Keywords

1 Introduction

Food security indicators include availability, affordability or access, stability, nutritional quality, safety, utilization, and retention of nutrient-rich food (Fig. 2.1). A critical and objective review of these indicators highlight the urgency of addressing the severe prevalence of food insecurity not only in South Asia (SA) but also in Central Asia (CA). Thus, the Sustainable Development Goal (SDG) 2 of the United Nations is not on track. Over two-thirds of the world’s poorest and most food-insecure people live in developing countries (Gautam and Andersen 2017), and SA is a region prone to poverty and food insecurity. SA has population of ~2 billion (B) people, and it is home to 22% of the world population and 40% of the world’s poor (Aggarwal and Sivakumar 2011). The ever-increasing population has stressed the finite soil and water resources (Nawaz et al. 2021), and aggravated food insecurity. The latter has persisted in SA despite the success of the Green Revolution which tripled cereal production during the second half of the twentieth century (Mughal and Fontan Sers 2020). The data in Table 2.1 indicate that the prevalence of food insecurity in SA during 2019 was 257.3 million (M) people or 13.4% of the total population. In comparison with 2005, the absolute number of food-insecure people in SA decreased from 328 M to 257.6 M in 2019, and it is projected to decrease further to 203.6 M by 2030. Similarly, the percentage (%) of food-insecure population in SA decreased from 20.6 in 2005 to 13.4 in 2019 and is projected to decrease to 9.5% by 2030 (Table 2.1). In comparison, food security in CA is relatively better than that in SA. The number of under-nourished people was 6.5 M in 2005, 2.0 M in 2019 and is projected to decrease by 2030. Similarly, the percentage of food-insecure population in CA in 2005 was 11.0 and declined to 2.7 to 2019 and will be less than 2.5 in 2030 (Table 2.1). Both regions, SA and CA, are far away from fulfilling their commitment to achieving the SDG 2 of the United Nations.

Fig. 2.1
A tree diagram. Utilization and retention of air and water quality leads to availability, access or affordability, nutrition, safety, and resilience or stability. Nutrition and safety jointly lead to quality. Other components along with quality lead to food insecurity.

Indicators of the prevalence of food insecurity

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Table 2.1 Prevalence of under-nutrition in Central and South Asia
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During the 25 years since 1995, significant progress has been made in reducing food insecurity in SA, including in India, Nepal, and Sri Lanka because of rapid economic growth. The Green Revolution of the 1960s and 1970s transformed cereal production (especially of wheat) (Shiferaw et al. 2013) and of rice in SA. However, the serious problem of food insecurity persists in SA because of (a) degradation of natural resources including soil, water, vegetation, biodiversity, and air; (b) land misuse and soil mismanagement; and (c) inappropriate and outdated policies. Therefore, the objectives of this chapter are to discuss the following: (1) the state of soil and per capita availability of key natural resources in the context of growing population; (2) basic principles and technological options for protection, sustainable management, and restoration of soil and other natural resources; and (3) some policy interventions needed to address undernutrition and malnutrition in Central and South Asia.

2 The State of Soil Resources of Central and South Asia

Agricultural land misuse and soil mismanagement are among the widespread causes of food insecurity, and their effects on soil degradation are being exacerbated by extreme events related to global warming. Soil degradation caused by land misuse and soil mismanagement, is a major challenge in both Central and South Asia contributing to widespread problems of food and nutritional insecurity in both regions. The state of the soil of these regions is reflected in the poverty and low wellbeing of the people, especially of those in SA. Similar to the SDG 2, the regions’ commitment to take an effective climate action (SDG 13) and achieve the land degradation neutrality (SDG 15) are also not on track of to be accomplished by 2030.

2.1 South Asia

SA region includes Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka. The SA region, often used synonymously with “Indian subcontinent,” is the most densely populated region of the world with the total population of ~2 B (United Nations 2019). The geographical area of SA is 5.1 M km2. It has a wide range of complex biomes south of the Himalayan Mountains. There are strong climatic gradients as characterized by regions receiving both the highest and the lowest amount of rainfall in the world. The region also has diverse soils and physiographic characteristics which create numerous opportunities and some serious challenges for transforming the food systems.

In SA, where more than 94% of the area suitable for agriculture is already being cultivated, heavy monsoonal rains on steep lands cause severe water erosion (Wijesinghe and Park 2017). Desertification of arid regions, ~100 ha/yr, is adversely affecting cropland in Pakistan and India (Hasnat et al. 2018). Extreme climatic events are aggravating soil degradation in SA (Farooq et al. 2019) which is caused by water and wind erosion, salinization, depletion of soil organic matter (SOM) content, decline of soil fertility and elemental imbalance, lowering of the water table, and loss of topsoil to brick making. However, data on the reliable estimates of the extent and severity of degradation, and its impact on agronomic productivity, are not available. The ISRIC and UNEP (1991) reports are 30 years old and need to be updated using standard methodology (Table 2.2). In this regard, some progress has been made at the country level (e.g., India, Pakistan, Bangladesh). For example, Bhattacharyya et al. (2015) reported that soil degradation in India affects 147 M ha of land, including 94 M ha from water erosion, 9 M ha from wind erosion, 16 M ha from acidification, 14 M ha from flooding, 6 M ha from salinity, and 7 M ha from a combination of factors (Table 2.3). In comparison, ICAR and NAAS (2010) reported that 104 M ha of land are prone to different soil processes (Table 2.3). The wide variation in these estimates highlights the need for improvement and standardization of methodology and application at a regional scale for all countries within SA which cover a wide range of climates, soil types, and ecoregions. Furthermore, such a severe problem has a major impact on the economy and human wellbeing. For example, India supports 18% of the global human population (Table 2.21 in Appendix) with 15% of the world’s livestock population on merely 2% of the global land area. Degradation of the finite soil resources has severe adverse impacts on the nation’s economy and wellbeing of its people, who are mirror image of the land, and the vice versa.

Table 2.2 Extent and severity of soil degradation by different processes in South Asia
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Table 2.3 Comparative estimates of soil degradation by different processes in India
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Hasnat et al. (2018) undertook a regional study on the environmental issues and problems of SA. They observed that most vulnerable ecoregions are grasslands and mountain forest ecosystems of the Himalayas and the Sundarbans delta of Ganges and Brahmaputra. Forests of SA are threatened by deforestation and urbanization. The Thar desert is expanding at the rate of 100 ha/yr. and this may adversely affect 13,000 ha of cropland in India and Pakistan. Water supplies are threatened by coastal flooding, changes in river flow, and high temperatures due to global warming. The severity and extent of soil degradation in SA are among major causes of food and nutritional insecurity.

2.2 Central Asia

The region is comprised of six countries that obtained independence from the former Soviet Union in 1991 (Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan) with a total land area of ~400 M ha (Lal 2007). Grazing land is the predominant land use. Soil degradation affects one-third of the terrestrial area in CA (Mirzabaev et al. 2015) and is adversely affecting economic growth, human wellbeing, social equity, and ecosystem services (Hamidov et al. 2016). About two thirds of the total land are drylands and prone to desertification. Consequently, a large proportion of the land in these countries is degraded (Lipton 2019), and estimates of soil conservation vary with changes in the projected climate (Table 2.4). The data on the extent of soil degradation in CA shown in Table 2.5 indicates the complexity of the diverse processes involved. Not only are the processes of degradation diverse, but there may also be interaction between land use and the degradation process. Development of the irrigation scheme had adverse and irreversible impacts on the Aral Sea (Table 2.6). Irrigation of 2 M ha of cropland in the Fergana Valley made the desert land bloom, but this devastated the fourth largest lake of the world even over the short period of five decades. It was a water management disaster (Micklin 1988). Excessive water withdrawal for irrigation has dried out the Aral Sea, desertified it into a sea-bed of salt-enriched dust blown into the surrounding land while adversely affecting the environment and wellbeing of the people of the region (Wæhler and Dietrichs 2017). While cotton production expanded, grazing lands were prone to desertification and irrigated lands to secondary salinization. While similar to SA, reliable estimates of the extent and severity of degradation by different processes are not available. Yet the problem of soil degradation is being aggravated by the current and projected climate change. Since the year 2000, the average temperature of the region has increased by +0.5 °C to +1.6 °C and major land uses (e.g., cropland, pastureland, and forest land) are prone to desertification. Land area affected by degradation of pastures is estimated at 20% in Kyrgyzstan, 89% of summer pastures and 97% of winter pastures in Tajikistan, and 70% of all pastures in Turkmenistan (Lipton 2019).

Table 2.4 Estimated soil conservation in Central Asia under the current temperature and precipitation (1996–2012) and with 1.5 °C and 2.0 °C global warming
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Table 2.5 Extent of soil degradation in Central Asia
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Table 2.6 Shrinkage of the area of the Aral Sea (103 Km2) over 50 years by water mismanagement for irrigation
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Soils are prone to desertification and erosion, salinization, and forest degradation, which are causing severe economic losses (Lipton 2019). Grazing and pasture lands are adversely affected (Reddy 2016), and the problem is aggravated by arid and semi-arid climates which are sensitive to anthropogenic perturbations (Zhang et al. 2017). Mirzabaev et al. (2015) estimated that because of the land use and cover change between 2001 and 2009, the annual cost of land degradation in CA was about US$6B. Of this $4.6B was caused by degradation of rangeland, $0.8B by desertification $0.3B by deforestation and $0.1B by abandonment of cropland. The costs of action against land degradation are found to be five times lower than the cost of inaction in CA over a 30-year horizon. The cost of action was estimated to be $53B over 30 years, compared to the cost of no action at $288B over that same time period. Robinson (2016) also reported that degradation from vegetation grazing affected 79% of pasture area. In addition to wind erosion and drought, secondary salinization is a major process of soil degradation, with adverse effect on soil quality in CA.

Global warming may further aggravate soil degradation by erosion and other processes. Soil conservation, the prevention of soil loss from erosion, and limiting the related decline in soil fertility by overuse, may also become major challenges by the present and projected global warming. Ma et al. (2020) estimated that future soil conservation may decrease with climate change by 4.7% with 1.5 °C global warming and by 7.9% with 2 °C warming (Table 2.4).

3 Yield Trends

Increased yields of cereals in SA during the second half of the twentieth century has caused the decline in prevalence of undernutrition in SA over time (Table 2.1). Therefore, additional increase in productivity of cereals is critical to eliminating food insecurity in SA. Mughal and Sers (2020) reported that each 1% increase in cereal production and yield would lead to 0.84% decrease in prevalence of undernourishment. The impact is significant over a period of 3 years and this positive impact is specifically significant with regards to the yield of rice and maize. Yields of cereals and pulses in SA from 1961 to 2019 show an increasing trend and are specifically high in Bangladesh and Sri Lanka (Table 2.7), with cereal yields greater than 4.7 Mg/ha. For example, the average yield of cereals in SA increased from 1 Mg/ha in 1961 to 3.4 Mg/ha in 2019. Yet, the mean yield of cereals in SA is lower than that of the world average (4.1 Mg/ha); the average yield in China is 6.2 Mg/ha and that of the US is 8.0 Mg/ha. Thus, there is room for vast improvement in productivity of cereals in SA.

Table 2.7 Temporal trends in crop yields in South Asia
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Similar to the trends of cereal yield, those of pulses are also improving, except those in Afghanistan, likely because of political instability. In Bangladesh, Nepal, and Sri Lanka, the average yields of pulses were more than 1.1 Mg/ha in 2019 (Table 2.7). Mean yield of pulses in SA of 700 kg/ha in 2019 is lower than that of the average yield for the world (~1 Mg/ha), China (1.8 Mg/ha) and the US (2.0 Mg/ha). Thus, the yield of pulses in SA can be improved, especially with effective conservation of soil water in the root zone and with integrated soil fertility management (ISFM). Drought stress is a major cause of low yield of pulses grown under rainfed conditions in India and Pakistan. In general, the mean yield of cereals and pulses can be increased by 25 and 50%, respectively, in SA by adoption of better agronomic management (i.e., soil, water, crop, pests) and improved varieties. It is also argued that food insecurity in SA Is aggravated by political problems. Thus, in addition to producing adequate amount of food, it is also critical to solve social and political issues (Zakaria and Junyang 2014). Conflicts must be resolved politically, ethnic violence mitigated amicably, international arm trades reduced judiciously, military expenditures minimized prudently, and civil and political rights protected socially. In the meantime, it is important to reduce food losses and wastes both morally and ethically to achieve food security in SA. Kummu et al. (2012) estimated that as much as a quarter of the food supply (614 kcal/cap/yr) is lost within the global food supply chain. The production of these wasted food accounts for 24% of the total freshwater resources used in food crop production (27m3/cap/yr), 23% of the total global cropland area, (31 × 10–3 ha/cap/yr), and 23% of the global fertilizer use (4.3 kg/cap/yr). Relative to the total food production, small resource losses in food waste occur in SA, but are substantial enough in the context of almost 2 B people who live in the region (Table 2.21 in Appendix). If the lowest food losses can be achieved globally, there would be enough food for 1 B extra people (Kummu et al. 2012). Above all, sustainable management of soil and agriculture must always be given a high national priority.

The population of CA is much less compared with that of SA, but it is also increasing rapidly and is projected to increase from 72 M in 2018 (Table 2.22 in Appendix) to 90 M by the end of the Century (Jalilov et al. 2016). Food demand in developing countries is growing 1% annually, which is equivalent to 170 kg per capita in CA (Shiferaw et al. 2013). Yield of cereals in CA is lesser than that of SA and has stagnated since 1992 (Table 2.8). The average cereal yield of 1.6 Mg/ha in 2019 is about one-third that of the world average, one-quarter that of China and one-fifth that of the US. Thus, the average cereal yield has even a greater potential of improvement in CA than that of SA. Cereal yields are relatively higher in Uzbekistan compared with those in most countries of SA. In contrast to cereals, the average yield of pulses in CA at 1.4 Mg/ha is almost double that in SA. The average yield of pulses in CA are more than that of the world average (1.4 vs 1.0 Mg/ha) but lower than that of China (1.8 Mg/ha) and that of the US (2.0 Mg/ha). Thus, yield of pulses in CA can be improved in Azerbaijan and Turkmenistan through improved agronomic management and by growing improved varieties (Table 2.8).

Table 2.8 Temporal trends in crop yield in Central Asia
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4 Natural Resources Available for Food Production

Densely populated countries of SA have limited cropland area, with no scope for horizontal expansion. Total cropland area of SA decreased from 277 M ha in 1961 to 238 M ha between 2010 and 2018. Of this, 70% of the total cropland area in SA is that in India (~169 M ha), followed by Pakistan (~31 M ha), Bangladesh/Afghanistan, (~8 M ha each) and Nepal/Sri Lanka (~12.3 M ha each) (Table 2.9).

Table 2.9 Temporal trends in cropland area (M ha) in South Asia
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Total cropland area of six countries in CA decreased from 44 M ha in 1992 to ~39 M ha in 2018 (Table 2.10). Of this, the largest land area (~30 M ha or >75%) is that of Kazakhstan, followed by 4.5 M ha in Uzbekistan, 2.4 M ha in Azerbaijan, 2 M ha in Turkmenistan, 1.4 M ha in Kyrgyzstan, and 0.9 M ha in Tajikistan (Table 2.12).

Table 2.10 Temporal trends in cropland area (M ha) in Central Asia
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The data in Table 2.11 show the temporal trends in land area under pasture in countries of SA that decreased from ~96 M ha in 1961 to 78 M ha between 2010 and 2018. Of this, the largest land area under pasture (grazing/rangeland) of 30 M ha (~40%) is in Afghanistan, followed by 10.3 M ha (~13%) in India, 5 M ha (6%) in Pakistan, ~ 2 M ha (~3%) in Nepal, 0.6 M ha in Bangladesh, and 0.4 M ha in Sri Lanka (Table 2.11). The land area under pastures in CA is constant at about 255 M ha (Table 2.12), of which 186 M ha is in Kazakhstan, 32 M ha in Turkmenistan and 21 M ha in Uzbekistan. Most pastureland in CA are degraded and prone to desertification. Dust storms are severe in now dried out Aral Sea Basin (see the above section) and affect the surrounding land area and its people.

Table 2.11 Temporal trends in land area under pasture (M ha) in South Asia
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Table 2.12 Temporal changes in land area under pastures in Central Asia between 1992 and 2018
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Land area equipped for irrigation in SA is large and canal irrigation in northwestern India and the Punjab province started since the 1930s (Table 2.13). Irrigated land area is especially large in the Indo-Gangetic Plains where both surface water (river water from the Himalayas) and ground water are being used. Total area equipped for irrigation in SA increased from 45 M ha in 1961 to 111 M ha in 2018. Of this, 70 M ha of irrigated land is in India and 20 M ha in Pakistan (Table 2.13). The irrigated land area in CA expanded during the Soviet era. The land area equipped for irrigation in CA was about 10 M ha in 1992 and has remained constant over the past three decades. Of the total irrigated area, 40% is in Uzbekistan and is mostly used for cotton production (Table 2.14).

Table 2.13 Irrigated land area (M ha) in South Asia from 1961 to 2018
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Table 2.14 Irrigated land area (M ha) in Central Asia from 1992 to 2018
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Rather than the total cropland and the pastureland allocated for food production, it is the per capita availability of land which is an appropriate determinant of food and nutritional security. The per capita crop land area in some countries of SA is already less than 0.1 ha in Bangladesh (0.053 ha) and Nepal (0.083 ha) (Table 2.15). The per capita cropland area in SA decreased from 0.374 ha in 1961 to 0.126 ha in 2018, primarily because of the rapid increase in population. The irrigated cropland area is an important factor affecting food and nutritional security. The per capita irrigated land area in SA decreased from 0.073 ha in 1961 to 0.059 ha in 2018. The maximum per capita irrigated land area in SA in 2018 is 0.095 in Pakistan, followed by that of 0.086 ha in Afghanistan, ~0.052 ha for each in India and Nepal, and 0.03 ha each in Bangladesh and Sri Lanka (Table 2.16). In comparison to SA, per capita cropland area in CA decreased from 0.853 ha in 1992 to 0.535 ha in 2018 (Table 2.17). The highest per capita cropland area is 1.631 ha in Kazakhstan and the lowest of 0.094 in Tajikistan (Table 2.17).

Table 2.15 Per capita cropland (ha/per capita) in South Asia
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Table 2.16 Per capita irrigated land (ha/per capita) for South Asia
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Table 2.17 Per capita cropland (ha/per capita) in Central Asia
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Per capita irrigated land in CA, because of the low population, is relatively more in CA (Table 2.18) than that in SA (Table 2.16). Comparatively, the per capita irrigated land area in CA of 0.215 ha in 1992 decreased to 0.142 ha in 2018. The maximum per capita irrigated land area in 2018 was 0.341 ha in Turkmenistan and the minimum of 0.09 ha in Tajikistan (Table 2.18). The per capita irrigated land area in 2018 was 0.162 ha Kyrgyzstan, 0.146 in Azerbaijan, 0.133 ha in Uzbekistan (Table 2.18). The per capita land area in semi-arid/arid countries is also prone to soil degradation by secondary salinization, which is a serious practice in CA countries. However, the risks of secondary salinization are even greater in CA and drying out of the Aral Sea has jeopardized future expansion of the irrigated land area.

Table 2.18 Per capita irrigated land (ha/per capita) for Central Asia
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Per capita pastureland area in SA decreased from 0.158 ha in 1961 to 0.041 ha in 2018. The highest per capita pastureland area in SA is that in Afghanistan at 0.807 ha and the least at 0.004 ha in Bangladesh (Table 2.19). Comparatively, the per capita pastureland in CA decreased from 4.951 ha in 1992 to 3.503 ha in 2018 (Table 2.20). The highest per capita pastureland area of 10.176 ha in 2018 is in Kazakhstan and the lowest of 0.245 ha in Azerbaijan. The per capita pastureland area in 2018 is 5.442 ha in Turkmenistan, 1.456 ha in Kyrgyzstan, 0.650 ha in Uzbekistan, and 0.426 ha in Tajikistan (Table 2.20).

Table 2.19 Temporal changes in per capita (ha/capita) pastureland in South
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Table 2.20 Temporal changes in per capita (ha/capita) pastureland in Central Asia
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5 Recommended Management Practices to Improve Soil Quality and Advance Food Security

Strategies to achieve food and nutritional security in SA and CA outlined in Fig. 2.2 include the following: (a) improving agricultural productivity, (b) increasing food distribution, (c) enhancing access to food, and (d) strengthening public/private sector partnership. Agriculture in SA and CA is challenged by resource-fatigue and declining crop productivity which are widening the yield gap because of soil and environmental degradation. The yield gap ranges from 14–47% for wheat, 18–70% for rice, and 36–77% for maize (Kumar et al. 2019). Sustainable soil management and soil restoration are critical to increasing and sustaining agronomic productivity. The need for a widespread adoption of recommended management practices (RMPs) is not only just for advancing food and nutritional security, but also critical for transformation to climate-resilient and negative emission farming techniques (Lal 2021) and reversing the widespread problem of soil degradation in SA (Lal 2010). The strategy is to create a positive soil/terrestrial carbon budget so that soil organic carbon (SOC) contents and stocks can be restored in the root zone (0–30 cm layer) and soil quality enhanced. Low agronomic yield, especially those of cereals, is because of suboptimal SOC content, often as low as 0.5% in the rootzone. In addition to improving crop yields, re-carbonization of soil (and the terrestrial biosphere) would also enhance the nutritional quality of the food, especially the density of micronutrients (Fe, Zn, Cu, I, Mo, etc.), vitamins, and protein content (Lal 2009). For restoring SOC content and improving soil quality, it is the right time to stop in-field (Shyamsundar et al. 2019) burning of crop residues. Viable alternatives must be identified and implemented to effectively address the serious and wide spread environmental problem of “fields-on-fire” (Shyamsundar et al. 2019) through discussions, education, technologies, incentives, policies and determining alternative uses of crop residues and implementing them in partnership with the private sector. Burning of the precious resource, degrading soil health, polluting the environment, and jeopardizing human health must stop.

Fig. 2.2
A radial diagram of road map to food security. The surrounding text clockwise are improved agricultural productivity, improved food distribution, enhancing access to food by addressing poverty, and public or private partnership. The circles are linked and have a few bullet points.

Strategies to achieve food and nutritional security

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5.1 Sustainable Management of Soil

Sustainable management of the finite and fragile soil resource is essential (Fig. 2.2). Some examples of sustainable soil management discussed here apply both to SA and CA. Protecting and restoring the quality of degraded soils is the critical determinant of improving food security in SA (Purakayastha et al. 2016). Thus, there is a need for identification and use of appropriate soil quality indices for the site-specific conditions for all crops, but specifically for the rice-based system in SA (Basak et al. 2016). Important among sustainable soil management issues are the following: declining and low SOM content, degrading soil structure and accelerating soil erosion, increasing drought stress and declining groundwater level, depleting soil fertility and increasing micronutrient deficiencies, accelerating heat wave and increasing risks of salinization, ad-hoc urbanization and growing trends in the removal of fertile topsoil for brick making (Nawaz et al. 2021). Important RMPs for SA (and CA) include restoration of SOM content, rainwater harvesting, efficient use of water and integrated soil fertility management. Site-specific factors must be considered in adaptation and fine-tuning of RMPs. Sustainable intensification (SI) involves strategies which enhance crop yield but reduce its negative environmental impacts (Jain et al. 2020). The concept of eco-intensification (EI) is also promoted and is focused on enhancing the use of efficiency of inputs and “producing more from less” (Lal 2018). EI is specifically suited for the rice-based systems in Asia (Ginigaddara 2018). Both SI and EI strategies are in accord with the One Health concept: the health of soil, plants, animals, people, ecosystems, and planetary processes is one and indivisible (Lal 2020a). The One Health concept, integrated agriculture, and “agroecology” to go together (Hall et al. 2011), and organic farming is a part of this wholistic approach (Sarker and Itohara 2010). The latter is enhanced by improving the understanding of the food-energy-water-soil (FEWS) nexus (Lal et al. 2017) or the food-energy-water (FEW) nexus (Rasul 2014; Putra et al. 2020). Key strategies for advancing food security in SA include measures to promote big agro-based industries with funding support from both the private and public sectors, increase agricultural productivity (SI and EI), enhance agricultural research and development, and manage food security risks and vulnerabilities (Galishcheva 2018).

5.2 Climate-Smart Agriculture (CSA)

Climate change, and especially global warming, is an important factor affecting food insecurity and must be addressed (Mehta et al. 2018). Climate change may aggravate food insecurity in SA (and CA) by reducing crop yield, increasing frequency of drought, adversely affecting the stability of food supply chain, and reducing accessibility of food to the poor. The rice-wheat system (RWS) is practiced on 12.3 M ha in India, 2.2 M ha in Pakistan, 0.5 M ha in Nepal, and 0.8 M ha in Bangladesh (Bhatt et al. 2019), and is feeding 2 B people (Kumar et al. 2019). Being a major production system for the Indo-Gangetic Plains and mid-hills of SA, enhancing and sustaining productivity of the RWS through adoption of integrated crop management is critical to achieving food security in SA (Regmi and Ladha 2005). The RWS is being affected by declining land and water productivity, degrading soil health, increasing micronutrient deficiencies and other resource degradation problems. Furthermore, the RWS affects and is being affected by global warming. The changing climate is affecting soil and natural resources where the RWS is practiced. Thus, conservation agriculture, negative emission farming (Lal 2021), and water footprints of the RWS must be managed/reduced by adoption of CSA technologies by converting water wasted by evaporation to its use for transpiration and for enhancing the grain yield. The goal is to grow more rice from less water by using direct-seeded and aerobic rice (Tuong et al. 2005). Altered rainfall patterns or temperature regimes caused by climate change may significantly affect crop productivity (Gurditta and Singh 2016). The Himalayan glaciers, a major source of waters in many rivers, are melting rapidly. The production of winter crops (rabi) may be more adversely affected by the projected 2 °C of warming. The net cereal production in SA is projected to decline by 10 to 40% by regional warming of 3 °C by the end of the century (Aggarwal and Sivakumar 2011). There are no one-size-fit-all practices for adaptation to climate change, and site-specific factors are important determinant of specific CSA practices, which include management options that adapt and mitigate climate change. Some adaptation strategies may include changes in planting dates, improved varieties, and new crop species (Aggarwal and Sivakumar 2011).

In Pakistan, Shahzad and Abdulai (2021) observed that adoption of CSA practices significantly reduced household food insecurity while also increasing household diet diversity and reducing poverty. CSA practices in Bangladesh include improved varieties for tolerance to salinity, flooding and drought, early maturing varieties, pond side vegetable cultivation, relay cropping, deep urea placement, organic fertilizers, mulching, rainwater harvesting, etc. (Hasan et al. 2018). More than 30% of cultivable area in Bangladesh is coastal area. Out of 2.9 M ha of coastal and offshore lands, 1.1 M ha of croplands are affected by varying degrees of soil salinity (Moslehuddin et al. 2015). Therefore, management of soil salinity is critical to sustaining crop yields in coastal regions, as it is in irrigated lands in SA and CA.

Agroforestry is also a widely used CSA option (Dagar et al. 2014a, b) and can be used in diverse regions by using the region-specific tree species.

5.3 Conservation Agriculture

System-based conservation agriculture (CAG) comprises several components: no till, residue mulch on soil surface, ISFM, complex rotations, and cover cropping (Lal 2015). Critical reviews on issues, challenges, prospects, and benefits of using CAG in SA have been widely discussed (ur-Rehman et al. 2015; Jat et al. 2020; Somasundaram et al. 2020). It is widely believed that CAG is specifically suited for cultivation of cereals in SA including rice, wheat, and maize (Kumar et al. 2019), and is an important option for adaptation to climate change (Paudel et al. 2015). However, the success of CAG depends on an effective use of crop residue as a surface mulch, growing a cover crop during the off season and adoption of ISFM. Residue management with a system-based CAG is also pertinent to restoring soil quality in the RWS system (Zahid et al. 2020). In India, Singh et al. (2016) studied the use of CAG for the rice-maize system in northwestern India. These practices involved: early direct seeded rice, no-till and residue retention as mulch and maize seeded through it for the winter (rabi) season. An increase in SOM content in a 0–30 cm layer enhanced grain yield and overall productivity. Singh and colleagues recommended that CAG practices can be adopted on sandy loam and other light-textured soils for sustaining soil and crop productivity in SA. Judicious use of crop residues and agro-wastes can improve soil functions in diverse agro-ecoregions of SA (Dey et al. 2020). A system-based CAG has also been widely researched in CA, as reported by Lal (2007) and exemplified by research reported by Suleimenov et al. (2004, 2006), and Boboev et al. (2019).

5.4 Sustainable Water Management

Technology for water saving and improving use efficiency are important to the semi-arid and arid climate of SA and CA and for avoiding water crises created by water scarcity. Asia on the whole accounts for 70% of the world’s irrigated area. However, the current state of affairs of these irrigation schemes leaves much to be desired and they need restoration (Mukherji et al. 2012). The strategy is to produce more crop per drop of water by changing flood-based to drip irrigation (Birkenholtz 2017). The primary metric to implement this strategy is the availability of fresh water for agriculture, which is primarily the combination of both surface and ground water. Instead, however, Swatuk et al. (2015) proposed the metric that comprises green water and virtual water with specific reference to Uzbekistan. Swatuk and colleagues argued that shortages in water are often the result of decision-making based on a narrow economic criterion rather than on the satisfaction of basic human needs. A study conducted in the Fergana Valley, CA, showed that replacing alfalfa by wheat can save water in the Syrdarya River basin (Karimov et al. 2018). Crop substitution combined with deficit (rather than full irrigation) can also maintain productivity and yet save water resources (Reddy et al. 2016) in the Fergana Valley and elsewhere. Similarly, substitution of maize and cotton for rice in the RWS may save water and enhance sustainability.

Drought in SA and CA, major constraints to obtaining high yields in rainfed agriculture, are being aggravated by soil degradation and climate change. It is argued that the worst droughts in SA in the future are likely to be more intense and widespread (Aadhar and Mishra 2021). Meanwhile, land equipped for irrigation in SA has tripled since 1950. Over 60% of irrigated land in India is supported by ground water. India’s ground water (and that of neighboring countries) is disappearing at an alarming rate (Kerr 2009), and this trend must be halted (Subhadra 2015). While the drip irrigation in India is truly booming (Birkenholtz 2017), India uses 230 Km3 of ground water annually (Chindarkar and Grafton 2019). Thus, identification of a reliable water supply to farmers is the single most important factor to advance food security in arid regions, such as those in Afghanistan and elsewhere in SA (Walters and Groninger 2014). Improved water management (e.g., bunding, stress-tolerant varieties, mulch farming, and drip irrigation) is also one of the options of CSA as discussed above (Ringler and Anwar 2013). Integrated water resource management for both blue and green water is critical to effectively use every drop of water (Rautanen and White 2013). Innovative water management to adapt to water supply fluctuations is essential to develop resilience against climate change in arid regions of Afghanistan (Salman et al. 2017). Farmers are advised to build water storage reservoirs to store wet year flows and use it during the dry years. Ali et al. (2018) reported that adoption of innovative water management practices improves yield of both rice and wheat.

Water scarcity, already a serious issue in SA and CA, is likely to worsen with climate change. Increase in climate extremes by 1.5 °C and 2 °C may adversely affect agricultural production in CA where ecological problems may become more severe (Liu et al. 2020). Thus, an adaptation strategy must be implemented as a priority to minimize the negative effects of climate change on CA’s agriculture. The FEW concept (see the previous section) is also a pertinent instrument to increasing food production in CA. It puts a strong emphasis on cross-sectoral and multilevel interaction and resource interdependencies including those in the Aral Sea Basin (Saidmamatov et al. 2020). In this context, Jalilov et al. (2016) outlined two critical choices: (a) using land and fertilizers for food production or for renewable energy production, and (b) using fresh water for energy or for irrigation. Decreases in water availability for irrigation may reduce cereal production by 37% in downstream countries of CA (e.g., Tajikistan and Uzbekistan).

5.5 Salinity Management

Secondary salinization is increasing in irrigated areas of SA and CA. Salinization is also increasing because of the climate change, increasing heat waves, rising ground water levels, deteriorating drainage systems and faulty agrotechnology (Kulmatov et al. 2021). In this regard, sustainable development of water resources for achieving water security in CA (and SA) are critical to achieving food security, and also the political stability of the region (Wang et al. 2020). For example, Kulmatov et al. (2021) observed that saline areas are progressively increasing in irrigated lands of the Aral Sea Basin. As large parts of the former Aral Sea have been dried out, dust storms are affecting the surrounding regions with adverse effects on human health (Shen et al. 2016; Opp et al. 2017). Every year millions of people are suffering from water scarcity for drinking and irrigation (Abdullayev 2010). SA must learn lessons regarding the overuse of water from the Aral Sea, and safeguard its precious and finite surface and ground water resources. Afterall, the mighty Indus Valley civilization perished because of the desertification of the land that supported the once thriving agrarian culture for millennia (Lal 2010).

5.6 Nanotechnology

Nanotechnology has specific application to addressing issues related to soil health, fertilizer management, water security, food quality in storage and distribution, and agronomic productivity (Sastry et al. 2011). It is therefore important to identify and prioritize potential areas for nanotechnology applications to advance food security in SA and CA with regards to development of nanotechnology infrastructure. For example, colloidal nano-silica can be used to enhance soil water storage and improve soil structure. Another innovative option is the use of Zeolites as amendment. Zeolites are naturally occurring alumino-silicate minerals, which have large internal and external surface areas and high charge density. Using zeolites as amendments can improve soil structure, enhance soil water storage, and improve fertilizer use efficiency (Liu and Lal 2014). Among numerous applications of nanotechnology in agriculture, using nano-fertilizers is an important option to enhancing nutrient use efficiency and improving soil water storage.

In this connection soilless agriculture (aquaponics, aeroponics, hydroponic, sand culture), and use of artificial/synthetic soils are also important options. For example, Zulfiqar et al. (2020) reported that urban agriculture positively contributed to household food security of urban dwellers and assisted in building livelihood strategies. Sky farming, based on tall glass buildings and recycling of gray and black water are among emerging innovations (Lal and Stewart 2017). Greenhouse agriculture, and specifically solar greenhouses in Himalayas (e.g., Nepal), are among innovative options to advancing food security (Fuller and Zahnd 2012) in SA and CA, as have been the case in eastern and northern Asia.

5.7 Improving Use Efficiency of Fertilizers in Central and South Asia

Some countries in SA (e.g., India) use a lot of fertilizers and other agrochemicals. Fertilizers are important, and the balanced use of fertilizer-based elements is essential to enhancing and sustaining productivity and improving nutritional quality of food. However, excessive and indiscriminate use of chemicals can be counterproductive. Rather than focusing on the rate and total amount of fertilizers used, the focus must be on restoring soil quality (e.g., SOM content, soil structure and green water storage in the root zone), which is critical to improving the fertilizer use efficiency so that these chemicals do not leak into the environment (in air as N2O and in water as NO3−). Fertilizer use efficiency, especially that of nitrogen, is low in SA and CA. Restoration of SOM content to above the critical level in the root zone (3–4% in 0–30 cm layer) is essential to improving use efficiency of all inputs (fertilizer, irrigation, pesticides, tillage, etc.). Improving SOM content, and through it the soil health and its functionality, is also essential to realizing the genetic potential of improved varieties. Restoring SOM content can increase green water supply (Lal 2020b). Therefore, ISFM, and use of crop residues (as mulch) and other organic amendments (e.g., cover crops, compost, and biochar), is widely recommended. Biochar combined with manure is an important option in the context of ISFM (Arif et al. 2016). To discourage in-field burning of crop residues, farmers should be rewarded financially (through payments for ecosystem services) for leaving the crop residues as mulch on the soil surface and for restoring SOM content of the soil for advancing security of food, climate, and the environment. Soils of a high SOM content are also disease-suppressive soils and require less pesticides than those with severely depleted SOM content because of the perpetual use of extractive farming practices.

6 Conclusions

The number of people is 2 B in SA, and 72 M in CA. Food and nutritional security is a widespread problem in SA, and it also persists in CA. The Green Revolution of the 1960s and 1970s brought about a quantum jump in agronomic yield of cereals (e.g., rice, wheat) and improved access to food. Yet, food and nutritional insecurity persists, and is also being aggravated by climate change and soil degradation, which are mutually reinforcing processes. Soil degradation affects as much as 230 M ha each in SA and CA. Wind erosion, dust storms from the dried-out Aral Sea and degradation of grasslands/rangelands are serious problems in CA. The available data on the extent and severity of soil degradation in SA are obsolete (30 years old). Although country level data exist (e.g., India, Pakistan, Bangladesh), they need to be improved and updated. The most vulnerable areas to soil degradation in SA are grasslands, mountain forest lands, arid and semi-arid regions. The Thar desert is increasing at the rate of 100 ha/yr, which may adversely affect 13,000 ha of agricultural land in India and Pakistan. Food and nutritional insecurity are aggravated by soil and environmental degradation, and there is a strong need to improve the regional database through cooperation among all countries of the region. Food insecurity in these regions is also aggravated by civil strife and political unrest.

There are a wide range of RMPs for soil, crop, and water resources management to protect, manage, and restore soils of these regions. These technologies for the widely used RWS include direct seeded aerobic rice and use of system-based CAG. The CSA technologies involve water conservation and management, complex cropping systems, crop diversification and substitution, ISFM, and nanotechnology. Widespread adoption of the resource conservation and soil restorative options are also important to enhancing and sustaining productivity for advancing food and nutritional security (SDG 2), taking climate action by sequestering SOC content in agroecosystems (SDG 13), and restoring degraded lands and accomplishing land degradation neutrality (SDG 15).

Reducing food waste is important because its loss translates into waste of finite and precious natural resources (e.g., soil, water, energy, fertilizers). Identification and implementation of policies (pro-nature, pro-agriculture, and pro-farmer) are needed to promote adoption of nutrition-sensitive agricultural practices. Achieving food security is the first step to achieving the much-needed peace and tranquility in SA and CA.