Organic farming methods - Natural farming methods - combine scientific knowledge and modern technology with traditional farming practices based on thousands of years of agriculture. The distinguishing principle is an avoidance of synthetic inputs, such as manufactured fertilizers and pesticides, and for this reason, organic methods are easiest to describe by contrasting them with conventional, agrichemical - based methods.

In general, organic methods rely on naturally occurring biological processes, which often take place over extended periods of time, and a holistic approach, while chemical-based farming focuses on immediate, isolated effects and reductionist strategies. In conventional systems, technology—hybrid seed, synthetic chemicals, high-volume irrigation, mechanization—is used to regulate local conditions. Beyond the strictly technical aspects, the philosophy, day-to-day activities and required skill sets are quite different.

Crop diversity is a distinctive characteristic of organic farming. Conventional farming focuses on mass production of one crop in one location, a practice called monoculture. This makes apparent economic sense: the larger the growing area, the lower the per unit cost of fertilizer, pesticides and specialized machinery for a single plant species. The science of agroecology has revealed the benefits of polyculture (multiple crops in the same space), which is often employed in organic farming. Planting a variety of vegetable crops supports a wider range of beneficial insects, soil microorganisms, and other factors that add up to overall farm health, but managing the balance requires expertise and close attention.
Farm size - Farm size in great measure determines the general approach and specific tools and methods. Today, major food corporations are involved in all aspects of organic production on a large scale. However, organic farming originated as a small-scale enterprise, with operations from under one acre to under 100. The mixed vegetable organic market garden is often associated with fresh, locally-grown produce, farmers' markets and the like, and this type of farm is often under 10 acres. Farming at this scale is generally labor-intensive, involving more manual labor and less mechanization. The type of crop also determines size: organic grain farms often involve much larger acreage. Larger organic farms tend to use methods and equipment similar to conventional farms, centered around the tractor.
Plant nutrition
Soil fertility - The central farming activity of - fertilization - illustrates the differences. Organic farming relies heavily on the natural breakdown of organic matter, using techniques like green manure and composting, to replace nutrients taken from the soil by previous crops. This biological process, driven by microorganisms, allows the natural production of nutrients in the soil throughout the growing season, and has been referred to as feeding the soil to feed the plant. In chemical farming, individual nutrients, like nitrogen, are synthesized in a more or less pure form that plants can use immediately, and applied on a man-made schedule. Each nutrient is defined and addressed separately. Problems that may arise from one action (e.g. too much nitrogen left in the soil) are usually addressed with additional, corrective products and procedures (e.g. using water to wash excess nitrogen out of the soil).
Organic farming uses a variety of methods to improve soil fertility, including crop rotation, cover cropping, application of compost, and mulching. Organic farmers also use processed natural fertilizers such as bone meal, blood meal, and various mineral powders such as rock phosphate and greensand, a naturally occurring form of potash.
Pest control - Differing approaches to - pest control - are equally notable. In chemical farming, a specific insecticide may be applied to quickly kill off a particular insect pest. Chemical controls can dramatically reduce pest populations for the short term, yet by unavoidably killing (or starving) natural predator insects and animals, cause an ultimate increase in the pest population. Repeated use of insecticides and herbicides and other pesticides also encourages rapid natural selection of resistant insects, plants and other organisms, necessitating increased use, or requiring new, more powerful controls.

In contrast, organic farming tends to tolerate some pest populations while taking a longer-term approach. Organic pest control involves the cumulative effect of many techniques, including:

allowing for an acceptable level of pest damage; encouraging predatory beneficial insects to control pests; encouraging beneficial microorganisms careful crop selection, choosing disease-resistant varieties planting companion crops that discourage or divert pests; using row covers to protect crops during pest migration periods;

rotating crops to different locations from year to year to interrupt pest reproduction cycles;
Using insect traps to monitor and control insect populations.
Each of these techniques also provides other benefits—soil protection and improvement, fertilization, pollination, water conservation, season extension, etc.—and these benefits are both complementary and cumulative in overall effect on farm health. Effective organic pest control requires a thorough understanding of pest life cycles and interactions.

Organic pest control is similar to integrated pest management in some respects.

Livestock - Raising livestock and poultry, for meat, dairy and eggs, is another traditional, farming activity that complements growing. Organic farms attempt to provide animals with "natural" living conditions and feed. Ample, free-ranging outdoor access, for grazing and exercise, is a distinctive feature, and crowding is avoided. Feed is also organically grown, and drugs, including antibiotics, are not ordinarily used (and are prohibited under organic regulatory regimes). Animal health and food quality are thus pursued in a holistic "fresh air, exercise, and good food" approach. In conventional livestock operations, animal needs are identified, isolated, and handled discretely. Drugs and synthetic food supplements are key components. Animals are often given preventive treatment of antibiotics in their daily feed, and supplements are added to increase the nutritional value of a variety of substances used as feed. Hormones may be used to optimize certain characteristics (e.g. produce more meat, or more milk). Living conditions are often set as the minimum necessary for survival and growth.

Also, horses and cattle used to be a basic farm feature that provided labor, for hauling and plowing, fertility, through recycling of manure, and fuel, in the form of food for farmers and other animals. While today, small growing operations often do not include livestock, domesticated animals are a desirable part of the organic farming equation, especially for true sustainability, the ability of a farm to function as a self-renewing unit.

Organic farming systems - There are several organic farming systems. Biodynamic farming is a comprehensive approach, with its own international governing body. The Fukuoka method focuses on a minimum of mechanical cultivation and labor for grain crops. French intensive and biointensive, methods are well-suited to organic principles. A farm may choose to adopt a particular method, or a mix of techniques.

While fundamentally different, large-scale agriculture and organic farming are not entirely mutually exclusive. For example, Integrated Pest Management is a multifaceted strategy that can include synthetic pesticides as a last resort—both organic and conventional farms use IPM systems for pest control.

Organic Crop Production Overview at ATTRA, the National Sustainable Agriculture Information Service.
References Organic farming methods and Biological pest control
Fertilizer Method 2023
Scientists accidentally created a novel method to make fertilizer ... Inverse
Producing fertilizer without carbon emissions Science Daily
Fertilizer could be made much more sustainably Futurity: Research News
How can nitrogen fertilizer be produced more sustainably? | World ... World Economic Forum