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This chapter presents management practices and technologies for climate change adaptation and mitigation. It covers practices with an explicit focus on adaptation to specific climatic stressors, and practices that simultaneously reduce production risks and lower greenhouse gas emissions. Most of these practices prevent soil damage that releases carbon and water into the atmosphere; promote soil and water conservation; and increase productivity. 

Table B1.1 presents the climate-smart management practices for different crop systems that can help farmers adapt to specific climate change risks and/or mitigate these risks. 

In some cases, radical changes, such as shifting to an entirely different agricultural production system, may be needed to adapt to new climate conditions. The important role policies and institutions play in supporting climate-smart strategies is dealt with in chapter B1-4.

An indispensable input for climate-smart crop production is quality seeds and planting materials of well-adapted varieties. It is impossible to harvest good crops with bad seeds (FAO, 2011).

National, regional and international plant breeding efforts usually involve multilocational trials and seek to develop crop varieties that are resistant to climate-related phenomena and more efficient in their use of resources to reduce their impact on the agricultural ecosystem and the wider environment. Resistance to drought, salinity and flooding are the most common climate-related traits for which crop varieties are bred. Other more location-specific factors include higher frequencies of frosts at the seedling and/or pollination stages; high temperatures at the grain-filling stage; heavy rains that compress the soil; and alternate light rains and hot temperatures that stimulate seed germination but prevent the establishment of seedlings.

The development, official release and registration of well-adapted crop varieties are the steps taken toward the ultimate goal of ensuring farmers have access to quality seeds and planting materials. However, achieving this ultimate goal also requires a reliable mechanism for delivering the seeds of the most suitable varieties to farmers. Farmers obtain seeds from formal systems and/or informal systems.

Formal seed systems are organized and underpinned by statutory requirements that ensure the seeds that farmers use pass through standardized quality assurance mechanisms. Delivering the improved varieties to farmers through formal systems is relatively straightforward. But, farmers, especially in developing countries, also obtain seeds from multiple unregulated sources. These sources can include saving seeds from their own harvests, purchasing seeds from local markets and exchanging seeds with family members and neighbours. This way of obtaining seeds constitutes the informal system or farmers’ seed system. Informal systems predominate in developing countries where crop production systems are the most vulnerable to extreme weather events. For such production systems, which are typically characterized by low-input agriculture, small-scale holdings and limited market engagement, it is particularly important to support community-based seed production and distribution channels. In parts of the world where climate change is expected to have the greatest impact, most of the seeds sourced through community-based delivery systems are important food security crops. These crops include beans, peanuts, cassava, cowpeas, open pollinated maize, sweet potato and yams. Small- and medium-scale enterprises are effective means for ensuring that quality seeds of the most suitable varieties are available to small-scale farmers and are within easy reach in their communities.

Ideally, irrespective of delivery system, seeds that are meant to be sold or otherwise distributed for planting must have their quality assured. There are different options for achieving quality assurance. In the formal system, there is official control and inspection, usually by government agencies or accredited entities such as farmers’ associations and seed companies, which result in certified seeds. A less demanding mechanism is the Quality Declared Seeds and Quality Declared Planting Materials systems, developed under the auspices of FAO. These options ensure that costs associated with standard certification processes do not hinder the availability of quality seeds. 

Box B1.1 describes the components of a system that provides farmers with affordable quality seeds and planting materials of well-adapted crop varieties in a timely manner. Mechanisms that facilitate seed trade between countries are discussed in Chapter B1-5.

Growing “a genetically diverse portfolio of improved crop varieties, suited to a range of agro-ecosystems and farming practices, and resilient to climate change” is a validated means for enhancing the resilience of production systems (FAO, 2011). When confronting abiotic changes (e.g. shifting rainfall and temperature patterns) and biotic disturbances (e.g. pest infestations), the level of existing biodiversity (both functional^xii and response^xiii diversity) can make the difference between a stressed agricultural ecosystem and a resilient one. Biodiversity management is dealt with in module B8.

All major grain crops, including maize, wheat, rice, and most other crops are often grown in monoculture systems^xiv that require significant investments in pesticides and herbicides. In nature, one species (and especially not one crop variety) is never found alone in one field. When agricultural ecosystems are simplified, whole functional groups of species are removed, and their capacity to respond to changes and provide ecosystem services is compromised (Folke, 2006). In a cropping system, greater diversity of crops and other living organisms is an important criterion for ensuring farm resilience, economic stability and profitability. This diversity is especially important in a climate-smart approach because it contributes to pest and disease management, which has direct effect on yields and revenues and can be very costly and labour-intensive if external inputs need to be used. Enhancing on-farm biodiversity^xv and integrating production (see module B5) also provides other environmental services, including pollination, that are essential to farmers and society as a whole. The level of biodiversity in the agricultural ecosystem influences the interactions of plant, animal, microbial species (above and below ground) at the landscape level. A landscape approach to climate-smart agriculture is addressed in module A3. At the territorial level, increasing the sustainable use of agricultural biodiversity in terms of both production and consumption in landscapes and diets offers great potential to shape rural and urban (city-region) food systems in ways that can safeguard the future food and nutrition security of expanding urban populations. Territorially-based climate-smart food systems are addressed in module B10.

The diversification of crop systems can take many forms, involving different crop species and/or varieties (intra- and/or inter-specific diversification), different spatial scales (landscape, farm, individual fields and/or crop) and different time frames. 

Integrating multipurpose crop varieties, whose biomass can be used in a range of combinations for food, biofuel, feed, and/or fiber, can improve the functional and productive management on the farm and be climate-smart. Examples of multifunctional crops include living fences that can provide food and feed and serve as windbreaks. The use of perennial species as multipurpose crops is discussed in chapter B1-3.1.

In individual fields, there are several ways in which the genetic diversity of crops can be enhanced. These practices all require that the dates and rates of seeding be tested locally to ascertain the most suitable combinations of crops, crop density and sequencing matter (Chapter B1-4.1). This is needed to ensure the crops selected are appropriate for the specific conditions of each farm system and do not compete for nutrients, water and light. These options include:

• Different crop varieties of the same species can be grown in mixtures as one crop (varietal mixtures). For example, growing a mix of varieties with the same growing length that can be planted and harvested at the same time, but that respond differently to different water regimes, is a strategy to cope with the unpredictable onset of the rainy season and increase the stability of yields.
• Different crop species can be grown:
  • simultaneously in the same surface area as mixtures or planting a second crop in the first crop (relay cropping);
  • simultaneously in different spaces (intercropping); or
  • planting a different crop after the previous crop has been harvested (crop rotations).
• Livestock and aquaculture can be integrated into crop systems. This subject is dealt with in module B5.

Climate change will affect the spread and establishment of a wide range of insect pests, diseases and weeds. This phenomenon will be in large part a consequence of changes in the distribution and health of naturally occurring host plants and crops, natural enemies, and the adaptive changes in farm management (see chapter B1-1.2). With the increasing globalization of the trade and exchange of germplasm, these changes will provide new challenges for pest management.

Integrated pest management is an ecosystem approach to crop production and protection. It is based on the careful consideration of all available pest management techniques. Integrated pest management involves the use of appropriate measures to discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified; reduce or minimize risks to human health and the environment; and disrupt as little as possible the agricultural ecosystem. The ability to make good decisions in the field is crucial for effective integrated pest management. The principles of FAO Integrated Pest Management approach include growing healthy crops; understanding ecological processes in the fields and encouraging natural pest management mechanisms that maintain ecological balances among populations of pests and their natural enemies (predators, parasitoids, antagonists); observing fields regularly; and building farmers' capacity and understanding of ecological needs so that they are empowered to take the best pest management decisions in their own fields. Chapter B1-2 on biodiversity management covers the role that diversified crop systems can play in enhancing the resilience of cropping systems and providing ecological insurance against crop failures. Chapter B1-3 on sustainable soil and land management addresses the links between soil management, integrated pest management and the impacts of climate change. In tilled soils, for example, when the soil surface remains exposed for parts of the season (e.g. between the harvest of one crop and the establishment of the next) and in specific spaces (e.g. between rows or beds until the crop has closed canopy), empty ecological niches are formed where the soil is unoccupied and moisture and nutrients are not utilized. In areas where humidity is guaranteed throughout the year, this is the ideal environment for annual weeds to proliferate. Controlling them requires energy, costly tillage, pulling, mowing and/or herbicides. In environments where the primary productivity is low, the exposed soil lead to losses in soil organic matter and biodiversity, increased compaction and greater erosion rates. Crops growing in these soils are less resilient and climate change affects them more (Chapter B1-1.2). 

Integrated pest management is valid in a variety of different and evolving farming conditions. Independently of how climate change will affect agricultural ecosystems, farmers who understand integrated pest management principles will be better equipped to cope with the effects of climate change and develop sound and location-specific adaptation strategies (Allara et al., 2012). This is why, on farms and in farming communities, FAO integrated pest management programmes are often implemented through Farmer Field Schools, which facilitate learning by doing and experimentation of different management options by farmers (see module C2). Specific details on the control of the parasitic weed Striga is presented in Box B1.2.

As the climate changes, national regulatory, policy and institutional frameworks must be strengthened to enable the adoption of integrated pest management practices on farms and in rural communities. In particular, frameworks should support farmer training in integrated pest management; maintain the surveillance systems, including those used in community groups, that are used to detect and report changes in the behaviours of pests and natural enemies; develop appropriate quarantine procedures to prevent the entry and establishment of plant pests; and formulate appropriate management strategies to respond to potential outbreaks. Other important elements of any strategy to promote a shift to resilient crop production systems include phytosanitary frameworks and measures that can facilitate the creation of markets for sustainable products; and the transparent collaboration among policy makers, industries and farmers on the national registration processes for the most appropriate pesticides to a climate-smart approach (FAO & INRA, 2016). 

Regionally and internationally, common regulations and strategic frameworks (e.g. the International Plant Protection Convention (IPPC) and the FAO International code of conduct on Pesticide Management to limit the impact of invasive species and the unregulated use of chemical pesticides. However, pest management systems would benefit from more coordinated actions to prevent crises associated with transboundary pests, major pest outbreaks and climate change. Greater coordination in this area can be achieved by building new partnerships and alliances that can connect stakeholders, including farmers, at local, national and regional levels, and enable them to address common challenges (Allara et al., 2012). 

The enabling environment for climate-smart crop production and protection is addressed in Chapter B1-4. 

Further information on integrated pest management can be found at the following web sites: FAO Plant Production and Protection Division: Integrated Pest Management; Vegetable Integrated Pest Management Asia programme; Integrated Production and Pest Management Programme in Africa.

Where water is a limiting factor, improving water management can be achieved through measures that conserve soil and water; and/or with deficit irrigation that can maximize crop yields per volume of water applied; and/or more efficient irrigation technologies that can reduce unproductive evaporation losses. Water management for climate-smart agriculture is dealt with in greater detail in module B6. 

Achieving greater efficiency in irrigation often involves additional energy costs (see module B9). For this reason, the expansion of irrigation needs to be accompanied by appropriate energy technologies (e.g. solar powered pumps). 

Strategies for changing agricultural water management and governance must be done by integrating a water balance analysis into decision-making processes. Water balance assessments, both at field level and at the catchment level, are necessary to understand the repercussions that changes in water use for agriculture will have on the hydrological cycle. For example, in upstream areas, the introduction of rainwater harvesting techniques on a large scale may affect ground water recharge rates and return flows and cause adverse effects for downstream water users.

Sustainable soil and land management are discussed in detail in module B7, and are also addressed in module A3 on integrated landscape management. 

At the landscape level, reducing land-use change by carefully limiting the need to expand cropland and grazing land can reduce emissions and increase the capacity of the soil to store carbon.

At the field level, increasing productivity allows to grow more from the land already under production. This eliminates the need to open new land for agriculture and helps reduce the emissions associated with agricultural expansion. In this chapter, the focus is on agronomic management for increasing crop productivity and improving the efficiency in the use of resources as a way of addressing climate change. The most cost-effective management strategies for sustainable intensification of crop production involve achieving a balanced cycling of nutrients through the production system and protecting the soil on the field. Nutrient cycling refers to the movement and exchange of organic and inorganic matter into the production of crops and it is dealt with in Box B7.3.

Soil protection can be achieved by practicing direct seeding in combination with the sustainable management of crop residues and within a broader framework of integrated soil fertility management. Box B1.3 provides a useful reference to optimize the management of crop residues and the decisions that influence their composition (i.e. the types of crop grown in rotation) and their decomposition (i.e. the conservation on the soil surface as opposed to its incorporation into the soil).

Conservation agriculture^xv is an approach that combines limiting soil disturbance to a minimum, maintaining soil cover and diversifying crop production. Although developed to reduce soil erosion and restore degraded soils, conservation agriculture provides a strategic entry point for climate change adaptation. Conservation agriculture seeks to reproduce the most stable soil ecosystem attainable in each agricultural ecosystem in order to reduce producers' reliance on external inputs for plant nutrition and pest management. Keeping the soil covered reduces moisture loss, stabilizes soil temperature, reduces erosion by water and wind, restores soil carbon through the decomposition of crop residues, and provides food for beneficial soil organisms. Rotating and diversifying crops reduces crop pests and diseases and replenishes soil nutrients. Avoiding mechanical soil tillage increases the populations of earthworms, millipedes, mites and other animals living in the soil. This microfauna takes over the task of tillage and builds soil porosity and improves soils structure. Conservation agriculture incorporates organic matter from the soil surface. The excrement from soil organisms provides stable soil aggregates and the vertical channels created by worms drain excess water. The organic matter incorporated by soil microfauna into the soil improves soil structure and water storage capacity, which in turn helps plants to survive longer during periods of drought. Because untilled soil can act as carbon sink by sequestering and storing carbon, conservation agriculture has also been recognized for its ability to mitigate climate change. Not tilling the soil also reduces the number of farm operations required for crop production, which lowers fuel consumption (Lal, 2003). The potential of conservation agriculture to bring about significant energy and fuel savings is one of the reasons why it has become a more attractive option to farmers in times of high energy costs (Doets et al., 2000). In 2013, conservation agriculture was practiced on around 157 million hectares worldwide. For more information, visit the FAO web pages on conservation agriculture and sustainable agricultural mechanization. The short video produced by World Bank provides information on the links among soil degradation, climate change and conservation agriculture. 

Minimum mechanical soil disturbance is a long-term management approach to increasing the amount of carbon stored in the soil. However, the accumulation of soil organic carbon is a reversible process, and any short-term disturbances, such as the periodic tillage of land otherwise under no-tillage, will not bring about significant increases in soil organic carbon (Jarecki and Lal, 2003; Al-Kaisi et al., 2008). Although the benefits and reduce risks and costs in the future gained from improving soil health and increasing soil organic carbon accrue slowly over decades, taking action can also bring immediate financial dividends, help maintain crop productivity. When soil rebuilds, it grows and stores more oil organic matter and water, thus improving ecosystem functions and services (e.g. the control of rainfall runoff and soil erosion) that are critical for climate change adaptation and mitigation.

The availability of appropriate machinery to carry out sustainable crop management practices increases productivity per unit of land. It also increases efficiency in the various production and processing operations and in the production, extraction and transport of agricultural inputs, including coal and oil. Specific examples of the appropriate use of farm machinery in crop production are listed.

• Using smaller tractors, making fewer passes across the field and reducing working hours, when combined with conservation agriculture, reduce carbon dioxide emissions, minimize soil disturbance, and curtail soil erosion and degradation that are common in tillage-based crop systems. 
• Tractor-operated tillage is the single most energy-consuming operation in crop production. Operating a plough is the main reason many farmers require high horse power, diesel-fueled tractors. Conservation agriculture is flexible enough to accommodate the socio-economic resources of smallholder farmers as well as large-scale farming operations. Minimum soil disturbance can be achieved through digging sticks, jab planters, or mechanized direct seeders specifically developed to drill the seed through a vegetative layer. With the introduction of conservation agriculture, the machinery park of mechanized farms changes to equipment that requires less pulling power than a plough does. This means that smaller tractors, including two-wheel tractors, can be used; less fuel is consumed; work time is reduced; and the depreciation rates of equipment is slower. All of this leads to emission reductions from the various farm operations and from machinery manufacturing (Lal, 2016).
• The timely availability of agricultural equipment, such as drills, harvesters and threshers, permits producers to plant, harvest and process crops in an efficient manner. This increases yields and reduces post-harvest losses. Case study B1.1 presents the case of smallholder conservation agriculture mechanization scheme in Zambia to increase smallholder farmers’ access to sustainable mechanization technologies for illustrative purposes.
• Precision farming equipment along with controlled release and deep placement technologies, make it possible to accurately match production inputs with plant needs. This improves efficiency in the use of inputs and reduces direct and indirect greenhouse gas emissions. In the future, larger orchards and plantations will be increasingly monitored by drones. Cameras with colour filters are able to reveal spots that require specific interventions.
• Agricultural machinery powered with renewable energy, such as wind and solar chargeable accumulators can lower producers' dependence on expensive fossil fuels. These renewable energy sources emit less greenhouse gases and reduce the need to engage in the complex logistics and construction of the heavy infrastructure required to supply fossil fuels to rural areas. However, examples of farm machinery powered by renewable energy are rare. They are often at piloting stage, but they have great potential to play a significant role in climate-smart mechanized systems.

Investments in mechanization enable farmers to expand the range of their activities and diversify their livelihoods in ways that can reduce their vulnerability to climate change. Sustainable mechanization can create opportunities to provide hired services for field operations, improve transportation and agro-processing and increase the possibilities for adding value to farm production. In a long-term approach, the initial investment in mechanization is compensated in the following years by higher returns on farming and labour; surplus production or increases in the amount of land under production; and greater efficiency in the use of resources and the associated savings.

Developing simple and robust scientific tools that can guide the decision-making of farmers on a seasonal and long-term basis is essential for planning strategies to address climate change. 

In terms of risk management, some of the most relevant technologies relate to weather forecasting and early warning systems. The improved timing and reliability of seasonal forecasts and hydrological monitoring enables farmers to make better use of climate information, take pre-emptive actions and minimize the impact of extreme events (Faurès et al., 2010; Gommes et al., 2010). Risk reduction strategies and technologies are addresses extensively in module C5.

In modern commercial horticulture production systems, weather stations often monitor irrigation in accordance with the water requirements of crops. In this way, the irrigation is automatically adjusted to changes in climate.

Information and communications technologies can also support the exchange of information that is needed to respond adequately to climate change (see module C1).