Current developments in organic farming

Organic farming uses almost exclusively biological and natural materials and processes to produce food. The practice aims to protect human health and conserve, maintain or enhance natural resources, with the goal to preserve the quality of the environment for future generations while being economically sustainable. Organic farming has grown rapidly throughout the world in recent years. Currently, Australia (Oceania) has the largest land areas under organic farming, Liechtenstein (Europe) the highest percentage of organic area, and Mexico (Latin America) the greatest number of organic farms worldwide. One of the most valuable benefits of Correspondence/Reprint request: Dr. N.V. Hue, Department of Tropical Plant and Soil Sciences, University of Hawaii, USA. E-mail: [email protected] M.E. Ortiz Escobar & N.V. Hue 2 organic farming is the improvement in soil quality, which can be expressed in terms of chemical, physical and biological properties and their interactions. In this article, we will discuss the properties, regulations and impacts of organic farming on human livelihood and the environment. Overview of organic farming Organic farming has expanded rapidly in recent years and is seen as a sustainable alternative to chemical-based agricultural systems (Stockdale et al., 2001; Biao et al., 2003; Avery, 2007). Its annual growth rate has been about 20% for the last decade (Lotter, 2003), accounting for over 31 million hectares (ha) and generating over 26 billion US dollars in annual trade worldwide (Yussefi, 2006). Nutrient management in organic farming systems is often based on soil fertility building via nitrogen (N) fixation and nutrient recycling of organic materials, such as farmyard manure and crop residues, with limited inputs from permitted fertilizers (Gosling and Shepherd, 2005). Although organic farming has been criticized for relying on the build-up of soil phosphorus (P) and potassium (K) by past fertilization before converting to organic (Nguyen et al., 1995; Greenland, 2000; Løes and Øgaard, 2001), its acceptance and popularity are growing due mostly to environmental and healthrelated concerns (Biao et al., 2003; Galantini and Rosell, 2006). A recent polling of residents of Ontario, Canada reveals that more than half think organic food is more nutritious; two-thirds believe organic food is safer than conventionally grown food; and 9 out of 10 believe organic fruits and vegetables are grown without pesticides of any kind (Avery, 2007). The aims and principles of organic farming, as presented in the International Federation of Organic Agriculture Movements (IFOAM) Basic Standards for production and processing are listed in Table 1. A shift to organic agriculture brings about significant changes: restricted use of synthetic fertilizers and pesticides, increases of other inputs such as organic materials, labor, perhaps machinery, cultural practices (e.g., crop rotation), and better knowledge of biological processes. These changes have serious implications. Thus, farmers should consider the following issues before practicing organics (FAO, 1998): * Labor inputs: Labor is important to the production process, and can be an impediment to the adoption of organic agriculture. Compared to large-scale mechanized agricultural systems, organic farming appears more laborintensive. Many techniques used in organic farming require significant labor (e.g., strip farming, non-chemical weeding, composting). In the developed Current developments in organic farming 3 Table 1. The principal aims of organic production and processing (IFOAM, 1998). world, labor scarcity and costs may deter farmers from adopting organic systems. This may also be true for cash-poor farmers and those supplementing their incomes with off-farm work. However, where labor is not a constraint, organic agriculture can provide employment opportunities, especially in rural communities. Furthermore, the diversification of crops typically found on organic farms, with their various planting and harvesting schedules, may result in more work opportunities for women and a more evenly distributed labor demand which helps stabilize employment. * Other production-related inputs: The absence of synthetic fertilizers and pesticides in organic farming necessitates other inputs from manure addition to crop selection or irrigation. Farmers' knowledge of local conditions and of traditional practices is essential to the success of organic farming. The emphasis of crop varieties and animal breeds used in organic agriculture is on local suitability with respect to disease resistance and adaptability to local climate. M.E. Ortiz Escobar & N.V. Hue 4 * Crop rotation: This operation is required under organic certification programs and is considered essential in organic management. Agricultural pests are often specific to the host (i.e., a particular crop), and will multiply as long as the crop is there. Alternating crops in time (rotations) or space (stripcropping and intercropping) is therefore an important tool for controlling pests, and also for maintaining soil fertility. As the use of synthetic fertilizers and pesticides allows the farmer to grow the crop that is financially most rewarding, not using those inputs may limit the choice of crops. The success of an organic farm depends on the identification of end-uses and/or markets for all the crops in the rotation, as few farmers can afford to leave fields fallow. This remains one of the most significant challenges in organic agriculture. * Yield: Yields on organic farms, although may not be as high as those produced by conventional practices, fall within an acceptable range (Avery, 2007). Encouragingly, organically produced yields currently are significantly higher than those produced before the 1950s. Part of this progress can be attributed to new varieties and better knowledge of biological processes used in farming. For example, if N mineralization is slow because of cool/wet growing-conditions, crops on organic farms may not have sufficient N early in the season. However, better knowledge on N synchronization between N release by manures and N demand by crops could minimize or even eliminate this N deficiency problem (Hue and Silva, 2000; Myers et al., 1997). Definition of organic farming There are many definitions of organic farming, which is also known as ecological agriculture (Gosling et al., 2006) or biodynamic agriculture (Lampkin, 2002). Some have considered organic farming and sustainable agriculture synonymous, because they are both based on sustainability of agroecological systems. Sustainability can be defined as meeting the need of the present without compromising the ability of future generations (WCED, 1987). The word "organic" is legally protected in some countries, avoiding their indiscriminate use in non-organic products. In the European Union (EU), for example, this word has been protected since the early 1990s in Englishspeaking countries. The equivalent in French, Italian, Portuguese and Dutchspeaking countries is "biological", and "ecological" in Danish, German and Spanish-speaking countries (FAO, 1998). Organic farming according to Henning et al. (1991) is both a philosophy and a system of farming, grounded in values that reflect an awareness of ecological and social realities and the ability of the individual to take effective actions. In practice, it is designed to work with natural processes to conserve resources, encourage self-regulation through diversity, to minimize waste and environmental impacts, while preserving farm profitability. Current developments in organic farming 5 According to Lampkin (1994, 1997), the aim of organic farming is: “to create integrated, humane, environmentally and economically sustainable production systems, which maximize reliance on farm-derived renewable resources and the management of ecological and biological processes and interactions, so as to provide acceptable levels of crop, livestock and human nutrition, protection from pests and disease, and an appropriate return to the human and other resources”. As such, organic farming shares the fundamental objectives of agricultural sustainability and is deserved to be assessed as a mainstream part of sustainable agriculture (Edward-Jones and Howells, 2001). IFOAM (2000) has defined organic agriculture as “a process that develops a viable and sustainable agro ecosystem”. In practical terms, organic farming is a form of agriculture that shies away from synthetic inputs such as pesticides and fertilizers (because of their negative effects on the ecological balance) but uses agricultural practices such as crop rotation, proper spacing between plants, incorporation of organic matter into the soil, and composting (Kuo et al., 2004). With restrictions on the use of chemical fertilizers, the principal challenge to converting a conventional farm to an organic one is to provide N, K (because these two elements are required at rather large quantities by most crops and because they are easily leached from soils), and to a lesser extent, other plant nutrients at rates and times to ensure acceptable crop yields (Rodrigues et al., 2006; Hue and Silva, 2000). Production requirements in organic farming While conventional farming needs abundant, man-made resources, organic farming makes use of functional integrity of the system (Boelling et al., 2003). Organic farming depends on the local environment (soil, water) and less powerful tools (heavy equipment). Although the exact production methods vary, general principles include the exclusion of most synthetic biocides and fertilizers, the management of soils through addition of organic materials and use of crop rotation (IFOAM, 1998). The requirements (which apply to the way the product is created, not to the measurable properties of the product itself) by the USDA National Organic Program (NOP) are summarized as follows (NOP, 2006).