◽

Marcin Baranski ◽

Gavin Stewart ◽

Majimcha Nobel-de Lange ◽

Paolo Bàrberi ◽

...

Keyword(s):

Organic Farming ◽

Crop Yields ◽

Meta Analysis ◽

Soil C ◽

C Stocks

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Effects of climate-smart agricultural practices on crop yields, soil carbon, and nitrogen pools in Africa: a meta-analysis

Journal of Soils and Sediments ◽

10.1007/s11368-021-02885-3 ◽

2021 ◽

Author(s):

Edith Kichamu-Wachira ◽

Zhihong Xu ◽

Kathryn Reardon-Smith ◽

Duan Biggs ◽

Geoffrey Wachira ◽

...

Keyword(s):

Soil Carbon ◽

Crop Yields ◽

Meta Analysis ◽

Agricultural Practices ◽

Carbon And Nitrogen ◽

Soil Carbon And Nitrogen ◽

Nitrogen Pools

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A short-term comparison of organic v. conventional agriculture in a silty loam soil using two organic amendments

The Journal of Agricultural Science ◽

10.1017/s0021859608008071 ◽

2008 ◽

Vol 146 (6) ◽

pp. 677-687 ◽

Cited By ~ 33

Author(s):

J. F. HERENCIA ◽

J. C. RUIZ ◽

S. MELERO ◽

P. A. GARCIA GALAVÍS ◽

C. MAQUEDA

Keyword(s):

Organic Farming ◽

Crop Yields ◽

Organic Amendments ◽

Chemical Properties ◽

Soil Nutrient ◽

Short Term ◽

Organic System ◽

Conventional Agriculture ◽

Silty Loam ◽

Loam Soil

SUMMARYThe transition from conventional to organic farming is accompanied by changes in soil chemical properties and processes that could affect soil fertility. The organic system is very complex and the present work carries out a short-term comparison of the effects of organic and conventional agriculture on the chemical properties of a silty loam soil (Xerofluvent) located in the Guadalquivir River Valley, Seville, Spain, through a succession of five crop cycles over a 3-year period. Crop rotation and varieties were compared in a conventional system using inorganic fertilizer and two organic systems using either plant compost or manure. At the end of the study, organic farming management resulted in higher soil organic carbon (OC), N and available P, K, Fe and Zn. The available Mn and especially Cu values did not show significant differences. In general, treatment with manure resulted in more rapid increases in soil nutrient values than did plant compost, which had an effect on several crop cycles later. The present study demonstrated that the use of organic composts results in an increase in OC and the storage of nutrients, which can provide long-term fertility benefits. Nevertheless, at least 2–3 years of organic management are necessary, depending on compost characteristics, to observe significant differences. Average crop yields were 23% lower in organic crops. Nevertheless, only two crops showed statistically significant differences.

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Can Organic Sources of Nutrients Increase Crop Yields to Meet Global Food Demand?

Agronomy ◽

10.3390/agronomy8100214 ◽

2018 ◽

Vol 8 (10) ◽

pp. 214 ◽

Cited By ~ 33

Author(s):

Jagadish Timsina

Keyword(s):

Climate Change ◽

Soil Fertility ◽

Organic Farming ◽

Crop Yields ◽

Food Demand ◽

Conventional Farming ◽

Chemical Fertilizers ◽

Organic Nutrients ◽

On Farm ◽

Global Food

Meeting global demand of safe and healthy food for the ever-increasing population now and into the future is currently a crucial challenge. Increasing crop production by preserving environment and mitigating climate change should thus be the main goal of today’s agriculture. Conventional farming is characterized by use of high-yielding varieties, irrigation water, chemical fertilizers and synthetic pesticides to increase yields. However, due to either over- or misuse of chemical fertilizers or pesticides in many agro-ecosystems, such farming is often blamed for land degradation and environmental pollution and for adversely affecting the health of humans, plants, animals and aquatic ecosystems. Of all inputs required for increased agricultural production, nutrients are considered to be the most important ones. Organic farming, with use of organic sources of nutrients, is proposed as a sustainable strategy for producing safe, healthy and cheaper food and for restoring soil fertility and mitigating climate change. However, there are several myths and controversies surrounding the use of organic versus inorganic sources of nutrients. The objectives of this paper are: (i) to clarify some of the myths or misconceptions about organic versus inorganic sources of nutrients and (ii) to propose alternative solutions to increase on-farm biomass production for use as organic inputs for improving soil fertility and increasing crop yields. Common myths identified by this review include that organic materials/fertilizers can: (i) supply all required macro- and micro-nutrients for plants; (ii) improve physical, chemical and microbiological properties of soils; (iii) be applied universally on all soils; (iv) always produce quality products; (v) be cheaper and affordable; and (vi) build-up of large amount of soil organic matter. Other related myths are: “legumes can use entire amount of N2 fixed from atmosphere” and “bio-fertilizers increase nutrient content of soil.” Common myths regarding chemical fertilizers are that they: (i) are not easily available and affordable, (ii) degrade land, (iii) pollute environment and (iv) adversely affect health of humans, animals and agro-ecosystems. The review reveals that, except in some cases where higher yields (and higher profits) can be found from organic farming, their yields are generally 20–50% lower than that from conventional farming. The paper demonstrates that considering the current organic sources of nutrients in the developing countries, organic nutrients alone are not enough to increase crop yields to meet global food demand and that nutrients from inorganic and organic sources should preferably be applied at 75:25 ratio. The review identifies a new and alternative concept of Evergreen Agriculture (an extension of Agroforestry System), which has potential to supply organic nutrients in much higher amounts, improve on-farm soil fertility and meet nutrient demand of high-yielding crops, sequester carbon and mitigate greenhouse gas emissions, provide fodder for livestock and fuelwood for farmers and has potential to meet global food demand. Evergreen Agriculture has been widely adapted by tens of millions of farmers in several African countries and the review proposes for evaluation and scaling-up of such technology in Asian and Latin American countries too.

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Outcomes of Long-Term Conservation Tillage Research in Northern China

Sustainability ◽

10.3390/su12031062 ◽

2020 ◽

Vol 12 (3) ◽

pp. 1062 ◽

Cited By ~ 3

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.

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Replacing Synthetic Nitrogen Fertilizer with Different Types of Organic Materials Improves Grain Yield in China: A Meta-Analysis

Agronomy ◽

10.3390/agronomy11122429 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2429

Author(s):

Xiaoru Fan ◽

Zekai Chen ◽

Zihan Niu ◽

Ruiyao Zeng ◽

Jingmin Ou ◽

...

Keyword(s):

Grain Yield ◽

Nitrogen Fertilizer ◽

Organic Materials ◽

Crop Yields ◽

Meta Analysis ◽

Chicken Manure ◽

Agricultural Practice ◽

Different Types ◽

Synthetic Nitrogen Fertilizer

Synthetic nitrogen fertilizer substitution (NSS) with different types of organic material is a cleaner agricultural practice for reducing the application of synthetic N input in farmlands while also relieving the environmental issues caused by the discharge of organic wastes. However, the effects of the NSS practice on crop yields, being the primary objective of agricultural activity, is still uncertain in China. This study conducted a meta-analysis to assess the impacts of the NSS practices with different types of organic materials on crop yields. Results showed that the average crop yield was increased by 3.4%, with significant differences under NSS, thereby demonstrating that this practice contributed to improving crop yields, especially of rice and maize. According to published reports, the NSS practices involving chicken manure, pig manure, and crop straw increased crop yields by 4.79, 7.68, and 3.28%, respectively, with significant differences, thus demonstrating the superior effects needed for replacing synthetic N fertilizer. Moreover, substitution ratios (SR) between 0% and 60% could be suggested when using the NSS practice, with the high SR recommended when the original soil fertility was adequate for crops. Considering the long-term effects of applied organic materials, improving the grain yield with the NSS practice should be expected in the long-term. By effectively applying the NSS, this study attempted to scientifically decide on the type of organic materials and the appropriate SR based on the conditions of the soil and the crop. The results provide research information for the development of clean agricultural production and food security in China.

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A comparative study on the costs and returns of organic vs. inorganic farming practices at selected areas near Dhaka, Bangladesh

Research in Agriculture Livestock and Fisheries ◽

10.3329/ralf.v6i2.43052 ◽

2019 ◽

Vol 6 (2) ◽

pp. 289-299

Author(s):

Md Arafat Islam ◽

Nazmul Ahsan Khan ◽

Raisa Bashar

Keyword(s):

Organic Farming ◽

Crop Yields ◽

Cost Effective ◽

Primary Data ◽

Farming Practices ◽

Structured Interviews ◽

Group Discussions ◽

Long Run ◽

Effective Choice

Inorganic farming is the norm in most areas of Bangladesh today, especially at croplands near Bangladesh’s capital - Dhaka. However, several recent studies have shown that such practices cause soil degradation overtime, consequently leading to long-term harm to the environment and economic profits. This long-term cost is often avoided by most farmers as inorganic farming is believed to fetch increased productivity/monetary gains, than its environmentally friendly, organic counterpart: the primary aim of this research was to find out the validity of this belief. The research used literature review and analysis of primary data collected about input costs, returns, crop yields, environmental effects, etc., from sixty respondents (mostly farmers and consumers involved in both types of farming), using one-on-one structured interviews, and three focus group discussions at the selected areas of Savar, Sreenagar and Rupganj, focusing primarily on two popular crops – tomato and corn; graphical and tabular analyses were conducted using MS Excel to propose interpretations and record findings. Keeping all other things constant and internalizing environmental externalities, while organic farming was found to produce around 50% and 33% less tomatoes and corns in net terms, respectively, than inorganic farming, the input costs and returns from one cycle of production were found to be lower (50%) and higher (around 200USD), respectively. Hence, from a long-run perspective, organic farming was concluded as the more cost-effective choice both in economic and environmental terms, given that the Dhaka market for organic products are managed better by the producers, consumers and government, alike. Res. Agric., Livest. Fish.6(2): 289-299, August 2019

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