Banning fertilizer imports

By Dr. C. S. Weeraratna
csweera@sltnet.lk

According to recent news, import of fertilizers is going to be banned. The President at a recent meeting highlighted the importance of shifting towards organic fertilizers by gradually decreasing the usage of chemical/inorganic fertilizers. According to the National Fertilizer Secretariat, in 2020, we imported around 580,000 MT of inorganic fertilizers costing Rs. 36 billion. Of this amount around 50% is used for paddy and the balance for planation crops and field crops.

In 2019 around Rs 300 billion worth of food has been imported. Among the imported food are green gram, red onions, big onions, maize, etc., which can be locally produced. If we are to reduce our expenditure on food imports it is essential that the local food production is increased. For effectively addressing this issue several inputs are important. Among these are good quality seeds/planting material, and use of appropriate technology. In this regard judicious use of fertilizers is important. .

There are two types of fertilizers. Inorganic fertilizers (IF) such as ammonium sulphate, urea, Triple Super Phosphate and muriate of potash which supply nutrients nitrogen, phosphorus and potassium respectively and are called macronutrients. Plants need them to grow and produce. Several research studies conducted in Sri Lanka and elsewhere indicate that the application of IF tends to increase growth and yields of crops.

Organic fertilizers such as compost, animal residues contain very small amounts of macronutrients, but some essential plant nutrients such as iron, manganese, copper, etc, called micronutrients which are not present in inorganic fertilizers.

Effects of banning fertilizers

Except for Eppawela Apatite Inorganic fertilizers are not manufactured locally. If the import of IF is going to be banned, and organic fertilizers (OF) used instead, it is likely that yields of all crops will decrease. As indicated research studies conducted in Sri Lanka and elsewhere indicate that application of IF tend to increase growth and yields of crops. Currently, the average paddy production in Sri Lanka is about 4 t/ha and this is likely to be reduced if inorganic fertilizers are not applied. The same will apply to other crops including tea as well which has a positive effect on the economy of the country. Already paddy farmers in some areas are complaining that basal fertilizers are not available for the Yala crop. If IFs are not available, llocal crop production will decrease causing food imports such as rice, pulses, etc.,to increase and reducing exports of plantation crops exacerbating the present economic and social problems. Thus, the final effect of banning fertilizer imports will be on the economy of the country which is already in a dire status.

If the imports of these IFs is going to be banned it is essential that alternatives are available as plants need nutrients to grow and produce. Organic fertilizers such as compost which is considered to be an alternative does not supply these macronutrients in adequate amounts unless large quantities of OFs are used. For example, to supply nitrogen in 100 kg of urea (urea has 46% N) a farmer has to apply around 2 tons of compost (only 2% N). OF are not alternatives to IF but supplementary.

Based on Central Bank reports, in 2019, expenditure on food and beverages is around Rs 300 Billion. The expenditure in 2021 on food imports is likely to be even more due to the depreciation of SL rupee. Banning IF will reduce our expenditure on imports by app. Rs. 36 billion but at the same time it will reduce local food production and increase our annual expenditure on food imports which at present is around Rs. 300 billion. It will also have an adverse impact on food security.

Alternatives:

If import of Inorganic fertilizers is to be banned, it is necessary to resort to alternative methods of supplying nutrients required by plants. Biological nitrogen fixation (BNF) if used will tend to reduce our N fertilizer imports to some extent. BNF is a process carried out by various groups of microorganisms. Studies on BNF have been conducted in Sri Lanka for almost three decades by scientists such as Prof. S. A. Kulasuriya. Results of these studies show that nitrogen-fixation by organisms such as azolla, blue-green algae and rhizobia can be used to supplement inorganic nitrogen fertilizers. BNF is used profitably by farmers in many other countries such as India, China, Vietnam etc. It is necessary to implement an integrated plan to promote the use of Biological Nitrogen Fixation in crop production.

Organic fertilizers can be used to supplement IF as OF supply micronutrients which are not present in inorganic fertilizers. OF production units, in each village, would maximise utilization of resources and provide employment on a large scale. Any type of organic material is not suitable to be applied to crops. For example, those made from city wastes may contain toxic elements such as heavy metals. OF can be used in intensive agricultural systems but in crops such as paddy, and planation crops which are cultivated extensively, compost is not effective enough to supply plant nutrients required by plants.

Application of inorganic fertilizers with organic fertilizers would give higher yields. Hence, it is necessary to implement a concerted plan to promote application of organic fertilizers. It is extremely important that the advantages and disadvantages of banning inorganic fertilizers need to be carefully considered by relevant authorities before deciding to ban these fertilizers.

Issues associated with IF

It has been reported that some farmers, apply phosphatic and potasic fertilizers more than what is required. Hence it would be desirable if the amounts of fertilizers to be applied are based on soil tests. There is a need for improving on-farm nutrient management using an integrated nutrient management approach, combining inorganic and organic fertilizers. In most of the annual cropping systems managed with IF, the application of organic fertilizer as a supplement is essential. Insufficient organic matter levels in soils would lead to leaching of the inorganic fertilizers added to soil. Around 40% of N in urea applied to soil tends to get lost due to volatilization and leaching. The total benefits of inorganic fertilizers can be realized only by having adequate organic matter levels in the soils by applying OF.

Although highly debated, some are of the opinion that fertilizers is one of the cause of increased incidents of chronic kidney disease with unknown aetiology (CKDU) in the country. An international expert consultation on CKDu was held in Colombo in April 2016. It was organized by the Presidential Task Force for Prevention of Chronic Kidney Disease and the Sri Lanka country office of the World Health Organization (WHO). The consultation concluded that there was no conclusive evidence to indicate that there was any relationship between CKDU and fertilizers.