Organic agricultureis an alternative agriculture that aims to obtain maximum nutritional quality of food, the environment and conserving soil fertility, through optimum use of local resources and without the application of chemical products synthetic.
Benefits of organic agriculture
- Obtaining a better quality of food (nutritional quality, taste, etc).
- Increased safety when consuming foods for consumers.
- Greater respect for the environment, maintaining the organic matter content of the soil and preventing erosion.
- Reduction of pollution in surface water and groundwater by accumulation of nitrates and phosphates.
- Conservation of indigenous genetic heritage.
- Sustainability of agricultural production, promoting soil fertility and maintenance of the natural cycle of ecosystems and crops.
- Preservation of the quality of life of people and animals that populate the countryside.
- More efficient use of resources (land, fertilizers, water, etc..) Intended exclusively for the achievement of the crop for optimum performance.
Organic Agriculture in Europe
In recent years, we are witnessing a development of organic agriculture that has contributed to the growing awareness by consumers of issues related to food safety and environmental problems. In this way, in 2002 the number of hectares under organic agriculture in Europe was close to 4.8 million hectares, an increase of over 26% over the previous year.
While in 2000 only accounted for 3% of the total farmland in the EU, organic agriculture has become one of the most dynamic agricultural sectors within the European Union. Between 1993 and 1998, the sector grew annually by 25% and it is estimated that since 1998 its growth has been estimated at 30% per annum. However, in some Member States, this growth seems to have stabilized.
One of the most important in organic production is Italy, with 1.2 million hectares under organic agriculture. However, Spain and England were the countries that experienced higher growth in 2002, an increase in the ecological area of 74%.
Spain exports more than 90% of national production to the EU countries, Germany being the largest importer.
Organic Agriculture in Spain
In recent years, organic agriculture has grown dramatically, becoming an important sector within the framework of national agricultural production. The number of hectares devoted to organic production already exceeds 700,000 hectares and the number of organic operators is higher than the figure of 17,500. The value of marketed production has grown in recent years at a rate of nearly 40 million euros in the last three years in 2004 stood at 250 million euros.
Among the most significant communities in this area include the Community of Andalusia, Extremadura, Catalonia and the Community of Aragon. The rest of the community, given its great importance in conventional agriculture, has a great potential short-term development in organic agriculture.
Mineral fertilizer in agriculture cannot be a closed circle without nutrient loss. This applies to all types of agriculture, therefore, also in organic agriculture.
Losses should be compensated for the duration of the productivity of our soil. Therefore mineral fertilizer, suitable for use in organic agriculture, is an ideal complement to subscribers and green organic fertilizer to get a complete nutrition of phosphorus, potassium, magnesium, calcium and sulfur.
These fertilizers, without having undergone any process of chemical synthesis, are covered in the rules of organic agriculture which came into force in the European Union 1991 (Regulation (EEC) No 2092/91).
The first important point to stress is that the organic waste, not only does not have a constant chemical composition, but at the same farm can exist a very high temporal variability in composition.
This obviously is a major disadvantage in deciding the dose of nitrogen, phosphorus and potassium to apply.
In addition there is a tendency to over-dosing, and therefore the application of excess nutrients with consequent environmental problems that would be created.
This imbalance is usually deficient in potassium and phosphorus excess, except in those organic wastes which have a high content in straw.
This happens in some of the organic fertilizers used in organic agriculture as a slurry or compost. The compost provides higher phosphorus content in the nitrogen and much higher than those for potassium. This is inconsistent with the requirements of crop plants that generally have high nitrogen requirements, and low in potassium in phosphorus.
A continued application of such fertilizers in a soil causes an accumulation of phosphorus in the horizon surface, in case of loss or erosion, can cause problems of eutrophication of waters.
One way to offset this imbalance of organic fertilizers is the incorporation of mineral fertilizers in the fertilization of a strategy of exploitation of agriculture. This will be better adjusted and the amounts of phosphorus and potassium supplied, and also provide other essential nutrients for plant growth such as magnesium or sulfur.
The crop rotations and associations used in organic agriculture are often leguminous crops with the capacity to perform bacterial symbiosis and fix atmospheric nitrogen. Because of this ability to take advantage of the nitrogen atmosphere, it makes little sense to make organic fertilizer as they all carry nitrogen in their composition.
From this point of view, mineral fertilizers can provide the other nutrients needed for these crops, provided that the soil analysis reflecting this need.
Ultimately, the use of organic fertilizers with legumes involves an excess of N in the rotation and therefore the problems associated with this event (environmental pollution, conflicts with other nutrients …).
Also we emphasize that some legumes such as alfalfa (Medicago sativa), requirements are very high in potassium, thus the mineral potassium fertilizer suitable for organic agriculture are practically the only source to provide this nutrient.
Therefore mineral fertilizer suitable for organic agriculture is not only an economic resource to provide nutrients to organic agriculture, but also complement well with the practices commonly used in organic agriculture.
Advantages of the use of mineral fertilizers
Mostly fertilizers with a high concentration of nutrients that can restore the deficiencies of crops that are very high in certain nutrients such as potassium, magnesium, etc. which cannot be restored through the compost.
Economic products generally do not produce an excessive increase in the total cost for the farmer.
They have a constant chemical composition compared to organic fertilizers, thus the amounts of nutrients are perfectly consistent with the needs of crops. Present a greater simplicity in the handling, transport and storage, as in the application by the farmer.
This nutrient’s losses to the environment are lower. They are an ideal complement to organic fertilizer or green manure, which would balance fertilization of crops in a more rational and obtain a complete nutrition are an ideal source for natural fertilization of the legume rotations incorporated in OA, and avoid excess N that would occur if such crops provide organic fertilizer.
The organic fertilizers are probably the most used fertilizer in farming. There is great diversity of this type of fertilizer, but the most widespread are the slurry and manure of different animals, green manure and compost organic waste.
Manure is a mixture of the beds of animals with their droppings, which has suffered more or less advanced fermentations, first in the barn and then in the dunghill. It may be solid or dissolved in water (slurry). This is a compost of organic-mineral, with a low content of mineral elements. Its nitrogen is found almost exclusively in organic phosphorus and potassium to 50 per 100 in an organic and mineral. We must make good use of manure, providing the quantities needed for the development of crops, to avoid the problems of pollution that would produce excessive contributions. The composition of manure varies between very wide limits, depending on the species, the nature of the bed, the food received, processing and handling of manure. Solely on the animal species, we can establish that the poultry manure is the richest and most concentrated of all. Among mammals, the horse is above the sheep, cow and pig. The following table represent the average nutrient content of different manures, depending on its origin and dry matter content, all expressed in kg / tonne of product.
The mulch should be applied in the autumn / winter to allow the action of microorganisms and thus obtain a greater availability of nitrogen in spring. Manure is incorporated into the soil burying it deep with a little work. One of the disadvantages of organic fertilizers is the loss of nutrients, especially nitrogen, which can occur during storage, handling and application. These losses cause unwanted effects on the environment such as air pollution and water pollution. With a base fertilization and only organic fertilizer is a risk of accumulation in soil phosphorus and some heavy metals such as copper or zinc. It is clear that these problems are unacceptable in the context of organic agriculture, which seeks to harmonize agriculture with the environment where it develops, causing minimal impact on it.
Fertilizers or green manures are intended for added to the soil, with a number of objectives including: improved soil fertility and soil structure, incorporation of N in case this is a green manure legume, and protection against soil erosion risk. These crops are used routinely in the time period between two crops, for example between the harvest of summer crops and the sowing of a spring to take advantage of autumn rains. There are also made in green-manure crops in the corridors of uncultivated perennial crops such as vineyards, olive groves and fruit trees. From a nutritional point of view, the green manure crops do not contribute to anything other than nitrogen if it is a legume. The phosphorus and potassium requirements of crops must be made through other channels, for example with mineral fertilizer suitable for organic agriculture.
Fertilizer suitable for OA
Although fertilization on soil organic matter can allow a balanced nutrition of the plant, most of the time, especially during the conversion (conventional organic agriculture), it may be necessary to balance the content on certain elements to a level sufficient to enable the crop did not suffer problems of nutritional imbalances, correcting problems of acidity, and so on.
This is also seen as the European Commission's Directorate General of Agriculture recommends and supports the implementation of certain natural mineral fertilizers with organic fertilizers, if proved its need.
In June 1991, the European Council adopted Regulation (EEC) No 2092/91 on organic production of agricultural products and indications referring thereto on agricultural products and foodstuffs. The adoption of this regulation involved the creation of a Community legal framework that determines in detail the requirements a product or a food to bring some sort of reference to organic production methods.
Mineral fertilizers that are currently being applied in agriculture in Annex II of EEC Regulation 2092/91 of fertilizers and soil conditioners are approved for use in organic agriculture.
Crop rotation and association
It is a common practice in organic agriculture. Cultivated species of different families or species alternately (rotation) or simultaneously (association).
This prevents the risk or hindering the rapid spread of pests and diseases that are increased in monoculture. To do this we must know the affinities of plants and antagonisms between them.
To develop an appropriate agricultural practice we must make tillage but always taking into account some assumptions:
- Muller should not turn the soil, avoiding tools bury the surface layers of soil.
- Never bury fresh organic matter, it is necessary to mix with the first few centimeters of soil to make a first aerobic decomposition.
- You need to work on the optimal time (Tempero), never when the soil is very wet or very early implementation of the crop.
- Reduce the number of passes with heavy equipment to avoid soil compaction.
Therefore tillage should be done in a rational manner, taking into account the living soil. Soils with abundant wildlife just need tillage, are themselves responsible for maintaining the soft soil structure.
About the author