Which Fertilizer?

The Environmental Impact of Organic vs. Conventional Fertilizer


There is an on going debate about whether vegetables grown using organic (natural) methods are any more nutritious or better tasting than those grown through conventional (inorganic/chemical) methods. The more important debate and the focus of this discussion are the environmental issues that come from farming and the argument that using organic methods of farming will put less stress on the soil, water, consumer and farmer than conventional methods.
The environmental problems that are caused by fertilizers include water pollution, nutrient starved soils and health hazards caused from the handling of chemicals in the fertilizers (to the farmer, animals and beneficial insects). Fertilizers available to the farmer contain one or more of the elements nitrogen (N), phosphorus (P), and potassium (K). Most inorganic fertilizers are sold labeled something like 12-12-12 or 8-8-8. The label is stating the percentage of the elements contained within the particular fertilizers always in the order of nitrogen (N) – phosphorus (P) – potassium (K).
Every farmer, from the backyard hobby gardener to the corporate conglomerate strives to grow healthy luscious plants that produce abundant quality fruit. Just as our bodies need nutrients to grow strong and healthy the same is for plants, specifically speaking of vegetables. Vegetable plants pull their nutrients from the soil. When the plant is harvested from the garden or field the nutrients which it has taken from the soil are also removed with the plant. To grow a new crop, nutrients need to be replaced through either organic (natural) fertilizers or chemical (inorganic) fertilizers.
Garden or field soil already contains the nutrients that plants need to grow. In order for specific plants to grow to their full potential they may need more or less of one element than another. Fertilizers provide the extra nutrients or elements that the plants need. This is where the separation between the organic and inorganic (chemical) fertilizers comes into question. What is the difference between the basic fertilizer elements NPK in organic fertilizers compared with conventional fertilizers? Consider the element nitrogen (N) in the two types of fertilizers, organic and conventional. It is the same in both fertilizers the difference lies in how it is available to the plant.
Conventional fertilizers for the most part are water soluble and the elements are readily available to the plant. The concept of this fertilizer is to feed the plant. The plant however only takes up the nutrients that it is lacking. This allows for strong plant growth but does nothing for the soil; no nutrients are being added to the soil causing the soil to be depleted. The rest of the nutrients in the fertilizer filters through or runs off the soil and into the watershed. The chemicals in this concentrated form are harmful to soil builders like earthworms and also beneficial insects. The runoff causes pollution to the water, contaminating it with concentrated chemicals.
Economically it looks as though the initial cost of the chemical based fertilizer is substantially lower than the organic. Pound for pound the farmer is purchasing more of the elements NPK when using conventional rather than organic fertilizers. Purchasing a fertilizer such as 8-8-8 or 12-12-12 is convenient and covers a broad range of nutrient needs. The farmer is able to produce more food for less cost to him and the consumer. As stated previously the plant is only going to take up the nutrients it needs. Purchasing and applying extra nitrogen is wasteful as well as harmful to the watershed and soil.
Organic fertilizers are not always as readily available to the plant. They are in their natural form so they must be “broke down” before the nutrients are available to the plant. This “breaking down” is done in the soil by beneficial bacteria and soil builders such as earthworms. This concept feeds or builds the soil rather than the plant. Over time the soil becomes “richer” and the health of the plants as well as the soil improves. Healthy soil and plants are not as susceptible to disease and harmful pest as barren soils.
Since most organic fertilizers are in their natural mineral form they are not water soluble and concentrated so they do not filter through or run off the garden or field. The organic farmer still must be careful when using certain types of fertilizers. Raw manure and urine can contain concentrated amounts of nitrogen and can be harmful to the environment when not used properly. This type of organic is best applied in the proper quantities at the proper time or better yet composted before application.
Economically the organic farmer or gardener is only going to purchase and apply the nutrients that his soil is lacking. Building the soil and only using what is needed will, overtime, be more economical than the conventional method. Some organic fertilizers such as compost and manure are available at no cost other than labor. There are also “green manures” that will not only build the soil but also provide a crop.
Organic fertilizers are the better choice for the farmer and gardener. They are not harmful to the environment when used properly. They not only provide the nutrients plants need but also build the soil. Healthier soil means healthier plants and less fertilizer over time.
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