Introduction to organic Agriculture

Organic Agriculture

• The term organic in chemistry refers to components containing the element carbon as an essential component, and refers to chemical components derived from living organisms of either animal or vegetable origin. Organic fertilizers are generally by-products of the processing of animal or vegetable substances that contain sufficient plant nutrients to be value of as a fertilizer without the need to add any synthetic materials.

• Organic Fertilizers - Should be 100% organic.

• Organic based Fertilizers – Blend of synthetic (in organic) as well as organic raw materials.

• Organic materials appear to be more ‘available’ to growing plants than inorganic materials, and do not leach as readily from the soil. This is thought to be due to the high cation exchange capacity of the organic matter in which nutrients are retained.

• Inorganic fertilizers because of its very nature of easy water solubility, when used in excess leads to heavy leaching of soluble phosphorus and nitrogen from the soil.

• Soil organic matter contains decomposed humus, decaying plant and animal matter and living soil organisms. Humus is a structure less colloidal matter resulting from the decomposition of any type of dead organic matter. It is a complex chemical mixture comprising proteins, lignin, fats, carbohydrates and organic acids. Humus is a storehouse of essential plant nutrients; including 95% of the Nitrogen 60% of the Phosphorus and 98% of the Sulphur available to plants. It has the ability to make some nutrients more soluble and available to plants because of increased activity by soil microorganisms.

• Always opt for organic based fertilizers because of their “slow release nature” resulting in minimum fertilizer wastage.

• Always apply Nitrogen in ammonium form rather than in nitrate form. Nitrogen in the ammonium form is attracted to and held by soil colloids and temporarily resistant to leaching. Plants can use Nitrogen in ammonium form but in most soils the ammonium form is gradually changed to the nitrate form before being taken up by plants. The conversion to nitrate form is more rapid where there is adequate air and moisture and where soils are warm. The change from ammonium form to the nitrate form, may take a few days to several weeks or months depending mainly on soil conditions, depth of application and temperature. This means that the nitrogen applied as ammonium form becomes available over a much longer period than is the case when nitrogen is applied in the nitrate form.