The authors have declared that no competing interests exist.
Monsoon rains provide relief from the sweltering summer heat conditions, replenish depleted profile moisture to breathe new life in soils. With appropriate management of rain water, Indian summer monsoons boost the level of ‘reservoir of life’. Our inability to manage spatial and temporal rainfall variation features of deficit and excess rainfall episodes and their interactions with soil variability is a major cause of uncertainty in agricultural production. In the past, entire focus of national efforts was on rainwater harvesting, storage and distribution through canal networks and greater reliance on ground water pumping to meet immediate crop water demands. These approaches have resulted in wide spread problems of natural resource fatigue and unsustainable water supplies. This paper analyses the complexities of climate change-land degradation-food security nexus and suggests the need for adopting alternate approaches emphasising on
Agriculture is practiced in India over a wide range of soil and agroclimatic conditions, and it has provided the basis for co-evolution of different crop production and land use systems to meet food, fibre and other associated needs of the people. Ensuring food security while sustaining the quality of natural resource base was the guiding principle which determined the evolution and adoption of management practices appropriate to mineralogically distinct soils formed in different agro-ecologies. Maintaining the pace of food production at par with population growth rates has always been a matter of serious concern. Notwithstanding rapid and significant gains in food production during the Green Revolution era (1960-1990), concerns for India’s food security continue and call for addition of 6 MT.Yr-1 food grains to its existing food basket
Recognising that Indian agriculture is monsoon dependent, country adopted a strategy of creating a public network of storage reservoir based canals and development of ground water for reducing its dependence on monsoon rains. Provision of a reliable irrigation source changed the production environment, enabled widespread adoption of high yielding cultivars, enhanced the use of agri-inputs besides converting 22 million hectares (Mha) of forest, pasture and fallow lands to arable lands. While these measures, undoubtedly, contributed to addressing the urgency of increasing food production within a short span, there were unintended consequences as well which now pose additional challenges. Expansion of irrigation provisions and adoption of inappropriate water, soil and crop management practices led to emergence of waterlogging and secondary salinization and ground water pollution problems in some parts of irrigation commands. Over-mining of aquifers for irrigation is threatening even the rural drinking water supplies
Intensive agri-input use strategy improved crop yields but did not improve the factor productivity of agri-inputs. It bypassed humid eastern India and the rainfed drylands where it was not easy to alter the production environments. Farmers relied heavily on use of urea for enhanced yields irrespective of inherent nutrient requirements of the mineralogically different soils. This has led to nutrient imbalances, emergence of multi-nutrient deficiencies, ground water pollution, GHG emissions and decline in crop yields. Organic matter content of most soils has declined. Organic matter plays an important role in development of stable soil structure, maintaining infiltration and regulating the release and uptake of nutrients and acts as food for soil organisms
In common with global community, India is a signatory to millennium development goals (MDGs) which, importantly, aim at eliminating hunger, ensuring food and nutritional security and achieving land degradation neutrality. The objective of this article is to draw attention to current production environment of Indian agriculture, elucidate and highlight the strong nexus that exists between elements of climate change (rainfall, terminal heat stresses), food security and land degradation. It is emphasized that for Indian agriculture to become more resilient to biotic and abiotic stresses, there is need to promote approaches which integrate concerns of enhancing land productivity, gene diversity, water scarcity and climate change. The paper also draws attention for a needed shift from an individual crop to cropping /farming system and land scape based approaches for resolution of the resource problems in different agro-ecologies.
Agriculture sector in India contributes nearly 16% of gross domestic product (GDP), holds 49% share in employment and meets the food demands of 1.3 billion people. India, primarily has two distinct cropping seasons namely the
In early sixties India produced nearly two-third of the total food grains during the Kharif season from 2/3 of its arable lands, dependent on monsoon rains. The situation has however, changed dramatically by 2000 when almost 2/3 of the total food grains were produced during the
Crop seasons | |||||
Previous study | Present study | ||||
1966-1990 | 1991-2006 | 1967-1991 | 1992-2007 | 2007-2016 | |
|
1.61 | 0.70 | 1.68 | 0.66 | 0.83 |
|
1.97 | 0.40 |
1.56 | 1.63 | 1.70 |
Total Food grains( |
|||||
2.7 |
1.2 | 1.8 |
Data sources:
Milsi et al. (2010);
Gadgil (2012)
Values affected by base year production and short time span including several drought years, affecting Rabi production.
Reserve Bank of India database, 2016.
In the same period (1965-2016), area under
India’s canal irrigation network is not designed to supply water as per demands during the crop season. In absence of good quality canal irrigation systems, most farmers (upto 80% ) rely on ground water use for timely crop management operations. Over the decades, dependency on groundwater has not declined even in excess rainfall years
Agriculture is practiced on a total 194 Mha of gross cultivated area, comprising 95 Mha of irrigated and close to 100 Mha of rainfed agriculture. For food grains production 128 Mha is cultivated to produce 278 million tons of food grains. Several reports indicate that irrigated agriculture is more efficient than the rainfed agriculture in terms of resource utilization and food production. However, rainfed agriculture is important because it has untapped potential for increasing food production through innovations.
Eastern India receives high rainfall (1000-1700mm/Yr.), increasing in the easterly direction (with longitudes). Most rivers flow from west to east. With the run of the rivers, finer textured alluvial soils are formed. In the Ganges, Brahmaputra and Mahanadi alluvial plains, hydrological situations favour high runoff from the catchment after a rainfall event besides large tracts subjected to inundation during monsoon months from July to September. In Eastern India, nearly 6.74 Mha area remain fallow during Kharif seasons due to flooding
As we move from west to the eastern districts located between 78.83 and 86.13o North longitudes, a strong connection between rainfall, agricultural productivity and poverty begin to emerge (
In spite of significant strides in research and development, uncertainty of good crop harvest continues as ever in rainfed dry lands, low lands, black soils and the hilly regions. Large areas remain fallow during Kharif and Rabi seasons. The main source of uncertainty in the Indian agriculture is the high variability in the amount, intensity and distribution of monsoon rainfall events (spatial and temporal variations). One can find areas of negative rainfall shocks (droughts) as well as areas having positive rainfall shocks (excessive) almost every year. The main crisis of Indian agriculture is rooted in our inability to manage spatial and temporal variations related with onset and withdrawal of monsoon rains, and related features across regions. Monsoon features have a significant influence on annual crop production cycles beginning with the Kharif season. Any delay in planting of Kharif season crops, delays field vacation and also delays seeding of succeeding Rabi season crops which reduce crop productivity. For example, late plating in wheat after mid-November reduces its productivity at the rate of 30-45kg/ha/day
India’s summer monsoon rains (SMR) are unique in many ways. Rains are bimodal in nature and more than 85 percent is received through southwest monsoon in the summer season. Winter rains through northeast monsoons constitute only 10-15 of the total rainfall but are important for Indian agriculture. Summer rains are highly variable in space and time and are received in several high intensity storms following the prolonged hot rainless summer periods. Country experiences drought and flood situations in one or the other part at the same time or even at the same place at different periods. South-west summer monsoons usually arrive by mid-June and are active up to September. About 10-15% of the average annual rainfall of 1170 mm is received in few short spells as pre-monsoon showers ( May – June). Pre-monsoon showers provide relief from the sweltering summer heat conditions. During peak summers, surface soil layers attain high temperatures of upto 48-50oC or even more. Hot summers desiccate and sterilise the soils and burn soil organic matter. Pre-monsoon rains in summer deep ploughed bare fields, promote slaking and break down of soil aggregates such as to facilitate erosion of fertile soil with runoff water. Thus, in the SAT region, land degradation by erosion is largely a monsoon phenomenon spread over a period of two months involving the loss of some or all of the following: soil, soil productivity, vegetation cover, biomass, biodiversity, ecosystem services, and environmental resilience
Summer monsoon rains (SMR) characterised by a range of inter-annual variations, is a reliable facet of Indian weather
When SMR anomaly is large, most parts in the country have a similar experience of excess water or drought. But when the anomaly is within ±5% (close to its average value), there is a large spatial variation in rainfall- indicating excess in some and deficit rains in other parts. Dips in food grains production during the Kharif season coincide with seasons of major deficit rainfall. A correlation (r =0.76**) of Kharif food grains production with rainfall anomaly suggests that monsoon rainfall has a significant impact on Kharif production
1. Impact of deficit rain fall has not changed over time. The negative impact of deficit rainfall has remained as large at present as it was over the past several decades.
2. Deficit rainfall impacted total food production more than the surplus rainfall, and
3. Before 1980, water was the primary resource limiting food production but in recent times other factors are determining crop productivity in years of normal and excess rainfall (
SMR anomaly | Food Grains Production % | |
1950-1980 | 1981-2004 | |
-25 | -19.13 | -18.81 |
-20 | -14.41 | -13.29 |
-15 | -10.13 | -8.65 |
-10 | -6.30 | -4.89 |
-5 | -2.93 | -2.00 |
0 | 0.00 | 0.00 |
5 | 2.48 | 1.12 |
10 | 4.50 | 1.37 |
15 | 6.08 | 0.73 |
Source: [15]Gadgil (2012)
Reduced crop response in seasons of better rainfall was attributed to inability of the farmers to use fertilisers and pesticides well in time. Beside this, the reduced crops responses could be ascribed to processes of land degradation resulting from increased runoff and loss of fertile surface soil.
On an average, a total of 4000 billion cubic meter (BCM) of rain water annually enters the hydrologic cycle over the Indian land mass. This has to find its way into rivers, large storage reservoirs, lakes, tanks and low lying areas (
Evidences presented earlier (section 2.1) have shown that rate of growth in food grains production has considerably decelerated. Besides climate change other factors which have contributed to declines in food grains production include (i) slowdown in expansion of crop lands during Kharif and Rabi seasons, and (ii) declines in solar radiation due to atmospheric pollution. In the arena of food security-climate change research, the most prominent facet is global warming which impacts the amount of rainfall, its intensity and frequency of extreme events. Besides rainfall anomalies, average temperatures have increased by 0.25oC during the Kharif and by 0.6oC during the Rabi season over the last five decades
Recent research findings (
Crop Season & Water provisions | Yield Decline (%) | |
Rainfall anomaly (Drier) | Temperature anomaly (Warmer) | |
Average |
12.8 | 4.0 |
Irrigated | 6.25 | 2.7 |
Unirrigated | 14.7 | 7.0 |
Average |
6.7 | 4.7 |
Irrigated | 4.1 | 3.0 |
Unirrigated | 8.1 | 7.6 |
Source: [36]Economic Survey of India (2018)
Globally, soils have been considered a large carbon sink but Indian researchers have long lived with a notion that carbon status of Indian soils cannot be enhanced under tropical climates. Several studies in recent years have examined the potential of Indian soils to sequester carbon
The chief concerns of the farming community relate to (i) rising farm costs and declining incomes, and (ii) increasing risks on account of weather uncertainties more than climate changes in the long term
During the Green Revolution era (1960s to 1980s), intensive use of external inputs in agriculture altered the production environments and helped in realizing the yield potential of improved dwarf crop cultivars. In high rainfall eastern India and in arid and semi-arid rainfed dryland regions wherever it was not possible to alter the production environment, benefits of green revolution could not be extended to the farmers. On the whole, enhanced input use strategy leap frogged India’s food grains production from 50.82MT/year to 275.8MT/year in past seven decades. Fivefold increase in production has come from a cropped area of 124.9Mha. In the ensuing sections we very briefly outline the key challenges now faced by Indian agriculture.
Over the past many decades, the net cultivated area in the country has fluctuated around 140Mha. In the face of increasing population, there is no possibility of expanding agriculture into new areas. Indeed for a variety of reasons such as increasing urbanization and industrialization, the area devoted to agriculture is likely to decrease. With current crop-water management practices, fresh water needs of Indian agriculture by 2030, are projected around 1500 billion cubic meter (BCM) as against the current water availability of 740 BCM
Total acreage of all the food grain crops is 125Mha. This is about 66 percent of the gross cropped area, as of now. Data presented in earlier sections indicate that the current Kharif food grain production growth rate is 0.83MT/ Yr. which is almost half of that observed during Green Revolution era. Rabi food production is relatively more stable (1.56- 1.70MT/Year). Higher growth rate in Rabi food grains production
Stagnating crop yields in general, are a consequence of a number of factors affecting crop production. A better understanding of these factors is critical to defining strategies for sustainability of Indian agriculture. Post 2000, declining food production trend in Kharif season and a flattening in the Rabi season, is viewed as the tipping point of Indian agriculture. It has brought into sharp focus issues related with deteriorating soil health, climate change and the declining water availability for irrigation. Timely planting as a stand-alone practice can improve wheat productivity mentioned earlier
Crops | # of districts growing | Total Crop Area. Mha in 2015.16 | Number of Districts with Yield growth Trends in Categories | ||
Stagnated, Never recovered, collapsed | Increasing slowly, increasing Moderately | Increasing Rapidly | |||
Rice | 313 | 43.39 | 56 | 32 | |
Wheat | 162 | 30.23 | 42 | 101 | 19 |
Maize | 343 | 8.69 | 133 | 181 | 29 |
Soybean | 77 | 11.67 | 37 | 28 | 12 |
Total | 93.98 |
Source: Ray DK et al. (2012)
Fertiliser nutrients are added to soil to replace those lost through crop off-take and other processes. It must be our endeavour to continuously replenish for any loss. For arresting and reversing soil degradation processes, soil organic carbon, soil microbes and soil moisture retention and nutrient supplies are critical for biomass production. Soil carbon sponge is of great significance for its influence on the soil ecofunctions, enhancing soil productivity, improve nutrient and water use efficiency, reduce production costs and significantly benefit the environment. Use of chemical fertilisers have played a crucial role in realising the potential of modern cultivars. In 2017-18, although a total of 26.7 million metric tons of chemical fertiliser nutrients were consumed in agriculture, yet the overall net nutrient balance was still negative by an order of 12-14 million tons
Reducing our dependence on chemical fertilisers is a laudable objective but has yet to ignite a debate on shifts that will be required from our singular focus on fertilisers. To save on fertilisers, we need to (a) emphasize on the potential agronomic practices that reduce use of synthetic nutrients, and (b) identify and adopt production management systems such as CA that have a targeted effect.
The term fallow lands refer to cultivated areas which are left uncropped in one of the two crop seasons [
Climate change has emerged as an overarching challenge to Indian agriculture. Low air quality due to particulate black carbon and dust is known to affect the solar radiation affecting maxima-minima temperatures. Long-lived greenhouse gases (LLGHGs) have had and will continue to have significant negative impacts on crop yields. Research in the last decade has underscored the critical importance of climate changes caused by short-lived climate pollutants (SLCPs) such as black carbon and ozone which impact temperature, precipitation, and radiation. Ozone—is known to be directly toxic to plants. The combined effects of climate change and the direct effects of SLCPs on wheat and rice yields in India has been studied. It has been reported that gains from addressing regional air pollution could counter expected future yield losses resulting from direct climate change effects of LLGHGs
Field surveys conducted in Punjab during 2009-10 revealed that wheat production was affected in the range of 10-26 % due to rise in temperature at reproductive and grain filling crop stages
Sustainable agriculture is envisioned as a continuous process of identification and prioritization of complex natural resource management constraints for enhancing productivity. It requires continuous improvement in strategies, institutional innovations and robust technologies to handle NRM issues. The five broad principles of agricultural research and development contributing to sustainability
Sustainable agriculture relies on sustainable land management (SLM) principles which ensure achieving land degradation neutrality and sustaining food security
This discussion brings out that our priorities in planning land degradation neutrality interventions should follow a response hierarchy:
Avoidance > Reduction > Reversing degradation/Rehabilitation/ Reclamation
Although all the 3- transects (head end, middle portions and tail ends) have to be handled carefully in the watershed approach, it must be kept in mind that activities must proceed from less affected areas (at the head end) to severely eroded areas (tail end) to be successful.
In 1980s, India established 120 zonal research stations (ZRS) in different agroclimatic zones (ACZ) for solving locally identified problems of land and water resource degradation and crop productivity. In the ACZs, agriculture production and land use systems generally co-evolve in response to shifts in consumer demands, production costs, pricing, procurement policies and infrastructure interventions. Since production systems depend on the quality of resource attributes and available management options at specific locations, integration of biophysical, social and economic parameters is required to characterize land management units, also referred to as resource management domains (RMD). Whereas ACZ refer to homogenous biophysical units, RMD concept integrates socio-economics with biophysical features of zones to define an area by resource issues for successful resource management and to handle the production constraints
Achieving land degradation neutrality and ensuring food security are among the key UN sustainable development goals
While summer monsoon rainfall is the life-line for Indian agriculture, runoff water mediated soil erosion processes at the same time result in loss of soil carbon, nutrients, moisture and contribute to reduced biomass production as well as restricting the farmers’ choices for diversification (biodiversity). Thus, Indian summer monsoons are both a boon and a bane, contributing to water supplies and land degradation, respectively. Loss of soil organic carbon at elevated summer temperatures and loss of surface soil by beating action of summer monsoon rain drops are by far, the major processes of soil degradation in the Indian subcontinent. Reversing processes contributing to land degradation is central to water availability, soil health, adapting to climate change and food security. It would also appear from fig (5) that rain water management has to be a crucial element of any strategy that enhances gene diversity and sequesters more carbon to offset the climate change effects, builds resilience and reverses land degradation.
Success of small holder farmers always depend on manipulations of their on-farm resources through a host of crop-soil-rainwater management practices. These practices included adjusting the sowing dates of crops, cultivar choices, crop rotations, mixed cropping/ farming systems etc. The underlying aim of these practices was always to make efficient use of rainwater. Traditionally, many farmers have practised tree-crop-livestock mixed farming systems in the fragile arid environments as a response to frequent climatic aberrations. Arid zone farmers adopt vigorously growing crops such as cluster bean, moth bean, pearl millet, henna and cotton which need less water and also make best use of rainwater made available in short spells. These crops are not only responsive to use of external inputs but are also attuned to make good use of prevailing nutrient, moisture and thermal regimes of soils. Use of appropriate land races in crop improvement programs can further enhance gene diversity (gene management) and make agriculture more resilient to biotic and abiotic stresses. High heterogeneity and uncertainty of rainfall patterns in rainfed environments make crop improvement scientist’s task extremely difficult. For rainfed agriculture, any crop improvement strategy must focus around efficient use of limited and uncertain soil moisture storage supplies which need a better understanding of rainfall variability, soil properties and moisture and nutrient release patterns of the soils.
In the drought prone, high temperature rainfed environments of the SAT region, farmers generally cover their risks through mobile household livestock capital. Since livestock need fodder to survive and be productive, preferred crop improvement objective should be to increase plant biomass over harvest index, develop some stress tolerance, harness the genotype x tillage x environment interactions and reduce production costs. Such an approach will greatly promote the primary livestock industry of rainfed dryland regions in the country. Clark-Sather et al.
Crop production and conservation of natural resources are parallel objectives but often pursued in isolation through fragmented schemes of the local governments. Production management systems require promoting adoption of soil, water, and crop management strategies that build soil organic carbon and improve resource use efficiency together with enhanced production. Conservation agriculture (CA) is one such innovative approach to management of production systems, which is close to organic farming. CA allows use of agrochemicals and its yield potential is hardly debatable, unlike the organic farming. The concept of CA rests on four broad entwined management principles: (a) drastic reduction in soil disturbance and adoption of direct sowing, (b) maintenance of a continuous vegetative soil cover; (c) sound crop rotations and (d) avoid free-wheeling to reduce soil compaction. CA based production systems mimic natural agroecosystems and hence result in numerous environmental benefits such as decreased soil erosion and water loss through runoff, decreased carbon dioxide emissions and higher carbon sequestration, organic matter build-up, efficient nutrient cycling, reduced fuel consumption, increased water productivity, reduced flooding, enhanced recharge of underground aquifers
Globally, there is a fair degree of consensus that conservation agriculture principles can be an important component of any national strategy to produce more food at lower costs, improve environmental quality and preserve natural resources
Low yields are linked to poor soil health and inefficient water management practices. For improvement in yields of different crops, there is an urgent need to improve agriculture water productivity through a mix of improved water application, soil moisture and tillage management practices linked with soil health
Given the fact that surface flooding is the most used water application method in India and elsewhere, there is an urgent need to promote the use of lay-flat gated pipes to surface irrigate the crops established in permanent ridge-furrow planting system
Direct dry seeding practice has the potential of improving the rain water productivity, reduce soil erosion hazards and make planting season independent of rainfall predictions
Hot summers followed by summer monsoon rains result in loss of organic carbon and fertile surface soil with runoff rainwater. Indian agriculture therefore, must promote approaches that integrate concerns of land degradation during monsoon season, declining water availability, gene diversity and climate change. In weather proofing agriculture, soils can play a tremendous role through moisture storage, its retention and enhanced availability in periods of intra-seasonal abnormalities during monsoon rains. Making Kharif crop sowing time independent of the onset of monsoon rains is equally important for the Indian sub-continent and to reduce crop losses due to land fallowing, late planting, soil moisture and terminal heat stresses beside providing a surface cover against monsoon rain-enhanced soil erosion to prevent loss of fertile surface soil. Practices that improve rainwater storage include: direct dry seeding, minimal soil disturbance (zero tillage), retention of crop residues, use of cover crops, and use of farm yard manure etc..
Indian agriculture made some rapid strides during the green revolution era but food gains and its growth rates have subsided after 2000s due partly to fatigue of natural resources and poor R&D investments. Additional food has to now come through increased productivity routes. In spite of developments of large canal networks, rainfed agriculture has continued to be important involving large acreage, however, the untapped potentials for increasing food production through innovations in agricultural practice such as efficient rainwater management, carbon and gene management. For improving productivity in the rainfed areas, crop water demands need to be attuned to seasonal rainfall cycles and allow for enhanced rain water use during periods of peak rainfall. Plant breeding strategies for rainfed dryland systems should focus on increasing plant biomass, develop crop stress tolerance and harness genotype x tillage x environment to improve crop yields and reduce production costs. This can be achieved through a shift from crop based to resource based research and developmental planning. Conservation agriculture is likely to be at the center stage of such a change to reduce production costs. Targetting technologies appropriate to enhanced efficiencies of resource management domains can reduce the acreages of fallow lands besides improving stagnating crop productivity. The primary goal of climate smart agriculture should be to improve rainwater storage, retention and availability in periods of intra-seasonal abnormalities and reduce soil erosion through conservation agriculture. From the discussion in the paper, it emerges that national water policy should also focus on
One of the author (Raj Gupta) is gratefully acknowledges the financial support, received for the study, from the Indian National Science Academy, New Delhi.