Impact of natural disasters on the efficiency of agricultural production: an exemplar from rice farming in Sri Lanka

  Sajeevani Weerasekaraa, Clevo Wilson, Boon Lee, and Viet-Ngu Hoang   |  

This study presents a number of policy implications that should be considered by every rice-producing country. It strongly suggests that policies should be tailor-made to suit specific agricultural sub-sectors, as many of the climate and disaster adaptation practices commonly applied to different agricultural sub-sectors could well lead to more harm than benefits.

There is sufficient evidence that climate change is already having global ramifications around the globe. However, just as some regions are more vulnerable to the impact of climate change, some agricultural crops are also more vulnerable to these changes. The rising average temperature and unpredictable rainfall, combined with the occurrence of extreme weather events, render some agricultural production systems more susceptible to crop failure.

South Asia is recognized as being highly vulnerable to climate variability and change – a region where average temperatures and changing seasonal rainfall patterns have already affected agricultural output. Although the agricultural sector is highly prone to the adverse impacts of natural disasters, a review of current literature indicates that a number of aspects of this critically important issue have received inadequate attention.

Whereas the direct impact of natural disasters is obvious in many ways, indirect impact is less visible and unclear. Over the last 3–4 decades, we noticed that as climate-induced disasters increase, many agriculture-dependent countries were gradually shifting to the service and industrial sectors.

Is there any connection between these developments? Why is agricultural productivity going down as evidenced by some historically rice-growing countries that started to import rice? These are some of the burning questions that have arisen lately.

Though not researched adequately, and often overlooked by policymakers, there can be little doubt that the increasing frequency and magnitude of natural disasters are factors that can be blamed for the reduced efficiency and productivity of rice cultivation.

Our study that investigated the impact of climate-induced disasters on the technical efficiency (TE) of rice production shed some light on this matter. The study was prompted by the fact that rice is the staple food of more than one-half of the world’s population, constituting more than 20%  of the daily calorific intake of a person. As 90%  of the total global rice production is from Asia, it was found appropriate to base this study in Sri Lanka. However, it is likely that the findings of this study can be applicable to any country with a similar agricultural background and where natural disasters
are a major impediment to the productivity of this sector.

Sri Lanka is an agricultural country highly prone to natural disasters. There are two main rainfall seasons based on the monsoon winds from the Indian Ocean and Bay of Bengal. The ‘Yala’ season, lasts from May to September (during the southwest monsoon). It brings rain to the south and west parts of the country as well as the central mountains. The ‘Maha’ season lasts from October to February (during the north-east monsoon) and it brings rain to the north and eastern part of the country.

Sri Lanka has historically been affected by numerous disasters. However, stronger and more frequent climate change-related weather aberrations are increasing the number and intensity of rainfall incidents producing increased floods and droughts. Across Sri Lanka, the rise in climate change-related weather aberrations has produced greater extremes in weather events.

According to the Global Climate Risk Index, Sri Lanka is the second most highly affected country by extreme weather events over the last 20 years. While climate-related variations affect the country at large, farmers and agricultural workers are most impacted by this variability. The increased frequency of flood and drought incidence in the last ten years has caused severe hardship to poor farmers across Sri Lanka.

But there is limited literature that compares the TE of different agro-ecological regions. In particular, we found no studies which assess the impact of climate-induced natural disasters on TE in different agro-ecological regions under different disaster environments in Sri Lanka or elsewhere.

 TE is assessed by comparing what is actually produced with what can ideally be produced using the same inputs, which in the case of rice farming include land, labor, fertilizer, machinery, etc. Inefficiency in farming may manifest itself in one of two ways. First, a farm may obtain less than the possible maximum rice production from a given quota of raw materials. Second, the farm does not optimally use the quota of raw materials by taking into account their respective prices.

Technically, farmers make choices from different varieties of raw material – final rice production (input-output) combinations. These production opportunities may depend on differences in the type of arable land, the experience of farmers, the amount that farmers have to pay for fertilizer and chemicals, etc. TE of rice production mainly depends on such choices.

Even though these matters may receive little attention, the sophistication of irrigation facilities, quality of soil, timely rainfall and sunshine, and the techniques that farmers adopt to cope with climate change are also matters that play a significant role in determining the efficiency of rice production.

Accordingly, our study seeks to address a number of key issues of relevance to the sector, such as how climate-induced disasters like floods, droughts, landslides, and strong winds impact the technical efficiency of rice production. Is rice production in some agro-climatic regions able to cope better with the impact of disasters during different seasons? Do differing magnitudes of disasters have different impacts on technical efficiency?

Our results clearly show that floods, droughts, landslides, and cyclones have different impacts on agricultural outputs under different agro-ecological conditions. Diverse agro-ecological conditions prevail in Sri Lanka just as in many other Asian economies engaged in rice cultivation. The study attempts to assess the TE of rice production in Sri Lanka’s dry, wet and intermediate zones, which experience two monsoonal seasons. The percentage of the population that was affected by the various disasters that happened across different regions used as a proxy for disaster impact.

After studying Sri Lanka’s main cropping seasons ‘Maha’ and ‘Yala’, which coincide with the North-East Monsoon and South-West Monsoon, respectively, it was found that disasters have more impact on TE during the Yala season than the Maha season.

As expected, the wet zone efficiency was higher than that of the dry zone, indicating the positive impact of rain on rice farming. The intermediate zone, which is not much prone to drought or floods, showed on average stable TE scores compared with the dry and wet zones during both seasons. However, confirming excessive and extreme rain and floods have a negative impact on efficiency, floods show consistently a negative impact on TE  under all scenarios studied.

The drought variable showed a negative and significant impact on TE under all scenarios except the wet-Yala scenario. Moreover, drought had a more adverse impact than floods on the TE of rice production. Further, the study observed that TE has decreased dramatically between the periods of 2009–2017 than that of 2000-2008.

This study presents a number of policy implications that should be considered by every rice-producing country. It strongly suggests that policies should be tailor-made to suit specific agricultural sub-sectors, as many of the climate and disaster adaptation practices commonly applied to different agricultural sub-sectors could well lead to more harm than benefits.

While regional programs designed to popularize planned adaptation practices play a crucial role, farmer level and plantation level awareness of climate change issues can be seen as necessary to mitigate the adverse impacts of climate-induced disasters. Altering cultivars, revising the timing of planting/ harvesting, and adjusting fertilizer dosing and application, are some of the methods to which the rice farmers should pay more attention.

Read the full study:
Weerasekara S, Wilson C,  Lee B, Hoang VN (2021) Impact of natural disasters on the efficiency of agricultural production: an exemplar from rice farming in Sri Lanka. DOI: 10.1080/17565529.2021.1893635

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