July 25, 2024, Thursday
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Alternative fertiliser options for Nepal

The Nepal Weekly
August 3, 2021

Opportunities to regain soil and producing organic food

Chemical fertilisers have been most necessary input for better farming in Nepal. This has been popular rapidly for last 60 years. The food productions by different crops have been increased. The ratio is said to be even double in case of some crops. However, experts and even farmers at grass root are experiencing that soil health has been deteriorated gradually. Impacts in human health due to involvement of food also have been experience in number of cases.

Moreover, Nepal imports chemical fertiliser from abroad or neighbouring countries spending a huge amount. In addition, the government provides a huge amount as subsidy to share the real cost of imported fertilisers. Even then imported fertilisers are not available to the farmers on time which results harassments and also decreased amount of production.

The government recently had approved a chemical fertiliser plant to install in Nepal. That will produce chemical fertilisers and will help consume the electricity generated in the country. Remarkably, agriculture sector in 1960s witnessed a tremendously enhanced the agricultural production mainly due to the abundant use of chemical fertilizers and pesticides. However, unilateral use of chemical fertilizers and pesticides, devoid of organic sources led to gradual deterioration of soil health, putting agricultural productivity at risk. Nepal, predominantly, is an agrarian country. It contributes one third to gross domestic product (GDP) and provides employment to two third of country’s population. With the advent of green revolution, use of chemicals has increased in Nepal over the years. Increased use of chemicals has increased the soil pH and deteriorated the soil health. However, farmers now have realized the disadvantages of chemical fertilizers and pesticides and are trying to adopt healthy agricultural practices. Minimization of chemicals used and encouraging farmers towards organic fertilizer has been the priority of Ministry of Agricultural Development (MoAD) over the past years. Agriculture has been rooted since long in the country with rich heritage of eco-friendly agricultural technologies. Farming in the hills is based on compost and Farm yard manure (FYM) application, which are the main external source of plant nutrients.

Renewable energy experts, professional, researchers bear the opinion that Nepal can produce bio-fertiliser as much as it needs by installing a number of large size biogas plants in the country. Domestic size biogas plants installed so far as much as 450,000 can contribute significantly.

Bio-fertilisers are the substance that contains microorganism’s living or latent cells. Bio-fertilisers increase the nutrients of host plants when applied to their seeds, plant surface or soil by colonizing the rhizosphere of the plant. Bio-fertilisers are more cost-effective as compared to chemical fertilisers.

The remains of fermentation after biogas formation are called slurry. Since it is obtained biologically, it is also called bio-slurry. The slurry contains the largest composition by mass with water, which are around 93% and rest of it which contains 4.5%of dry matter and 2.5% of inorganic matter. Slurry contains scum, liquid effluent, sludge and many other organic and inorganic substances. Scum is the fluid present above the surface of solid slurry. Liquid effluents contain some of the macro and the micro nutrients. The macro nutrients which is present in them are ‘N’, ‘P’‘K’ and other micro nutrients present in them are calcium, Mg, Fe, Mn, Zn. Sludge is the substances present as a residue in a biogas. The sludge materials can also be used as fertiliser for the plants. It contain very high amount of nutrients and it can be settled in the bottom of the digester for many years.

When the bio-slurry is exposed for a long period in the atmosphere, the ‘N’ which is present in the slurry will be lost and it destroys the quality of the fertilizer. The use of bio-slurry for seeding and conditioning of ponds for the fresh water fishes, the growth of fish increases and the net productivity will be more. When the bio slurry is used in the compost form, then the ammonia present in the bio slurry will be lost which is the basic source for ‘N’. Bio-slurry can be composted by mixing it with organic materials such as food waste, kitchen waste, dung and most other types of organic materials and straws. Nitrogen in the form of ammonia which is present in the bio-slurry will be partly taken by the plants and remains in the form of ‘N’. Fresh slurry is also enriched with azospirillum. It is an efficient ‘N’ fixing organism in microscopic scale. It also acts as a bio-fertiliser. When compared with farm yard manure, bio-slurry will have high organic content. Bio-slurry should have higher pHBio-slurry being fully fermented, it is odourless and it does not attract flies. It also repels the termites and pests that are attracted to raw dung. Bio slurry reduces weed growth. Application of bio slurry has proved to reduce weed growth up to 50%. Bio-slurry is an excellent soil conditioner, adds humus, and enhances the soil’s capacity to retain water. Bio-slurry is pathogen free. The fermentation of dung in the reactor kills organisms that cause plant disease. Synthetic fertilisers increase the soil’s nutrients more than organic fertilisers but they could only provide specific nutrients to the crops. The Government of Nepal (Federal Government) formed a high level committee to promote bio-fertiliser in Nepal. The committee has been learned to develop and promote bio-fertiliser for agricultural activities.

Bio-gas plants of domestic size installed more than 350,000 are one of the producers of bio-fertilisers as ‘slurry’ as bi-product besides gas for kitchen. Likewise, plants to manage municipal waste also produce bio-fertiliser good for farmers. The large bio-gas plants of 3,000 cubic meter or even larger are showing big hopes on producing bio-fertiliser at large scale. The quality and efficiency of the bio-fertilisers produced are said to almost equal to chemical fertiliser. Adding bio-char make bio-fertiliser more efficient.

As such, Government may be advised to consider on speeding promoting production of bio-fertiliser. Research and study on impact of recovering soil quality by using bio-fertiliser will be a rewarding achievement while use of chemical fertilisers deteriorates the soil quality. The agricultural products are good for human health as well as part of its contribution relates to reduce climate change effects.    

The investment summit shows that Nepal should go for bio-fertiliser promotion and production to tap many healthy impacts and also to reduce the cost of import bill in near future.

However, some 450 such units 4,000 cubic meter capacity Large Bio-gas Plants will need for the country to check import of 900,000 MT of chemical fertiliser. Likewise, development of large size livestock farms will be needed to produce inputs for the Large Bio-gas Plants. These activities will certainly contribute to socio-economic impact including creation of employment opportunities.

Recently, Renewable Energy Confederation of Nepal (RECON) organised a webinar to discuss and exchange of knowledge and experiences of researchers and professionals. Former Minister Er. Ganesh Shah spoke on need of stakeholders’ synergy to forge for influencing the policymaker and planners to be serious on research, development and promotion of bio-fertiliser as alternative fertiliser for Nepal.

Dr. Surya P. Bhattarai Associate Professor at Central Queensland University was the key speaker of the event. He elaborated the practices conducted in various countries stressing possibility in Nepal for replacing use of chemical fertilisers and regain soil health. Prof. Dr. Hom Bahadur Basnet, Dr. Shantikala Subedi, Dr.Keshav Raj Adhikari, Dr. Indira Shakya, Mr. KushalGurung, Mr. Mukesh Ghimire, Chairperson of RECON Mr. Guna Raj Dhakal also spoke on the occasion highlighting need of promoting alternative fertilisers for agriculture in Nepal which can fetch multiple benefits. (By R. P. Narayan)