Fertilizer research in Iran is carried out mainly by the SWRI. The research is carried out at different agricultural universities, which provide the SWRI with the data they require.
In 1995, the SWRI initiated the study of fertilizer application rates in relation to the levels of soil nutrients and crop needs/uptake. The result has been a tangible improvement of the N-P2O5-K2O+ percent micronutrients ratio to 100-45-23+1.5 percent micronutrients. SWRI intends to achieve by 2015 a ratio of 100-45-35 for primary nutrients, to increase the use of sulphur to 500 000 tonnes and to increase the consumption of micronutrients to 4 percent of the total national fertilizer use level.
SWRI's achievements in the balanced use of different mineral fertilizers have been instrumental in improving the soil fertility of major farming areas to such an extent that, despite the persistent droughts of the last few years, sustainable farming is now in evidence in some main regions. SWRI has contributed significantly to a reduction of the overuse of fertilizers, thereby reducing the pollution of rivers and underground water reservoirs.
The average yields per unit area of the three major crops, i.e. wheat, rice and sugar beet, have improved to the extent of 25 to 30 percent during the past five years.
Through SWRI's efforts, for the first time in 2005, the state-guaranteed purchase price of wheat from the farmers will be determined by the protein content of the grain. In addition, SWRI's efforts in the production and promotion of the use of enriched (biofortified) seeds are contributing substantially to the qualitative enhancement of crops.
SWRI's research and its implementation have improved the balance of nutrition of horticultural and field crops. For example, there has been a substantial increase in the importation and consumption of potassium chloride and potassium sulphate, almost non-existent in Iran as late as 1998. Today, Iran is the largest consumer of potassium fertilizers in the West Asia and North Africa (WANA) region. By putting emphasis on the value of sulphur as a plant nutrient and soil amendment, SWRI's research has been effective in initiating the consumption of elemental sulphur with Thiobacillus bacteria. This also provides an outlet for excess recovered sulphur produced by the oil and gas industry.
Researchers have actively assisted in the establishment of 65 soil and plant analysis laboratories by the private sector.
Finally, thanks to SWRI's efforts, a High Council of Health has been formed, headed by the President of Iran.
Most of the research is in the following fields.
The relationship between plant nutrients and fruiting.
The reasons for physiological problems in fruit trees.
Explanation of calcium deficiency in fruits.
Study of Zn, Mg and S levels in the soils of the country and their role in increasing or reducing agricultural production.
Promoting balanced fertilization as a contribution to a sustainable land use system.
Devising and implementing innovative methods for cost effective, systematic studies and land evaluation schemes to facilitate the collection of data relevant to advanced techniques such as remote sensing (RS) and the geographical information system (GIS), for the integration of different data on Iran's soil resources.
Fertilizer recommendations, their types and use.
Appropriate fertilizer nutrient application ratios.
Use of the chlorophyll meter to identify nitrogen deficiency.
Identification of critical and optimum levels of nutrients in soil and plants.
Tailoring fertilizer application rates to the specific soil-plant needs of different regions.
Limiting the application of P-fertilizers to the specific soil-plant requirements of the different regions.
Foliar application of nutrients, especially micronutrients such as zinc and Fe-EDDHA to deal with lime induced chlorosis and the proper method of application.
Injection of nutrients into the stock of trees.
Promoting split and foliar applications of fertilizers to increase the absorption efficiency of plant nutrients, optimizing the amount and frequency of fertilizer application according to the soil-plant needs.
Improving plant nutrient uptake by practices such as the band application of fertilizers for field crops, localized deep placement of fertilizers mixed with farmyard manure in orchards and the acidification of irrigation water to reduce the pH in calcareous soils prior to fertilizer application.
Improvement of public health through the fortification of wheat.
Sharing with researchers and experts information regarding harmful contaminants such as nitrate and cadmium in vegetables, fruits, potatoes, onions, other agricultural products, and their presence in underground water.
Research on biological fertilizers including: Thiobacillus, Chickpea and Bean Rhizobium, granulated phosphatic bacterial biofertilizers, Azotobacter bacteria, Mycorrhiza fungi, etc.
Research on the production of vermi-compost from agricultural residues for soil improvement.
Technical information concerning the production of liquid humus fertilizer.
Work on sulphur coated urea (SCU) Rhizobium, Thiobacillus, plant growth promoting Rhizobium (PGPR) and P-solubilizing inoculants, in collaboration with the Scientific Research and Industrial Organization of Iran (SRIO). The know-how is licensed to the private sector for the mass production (more than 100 000 tonnes per year of biofertilizers).
Endeavours to justify, obtain approvals and acquire funds for the further production of organic fertilizers, biofertilizers and micronutrients.
Beneficial changes in national fertilizer policies.
Encouragement and guidance of the private sector in the production of fertilizers.
Provision of technical information concerning new fertilizers, for example on citron, a locally patented type of chelated iron fertilizer.
Practical recommendations for farmers and fruit growers.
Establishment of an on-line answering system to provide information to growers on the fertilizer needs of the field and fruit crops.
Publication of relevant books, papers and recommendations.