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: P2O5 ratio of 1:0.7 and contains 13 percent of N and 9 percent of P2O5, the second has an N: P2O5 ratio of 1:0.5 and contains 14 percent of N and 7 percent of P2O5. 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 P2O5 with an N: P2O5 ratio of 1:0.7. The second contains about 26 percent of nutrient, 17 percent of N and 9 percent of P2O5, with an N: P2O5 ratio of 1:0.5. These fertilizers also contain 45 percent to 48 percent of S as sulphate ions.
The prices of some fertilizers produced in Uzbekistan are as follows:
(in Uzbek "sum" per tonne*)
Ammofos: 128 000
Ammonium sulphate: 48 000
Ammonium nitrate: 36 000
Urea: 58 000
Single superphosphate: 52 000
* The official rate of the Uzbek "sum" in June 2002 was: 1 US$ = 739.38 sum
Source: MAWRRUz, 2002.
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).
The totals for Uzbekistan given in Table 8 compare with 1 309 thousand tonnes of N (683) + P2O5 (411) + K2O (215) in 1989.
Table 8
Delivery of mineral fertilizers to agriculture ('000 tonnes)
|
Zones |
Nutrient |
Average 1996/98 |
1999 |
2000 |
|
Karakalpakstan Republic |
Total |
70.5 |
61.0 |
54.0 |
|
N |
56.0 |
49.0 |
47.8 |
|
|
P2O5 |
10.1 |
10.8 |
5.5 |
|
|
K2O |
4.5 |
1.2 |
0.7 |
|
|
Oblasts |
||||
|
Andijan |
Total |
67.3 |
64.8 |
59.5 |
|
N |
49.1 |
47.3 |
47.0 |
|
|
P2O5 |
12.6 |
14.2 |
11.4 |
|
|
K2O |
5.7 |
3.3 |
1.1 |
|
|
Bukhara |
Total |
67.4 |
61.1 |
56.6 |
|
N |
51.5 |
46.7 |
45.3 |
|
|
P2O5 |
9.5 |
11.5 |
10.2 |
|
|
K2O |
6.4 |
2.9 |
1.1 |
|
|
Djizak |
Total |
48.5 |
50.9 |
45.4 |
|
N |
36.9 |
38.8 |
38.3 |
|
|
P2O5 |
7.8 |
9.9 |
6.4 |
|
|
K2O |
3.6 |
2.2 |
0.7 |
|
|
Kashkadarya |
Total |
85.5 |
75.1 |
67.1 |
|
N |
64.3 |
56.6 |
54.0 |
|
|
P2O5 |
14.5 |
15.9 |
10.9 |
|
|
K2O |
6.8 |
2.6 |
2.2 |
|
|
Navoiy |
Total |
24.6 |
26.4 |
20.3 |
|
N |
18.6 |
20.6 |
15.4 |
|
|
P2O5 |
3.6 |
4.5 |
4.0 |
|
|
K2O |
2.4 |
1.3 |
0.9 |
|
|
Namangan |
Total |
64.6 |
57.1 |
52.1 |
|
N |
48.1 |
41.8 |
40.8 |
|
|
P2O5 |
10.6 |
12.0 |
10.3 |
|
|
K2O |
5.8 |
3.3 |
1.0 |
|
|
Samarkand |
Total |
65.1 |
? |
? |
|
N |
48.7 |
43.6 |
41.5 |
|
|
P2O5 |
12.1 |
12.0 |
9.3 |
|
|
K2O |
4.4 |
2.8 |
1.8 |
|
|
Surkhandarya |
Total |
65.2 |
62.8 |
54.2 |
|
N |
50.8 |
47.5 |
46.5 |
|
|
P2O5 |
9.2 |
12.6 |
7.1 |
|
|
K2O |
5.3 |
2.7 |
0.6 |
|
|
Sirdarya |
Total |
54.0 |
51.7 |
47.1 |
|
N |
39.1 |
39.6 |
39.0 |
|
|
P2O5 |
10.3 |
10.9 |
7.1 |
|
|
K2O |
4.6 |
1.2 |
1.0 |
|
|
Tashkent |
Total |
64.5 |
60.2 |
54.2 |
|
N |
47.8 |
45.4 |
44.0 |
|
|
P2O5 |
12.0 |
12.5 |
9.2 |
|
|
K2O |
3.9 |
2.3 |
1.0 |
|
|
Fergana |
Total |
78.7 |
64.7 |
62.0 |
|
N |
60.0 |
47.2 |
48.3 |
|
|
P2O5 |
13.7 |
14.0 |
12.6 |
|
|
K2O |
5.0 |
3.5 |
1.1 |
|
|
Khorezm |
Total |
80.6 |
60.9 |
50.6 |
|
N |
63.0 |
47.8 |
43.0 |
|
|
P2O5 |
13.5 |
11.3 |
6.6 |
|
|
K2O |
4.1 |
1.8 |
1.0 |
|
|
Uzbekistan |
Total |
840.0 |
755.4 |
677.0 |
|
N |
637.3 |
571.9 |
551.0 |
|
|
P2O5 |
140.2 |
152.4 |
110.6 |
|
|
K2O |
62.5 |
31.1 |
15.4 |
|
Source: MAWRRUz, Reports 1996 to 2000.
The distribution of fertilizers in Uzbekistan is carried out by the state joint-stock 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 1964. At first the cyans, in particular cyangunidine (CG), and haloid derivatives of annelids were 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 14-16-16-0.3 (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.
