Challenge of Adaptation of Agricultural Crops to Cope with Climate Change

SUMMARY

Agriculture needs a significant transformation to meet the challenges of achieving climate change adaptation and food security. Based on population growth and consumption patterns, projections indicate that agricultural production will have to increase at least 70% to meet the demands by 2050. Estimation indicates that climate change is likely to reduce agricultural productivity, production stability and incomes in some areas that already have high levels of food insecurity. Thus, development of sustainable agriculture is crucial to achieve future goals on climate change and food security. Agricultural productivity varies on climatic regions; therefore, knowledge about management of landscape, habit and habitats of plants and animals are the critical factors for adaptation and sustainable agriculture. This paper investigates into some of the key scientific and technical responses and ecosystem services required to have sustainable agriculture. Biodiversity is the root of plenty and provides greater scope for agriculture in the quickly changed climatic conditions. This paper outlines a range of practices, approaches and tools aimed at increasing the resilience and productivity of agricultural production systems, while also reflects light on reducing and removing emissions. It also considers current scientific knowledge and financial gaps and makes innovative suggestions regarding the combined use of different sources and dissemination of appropriate knowledge of adaptations to cope with the climate change.

Agriculture

Agriculture is the science and art of producing crops and animals under supervision of humans in a specific location. It is the practice by which people began to grow plants on purpose and domestic animals from the start of colonization and civilization of the ancient humans survived by hunting animals, fishing and gathering plants for food, termed “hunter-gatherers”. Views of agricultural origins are diverse, ranging from mythological to ecological; prompted humans to purposely raise their plants or domesticate the animals, was an evolutionary process that eventually transformed plants from being independent, wild progenitors, to fully dependent and domesticated cultivars, with concomitant economies. According to the theory of “Domestication by Crowding” or “The Propinquity Theory” of Gordon Childe suggests that wild animals and for that matter plants were forced into closer cohabitation when advancing dry climatic conditions pushed humans and animals into more habitable areas such as the banks of perennial rivers (Acquaah 2002).

Humans and other animals require energy, amino acids, hormones, vitamins and minerals for growth and development. The energy of sun is harnessed by plants which are used as food and fuel and crop plants are major sources of food, feed, oil, fiber and medicine for modern societies. The 30 most important crops in the world include cereals, roots, fruits, vegetables, legumes and corms and yams are widely distributed in the phyto-geographic areas are: wheat, rice, corn, potato, barley, sweet potato, cassava, grapes, soybean, oats, sorghum, sugarcane, millets, banana, tomato, sugar beet, rye, oranges, coconut, cottonseed oil, apples, yam, peanut, watermelon, cabbage, onion, beans, peas, sunflower and mango (Harlan 1976).

Crop production

Crop production is a complex operation. Its success depends on both the crops themselves and environmental factors, coupled with socioeconomic and political factors. The art of production has involved over the ages, taking on the sophistication of the day. People learnt to understand the life-cycle, adaptation, and the distribution of plants to be able to anticipate and locate their abundant sites. Crop producers in primitive cultures selected specific crops, specific varieties and prepared the land prior to planting. They planted in the right season, protected the crop from pests and adopted techniques to increase productivity. These artistic values are perpetuated in modern agriculture but at improved levels. Farmers still exchange ideas and experiences and have access to improved cultivars and agronomic practices and better harvesting and storage facilities. As technology advanced, some of the labor in production was transferred to draft animals that were used in various ways, including transportation and tillage. The development and use of machines has further reduced the need for labor. An individual using a variety of machines and implements can single-handedly operate a large farm. Technology-based mechanical innovations; chemical, biological, cultural and general knowledge and expertise are involved for management of crops.

A crop is a man-made culture involving biological and non-biological activities which was a human’s first biased act on the virgin earth. Crops play a very significant role in changing the environment. Crops allow man to meet his day-to-day needs from a limited source, utilizing merit, labor and natural resources to ensure a continuous supply by regenerating as per choice and requirement. They may be for their direct, indirect, primary, secondary and tertiary purposes, e.g. food, fodder, cash crops, medicinal, fiber, forest, agriculture, horticulture, aquatic and marine crops etc.

The word CROP can be analyzed as follows:

‘C’ for Colonization, Civilization, Culture and Cultivation
‘R’ for Regeneration, Re-growth, and Recycling
‘O’ for Organism, Organization, Operation, and Optimization
‘P’ for Production, Processing, Preservation, and Programming

Populations naturally increase and colonize under suitable conditions depending on the adaptability and availability of food and shelter. As the size of the population increases, the zone of exploitation grows or they migrate to other places. Nomadic life passed in the early ages through exploitation and migration. With the beginning of civilization, men first started to culture and grow their desired plants while suppressing or eliminating undesired ones from their surrounding environment (Rahman, 2004).

Unlike other organisms, man has special demand and better adaptability since they possess wisdom and is superior to other. Therefore, all creation of the universe is meant for the goodness of the mankind. Thus man started cultivation of their required things, the crops.

Alphonse de Candolle and Vavilov theorized the origin of cultivated plants by analyzing the variations and genetic diversity and Vavilov proposed 8 “Centers of Origin” of the most cultivated plants in 1926. On the basis of cosmopolitan nature and huge diversity of the plants and animals form agriculture, enabled farming systems to evolve about 10,000 years ago in Mesopotamia, New Guinea, China, Mesoamerica and the Andes.

Crop Productivity

Harnessed solar energy converts into chemical energy during photosynthesis by the plants taking CO2 from air and water from the soil. Although carbohydrate is the primary product but it is converted into other forms of carbohydrates, oils, proteins, vitamins, hormones and steroids etc., up-taking other necessary available nutrients from the soil. The overall energy absorption and biomass production depend on the absorptive spectrum of visible light, 380 to 760nm, availability of soil nutrients and capability of absorption through heredity environment adaptive mechanism.

The productivity of biomass depends on the climatic components and interaction of ecosystem services viz. light, temperature, humidity, precipitation and soil ingredients. It varies in different climatic zones; tropical monsoon and Mediterranean climatic regions are the most productive and have the highest biodiversity in the world. This is due to two distinct dry and wet phases and moderate weather condition which help formation of favorable environment for lives especially with fertile soil, and recycling of biomass, biological and a-biological and hydro-meteorological cycles.

Adaptation to climatic conditions and ecosystem services

Morphological, physiological and reproductive adaptations are developed according to climatic and other environmental factors. Countless species contribute to the essential ecological functions upon which agriculture depends, including soil services and water cycling. Millennium Ecosystem Assessment (MEA)-2005, served to emphasize that the health and well-being of humans and other species across the planet depends on a variety of ecosystem goods and services. The services include:
• Provisioning services: food, fiber, fuel, biochemical, genetic resources, and fresh water
• Regulating services: flood, pest control, pollination, seed dispersal, erosion regulation, water purification, and climate and disease control
• Cultural services: Spiritual and religious values, knowledge systems, education and inspiration, and recreational and aesthetic values; and
• Supporting services: Primary production, nutrient cycling, provision of habitat, production of atmospheric oxygen, and water cycling.

Ecosystem services to agriculture include:
• Regulation of pests and diseases
• Nutrient cycling: decomposition of organic matter
• Nutrient sequestration and conversion e.g. N-fixing bacteria
• Regulating soil organic matter and soil water retention
• Maintenance of soil fertility and biota, and
• Pollination by bees and wildlife

Soil and ground habitat:
• Soil compositions: Minerals, air, water, organic matters and microbes and lives viz. bacteria, fungi, protozoa, mites, worms, ants, spiders etc.
• A teaspoonful grassland soil contains 6-8 million bacteria, 12,000 species of protozoa and a million fungi and many other microbial floras which are directly involved in soil environmental activity.
• Diverse habitat, soil organism provides essential services toward sustainable functioning of all ecosystems for sustainable management of agriculture
(www.fao.org/landandwater)

Climate change and consequences of agriculture

Climate change threatens production’s stability and productivity. In many areas of the world where agricultural productivity is low and the means of coping with adverse events are limited, climate change is expected to reduce productivity to even lower levels and make production to more erratic (Stern Review 2006; Cline 2007; Fisher et al. 2002; IPCC 2007). Long-term changes in the patterns of temperature and precipitation, that are part of climate change, are expected to shift production seasons, pest and disease patterns, and modify the set of feasible crops affecting production, prices incomes and ultimately, livelihoods and lives. Despite the fundamental importance of biodiversity and ecosystem services to the earth’s functioning and to human society, human activities are driving force for the loss of biodiversity at an unprecedented rate, up to 1000 times of the natural rate of species loss, and despite the specific importance of crop and livestock diversity, and of associated agricultural biodiversity, advances in agricultural production over recent decades have been achieved largely without major regard to the destruction of biodiversity. Climate change has become a major driver of biodiversity loss as well as a serious challenge to agriculture, whose response, to adapt, will draw upon the genetic diversity of crops and livestock and the services provided by other components of agricultural diversity.

Climate is the most important environmental factor affecting agricultural production and is also now significantly influenced by agriculture. About 24% of the earth’s land surface is covered by cultivated systems and the cumulative impact of worldwide agricultural practices on the global climate is significant. Global agriculture is estimated to account for about 20% of the total anthropogenic emissions of GHG (UNEP-2009). The most important categories of agricultural emissions are:
1. Increasing land under cultivation by decreasing sinks, including deforestation and the conversion of wetlands, specially peat lands
2. Carbon dioxide emissions from burning forest, crop residues, and land
3. Methane emissions from rice cultivation
4. Methane emissions from ruminant livestock such as cattle
5. Use of nitrogen fertilizers that release Nitrous oxide, and
6. Carbon dioxide emissions from farm machinery, facilities, processing and transport
Climate change poses a serious challenge to agriculture and is expected to affect agricultural activities through a number of factors, including:
• Changes in water availability
• Increased exposure to heat stress
• Changes in destruction of agricultural pests and diseases
• Greater leaching of nutrients from the soil during intense rain
• Greater soil erosion due to stronger wind and rainfall
• Frequent wildfires in dry regions
• Increased flooding and tidal surges
• Increased droughts
• Intrusion of salinity
• Increased cyclonic storms and hailstorms
Against the backdrop of a declining natural resource base and environmental change, food production in the coming decades will need to increase. Genetic diversity within crop and livestock species will be an invaluable resource to enable adaptation to changing conditions through breeding and bringing more species under cropping culture.

Preserving and enhancing food security requires agricultural production system to change in the direction of higher productivity and also, essentially, lower out variability in the face of climate risk and risks of an agro-ecological and socio-economic nature. In order to stabilize output and income, production systems must become more resilient, i.e. more capable of performing well in the face of disruptive events. More productive and resilient agriculture require transformations in the management of natural resource (e.g. land, water, soil nutrient, and genetic resources) and higher efficiency in use of these resources and inputs for production. Transitioning to such systems could also generate significant mitigation benefits by increasing carbon sinks, as well as reducing emissions per unit of agricultural product.

Transition of agriculture

Transformations are needed in both commercial and subsistence agricultural systems, but with significant differences in priorities and capacity. In commercial systems, increasing efficiency and reducing emissions, as well as other negative environmental impacts, are key concerns. In agriculture-based countries, where agriculture is critical for economic development (World Bank 2000), transforming smallholder systems is not only important for food security but also for poverty reduction, as well as for aggregate growth and structural change. Achieving the needed levels of growth, but on a lower emissions trajectory will require a concerted effort to maximize synergies and minimize tradeoff between productivity and mitigation.

Considerations for climate-smart production systems involve production, processing and marketing of agricultural goods are central to food security and economic growth. Products derived from plants and animals include foods (e.g. cereals, vegetables, fruits, fish and meat), fibers (e.g. cotton, wool, jute, hemp and silk), fuels (e.g. dung, charcoal, bio-fuels from crops and residues) and other raw materials (including building materials, medicines, resins etc.). Production has been achieved through a number of production systems which range from smallholder mixed cropping and livestock systems to intensive farming practices e.g. large monocultures and intensive livestock rearing. The sustainable intensification of production, especially in developing countries, can ensure food security and contribute to mitigate climate change by reducing deforestation and the encroachment of agriculture into natural ecosystems (Bellassen 2010; FAO 2010).

Other key issues are access to markets, inputs, knowledge, finances and issue related to landtenure are also fundamental for ensuring food security. Soil and nutrient management the availability of nitrogen and other nutrients are essential to increase yields which can be done through composting manure and crop residues, more precise matching of nutrients with plant needs, controlled release and deep placement technologies or using legumes for natural nitrogen fixation. Using methods and practices that increase organic nutrient inputs, retention and use are therefore, fundamental and reduces the need of synthetic fertilizers which, due cost and access, are often unavailable to smallholders and, through their production and transport, contribute to GHG emissions.

Water harvesting and use are fundamental for increasing production and addressing increasing irregularity of rainfall patterns. Today, irrigation is practiced on 20% of the agricultural lands in developing countries but can generate 130% more yields than rain-fed system. The expansion of efficient management technologies and methods, specially those relevant to smallholders, is fundamental (FAO 2010). But huge water is being misused during dry season irrigation and ground water-table often goes down that creates water crisis for drinking as well as domestic purposes.

The incidences of pest and disease are altering the distribution, occurrence and intensity of plant pest and diseases as well as invasive alien species due to climate change. The recent emergence in several regions of multi-virulent, aggressive strains of wheat yellow rust adapted to high temperatures is a good indication of the risks associated with pathogen-adaptation to climate change.

Resilient ecosystem

Improving ecosystem management and biodiversity can provide a number of ecosystem services, which can lead to more resilient, productive and sustainable systems that may also contribute to reducing or removing greenhouse gases.
Services include, control of pests and disease, regulation of microclimate, decomposition of wastes, regulating nutrient cycles and crop pollination. Enabling and enhancing the provision of such services can be achieved through the adoption of different natural resource management and production practices.

Genetic resources

Genetic make-up determines a plants and animals tolerance to shocks such as temperature extremes, drought, flooding and pests and diseases. It also regulates the length of growing season/production cycle and the response to inputs such as fertilizer, water and feed. The preservation of genetic resources of crops and breeds and their wild relatives is therefore fundamental in developing resilience to shocks, improving the efficient use to resources, shortening production cycles and generating higher yields (quality and nutritional content) per area of land. Generating varieties and breeds which are tailored to ecosystems and the needs of farmers is crucial.

Harvesting, processing and supply chains

Efficient harvesting and early transformation of agricultural produce can reduce post-harvest losses (PHL) and preserve food quantity, quality and nutritional value of the product. It also ensures better use of co-products and by-products, either as feed for livestock, to produce renewable energy in integrated systems or to improve soil fertility. As supply chains become longer more complex, it becomes evermore important to increase the operational efficiency of processing, packaging, storage, transport etc, to ensure increased shelf life, retain quality and reduce carbon footprints. Food processing allows surplus to be stored for low production years or allows a staggered sale. This ensures greater availability of food and income through out the season and in years of low production. Food processing creates jobs and income opportunities, especially for women.

Achievements and constraints

Modern technologies and advances in the agriculture sector, such as inorganic fertilizers, pesticides, feeds, supplements, high yielding varieties, and land management and irrigation techniques have considerably increased production. This has been fundamental in meeting the food needs of a growing population and in generating economic growth needed for poverty reduction. However, in certain circumstances these practices and techniques have caused ecological damage, degradation of soils, unsustainable use of resources; outbreak of pests and diseases and have caused health problems to both livestock and humans. Such unsustainable practices have resulted in lower yields, degraded or depleted natural resources and have been a driver of agriculture’s encroachment into important natural ecological areas e.g. forests. The quest to increase yields and to do this without expanding the amount of land under cultivation has often heightened the vulnerability of production systems to shocks e.g. outbreaks of pests and diseases, droughts and floods and changing climate patterns. In addition, there are many production systems in developing countries that due to a lack of finance, resources, knowledge and capacity are well below the potential yield that could be achieved.

Existing systems, practices and methods suitable for climate-smart agriculture

There are several challenges in transitioning to high production, intensified, resilient, sustainable, and low-emission agriculture. However, careful selection of production systems, adoption of appropriate methods and practices and use of suitable varieties and breeds, can allow considerable improvements to be made. There are numerous FAO resources, guidelines, tools, technologies and other applications to assist policy makers, extension workers and farmers in selecting the most appropriate production systems, undertaking land use and resource assessments, evaluating vulnerability and undertaking impact assessments. Recently, FAO has developed a carbon-balance tool (EX-ACT) to appraise mitigation impact of newly proposed food security, agriculture policies and projects (FAO-2010).

However, there are considerable knowledge gaps relating to the suitability and use of these production systems and practices across a wide variety of agro-ecological and socio-economic contexts and scales. There is even less knowledge on the suitability of different systems under varying future climate change scenarios and other biotic and a-biotic stresses.

Crops: Rice production systems
Rice is fundamental for food security with approximately 3 billion people, about half of the world population, consume rice everyday. It is the staple food in many countries and 144 million ha land is cultivated under rice each year. But waterlogged rice production system, especially manuring with chemical fertilizers, emits a large volume of methane, an important GHG. Irregular rainfall, drier spells in the wet season, drought and floods are all having an effect on yields. Outbreaks of pests and diseases, with large losses of crops and harvested products up to 20% (Peng et al. 2004), have also profound effects.

Management of soil fertility

Management of soil fertility and organic matter, and improvement of the efficiency of nutrient inputs, enable more to be produced with proportionally less fertilizers and saves energy but sequesters carbon in soil. Permaculture, crop rotation, no-tillage and mulch management, short cycle biomass recycling have great importance on specific environments to ensure nutrient loss in intense cropping culture.

Urban and Peri-urban agriculture

About 50% of the world populations now live in cities and this will rise to 70% by 2050 which will cause the encroachment of the city into surrounding natural ecosystems and agricultural lands. Foods and other essentials are coming from the country sides to feed the city population. The wastes produced by the city people are huge, 80% of which are agricultural green garbage. These wastes are valuable nutrients and should be utilized through recycling, although in the developing countries like Bangladesh these valuable resources are not well-managed and usually dumped for land-filling. Therefore, utilization of these huge green wastes can produce necessary food crops for the urban people through kitchen garden, roof top garden, roadside plantation crops, peri-urban gardening etc. for recycling the biomass and food production.

Biodiversity and agriculture

Biodiversity and agriculture highlights the importance of sustainable agriculture to preserve biodiversity to feed the world, sustainable agricultural livelihoods and enhance human well-being, now and in future. The need for adaptation and potential improvement in productivity provides an incentive for the conservation of a diverse range of genetic resources. Biodiversity manage ecosystem services to contribute substantially for wider functioning: maintenance of water quality, waste removal, reducing runoff, and promoting water infiltration, soil moisture retention, erosion control, carbon sequestration and pollination. Biodiversity provides more scope for crop diversity also contributes towards quality of nutrition which improves with the consumption of greater food diversity, particularly in fruits, and vegetables. Diverse diets can contribute to the fight against malnutrition, obesity and other health problems in both developing and developed countries (Convention on Biological Diversity 2008).

References:
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Keynote paper
Seminar on CHALLENGE OF ADAPTATION OF AGRICULTURAL CROPS TO COPE WITH CLIMATE CHANGE Date: January 27, 2011 Venue: IUBAT Conference Hall, Uttara, Dhaka, Bangladesh