The relative advantages and disadvantages of organic fertilizer have been the subject of debate for nearly 100 years, with the history of the organic movement dating back to the earliest days of chemical alternatives. For most people, a careful weighing of the options will help you determine which method is best for your lawn or garden.
Until early in the twentieth century, composted manure, kitchen scraps, and other organic wastes represented the only means of improving soil fertility. Organic farming and gardening were not moral or environmental choices, but simply the way of life. The advantages of such a system are many, including the following points.
Improved Soil Health
Virtually every aspect of organic gardening revolves around the health of the soil. Organic fertilizer contributes to soil health in the following ways:
- Increased Organic Matter: Natural soil is rich in organic matter. Increasing organic matter in agricultural soil improves the soil structure, creating more air space and water retention within the soil.
- Reduced Soil Erosion: A higher proportion of organic material in the soil will also prevent soil erosion, helping to avoid the dust bowl effect seen in the 1930s.
- Healthy Ecosystem: Organic fertilizer is gentler on microorganisms and earthworms living in the soil, creating a healthy ecosystem that is sustainable and conducive to long-term use.
Steady Release of Nutrients
The slow and gradual release of nutrients is listed among both the advantages and disadvantages of organic fertilizer. As an advantage, the natural release of elements means that there is a reduced risk of nutrient burn from over-fertilization. This approach also means that fertilizer application is required less frequently, reducing operating cost and manual labor.With organic fertilizer, nutrient availability and uptake by plants occur at roughly an equal rate, meaning nutrients are preserved in soil and plant matter rather than leaching away with rainwater. The resulting plant growth occurs at a natural, healthy pace. This tends to produce stronger, more stable plants than those grown at an artificially accelerated rate, theoretically producing improved taste and nutritional value at the same time.
Organic fertilizer is potentially a cheaper option than chemical alternatives. If you have a compost or live in a rural area, the only cost is time. Many farmers will sell manure by the truckload or even give it away if you are willing to pick it up. In urban and suburban neighborhoods, a composting unit can be cheap, effective, and unobtrusive. For a nominal upfront investment, even apartment dwellers can have their own organic worm bin composting system to feed a balcony garden.
Better for the Environment
The combined influence of increased organic matter and reduced nutrient leaching means that elements such as nitrogen and phosphorus will end up in your plants' roots instead of the local waterways. Nutrient leaching from agriculture is a major culprit in the development of algae blooms on lakes and ponds. This process, known as eutrophication, disrupts ecosystems and renders water unfit for human use.
Organic fertilizer holds many advantages over chemical alternatives, but it may not be best in every situation. Some potential disadvantages include:
- Limited Nutrient Availability: The slow-and-steady approach that makes organic fertilizer perfect for most applications can pose a problem in certain situations. The release of nutrients from organic fertilizers can be dependent on both ambient temperatures and the presence of microorganisms in the soil. Damaged soils may lack the necessary biological conditions for effective composting. Severely nutrient-deprived plants needing a boost might do better initially with a readily available nutrient mixture in a liquid form.
- Labor-Intensive: Organic fertilizers can be bulky, messy materials. Some would argue that working with organic fertilizer is a labor of love, but turning compost piles, moving manure, and spreading solid fertilizer are not for everyone. This also means that applying fertilizer on a large scale can be more difficult, as heavy manure or blood meal granules are less suitable for mechanical spreaders.
- Potentially Pathogenic: Incomplete composting can leave certain pathogens in the organic matter. These pathogens can enter the water system or the food crops, causing human health and environmental problems.
- Expensive: Commercial organic fertilizers are often more expensive per unit than comparable chemical products.
Weighing the Advantages and Disadvantages of Organic Fertilizer
Depending on your situation, you will likely find that some of these factors outweigh the others. Cost, convenience, or the physical aspects of handling organic fertilizer might be a determining factor for some, while the ecological and health benefits might take priority for others. Whatever you decide, applying the minimum amount of fertilizer necessary and doing so at the optimal time will offer the best overall return for your time, money, and labor.