Before the advent of the chemical industry in the late 19th and early 20th century, all gardening soil augmentation was organic. Modern gardeners use organic fertilizers to help reduce pollution and help prevent environmental degradation. By understanding how organic fertilizers work, you can better plan and implement an organic fertilization plan for your flowers and vegetables.
Organic fertilizers have likely been used since Neolithic times, according to the Soil Sciences Society of America. The first chemical fertilizer was synthesized in the 19th century by treating bones with sulfuric acid. By 1958, synthetic versions of plant nutrients were readily available. About 100 years later, agriculture went from using organic fertilizers to using a larger percentage of chemicals.
Organic fertilizers break down in the soil to replace nutrients used by the plants in growth and either flower or vegetable production. Plants use a number of nutrients. In addition to the commonly known nitrogen, phosphorus, and potassium, often notated on the packaging as N-P-K, there are many micro-nutrients like iron, copper, and other elements. In nature, leaves would fall from the plants and the plants would eventually die and be reabsorbed back into the soil. By consciously farming a particular area, the plants remove nutrients from the soil more quickly than they can be naturally replaced. Organic fertilizers help replace those nutrients.
Organic fertilizers are more gentle than chemical fertilizers. They improve the condition and structure of soil. Because they offer a variety of nutrients, organic fertilizers help to feed beneficial soil organisms. These organisms are often responsible for converting higher level organic fertilizers into elements that can be used by the garden's plants. Organic fertilizers often also improve the soil's ability to hold water.
Although organic fertilizers provide many benefits, they can take longer to deliver nutrients to the plants. This is because organic fertilizers are not in forms that are ready for plant use. The nutrients need further breakdown by soil organisms before most of the nutrients are available for plants. You might have to wait a week or two to see increased growth from organic fertilization.
When using organic fertilizers, regular soil management is important. By starting the season with organic compost, you are starting the process of nutrient breakdown and conversion early. Through regular addition of organic fertilizers, the soil has an adequate supply of raw materials for plant and soil health.