BALANCED USE OF FERTILIZER
A long term, rigid, stable and sound policy on fertilizers is needed
By Dr. S.M. ALAM, NIA,
Apr 02 - 08, 2001
Fertilizer is kingpin in enhancing crop production and contributing about 40-50 per cent in the total good grain production. Every kilogram of plant nutrients applied to crop results in 8-10 kg of food-grain production. After independence, the fertilizer consumption in Pakistan was very low. The real boost in fertilizer consumption came after mid 60's with the introduction of high yielding varieties in wheat, rice and other cereals. Fertilizers are considered essential component of crop production in order to feed the increasing and burgeoning population and general improvement in diet of the citizens of Pakistan. It is estimated that globally 40-45 per cent of the protein in human diet is derived from fertilizers. It is also a key to securing the food-grain need of a country. No country has been able to increase agricultural productivity without expanding the use of fertilizer industry. One of the factors responsible for poor production and crop yield in agriculture sector is the nutrient deficiency of the soils under cultivation. An appropriate use of chemical fertilizers, a balanced combination of nitrogen, phosphorus and potassium (N, P, K) can definitely help and promote in overcoming the problems of crop productivity in the country.
The most important constraints crop productivity are those caused by inefficient and imbalance use of plant nutrients in the form of fertilizers. The fertilizers constitute the most important scientific breakthrough in feeding the growing population of Pakistan. As far as fertilizers are concerned, they offer tremendous scope and assistance to enhance agricultural production. Proper use of fertilizers can indeed increase crop yields significantly, particularly in case of cereals. Food and Agriculture Organization (FAO-Rome) of the United Nations has estimated that contribution of fertilizers in increasing crop productivity is about 50 per cent. Studies in Pakistan have shown that contribution of chemical fertilizers through crop production ranges between 30 to 50 per cent under a given soil climatic conditions. Of all the farm inputs, fertilizers have been one of the most profitable for the fertility of soils and ultimately to crop productivity. Fertilizer responsive plant crops, the rapid development of weedicides and pesticides, narrow rows, sophisticated fertilizer placement implements, the low cost of fertilizer and efficient soil testing service have all contributed to the economic response and the continuous popularity of fertilizers all over the world. Among the crop production factors, fertilizers play a key role to improve productivity and to achieve national food security. The use of different fertilizers has resulted in pivotal increase in crop yield in the country. During the past forty years, with the introduction of yielding crops varieties of wheat, rice, cotton, sugarcane and other important crops, the use of chemical fertilizers of the kinds nitrogenous, phosphatic and potassic fertilizers have been significantly increased. At the same period the crop productivity of wheat increased from 305 million tons to 20 million tons, 50 million tons sugarcane has also increased from 20 million tons to 46 million tons, cotton production increased from 2 million bales to 10 million bales. Similarly, along with the increased in crop production the increases in acreage, supplies of irrigation water, increase in the use of certified seeds of crops, high yielding varieties, improved pest management, and improvement in modern agriculture practices, the increase in food production of different commodities have tremendously been increased along with the fertilizers. Soil is the storehouse of essential plant nutrients and generally supplies more than 13 plant nutrients. From the air plants take carbon, oxygen, hydrogen and nitrogen. Water is the carrier of nutrients from the soil to plant and provides hydrogen as well to the plant. Nitrogen, phosphorus and potassium, which are available to plants through chemical fertilizers are the major nutrient elements, and they are consumed by plants in large quantities, while calcium, magnesium and sulphur are known as secondary elements are required by plants in relatively lesser amounts. Along with these, these are nutrients as iron, manganese, zinc, copper, boron, chloride and molybdenum, which are required by plants in small amount and they are known as micronutrients.
The soil of the earth body remains to be the major contributor of plant food. It is a known act that a farmer puts about 100 kg of wheat as seed rate for one hectare of land and at the end harvest about 4000 kg of wheat-grain. The weight gained of 3900 kg per hectare is contributed by air, water and soil.
An IFA world fertilizer manual has revealed that for producing 5 tons of rice grain hectares, about 304-kg nutrients (111 kg N, 35 kg P2O5 and 148 K2O/ha) are needed. For producing 5 t/hectare of wheat-grain, 367.7 kg nutrients (139.6 kg N, 41.2 kg P2O5 and 188 kg K2O/ha) are needed. For producing 8.8 tons of grain yield per hectare of wheat and rice in rice-wheat system 663 kg nutrients (235 kg N, 92 kg P2O5 and 336 kg K2O/ha) are required.
In the old days, when the population of the world was much lower than the present time and the agricultural land was adequate and sufficient, the farming community used to work mostly in one area for a few years and when the productivity of the food-grain became low due to depletion of soil nutrients, the farmers use to abandon that piece of land and more other pieces of land. But now, the situation has become different and completely changed and the agricultural land has become a scare source for agricultural growth: At the time of partition of 1947, the population of Pakistan was nearly 30 million and now it has rose to a level of more than 140 million in the year 2000. In the same context, the total geographical area of the country is 80 million hectares and only 21 million hectares are cultivable. The acreage of land on the basis of present population is decreasing, and also the land is becoming deficient in nutrients. Therefore, to support the growing population, the production of food-grain has to increase from the same deficient land and chemical fertilizers have to be used to make the soil sufficient in plant nutrients by supplying them at proper time and thus to obtain good crop yields.
The chemical fertilizers provide plant nutrients in a most available form. They provide all primary nutrients, secondary and micronutrients to replenish the soil nutrients, which are taken by the plants. The high yield crop varieties generally need more food from the soil that has been supplemented with chemical fertilizers. The proper use of fertilizers on soils of low natural fertility makes it possible to grow a wider variety of crops. The net result of the liberal use of fertilizers is greater efficiency in the utilization of land, labour and water. The current use of the three major fertilizers of NPK is about 110 kg per hectare. This combination is very low for agricultural productivity compared to other countries of the world. The use of chemical fertilizers in European countries is between 300-600 kg of NPK per hectare. Even in countries like China and Egypt the use of NPK in the form of chemical fertilizer is over 300-350 kg per hectare. It has also been reported that the average wheat yield obtained by the countries mentioned above is about 4000-7000 kg per hectare whereas the average yield of wheat in Pakistan is little over 2000 kg per hectare. With the use of current technology we can obtain wheat yield of 4000-5000 kg per hectare, but unbalanced use of chemical fertilizers is one of the important factors responsible for the gap between the potential and average yield of wheat crop in Pakistan. Thus one main reason of static crop yields in inadequate and imbalanced use of fertilizers. The nutrient balance sheets established in crop production regions show negative balance of all nutrients. Crop yields are much below than proven potential. Without balance fertilizations, and efficient use of applied nutrients the proven potential of crop nutrients is difficult to realize. The fertilizer industry faces a permanent challenge to improve the efficiency of its products. This is done either through improvement of fertilizers already in use or through development of new specific fertilizer types. Fertilizer use efficiency has in fact been improving in the developed countries.
Fertilizer use has been increasing rapidly in Pakistan over many years, but there is a stagnation of crop production. This seems to be due largely to the incorrect use of fertilizers. Farmers have been applying high amounts of nitrogen, but only small quantities of phosphate. Other fertilizers, such as potash and micronutrient are hardly used at all. Fertilizer promotion activities undertaken by the industry, in the beginning aimed at increasing per hectare fertilizer consumption, however, presently it is also providing and pinpointed focus on balanced, efficient and economic use of fertilizers. The highly imbalanced use of fertilizer is one of the major reasons for the stagnant yield levels of most of our major crops. Although, fertilizer use in Pakistan as compared to other countries is still much below the desired level, a judicious and balanced use of fertilizer can, never-the-less, bring about a substantial increase in crop productivity. Although, fertilizer use in Pakistan has increased by manifolds during the last three decades. Application of fertilizers should be timed according to period of nutrient uptake by the crop. Several split dressings may be required especially for water crop to maximum nutrient uptake.
The application of nitrogen fertilizers tends to be preferred by farmers, because of their relatively low cost per unit of nutrient, their widespread availability, and the quick and evident response of the plant. However, increased yields deplete the soil of the other plant nutrients removed by the harvested crops, unless they are replenished.
Domestic production of fertilizer: The year 1998-99 witnessed a modest increase in fertilizer production. The overall domestic production of fertilizer of all types during the year 1998-99 was about 4,242 thousand product tons compared to 3,894 thousand tons in 1997-98, showing an increase of 8.9 per cent. Nutrient wise total production was 1,886 thousand tons in 1998-99, compared to 1,728 thousand tons in last year, thereby an increase of 9.1 per cent was achieved. The production in nutrients was 1,795 thousand tons of nitrogen and 91 thousand tons of phosphate. Urea production was 3,550 thousand tons. The share of private sector was 76.2 per cent and of public sector 23.8 per cent. Of total fertilizer product produced in the country, public sector share was 35.2 percent compared to 64.8 per cent of private sector. It may be stated that five products Urea, calcium ammonium nitrate (CAN) and nitrophos (NP) (23:23) single super phosphate (SSP) and di-ammonium phosphate (DAP) are manufactured in the country. The production of CAN, NP and SSP are completely handled by the public sector. The private sector had only recently begun producing DAP. It may be pointed out that urea is the most important single straight nitrogenous fertilizer produced in the country. All the companies are involved in the production of urea. The share of urea in total fertilizer production was 83.7 %, followed by CAN (8.0 %) NP (6.7 %) DAP (1.1 %) SSP (0.5 %). In summary, the following product tonnage's were urea 3,550, CAN 339, NP (23:23) 285, DAP 46 and SSP 22 thousand tons.
Fertilizer imports during 1998-99: Domestic production met about 72.4 per cent of the country's product requirements during 1998-99 (65.2 per cent during 1998-99). This shows that the domestic production was not able to meet the demand and country is heavily dependent on imports. Country is self sufficient in urea at present. However the phosphate (DAP/TSP) imports will continue. All potassium fertilizer will be imported. Fertilizer imports have become a regular feature of the fertilizer sector. There is no ban on the fertilizer import. Fertilizer imports are therefore, undertaken by public as well as private sectors.
Fertilizer consumption during 1998-99: The consumption of all nutrients (N+P2O5+K2O) was 2,584 thousand tons during 1998-99 compared to 2,646 thousand tons during 1997-98, thereby showing a decrease of 2.3 per cent. The decrease in fertilizer consumption can be attributed to a number of factors, (i) sanctions against Pakistan and delayed imports, (ii) liquidity problem with farmers due to cotton failure and non payment of sugarcane sale proceeds, (iii) no increase in support price of wheat and (iv) escalation of DAP prices.
The share of nitrogen in total fertilizer consumption was 81.2 per cent during 1998-99 (78.5% during 1997-98). Phosphate captured 18.0% share (20.7 per cent share during 1997-98) and potash 0.8 per cent (0.8% during 1997-98). A substantial decrease in phosphate off take during 1998-99, in comparison to nitrogen widened the N:P ratio to 4.51 over previous year's 3.77. This clearly demonstrated that the consumption of the main nutrients was not balanced. The imbalance in the use of nitrogen and phosphorus is one of the major factors for low fertilizer use efficiency, which is also impacting crop yields. Experience has shown that farmer's tend to apply more nitrogenous fertilizers is because of its relatively low cost per unit of nutrient, easy availability and the quick response of the crops.
General conclusion: There are a number of issues in fertilizer sector which is impacting its development interalia the growth in agriculture. Some are listed below with recommendation. The overall fertilizer policy environment has been very conducive since 1980's. This attracted investment and urea production in the country has reached a level of 4.3 million tons, DAP 450 thousand tons, CAN 450 thousand tons, nitrophos 305 thousand tons and SSP 180 thousand tons. The country will remain self sufficient in urea till 2001, after which shortages will start emerging. The current phosphate production meets hardly 40 per cent of the total requirements. There is no potash production in the country. The fertilizer policy of 1980's gave good results and there is need to have fertilizer policy to attract investment in fertilizer sector. The conservative estimates show that in the first decade of this millennium N and P requirement will grow at the rate of about 3.5 and 5.0 per cent per annum. Thus to meet the requirement of the plant nutrients, country has to import about 2.0 million tons each of urea and DAP by year 2010. Therefore, with a long term, stable and conducive policy on fertilizers sooner than later in order to attract investment in fertilizer, ensure supply of essential plant nutrients at farm level to achieve food security and foster economic development. With the increased participation of private sector in the fertilizer imports and distribution, an uncertainty exists about the timing of imports, type and quantity of products imported, the quality of products and their sale in different crop production regions of the country. There is dire need to ensure quality of products under deregulated regime to safeguard interests of farmers. All importers should be registered with some authority and it should be made mandatory for them to supply information regarding plan of import/distribution, quantity, product specification, and areas of distribution for proper monitoring of supply/demand in the country and quality control. Over period due to continuous imports of DAP phosphatic fertilizers, the market is completely DAP demand driven. So far so the farmers will always look black DAP and producers of white DAP are colouring it black for sale to Pakistan. It has resulted in very low demand for good quality straight phosphatic fertilizers such as TSP and locally produced SSP. The country is currently surplus in urea (nitrogen). With DAP, we import lot of nitrogen, which further worsens N:P ratio. DAP imports of 775 thousand tons during 1998-99, brought about 140 thousand tons of nitrogen or equivalent to 300 thousand tons of urea. By promoting straight phosphate products not only N:P ratio will improve but it will result in substantial saving of foreign exchange. Straight phosphatic fertilizers should be promoted for their acceptability among the farmers.
The consumption of all fertilizers in Pakistan is 112 kg/ha, which is 37 percent of use in Egypt, 42 per cent of China, and 21 per cent of Netherlands. The problems in Pakistan are not of under use only, which lead to nutrient mining and soil degradation, but imbalance and incorrect methods of application. Moreover, organic sources have their limitations to properly supplement the chemical fertilizers. It is therefore, of paramount importance that farmers should be educated on balanced use of fertilizers, application at right time crop needs and through proper methods.
The review showed that the consumption of the main nutrients was not balanced. The imbalance in the use of nitrogen and phosphate is one of the major factors for low fertilizer use efficiency, which is also impacting crop yields. The main problem in improving balanced fertilizer use is price difference between urea and DAP, lack of phosphate and potash promotion and shortages at peak demand months. Attention should be given to proper balance of NPK with micronutrients and organic sources. Availability at farmers level should be improved and extension efforts accelerated to convince farmers about the benefit of proper nutrient balance.
The isolated and individual efforts are not addressing the challenging issues and occasionally confusion is created about rate of fertilizer for different crops, sources, methods and time of application, fertilizer use efficiency and impact on yields. A number of fake and substandard products are also marketed as miracle fertilizers or substitutes for organic and chemicals fertilizers. Thus the farmers are cheated. A national collaborated programme should continue to provide linkages, coordination, sharing of information, addressing crucial issues of applied research for benefit of the farming country and agricultural development of the country. The integrated plant nutrition management system which envisages organic and inorganic sources should be tested and validated at farm level.
Fertilizer sector in Pakistan is entering new millennium with pride over if contribution towards local production capacity, increased crop productivity and economic development of the country. However, entry in 21st century also brings with it lot of hopes, expectations and concerns for the future. A long term, rigid, stable and sound policy on fertilizers is needed to ensure timely availability at maximum affordable prices to farmers throughout the country and to promote their efficient, balanced and environment friendly use at farm level.