A middle path for Sri Lankan agriculture: Sustainable intensification – PART I

By Prof. W.A.J.M. De Costa

Senior Professor and Chair of Crop Science, Faculty of Agriculture, University of Peradeniya

Sri Lankan agriculture appears to be recovering from its recent upheavals brought about by the ill-fated experiment of converting to 100% organic overnight. However, some of the core issues that existed prior to the ‘100% organic agriculture experiment’ remain. These issues bring in to focus the long-term sustainability of Sri Lankan agriculture and its capacity to ensure national food security while ensuring a reasonably prosperous livelihood to its farmer community. The social dialogue and the consequent increase in awareness during the ‘100% organic agriculture experiment’ and its aftermath highlights the need to modernize Sri Lankan Agriculture by infusing new technologies and be in better shape to meet the challenges posed by climate change and concerns on environmental and food safety. The current phase of partial recovery from the recent crises affords a ‘window of opportunity’ to shift from long-held views and practices and embark on a new pathway which addresses both the food security concerns as well as the sustainability concerns while taking on board the need to be climate resilient and eco-friendly. However, the recent steps taken by the Sri Lankan authorities (e.g. provision of the full quota of the inorganic fertilizer triple super phosphate and diesel free of charge to farmers etc.) and the demands of the farming community (e.g. heavily-subsidized or free inorganic fertiliser, unrestricted availability of synthetic agrochemicals, full compensation for crop losses, etc.) brings in to question whether a ‘window of opportunity’ for Sri Lankan Agriculture to be technologically-advanced, climate-resilient and eco-friendly is being missed. This article discusses ‘Sustainable Intensification’ as an option, which is worth considering when striving to achieve the above-mentioned multiple goals of future Sri Lankan Agriculture.

What is Sustainable Intensification (SI)?

Sustainable intensification (SI) refers collectively to strategies and practices that aim to increase crop yields without adverse environmental impacts and without expanding the presently-cropped area. Increasing yields generally requires greater investment of land resources (i.e. nutrients, water, energy etc.). Sustainable intensification aims to achieve yield increases with a proportionately lower increase in resource use (i.e. ‘producing more with less’). As such, SI aims to conserve and, possibly, regenerate the resource base (i.e. land, soil fertility, water, biodiversity, etc.) while meeting the food demand of a continuously increasing population. Climate change adds an overarching layer of challenges on all SI strategies. This short article identifies SI strategies that are feasible in crop production systems in Sri Lanka. It then explores how the additional challenges posed by climate change on the feasible SI strategies may be addressed.

The challenges faced by the food production systems in Sri Lanka

The global population which reached 8 billion in 2022 is projected to rise to 9.7 billion in 2050 and 11 billion in 2100. The corresponding trend in Sri Lanka is different where the current (March 2023) population of 21.65 million (0.27% of the global population) is projected to rise to 22.19 million in 2040 (0.24% of global). The annual rate of population growth in Sri Lanka which was 2.43% in 1967 has almost continuously declined to the present rate of 0.42% in 2020. These demographic trends will, to a certain extent, lessen the pressures exerted on food production targets and the demands exerted on essential environmental resources. However, many other natural and socio-economic drivers are likely to increase these pressures. Climate change is one such driver where the temperatures in key agroecological regions have been shown to have increased at rates which are greater than that of the global average temperatures. The recent economic down-turn and short-sighted government policies have combined to reduce the capacity of farmers to invest in essential inputs such as fertiliser, good quality seed and Good Agricultural Practices (GAPs) in crop management. This has left the soils impoverished and imbalanced in terms of essential plant nutrients and crops susceptible to a range of biotic (e.g. diseases and pests) and abiotic stresses (e.g. drought, heat, salinity, climate change).

Inadequate investment in research and development has left the national agricultural research system (NARS) severely depleted so that generation of new technologies through research to overcome these challenges has slowed down to a trickle. Similarly, the national agricultural extension network has been depleted, fragmented and made ineffective during the last three decades, thus depriving the farmers of knowledge and advise on existing and emerging technologies to overcome the challenges faced by them. Furthermore, arguably, Sri Lankan agriculture and its farmers have, for a long time, been dependent on cultivation practices which are heavily reliant on addition of large quantities of external inputs (e.g. inorganic fertilizer, synthetic pesticides and fossil fuel).

There has been inadequate attention, willingness and effort on the part of all stakeholders to introduce and engage in agricultural practices which are less demanding on external inputs and aim to regenerate and replenish the resource pool in the croplands that are being used to produce the crops. Now, the Sri Lankan Agriculture is at a critical juncture where the substantially reduced economic capacity to provide external inputs (e.g. inorganic fertilizer, fossil fuel, synthetic pesticides) has forced its stakeholders to explore options and avenues which will enable them to meet the national agricultural production targets with reduced inputs. Thus, I would argue that we have a ‘window of opportunity’ to steer the Sri Lankan Agriculture towards a more sustainable pathway while engaging in efforts to increase its productivity. This is where ‘Sustainable Intensification’, comes in to focus for Sri Lanka at the present juncture.

Strategies for Sustainable

Intensification (SI) in Sri Lanka and required paradigm shifts

Any SI strategy should satisfy three criteria for it to be implementable, effective, and adopted by the farmers. First and foremost, the strategy should be based on valid scientific principles. In addition, its environmental cost should be minimum. Furthermore, the strategy should be within the economic capability of the potential end-users (e.g. farmers) and also socially and culturally acceptable. The specific SI strategies that satisfy the scientific, environmental and socio-economic criteria are different for different scales of agricultural production. Accordingly, the strategies that may be applicable to large scale and extensive production systems such as plantation crops and paddy would be different from the SI strategies that are suitable in small-scale and subsistence farming systems which produce a high proportion of the Other Field Crops (OFCs) and vegetables in Sri Lanka.

Some key paradigm shifts are essential in identifying feasible SI strategies for different production systems in Sri Lanka. Currently, the specific crops (and specific crop varieties) are selected via a crop-based approach, which is determined by climatic and soil considerations as well as by economic (e.g. market forces) and social considerations (e.g. farmer preference) with little consideration on sustaining and regenerating the resource base (e.g. nutrient recycling, soil conservation etc.). Selection of crops to be grown based on a ‘Cropping Systems Approach’ (instead of a crop-based approach) constitutes a key paradigm shift in moving Sri Lankan Agriculture towards SI. A cropping systems approach considers the crop as one component of a broader faming- and eco-system which includes the soil resource base, water resources, biodiversity, natural vegetation, livestock, wildlife, industries, marketing channels and the socio-cultural setting. Such a paradigm shift forces all key players (e.g. farmers, researchers, extensionists and policy makers) to explore the possibility of increased adoption of crop rotations, crop mixtures (e.g. intercropping), cover crops, ‘crops for the period between seasons’ and fallowing, where minimising resource losses and maximising resource recycling are given due consideration in decision-making.

A second paradigm shift that is needed for SI of Sri Lankan Agriculture is to shift focus from attempting to maximise yield per unit land area to maximise yield per unit of limiting resources (e.g. maximizing yield per unit of water used and yield per unit of nitrogen used, etc..). This requires a significant shift of focus in crop improvement programmes through plant breeding from developing higher yielding varieties to developing varieties with greater resource use efficiency which give an adequate, but not necessarily the highest, yield. Greater emphasis should be accorded to the improvement nutritional quality during the development of new crop varieties to address the growing concerns about increasing malnutrition.

Developing perennial rice varieties (i.e. a variety of rice that will yield a crop for 4-5 seasons from the same plant), an initiative that is being pursued in the US and tested in China, could reduce the economic and environmental cost of rice production. Development of these new resource-efficient and more nutritious crop varieties should be accompanied by the development of a range of new agronomic crop management practices/strategies/packages which focus on the key requirements of SI (i.e. sustainability of the resource base). In particular, these strategies include irrigation and water management practices which minimize evaporative losses while maximizing efficient delivery and uptake and nutrient management practices to minimize leaching and volatilization losses while releasing the nutrients which are fixed in the soil minerals. In this regard, the potential of new technologies such as drones, artificial intelligence, machine learning and the Internet of things needs to be harnessed in developing new crop management packages to provide detailed location-specific information to optimize resource use in crop production.

Shifting from single strategy-based crop management to integrated crop management is the third paradigm shift that is needed to move Sri Lankan Agriculture towards SI. Most single strategy-based crop management practices (e.g. crop protection, nutrient management etc.) are heavily reliant on inorganic and synthetic substances. Broadening the strategies used and thereby reducing their reliance on synthetic substances during crop protection (e.g. Integrated Pest Management) and nutrient management (Integrated Nutrient Management) addresses one of the key requirements of SI by ensuring protection of the agroecosystem and its services (e.g. biodiversity, clean water, safer food etc.). Integrated nutrient management should include strategies to harness the potential of biochar (charcoal-like material containing highly stable carbon obtained by burning any type of biomass in a zero-oxygen environment) to improve the fertility of Sri Lankan soils. (To be condluded)

This article is adapted from a keynote address delivered by the author at the 3rd International Symposium on Agriculture organized by the Faculty of Agriculture of the Eastern University of Sri Lanka on the theme ‘Self-Sustaining Agriculture: Way forward for food security and safety’ on the 9th of March 2023. It has incorporated valuable comments on a first draft from Raj Gonsalkorale, Suchira Peiris, Vijith Gunawardena and Parakrama Jayasinghe.