The fertilizer sector

Transcription

1 Fertilizer use by crop in Uzbekistan 15 Chapter 3 The fertilizer sector MINERAL FERTILIZER PRODUCTS The most frequently used straight nitrogen fertilizers are ammonium nitrate, ammonium sulphate, urea and anhydrous ammonia. Seventy to 80 percent of the nitrogen is applied as ammonium nitrate. Urea is used mostly in regions with a wet and warm climate; in regions with more severe climatic conditions, it is less effective. Straight fertilizers with a low content of nitrogen are gradually losing their importance the importance of ammonium sulphate has declined during the last few years. The main form of liquid nitrogen is anhydrous ammonia. The main straight phosphate fertilizer is superphosphate. However, in recent years its use has been considerably reduced, phosphate being applied mainly in complex fertilizers, whose proportion in total usage has been increasing for the last 10 to 15 years. The main form of potassium fertilizers remains potassium chloride. In Uzbekistan it is applied directly to the soil. Some 15 percent to 20 percent of the total potash is in the form of chlorine-free potassium fertilizers, essentially potassium sulphate, used for tobacco, grapes, potato and citrus. All potash requirements are imported from the countries of the Commonwealth of Independent States (CIS). As regards NP products, ammosuperphosphate contains 21 percent to 22 percent of nutrient and is produced in two forms: the first form has an N: ratio of 1:0.7 and contains 13 percent of N and 9 percent of, the second has an N: ratio of 1:0.5 and contains 14 percent of N and 7 percent of. These fertilizers also contain 38 percent to 42 percent of S as sulphate ions. There are also two forms of sulphoammofos. The first contains about 30 percent of nutrient, 18 percent of N and 12 percent of with an N: ratio of 1:0.7. The second contains about 26 percent of nutrient, 17 percent of N and 9 percent of, with an N: ratio of 1:0.5. These fertilizers also contain 45 percent to 48 percent of S as sulphate ions.

2 16 The fertilizer sector The prices of some fertilizers produced in Uzbekistan are as follows: (in Uzbek sum per tonne*) Ammofos: Ammonium sulphate: Ammonium nitrate: Urea: Single superphosphate: * The official rate of the Uzbek sum in June 2002 was: 1 US$ = sum Source: MAWRRUz, FERTILIZER PRODUCTION AND EXPORTS Manufacturers of fertilizers in Uzbekistan Samarkand Chemical Plant, Samarkand city; ammofos and other NP products, ammonium sulphate. Chirchik Industrial Association, Elektrochimprom, Chirchik city; ammonium sulphate and ammonium nitrate. Industrial Association Fergana azot ; urea and ammonium nitrate. Kokand Superphosphate Plant, Kokand city; single superphosphate. Industrial Assocation Navoiy azot ; ammonium nitrate. In 2001 about 650 thousand tonnes of mineral fertilizers were due to be produced in Uzbekistan, but only 83 percent of the expected amount was in fact produced. Uzbekistan normally imports potassium fertilizers and exports nitrogen and phosphate fertilizers. Uzbekistan annually exports 15 percent to 18 percent of total nitrogen fertilizer production and 10 percent to 12 percent of total phosphate fertilizer production. The destinations are nearby countries (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan) and more distant countries (Afghanistan, India, Pakistan, China and others). FERTILIZER CONSUMPTION The totals for Uzbekistan given in Table 8 compare with thousand tonnes of N (683) + (411) + O (215) in 1989.

3 Fertilizer use by crop in Uzbekistan 17 Table 8 Delivery of mineral fertilizers to agriculture ( 000 tonnes) Zones Nutrient Average /98 Karakalpakstan Republic Total N O Oblasts Andijan Total N Bukhara Total N O Djizak Total N O Kashkadarya Total N O Navoiy Total N O Namangan Total N Samarkand Total 65.1?? N O Surkhandarya Total N

4 18 The fertilizer sector Zones Sirdarya Tashkent Fergana Khorezm Uzbekistan Nutrient Average 1996/ Total N O Total N O Total N Total N O Total N O Source : MAWRRUz, Reports 1996 to The distribution of fertilizers in Uzbekistan is carried out by the state jointstock companies «Uzhimprom» and «Uzselhozhimiya». In all the regions (oblasts) of Uzbekistan, many stores have been opened for selling mineral fertilizers to cooperatives, individual farmers and to the population. Nitrification inhibitors The application of different forms of nitrification inhibitors, in order to reduce the nitrogen losses, is increasing. Nitrification inhibitors, used mostly with ammonium nitrate, slow the process of nitrification for 1.5 to 2 months. By increasing the maintenance of nitrogen in the ammoniacal form, it reduces losses and increases efficiency. In Uzbekistan the study of nitrification inhibitors started in At first the cyans, in particular cyangunidine (CG), and haloid derivatives of annelids were

5 Fertilizer use by crop in Uzbekistan 19 used as inhibitors. Since 1975 chloride derivatives of pyridine and pyrimidine have been tested extensively. In Uzbekistan the following non-volatile inhibitors have been mostly used: 1. ATS-60: (4-amino-1,2,4 triazol) as a 60 percent aqueous solution. This is incorporated in the structure of nitrogen-containing complex fertilizers, such as (last figure specifies the content of inhibitors). 2. CMP: (1-carbomoyle-3-methylpirazole) is considered to be an effective nitrification inhibitor. It is effective for 4 to 8 weeks. CMP is applied alone or incorporated at 2 percent to 3 percent CMP N of the total nitrogen content. 3. DCD: (dicyanamide), CG or DD (Didine), formed as a co-product in the manufacture of calcium cyanamide. It is incorporated at 5 percent to 10 percent DCD-N of the total nitrogen content. Despite its high dose (4 to 5 times more than CMP), CG is not a ballast in the fertilizer, since it contains 66.6 percent of nitrogen. In the soil it is easily decomposed and becomes available to plants. These nitrification inhibitors increase the efficiency of nitrogen by 12 percent to 14 percent.

6 Fertilizer use by crop in Uzbekistan 21 Chapter 4 Fertilizer use by crop The extent of mineral fertilizer use on different crops in the various regions of Uzbekistan is determined by a combination of complex factors. The most important are soil and climatic conditions in Uzbekistan, the soil nutrient content, the crop yields, the use of organic fertilizers, the relationship between the prices for the fertilizers and those of agricultural products. The average rates recommended by the scientists of Uzbekistan for the main crops are given in Table 9. The quantities and rates of application of mineral fertilizers in Uzbekistan are shown in Tables 10 and 11. The rates of application of mineral fertilizer to Table 9 Average standard rates of fertilizer application for the main agricultural crops (kg nutrient/ha) Crops Nitrogen (N) Phosphorus ( ) Potash ( O) Cereals - Irrigated land 150 to to Arid land 50 to to 50 - Cereals for seed 180 to to to 90 Rice 200 to to to 180 Cotton - Average fibres 215 to to to Fine fibres 230 to to to 110 Kenaff 160 to to to 90 Tobacco 120 to to to 45 Potatoes 120 to to to 75 Vegetables 145 to to to 75 Gourds 50 to to to 80 Fodder roots Maize for silage Established alfalfa to to 60 Orchards and vineyards 120 to to 90 65

7 22 Fertilizer use by crop Table 10 Main crops: use of mineral fertilizers and yields Crop/year Use of mineral fertilizers, thousand tonnes Yield Total N O (t/ha) Cotton Cereals Source : MAWRRUz, Table 11 Main crops: rates of fertilization Crop/year Rates, (kg/ha) Cotton Total N O Cereals Source : MAWRRUz, cotton have been declining in recent years in relation to recommendations. In the case of cereals it is the other way round and rates have been increasing. In Uzbekistan, the rate of application of fertilizers per hectare on grain crops in the past reached nearly 250 kg/ha; today it is about 180 kg/ha. Farm managers as a rule consider that it is unprofitable to apply the average recommended rates of fertilizer application if the ratio between the expenditure and the profit is not at least 1:2 to 1:3. It should also be noted that part of the cereal crop is grown under partial irrigation in zones with insufficient moisture, where the usage of larger quantities of fertilizers is less effective.

8 Fertilizer use by crop in Uzbekistan 23 According to the assessments of the Institute of Soil Science and Agro Chemistry of the State Committee of the Land Resources of the Republic of Uzbekistan, at the present time in Uzbekistan the overall use of mineral fertilizers has become 20 percent to 30 percent less than is recommended by the scientific institutions. This is confirmed by data provided by the Ministry of Agriculture and Water Resources of the Republic of Uzbekistan (MAWRRUz), which show that in all the regions studied, fertilizers are applied on cotton, cereals and potatoes at lower rates than those recommended by scientific establishments. According to the calculations of the Central Scientific Institute Agrochemical Service (CSIASUz), in Uzbekistan, on average 1 kg of nitrogen provides, depending on the rate, from 4.2 to 7.5 kg of wheat; 1 kg gives 3.8 to 7.2 kg of wheat and 1 kg O from 2.0 to 3.5 kg/ha of wheat. The simultaneous use of nitrogen, phosphate and potassium significantly increases their efficiency.

9 Fertilizer use by crop in Uzbekistan 25 Chapter 5 Organic manures The systematic use of farm manure for 30 years on the typical gleysols in Uzbekistan has doubled their humus content (from 0.83 percent to 1.65 percent). Annually million tonnes of organic manure are produced in Uzbekistan. This is equivalent to the annual application of 80 to 90 kg of nitrogen, 40 to 45 kg phosphate and 50 to 60 kg potassium per hectare of cropland. The possibilities of storing and applying organic manure are not used completely. Today, less than a quarter of Uzbekistan s need for organic manure is satisfied. Instead of the 20 to 30 tonnes of manure per hectare of cropland that are required, only 4.8 tonnes are applied. At the same time, the annual losses of animal manure resulting from discharge into water is nine millions tonnes. The total loss resulting from poor management amounts to 15 million tonnes, which could be used to fertilize an additional 750 thousand ha, taking 20 t/ha as the average. The rational and effective application of manure would increase the productivity of agriculture and decrease the pollution of the environment.

10 Fertilizer use by crop in Uzbekistan 27 Bibliography About the land resources of Republic of Uzbekistan, 2001, SCLRRUz (State Committee for Land resources of the Republic of Uzbekistan), Tashkent. Production indicators in of the enterprises concerned with the Ministry of Agriculture and Water Resources of the Republic of Uzbekistan, MAWRRUz (Ministry of Agriculture and water resources of the Republic of Uzbekistan), Tashkent. Statistical Abstracts on the Environment of the Republic of Uzbekistan, Development Alternatives Incorporated (DAI), Tashkent. Turkistan - our common home - Ecological and environmental problems in the region of Central Asia, Konrad Adenaur-Stiftung, Turan. The Aral in crisis, UNDP, Tashkent. The Aral Sea basin problems, 1998 (Research, projects, recommendations) Tashkent. Practical recommendation for agriculture: land, water, and fertilizers, Edited in cooperation with MAWRRUz, Academy of Agricultural Sciences, and Uzplodovoshvinprom association of the Republic of Uzbekistan, Tashkent Organic fertilizers in intensive agriculture, 1984, edited by V. G. Mineeva, Moscow. (Kolos). Ergashev Abdi-Kadir, Ecological and socio-economic aspects of the use of mineral fertilizers in Aral Sea Basin countries, 67 th IFA Annual Conference, Manila.

11 Fertilizer use by crop in Uzbekistan 29 Annex Soil types in Uzbekistan The genesis of the soil forming rocks in Uzbekistan is very varied. This, combined with the complexity of the litological structure of the soils, the different hydro-geological conditions, an arid continental climate and the vegetation has led to the formation of many different soils. In Uzbekistan, the soils are of highaltitude belts and desert zones. Table A.1 Types and subtypes of soil in Uzbekistan Soil 000 ha Percentage Light-brown, meadow desert, high mountain Brown and dark brown, mountain-wood, middle mountain Dark sierozem Typical sierozem Light sierozem Meadow-sierozem and sierozem-meadow Meadow of sierozem belt Marshy-meadow sierozem Sub-total Grey brown Desert sandy Dry lands Meadow and dry-meadow Desert zone meadow Desert zone marshy meadow Saline, alkali soils Sand Others land (rocks, wetland etc.) Sub-total All land Source: National Report SCLR, 2002.

12 30 Annex Soil types in Uzbekistan Table A.2 Types of soils in rainfed agricultural areas in Uzbekistan Zones & soil types Total area 000 ha Percent of total Typical annual rainfall (mm) Totally rainfed Brown, leached soils to 900 Dark sierozems to 500 Well drained, dark sierozems to 500 Total Partially dry Typical sierozems to 350 Well drained, typical sierozems to 350 Total Wholly dry Light sierozems to 350 Total rainfed Table A.3 Types of soils in irrigated agricultural areas in Uzbekistan, lower* and middle** reaches Soil type Lower reaches Middle reaches 000 ha Percent 000 ha Percent Takir and grey Light sierozem Typical sierozem Dark sierozem Grey meadow Old irrigated meadow Meadow and marsh Marsh alluvium Total *- Karakalpakstan Republic, Khorezm, part of Bukhara and Navoiy regions (oblasts) are in the lower reaches. **- Samarkand, Surkhandarya, Kashkadarya and Jizzak regions are in the middle reaches.

13 Fertilizer use by crop in Uzbekistan 31 Table A.4 Types of soils in irrigated agricultural areas in Uzbekistan, upper reaches* Soil type Upper reaches Upper reaches 000 ha Percent Takir and grey 0 0 Light sierozem Typical sierozem Dark sierozem 32 3 Grey meadow 7 1 Old irrigated meadow 0 0 Meadow and marsh Marsh alluvium Total *- Tashkent and other regions are in the upper reaches.