Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140

International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Special Issue-11 pp. 1115-1140 Journal homepage: http://www.ijcmas.com

Review Article

Precision-Smart Water Technologies for Improving Water Use Efficiency and Water Productivity under Concept of Sustainable Farming as in Climate Change Situations

Raghuvir Singh Meena1, Ganga Ram Mali2, Komandla Venkatkiran Reddy3, B. Sri Sai Siddartha Naik4, Somdutt5, Tirunagari Rupesh6, Jitendra Singh Bamboriya7 and Swetha Dhegavath8

1Department of Agronomy, RCA, MPUAT, Udaipur, Rajasthan, India 2KVK Gudamalani, AU Jodhpur Rajasthan, India 3Department of Agronomy, College of Agriculture Rajendranagar, PJTSAU, Hyderabad, Telangana, India 4Department of Agronomy, RCA, MPUAT, Udaipur, Rajasthan, India 5Directorate of Research, SK Rajasthan Agricultural University, Bikaner Rajasthan, India 6Division of Soil Science and Agricultural Chemistry, ICAR-IARI, New Delhi, India 7Soil Science and Agricultural Chemistry, MPUAT, Udaipur, Rajasthan, India 8Department of Soil Science and Agricultural Chemistry, PJTSAU, Hyderabad, India

*Corresponding author

ABSTRACT

Water is considered as the most critical resource for sustainable agricultural development worldwide. Irrigated areas will increase in forthcoming years, while fresh water supplies will be diverted from agriculture to meet the increasing demand of domestic use and industry. Furthermore, the efficiency of is very low, since less than 65 % of the applied water is actually used by the crops. Worldwide water management in irrigated and rain-fed agriculture is becoming more and more complex to overcome the expected water scarcity stress. The sustainable use of irrigation water is a priority for agriculture in arid areas. So, under scarcity conditions and climate change considerable effort has been devoted over time to

introduce policies aiming to increase water efficiency based on the assertion that more can be achieved with

K e yw or ds less water through better management. Better management usually refers to improvement of water allocation and/or irrigation water efficiency. Agricultural practices, such as soil management, irrigation and Climate change, fertilizer application and disease and pest control are related with the sustainable water management in Climate -smart agriculture and protection of the environment. Socio-economic pressures and climate change impose water restrictions to water allocated to agriculture. In addition to this, challenges of global warming and climate technologi es, change would have to be met through the judicious application of water in agriculture through climate-smart Water use efficiency, Water water technologies. Agriculture is an important sector in India and many developing countries, providing saving huge employment opportunities to rural populations, and supporting them to achieve food and nutritional technologies, security goals. In this paper, an attempt has been made to address challenges of increasing food production Innovation and improving rural livelihoods, while safeguarding critical water resources for sustainable use through adaptive measures for effective water management, particularly in drought-prone regions and to facilitate an improved understanding of the potential implications of climate change and adaptation options for agricultural water management and thereby assist policymakers in taking up adaptation challenges and developing measures to reduce the vulnerability of the farming sector to climate change. An integrated approach needs to be implemented in agricultural water management through adoption of innovations such as water harvesting, micro-irrigation and resource conservation farming to increase water-use efficiency in agriculture and other critical services to humans and animals.

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Introduction Rain-fed agriculture will be primarily impacted due to rainfall variability and Water is considered as the most critical reduction in the number of rainy days. India resource for sustainable development in most has a net cultivated area of 142 million Mediterranean countries. It is essential not hectares (Mha), out of which, about 54% is only for agriculture, industry and economic rain-fed (Sikka et al., 2016). The estimated growth, but also it is the most important impacts of climate change on cereal crop component of the environment, with yields in different regions of India indicate significant impact on health and nature that the yield loss could be up to 35% for conservation. Currently, the rapid growth of rice, 20% for wheat, 50% for sorghum, 13% population along with the extension of for barley and 60% for maize depending on irrigation agriculture, industrial development the location, future climate scenarios and and climate change, are stressing the quantity projected year. and quality aspects of the natural system. Because of the increasing problems, man has On the other hand, 8-15% of fresh water begun to realize that he can no longer follow supplies will be diverted from agriculture to a "use and discard" methodology either with meet the increased demand of domestic use water resources or any other natural resource. and industry. Furthermore, the efficiency of As a result, the need for a consistent policy of irrigation is very low, since only 55% of the rational management of water resources has water is used by the crop (Fig. 1). To become evident. Global irrigated area has overcome water shortage for agriculture is increased more than six-fold over the last essential to increase the water use efficiency century, from approximately 40 million and to use marginal waters (reclaimed, saline, hectares in 1900 to more than 260 million drainage) for irrigation. In the 21st century, hectares (FAO, 1999). Today 40% of the climate change has emerged as a significant world‟s food comes from the 18% of the challenge to agriculture, freshwater resources cropland that is irrigated. Irrigated areas and the food security of billions of people in increase almost 1% per year and the irrigation the world (Goyal and Rao 2018). water demand will increase by 13.6% by 2025. The per capita annual availability of water in India is expected to reduce to 1,465 m3 by Water is considered as a powerful indicator 2025 and 1,235 m3 by 2050 (Kumar et al., of ecological sustainability and economic 2013). Projected impacts of climate change prosperity (Kumar et al., 2013). Seventy on hydrology and water resources may be percent of the Earth‟s surface is covered with different in different river basins depending water but 97.3% of the total water on Earth is upon the hydrological model, climate change saline, and only 2.7% is available as fresh scenarios and downscaling approaches used. water (Kumar et al., 2013). Almost 85% of all the water taken from rivers, lakes, streams Studies on the impact of climate change have and aquifers in India and in many of the shown clear evidence for an observed change developing countries is used for agriculture. in global surface temperature, rainfall, The influence of global warming and climate evaporation and extreme events (Altieri and change on the regional hydrological cycle Nicholls 2017). The Fifth Assessment Report would affect water resources and reduce the of the International Panel on Climate Change availability and reliability of water supplies (IPCC) has reported on climate change and in many places which are already subject to its observed consequences in South Asia water scarcity.

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(IPCC 2014). The effect of variation in Mha and a cumulative catchment area of rainfall patterns may affect the natural 252.8 Mha (Pathak et., al2014). The other recharge process, and increased temperatures rivers with a catchment area of more than 10 may enhance crop evapotranspiration and Mha are the Indus (32.1 Mha), Godavari irrigation demand in a different part of the (31.3 Mha), Krishna (25.9 Mha) and world (Patle et al., 2017). An analysis of Mahanadi (14.2 Mha). The degree of ensemble probabilistic scenarios for India development of ten river basins covering derived from more than 50 CMIP5-GCMs 75% of the total population will be over 60% data for 2020, 2050 and 2080 indicated that by 2050. The total annual discharge in the the rise in minimum temperatures is projected rivers that flow in various parts of the country to be more than the increase in maximum amounts to 1,869 km3. Rivers do not remain temperatures, whereas a rise in temperatures at a high stage throughout the monsoon would be greater during Rabi season than season, but only a spell of heavy rains lasting during Kharif season (NICRA 2016). for a period of several hours to a few days may generate significant runoff in Water resources and it’s their in India catchments. Due to the increasing population in the country, the national per capita annual India has a geographical area of 329 million availability of water has reduced from 1,816 ha which amounts to 4,000 billion cubic cubic metres in 2001 to 1,544 cubic metres in metres (BCM) of water from annual 2011 (CWC 2015). precipitation. Due to large spatial and temporal variability in the rainfall, Green and blue water distribution of water resources in India is highly skewed in space and time. Surface and Water resources are classified into green and groundwater resources have played an blue water resources, and rainfall is important role in the socio-economic partitioned into blue and green water development of India. Groundwater is an resources via important hydrological important source of irrigation. The static processes. Green water is the large fraction of fresh groundwater reserves of the country precipitation that is held in the soil and is have been estimated as 1,082 BCM. The available for plant consumption on-site, and it dynamic component which is replenished returns to the atmosphere through the process annually has been assessed as 432 BCM. The of evapotranspiration (ET). overall contribution of rainfall to the country‟s annual groundwater resource is The process by which a fraction of green 68% and the share of other resources, such as water is consumed by plants is known as canal seepage, return flow from irrigation, transpiration and the process through which recharge from tanks, ponds and water an amount of green water returns back to the conservation structures taken together is 32% atmosphere directly from water bodies and (CGWB, 2014). The primary sources of the soil surface is known as evaporation. Blue irrigation are canals, reservoirs and wells, water is the portion of precipitation which including tube-wells. Groundwater provides enters streams and lakes, and also recharges about 61.6% of water for irrigation, followed groundwater reserves. Humans can consume by canals with 24.5% (CGWB, 2014). blue water directly for domestic and industrial use, and also for food production There are 12 major river basins in India with off-site (away from the area it originates). an individual catchment area of more than 10

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Water and agricultural production crops depends on various factors, such as weather conditions and soil type as well as Agriculture currently uses about 70% of the the reduction of the agricultural inputs like total water withdraw, mainly for irrigation. fertilizers and pesticides (Fig. 2). Therefore, Although irrigation has been practiced for it is difficult for a farmer to tell at any given millennia, most irrigated lands were moment whether there is a water deficit or introduced in the 20th century. The intensive not. Since overabundant water usually does irrigation could provide for the growth of not cause harm, farmers tend to “play safe” irrigated areas and guarantee increased food and increase irrigation amount, especially production. In the 1980s, the global rate of when associated costs are low. increase in irrigated areas slowed considerably, mainly due to very high cost of Influence of climate change and irrigation system construction, soil groundwater withdrawal salinization, the depletion of irrigation water- supplying sources, and the problems of Groundwater supports about 60% of irrigated environmental protection. However, as the agriculture and is the major source of population is growing at a rapid rate, irrigation in the arid and semi-arid regions of irrigation is being given an important role in the country (Patle et al., 2017). Groundwater increasing land use and cattle-breeding levels have declined tremendously during the efficiency. Thus, irrigated farming is last three decades in many parts of the expected to expand rapidly in the future with country due to overexploitation mainly in the subsequent increase of water use for agriculturally intensive irrigated areas. irrigation. Decreased groundwater irrigation would have severe detrimental effects on many basins, Irrigation is not sustainable if water supplies and groundwater extraction ratios of many are not reliable. Especially in areas of water basins are significantly high. The recharge scarcity the major need for development of patterns in these basins indicate that the irrigation is to minimize water use. Effort is groundwater use is not sustainable. The level needed to find economic crops using minimal of groundwater development is very high in water, to use application methods that the states of Delhi, Haryana, Punjab and minimize loss of water by evaporation from Rajasthan, where groundwater development the soil or percolation of water beyond the is more than 100% (Patle et al., 2017). This depth of root zone and to minimize losses of implies that in these states, the annual water from storage or delivery systems. groundwater consumption is more than the Nowadays, during a period of dramatic annual groundwater recharge. changes and water resources uncertainty there is a need to provide some support and In the states of Himachal Pradesh, Tamil encouragement to farmers to move from their Nadu and Uttar Pradesh and the Union traditional high-water demand cropping and Territory of Pondicherry, the level of irrigation practices to modern, reduced groundwater development is 70% and above. demand systems and technologies. In the rest of the states, the level of groundwater development is below 70%. It is well known that crop yield increases Over the years, the usage of groundwater has with water availability in the root zone, until increased in areas where the resource was saturation level, above which there is little readily available. In India, about 52% of effect. The yield response curve of specific irrigation consumption across the country is

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 extracted from groundwater; therefore, it can Localized irrigation be an alarming situation with a decline in groundwater and increase in irrigation Localized irrigation is widely recognized as requirement due to climate change one of the most efficient methods of watering (Pathak,2014). crops. Localized irrigation systems (trickle or , micro-sprayers) apply the Globally, the rate of groundwater abstraction water to individual plants by means of plastic is increasing by 1% to 2% per year pipes, usually laid on the ground surface. (WWAP,2012). If the world continues to use With drip irrigation water is slowly applied water at the current rates, it is estimated that through small emitter openings from plastic demand could exceed supply by as much as pipes with discharge rate ≤ 12 l/h. With 40% by 2030, putting both water and food micro-sprayer (micro-sprinkler) irrigation security at risk. Demands on agricultural water is sprayed over the part of the soil water are likely to increase in future as surface occupied by the plant with a domestic, industry and environmental uses of discharge rate of 12 to 200 l/h. The aims of water continue to grow. Therefore, judicious localized irrigation are mainly the application utilisation of available water resources in of water directly into the root system under agriculture, given the due concern for water conditions of high availability, the avoidance storage, conveyance and distribution, needs of water losses during or after water to be planned for the sustainability of application and the reduction of the water agriculture throughout the water-scarce application cost less labour. countries. Large-scale adoption and use of drip, sprinklers and conjunctive water use Irrigation scheduling irrigation methods need more attention, particularly for small and marginal farmers. Irrigation scheduling is the decision-making process for determining when to irrigate the Precision-smart water management crops and how much water to apply. It forms technology in sustainable agriculture to the sole means for optimizing agricultural enhance water productivity and water use production and for conserving water and it is efficiency the key to improving performance and sustainability of the irrigation systems. It Sustainable water management in agriculture requires good knowledge of the crops' water aims to match water availability and water requirements and of the soil water needs in quantity and quality, in space and characteristics that determine when to time, at reasonable cost and with acceptable irrigate, while the adequacy of the irrigation environmental impact. Its adoption involves method determines the accuracy of how technological problems, social behavior of much water to apply (Fig. 3). In water scarce rural communities, economic constrains, regions, irrigation scheduling is more legal and institutional framework and important than under conditions of abundant agricultural practices. water, since any excess in water use is a potential cause for deficit for other users or However, this frequency depends upon the uses. irrigation method and therefore, both irrigation scheduling and the irrigation Irrigation scheduling techniques and method are inter-related. varies greatly and has different characteristics relative to their applicability and

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 effectiveness. Timing and depth criteria for Climatic parameters irrigation scheduling can be established by using several approaches based on soil water Climatic parameters are widely used for local measurements, soil water balance estimates or regional irrigation schemes. Weather data and plant stress indicators, in combination and empirical equations that, once they are with simple rules or very sophisticated locally calibrated, provide accurate estimates models. Many of them are still applicable in of reference evapotranspiration (ETo) for a research or need further developments before given area are used. Then, crop they can be used in practice. evapotranspiration (ETc) is estimated using appropriate crop coefficients. Information Most of them require technical support by may be processed in real time or, more often, extension officers, extension programmes using historical data. These techniques and/or technological expertise of the farmers. include evaporation measurements for ETo However, in most countries these calculation, assessment of crop programmes do not exist because they are evapotranspiration using climatic data (air expensive, trained extension officers are temperature, RH, wind speed, sunshine lacking, farmer‟s awareness of water saving hours) and remote sensed ET. in irrigation is not enough and the institutional mechanisms developed for Crop stress parameters irrigation management give low priority to farm systems. Therefore, in general, large Instead of measuring or estimating the soil limitations occur for their use in the farmers‟ water parameters, it is possible to get a signal practice. A brief description of irrigation from the plant itself indicating the time of scheduling techniques with reference to their irrigation but not defining the irrigation applicability and effectiveness are reported depths. This message can either come from below. individual plant tissues, where a correct sampling is required, or from the canopy as a Soil water estimates and measurements whole. Therefore, crop stress parameters are useful when irrigation depths are predefined Soil water affects plant growth directly and kept constant during the irrigation through its controlling effect on plant water season. Crop water stress parameters include status. There are two ways to assess the leaf water content and leaf water potential, availability of soil water for plant growth: by changes in stem or fruit diameter, sap flow measuring the soil water content and by measurement, canopy temperature, remote measuring how strongly that water is retained sensing of crop stress. in the soil (soil water potential). The accuracy of the information relates to the sampling Soil - water balance methods adopted and to the selection of locations where point observations are The aim of soil water balance approach is to performed due to the soil water variability predict the water content in the rooted soil by both in space and depth. Soil water estimates means of a water conservation equation: and measurements used for irrigation scheduling include: soil appearance and feel, Δ (AWC × Root depth) = Balance of entering soil water content measurement (TDR), soil + outgoing water fluxes, water potential measurement (tensiometers, soil spectrometers and pressure transducers), where AWC is the available water content. remotely sensed soil moisture. Soil water holding characteristics, crop and 1120

Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 climate data are used by sophisticated models Fertigation to produce typical irrigation calendars. This approach can be applied from individual The application of fertilizers through the farms to large regional irrigation schemes. irrigation system (fertigation) became a However, it needs expertise, support by common practice in modern irrigated strong extension services or links with agriculture. Localized irrigation systems, information systems. Its effectiveness is very which could be highly efficient for water high, but depends on farm technological application, are also suitable for fertigation. development and/or support services (FAO, Thus, the soluble fertilizers at concentrations 1999). required by crops are applied through the irrigation system to the wetted volume of the Effective irrigation scheduling soil. Possible disadvantages include the non- uniform chemical distribution when irrigation It is recognized that appropriate irrigation design or operation are inadequate, the over- scheduling should lead to improvements in fertilization in case that irrigation is not based irrigation management performance, on actual crop requirements and the excessive especially at farm level. The farmer should be use of soluble fertilizers. able to control the timing and the depth or volume of irrigation. However, the practical Deficit irrigation practices application of the techniques and methods has been far below expectations. The In the past, crop irrigation requirements did dependence on a collective system implies not consider limitations of the available water social, cultural and policy constraints. supplies. The irrigation scheduling was then based on covering the full crop water The main constrains are the lack of requirements. However, in arid and semi-arid flexibility, either due to rigid schedules or the regions increasing municipal and industrial system limitations, the non-economic pricing demands for water reduce steadily water of water (price covers less than 30% of the allocation to agriculture. Thus, water total cost), the high cost of irrigation availability is usually limited, and certainly scheduling (either for technology and/or not enough to achieve maximum yields. labour), the lack of education and training of Then, irrigation strategies not based on full the farmers, the institutional problems, the crop water requirements should be adopted behavioural adaptation, the lack of interactive for more effective and rational use of water. communication between research, extension Such management practices include deficit and farmers and finally the lack of irrigation, partial root drying and subsurface demonstration and technology transfer. irrigation.

The effective application of any irrigation Regular deficit irrigation scheduling method and effective implementation of the corresponding delivery Regulated deficit irrigation (RDI) is an schedule are subject to the physical capability optimizing strategy under which crops are of the collective system for delivering water allowed to sustain some degree of water according to this schedule and to the capacity deficit and yield reduction. During regulated of the management for operating the system deficit irrigation the crop is exposed to properly. certain level of water stress either during a particular period or throughout the growing

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 season. The main objective of RDI is to water availability falls following the increase water use efficiency (WUE) of the cessation of irrigation, the ABA is crop by eliminating that have little synthesized in the drying roots and impact on yield, and to improve control of transported to the leaves through the vegetative growth (improve fruit size and transpiration stream (Loveys et al., 1999). quality). The resulting yield reduction may be Stomata respond by reducing aperture, small compared with the benefits gained thereby restricting water loss. Improvement through diverting the saved water to irrigate of WUE results from partial stomatal closure. other crops for which water would normally However, an inevitable consequence is be insufficient under conventional irrigation reduced photosynthesis. With PRD, practices. switching the wet and dry sectors of root zone on regular basis, this transient response RDI is a sustainable issue to cope with water was overcome. scarcity since the allowed water deficits favour water saving, control of percolation PRD has been successfully applied with drip and runoff return flows and the reduction of irrigation in grapevines (Dry et al., 2000), losses of fertilizers and agrochemicals; it with subsurface irrigation in grapevines and provides for leaching requirements to cope even furrow irrigation in pear, citrus and with salinity and the optimization approach grapevines. The cost of PRD application leads to economic viability. The adoption of varies according to the irrigation system deficit irrigation implies appropriate employed and whether it is applied to new or knowledge of crop ET, of crop response to existing vineyards. In pre-existing irrigation water deficits including the identification of systems an additional line must be added. critical crop growth stages, and of the The additional cost of installing PRD is economic impact of yield reduction economical where the cost of irrigation water strategies. Therefore, appropriate deficit is high and as water becomes an increasingly irrigation requires some degree of valuable and scarce resource. In these areas technological development to support the the true environmental cost of water justifies application of irrigation scheduling the implementation cost of PRD. techniques. Subsurface drip irrigation Partial root drying Subsurface drip irrigation (SDI) is a low- Partial root drying (PRD) is a new irrigation pressure, low volume irrigation system that technique, first applied to grapevines that uses buried tubes to apply water. The applied subject one half of the root system to dry or water moves out of the tubes by soil matrix drying conditions while the other half is suction. Wetting occurs around the tube and irrigated. Wetted and dried sides of the root water moves out in the soil all directions. system alternate on a 7-14-day cycle. PRD uses biochemical responses of plants to water The potential advantages of SDI are: stress to achieve balance between vegetative and reproductive growth. During water stress a) water conservation, b) enhanced fertilizer development the vine‟s first line of defence is efficiency, c) uniform and highly efficient to close its stomata to conserve moisture. One water application, d) elimination of surface of the principal compounds that elicit this infiltration problems and evaporation losses, response is the abscisic acid (ABA). As soil e) flexibility in providing frequent and light

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 irrigations, f) Reduced problems of disease Effort should be made in their rational use of and weeds, g) lower pressure required for chemicals for pest and weed control in operation. order not to further pollute the environment. The soil management The main disadvantages are the high cost of consists of, Soil surface tillage, which initial installation and the increased concerns shallow tillage practices to possibility for clogging, especially when poor produce an increased roughness on the soil quality water is used. Subsurface irrigation is surface permitting short time storage in suitable for almost all crops, especially for small depressions of the rainfall in excess high value fruit and vegetables, turfs and to the infiltration. landscapes. Contour tillage, where soil cultivation is made along the land contour and the soil is Agricultural practices left with small furrows and ridges that prevent runoff. This technique is also Agricultural practices, such as soil effective to control erosion and may be management, fertilizer application, and applied to row crops and small grains disease and pest control are related with provided that field slopes are low. the sustainable water management in Bed surface profile, which concerns agriculture and the protection of the cultivation of wide beds and is typically environment. used for horticultural row crops. Agricultural practice today is characterized Conservation tillage, including no-tillage and by the abuse of fertilizers. Farmers very reduced tillage, where residuals of the rarely carry out soil and leaf analyses in previous crop are kept on the soil at order to clarify the proper quantity and planting. Mulches protect the soil from type of fertilizer needed for each crop and direct impact of raindrops, thus controlling they apply them empirically. This practice crusting and sealing processes. increases considerably the cost of Conservation tillage helps to maintain high agricultural production and is potentially levels of organic matter in the soil thus it critical for the deterioration of the is highly effective in improving soil groundwater quality and the environment. infiltration and controlling erosion. Agrochemicals (herbicides and pesticides) Mulching with crop residues on soil surface are also excessively used, endangering the which shades the soil, slows water quality of the surface water and negatively overland flow, improves infiltration affecting the environment. Plant-protection conditions, reduces evaporation losses and products (pesticides) are often used also contributes to control of weeds and preventively, even when there is not real therefore of nonbeneficial water use. threat in the area. Increasing or maintaining the amount of There is a large variety of traditional and organic matter in the upper soil layers, modern soil and crop management since it provides for better soil practices for water conservation (runoff aggregation, reduced crusting or sealing on control, improvement of soil infiltration soil surface and increased water retention rate, increase soil water capacity, control capacity of the soil. of soil water evaporation) and erosion Addition of fine material or hydrophilic control in agriculture, some of which chemicals to sand/coarse soils. This apply also for weed control (Pereira et al., technique increases the water retention 2002). capacity of the soil and controls deep

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percolation. Thus, water availability in sustainability and resilience of agricultural soils with low water holding capacity is production under predicted climate scenarios. increased. In view of the above, there is an urgent need Control of acidity by liming, similarly to to determine the impacts of climate change gypsum application to soils with high pH. on crop production and water to develop This treatment favours more intensive and possible innovative climate water-smart deep rooting, better crop development and adoption technologies. contributes to improved soil aggregation, thus producing some increase in soil water Best management practices in agriculture and availability. Adoption of appropriate weed technologies, namely, minimum tillage, control techniques to alleviate competition different methods of crop establishment, for water and transpiration losses by nutrient and irrigation management and weeds. residue incorporation can improve crop yields, improve the water and nutrient use Enhance water use efficiency through efficiency and minimise the emissions of climate-smart water management greenhouse gases from agricultural activities. technologies Similarly, water smart technologies, namely, micro-irrigation, furrow irrigated raised bed, Water-smart agricultural technologies rainwater harvesting structure, reuse integrate traditional and innovative practices, wastewater, cover crop method, partial root technologies and services that are relevant for dry (PRD), deficit irrigation, greenhouse, a particular location to adopt climate change laser land levelling and drainage management and variability (CIAT, 2014). Location- can also help farmers to reduce the impact of specific water-smart technologies, either climate change and variability (Altieri and individually or in combination, have Nicholls, 2017). National Initiative on substantial potential to reduce climate change Climate Resilient Agriculture (NICRA, 2016) impacts on water resources with proper has suggested several interventions such as planning and implementation. A meta- adoption of scientific water conservation analysis carried out for crop simulation under methods, precise estimation of crop water several climate scenarios showed that farm requirement, irrigation scheduling, level adaptations could increase crop yields groundwater recharge techniques, use of by an average of 7 to 15% and water saving drought tolerant varieties, adjusting the from 25 to 50% when compared to without planting dates, modifying the fertiliser and adaptation (Challinor et al., 2014). irrigation schedules and adopting zero-tillage which may help farmers to achieve Simple adaptation measures such as changes satisfactory crop yields, even in deficit in crop sowing dates and adoption of rainfall and warmer years. It is therefore irrigation technologies can result in higher imperative to promote water saving practices yields with less variation than without in irrigated as well as rain-fed agriculture on adaptation. Altieri and Nicholls (2017) a large scale. reported that traditional management systems combined with the use of agro-ecologically Many factors influence the extent of adoption based management strategies (bio- of smart water technologies such as socio- diversification, soil management and water economic characteristics of farmers, the bio- harvesting) could prove the only viable and physical environment of a particular location, robust path to increase the productivity, and the attributes of new technologies

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(Campbell et al., 2012). The identification, through enhanced WP by adopting prioritisation and promotion of available appropriate soil, water and crop management water-smart technologies considering local options. The vast potential of rain-fed climatic risks and demand for technology are agriculture needs to be unlocked through significant challenges for scaling out smart knowledge-based management of soil, water water technologies in diverse agro-ecological and crop resources to increase productivity zones. Problems of water scarcity could and water use efficiency (WUE) through adequately be addressed through the adoption sustainable intensification. of smart water management interventions and modern irrigation technologies to enhance Potential for enhancing WUE water use efficiency by involving the combination of area-specific approaches for A linear relationship is generally assumed both supply and demand side management. In between biomass growth and vapour flow view of the above, this paper brings together (ET), which describes WP ranging between the current technical knowledge for the 1000 and 3000 m3 t −1 for grain production. It successful implementation of smart water is recognized that this linear relationship does technologies for climate-smart sustainable not apply for the lower yield, up to 3 t ha−1, agriculture. which is the yield level of small-scale and marginal-scale farmers in dry land/rain-fed Climate/precision water smart areas. The reason is that improvements in technologies for rainfed and water limited agricultural productivity, resulting in situations increased yield and denser foliage, will involve a vapour shift from non-productive Current status and importance evaporation (E) in favour of productive transpiration (T) and a higher T/ET ratio as Eighty per cent of the cultivated area transpiration increases (essentially linearly) worldwide is rain-fed and contributes to with a higher yield. nearly 60% of the world‟s food production (Wani et al., 2012). In India, the rain-fed In temperate arid regions, such as West cropped area comprises 53% of the total Africa and North Africa, a large portion of agricultural land, that is, 75 Mha. A large the rainfall is generally consumed by fraction of canal command areas has reached farmers‟ fields as productive green water a plateau in terms of productivity, and there is flow (45–55%), resulting in higher yield a growing concern with regard to feeding a levels (3–4 t ha−1 compared with 1–2 t ha−1), rapidly growing population. The option of 25–35% of the rainfall flows as non- increasing arable land has been exhausted, productive green water flow and the and there are limited opportunities for remaining 15–20% generates blue water irrigation expansion. flow. Agricultural water management interventions in the watershed in the Indian However, evidence shows that a large yield SAT converted more rainfall into green water gap exists in Asia and Africa between current and also reduced the amount of run-off by productivity and achievable potential, with 30–50%, depending on rainfall amount and farmers‟ yields being a factor of twofold to distribution. There is vast untapped potential fourfold lower than the achievable yields. in rain-fed areas using appropriate soil and Studies involving rain-fed agriculture show water conservation practices (Anantha and opportunities for enhancing food production Wani, 2016).

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minimise the effects of variations in water Data obtained from long-term experiments availability and to enhance the reliability of conducted at ICRISAT‟s heritage watershed the agricultural output (fig 4). Water site have shown that due to Integrated Water harvesting may be operated by collecting Resources Management (IWRM) water in ponds, tanks and other storage tanks interventions, the average crop yield is created for the specific purpose. Rainwater fivefold higher than that by traditional harvesting structures consist of dugout ponds, farming practices. Similar results were also embankment type ponds, check dams, etc. recorded at Adarsha watershed, Kothapally, Agronomic and engineering measures are Southern India, where implementing IWRM beneficial for rainwater harvesting. For arable interventions enhanced crop yields almost land at farm level, it may be done through twofold to threefold than those in the baseline agronomic methods such as contour situation (Karlberg et al., 2015). Yield gap cultivation, mulching, trench plantation, analyses carried out for major rain-fed crops furrow irrigation, deep tillage, contour in semi-arid regions in Asia and Africa and farming, raised bed techniques of cultivation, rain-fed wheat in West Africa and North ridges, etc. Africa revealed large yield gaps which were a factor of twofold to fourfold lower than On the other hand, engineering techniques achievable yields. include contour bunds, graded bunds, bench terraces, contour trenches, conservation Climate water-smart technologies for ditches and broad bed and furrow systems, national and international applicability etc. Similarly, rainwater harvesting from the roofs of houses in urban and rural areas and To tackle the challenges of increasing food rainwater harvesting from the sloped roofs of production and improving rural livelihoods, low-cost and hi-tech polyhouses are necessary measures should be undertaken for increasingly important, especially in the effective water management in rain-fed and northeastern hill states of India. Rainwater irrigated regions. An integrated approach harvesting (RWH) is an adaptation strategy needs to be adopted for agricultural water for people living with high rainfall variability management through adoption of innovative both for domestic supply and to enhance technologies with national and international crops, livestock and other forms of applicability, such as rainwater harvesting, agriculture. IPCC (2014) advocated that sprinkler and drip irrigation, laser land rainwater harvesting structures are extremely levelling, floating agriculture, floating solar important for mitigating the impact on panels, resources conservation farming, agriculture and increasing agricultural conveyance of water through underground productivity. pipeline systems, etc. Some important water- smart technologies are explained as follows. Furrow irrigated raised beds

Water harvesting Raised beds of 1 to 1.5 m width alternating with furrows are often constructed for The term water harvesting infers the growing vegetables, medicinal and aromatic collection of inevitable runoffs, efficient and cereal crops (Fig. 5). Two rows of plants storage of harvested water, its application and are usually raised on two sides of a bed or optimum utilisation for maximising ridge. A furrow runs between two rows of the production. Rainwater harvesting aims to adjacent ridges of beds and supplies water to

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 the plant rows. The method ensures saving a wastewater treatment ponds, etc. These solar large amount of water. The surface soil of panels are naturally cooled, and due to the beds or ridges remains dry, and the creeping increase in the temperature of panels being plants and their fruits are not damaged. Water less as compared to rooftop solar power from the furrow moves laterally into the soil panels they give a higher performance. below the bed or ridge to meet the crop need. Floating solar panels are a source of clean, It prevents the accumulation of salts at the renewable electricity and help to minimise base of plants and reduces the salt injury to greenhouse gases. The floating solar panel crops in areas where raised bed and furrow structure shades the body of water and salt is a problem. This method offers a more reduces evaporation from these ponds, effective control over irrigation and drainage reservoirs and lakes (Taboadaa et al., 2017). as well as rainwater management during the Another advantage of using floating solar monsoon. power plants is that the ecology of the water body is not affected and it also reduces Precision land levelling evaporation losses to about 70%. Thus, it helps to preserve water levels during extreme Precision land leveling is a proven summers (Taboadaa et al., 2017). agricultural on-farm technology that not only reduces farm irrigation needs but is also According to Hassan and Pierson (2016), in highly useful to reduce irrigation time and many parts of Australia, the annual average increase water use efficiency. A more evaporation exceeds the annual precipitation levelled and smooth soil surface reduces the by more than five times. A high rate of consumption of seeds, fertilisers, chemicals evaporation and a prolonged drought period and fuel. The use of a laser leveller for land is a significant threat to water availability for levelling has increased many-fold in some agricultural production. Covering of water states – Haryana, Punjab, Uttar Pradesh and bodies using recycled clean plastic containers Madhya Pradesh, etc. precision levelling as floating modular devices helps to mitigate could save 20–25% of irrigation water. Most evaporation. The concept of floating solar of the farmers in the Haryana state of India power plants is increasing in the US, China, hire the equipment on an hourly basis. Japan, the UK, India and many more Farmers pay between 600 and 700 rupees per countries. Floating solar power plants are a hour to use the machinery. Wakchaure et al., new and emerging concept in India and have (2015) reported that precision levelling immense potential for overcoming the significantly improved the soil and canopy problem of energy and water crises in future. micro-environment and favoured increasing the sorghum yield by 27–73% and Floating agriculture substantially saved irrigation water (30.9%) compared to unlevelled fields. Floating agriculture is an indigenous technique of farming which involves planting Floating solar power plants crops on soil-less floating rafts. This technique has enough potential to help Floating solar power plants are a new farming communities in the flood-prone emerging technology throughout the world. regions during floods and long-term Solar panels are fastened to a rigid buoyant waterlogged conditions (Chowdhury and structure. Floating solar plants float on top of Moore, 2017). Historically, these rafts were a body of water such as reservoirs, made of composted organic material,

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 including water hyacinth, algae straw and toilets. Freshwater resources can be preserved herbs. Water hyacinth (aquatic weed) is using municipal recycled wastewater and commonly used for constructing floating beds stormwater for irrigation. Phytorid is a in different regions of Bangladesh. wastewater treatment constructed wetland technology for the treatment of municipal, The floating are used for agricultural urban, agricultural and industrial wastewater. production, for example, vegetables and The system is based on specific plants, such spices for local communities. Because prime as elephant grass (Pennisetum purpurem), nutrients such as nitrogen, potassium and cattails (Typha sp.), reeds (Phragmites sp.), phosphorus are abundant in the floating beds, Cannas sp. and yellow flag iris (Iris there is almost no need for fertiliser. pseudocorus), normally found in natural Additionally, water prevents vermination and wetlands with filtration and treatment almost no pesticides are applied. The capability. Some ornamental, as well as productivity of floating vegetable cultivation flowering plant species such as golden is estimated to be ten times higher than on dhuranda, bamboo, Nerium, colosia, etc., can similar sized land-based agriculture. Floating also be used for treatment as well as cultivation would help to mitigate this landscaping purposes. situation and reduce the pressure on arable lands by turning the flooded and waterlogged Deficit irrigation areas into productive ones. Partial root drying (PRD) is a new irrigation According to Chowdhury and Moore (2017), and plant growing technique which improves floating agriculture has greatly supported water use efficiency without significant yield farming communities to adapt to adverse reduction. PRD involves alternate drying and waterlogged conditions by allowing wetting of subsections of the plant root zone vegetable production for daily consumption, by exploring the plant physiological and income generation, community mobilisation biochemical responses (Alrajhi et al., 2017). along with providing food and nutrition It requires part of the root system being security in Bangladesh. exposed for drying soil while the remaining part is irrigated normally. The wetted and Re-use of wastewater in agriculture dried sides of the root system are alternated with a frequency according to soil drying rate Due to water scarcity in the agriculture and crop water requirement. PRD irrigation sector, recycling of wastewater is becoming technology is widely used in horticultural more popular to augment water demand for crops. Abdelraouf (2016) found that PRD is agriculture in many parts of arid regions of promising for application in arid regions for the world (Alrajhi et al., 2017). Re-use and saving water of up to 50% from crop water recycling of municipal wastewater and requirements without reduction of crop yield. industrial effluent are significant to minimise the pollution load in the receiving water and Drip irrigation/ sprinkler irrigation the reduction in the requirement of freshwater for various uses. Re-use of municipal Technology of more crops per drop of water wastewater after treatment is necessary to Drip irrigation is one of the advanced meet industrial water requirements and is methods of irrigation by which water can be being used for horticulture, watering of supplied directly into the root zone of the and even for flushing public sewers and soil. There are several methods of pressure

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 irrigation, such as sprinkler irrigation, centre fertiliser; repelling or attracting insects; and pivot and LEPA, microjets, drip/micro- or manipulating soil temperature. Gao et al., trickle irrigation and surface or subsurface (2019) carried out a metaanalysis to quantify irrigation. Drip irrigation systems are more and analyse the effects of plastic film efficient than other surface irrigation methods mulching and residual plastic on yield and in terms of water savings, yield and water use water use efficiency (WUE) of maize, wheat, efficiency. There is an increase in crop yields potato and cotton in China. They reported a and reduction in the cost of fertilisers, significant increase in crop yield (24.32%) pesticides and power for irrigation when and WUE (27.63%). Use of plastic mulching using this method of irrigation. Thus, drip increases the potato yield by 30.62% and irrigation minimises conventional losses such WUE 30.34% in China. as deep percolation, runoff and evaporation. The total potential of micro-irrigation in India Cloud seeding is estimated at around 69.5 Mha. However, the coverage of micro irrigation is only 7.7 Cloud seeding has been applied to many Mha (FICCI 2016). Under drip irrigation the agricultural areas around the world where area covered was 3.37 Mha while sprinkler rain is scarce and needed for crop survival. It irrigation total coverage area was 4.36 Mh. is a form of weather modification or making artificial rain from clouds. It is also used to Plastic mulching suppress hail, and has been practised in Israel for the last 30 years and is being used in Plastic mulching, a technique to cover the many other countries. Originally, seeding soil around the root zone of a plant with a with the aid of silver iodide began with the plastic film, is a useful practice to restrict use of ground incinerators. The process has weed growth, conserve moisture and reduce been improved, and special aircraft are used the effect of soil-borne diseases. The states in for this purpose, including the use of brine as India that have played a dominant part in the seeding material. implementing the mulching activity in horticulture are Manipur (21%), Assam Bangsund and Leistritz (2009) analysed the (20%), Uttarakhand (17%) Meghalaya (13%) economic impacts of cloud seeding on and Nagaland (12%), with a combined share agricultural crops in North Dakota and of about 83% in the total programme of reported that the cloud seeding increased the mulching. Plastic film mulch is one of the amount of precipitation and reduced the risk most extensively used forms of plasticulture, of hail in the western North Dakota counties. and it is currently used on a vast scale in The attempts helped to improve agricultural China, India, Israel and Italy. While plastic production and were a huge economic benefit mulch is used to enhance water savings of to the region. Cloud seeding is also helpful to micro-irrigation in developed countries, its prevent the development of hail storms which adoption in developing countries is often cause severe damage to crops. independent of micro irrigation technology. China accounts for 40% of the world‟s plastic Greenhouse technology mulch use. Plastic mulch performs a variety of functions, including soil disinfestation by Greenhouse crops are one of the most solar energy (solarisation); covering the soil innovative modern agriculture technologies. for heat collection; preventing the growth of Use of greenhouses is useful in conserving weeds; minimising evaporation and escape of water while simultaneously enhancing

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 agricultural productivity (fig: 6) Greenhouses production. uses substantially offer a stable alternative to traditional open- less water as compared to soil farming. The air farming practices, as they allow for (NFT) system of consistent, year-round crop growth, all while hydroponics is mostly used for the successful reducing water usage (Connor and Mehta production of leafy and other vegetables with 2016). It is one of the highest human-made 70–90% savings of water throughout the forms of agricultural activity, because of its world (Sharma et al., 2018). Leading intense technological and bio-agronomic countries in hydroponic technology are the input in confined portions of the farm Netherlands, Australia, France, UK, Israel, environment. Canada and the USA. Growers should be well-versed about plant growth, nutrient Greenhouse farming reduces water balances and cultural media characteristics. consumption as compared to open-air agriculture, mainly due to reduced is also a technique for growing evapotranspiration rates inside greenhouses. plants in air and a humid environment Use of drip irrigation systems improves the without soil. This technique is an efficient efficiency of water usage. By increasing the way of controlling humidity, temperature, efficiency of irrigation, drip irrigation soil pH and water conductivity. In systems reduce water usage by 30–50% when aeroponics, plant roots are suspended in the compared with regularly used surface air. The main advantage of the aeroponics irrigation. system is limited water consumption.

Retaining stubble/low till technique Adaptation strategie’s

Retaining stubble/low till is a technique Potential impacts of climate change depend widely applied in China. In this technique, not only on climate per se but also on the stubble from one crop is left on the field after system‟s ability to adapt to change. that crop is harvested. The low till method Depending on the vulnerability of individual can improve water use efficiency by reducing crops in an agro-ecological region and the soil evaporation and increasing yields in growing season, crop-based adaptation comparison to traditional agronomic strategies need to be developed, integrating techniques. all available options to sustain productivity.

Hydroponics and aeroponics These available technologies could be integrated and used for reducing the adverse The hydroponic technique replaces the impacts of climate change and climate conventional method of growing plants in variability. Some possible adaptation soil. In this method, the liquid nutrient strategies that are relevant to current climatic medium is provided for the growth of plants. risks are described in Table 1. It minimises the use of fertiliser and irrigation but requires continuous monitoring of plants. Efficient use of water and its management in The benefits of hydroponic agriculture agriculture is very critical for adaptation to include less growing time, minimal disease, climate change. Under rising temperatures higher yields and water efficiency. and fluctuating precipitation patterns, water Use of hydroponics in a controlled will become a scarcer resource in several environment helps to achieve year-round parts of the world. Therefore, the

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 amalgamation of traditional wisdom and and fertiliser. It also helps in plant stand, modern innovative water management and enhanced nutrient use efficiency and water saving techniques needs to be increased crop yield (Pathak et al., 2014). thoughtfully implemented for sustainable crop production in water-scarce areas. Water requirement varies from 775 to 3,000 Serious efforts towards water conservation, mm according to climate, soil, crop and water water harvesting, improvement of irrigation management practices followed in a region accessibility and water use efficiency would (Patle et al. 2017). Water management in rice help in the strategic planning and is possible through improved cultivation management of available water resources in methods such as alternate wetting and drying the region. In situ and ex situ water (AWD), direct-dry seeding, aerobic rice, non- conservation techniques, micro-irrigation flooded mulching cultivation, and the system systems and selection of appropriate need- of rice intensification (SRI) which also helps based irrigation must be encouraged among to reduce the emission of greenhouse gases the farmers with proper training and skill and saves water. Direct-seeded rice (DSR) development. could be a potential option for water saving and reducing CH4 emission compared to The principles of increasing water infiltration conventional puddled transplanted rice. The by improving soil aggregation, decreasing system of rice intensification (SRI) appears to runoff by using contours, ridges, vegetative be a suitable and sustainable way of growing hedges and reducing soil evaporation by rice for resource-poor farmers, and besides, it using crop residue mulch could be employed also has the potential of being able to for better management of soil–water. increase soil fertility through increased Development of technologies along with carbon pool and mitigation possibilities of higher investments would help improve water greenhouse gases. management efficiency. Well-timed management of deficit irrigation can make a Policy analysis and suggestion’s substantial difference in crop productivity in regions with limited access to irrigation. In There is an urgent need for strong policies the non-irrigated areas, water conservation and programmes to promote rainwater and water harvesting techniques need to be harvesting. These should target areas that are disseminated as an alternative for poor water scarce, those that have become highly farmers. However, the adoption of such dependent on groundwater, and where rapid practices will require investments in capacity declines in groundwater levels are taking building and agricultural extension. place. Substantial funding is required for the creation of rainwater harvesting structures Rainwater harvesting can meet water demand and given the costs and externalities in water-scarce regions. Improved irrigation involved, it calls for public support. methods like drip irrigation, sprinkler Conditions of institutional success such as irrigation and use of laser-aided land clear objectives, good interaction, levelling methods can also help in increasing adaptiveness, appropriate scale and water-use efficiency. Laser aided levelling compliance need to be addressed by the provides smooth and levelled fields, which policies and programmes to ensure proper allows proper water distribution with performance. The check dam movement in negligible water loss and facilitates Rajasthan and Gujarat shows that community uniformity in the placement of seed/seedlings involvement in rainwater harvesting projects

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 and activities is essential for success. It also during no windy periods, adoption of smaller shows that creating effective village spacing and large sprinkler drops and institutions with active participation can go a application rates in windy areas, the adoption long way in improving results. of application rates smaller than the infiltration rate of the soil and careful system Other experiences indicate that to improve maintenance. the impact of rainwater harvesting, it is necessary to go beyond natural resource Increase water use efficiency: Can be management to add productivity achieved with the obligatory use of localized enhancement activities. These may include irrigation systems by the farmers (with or measures to improve water use efficiencies without subsidies), the proper irrigation such as drip and sprinkler irrigation, and scheduling according to actual needs of the promotion of appropriate crops, varieties and crops, the establishment of a system for modern inputs to enhance physical advising farmers on their irrigation schedules, productivity and economic returns. the introduction of appropriate agronomical practices and the application of salinity Recommendations for best irrigation management techniques. practices Adoption of innovative irrigation The major agricultural use of water is for techniques: In water scarce regions irrigation irrigation and its supply is decreasing steadily approaches not necessarily based on full crop due to competition with municipal and water requirements like regulated deficit industrial sectors. Therefore, technological, irrigation (RDI) or subsurface irrigation (SSI) managerial, policy innovation and human must be adopted. Fertigation (efficient resources management are needed to increase fertilizer application) and chemigation (easy the use efficiency of the available water. control of weeds and soil born diseases) Sustainable water management in agriculture should also be promoted. can be achieved by: Water pricing policy: For proper water Reduction of water losses in the conveyance, pricing volumetric water metering and distribution and application networks. Water accounting procedures are recommended. leakages should be detected via advanced Progressive, seasonal and over-consumption technologies, e.g. telemetry systems, GIS, water tariffs as well as temporary drought remote sensing. Old water projects surcharges rates contribute to water savings experiencing considerable water losses and should be promoted. should be rehabilitated and modernized. Reuse of marginal waters (reclaimed or Improve the efficiency of irrigation brackish) for irrigation: Reclaimed waters system: Improvements in sprinkler irrigation can be used under some restriction for systems (efficiency up to 85%) include the irrigation of tree, row and fodder crops. In adoption or correction of sprinkler spacing, addition to water they provide the soil with the design for pressure variation not nutrients, minimizing the inorganic fertilizer exceeding 20% of the average sprinkler application. Treated sewage is looked upon pressure, the use of pressure regulators in with scepticism by farmers. They instead sloping fields, the monitoring and adjustment prefer to use surface and/or groundwater. pressure equipment, application of irrigation Special effort should be given in educating

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Int.J.Curr.Microbiol.App.Sci (2020) Special Issue-11: 1115-1140 farmers to accept treated sewage. In addition, Need -based irrigation application the tariff for this source of water should be lower than the tariff of the primary sources. In general, farmers practise calendar-based irrigation scheduling that results in over Capacity building: The existing “capacity irrigation and poor WUE. Due to inherent building” is poor. It requires an appropriate variability of bio-physical (soil hydraulic mix of competent personnel, technologically parameters, soil depth, etc.), topographical advanced devices and facilities, legal and land management (cropping sequence, guidelines and administrative efficient and time of sowing, etc.) factors, calendar-based effective processes for the sustainable irrigation scheduling does not always match management of the water resources. It with crop water requirement, resulting in includes: reduced crop yield and poor WUE. Therefore, it is necessary to follow a need- a. Education and training of professional, based water application to optimize the technical staff and decision makers and available water resources. A decision support others, including non-public organizations, system called the „Water Impact Calculator‟ on a wide range of subjects related to (WIC) was developed at ICRISAT using sustainable water management. strategic data collected at its research station (Garg et al., 2016) b. Manpower build-up: An ICRISAT-led consortium with local Institutions to be staffed with qualified partners, non-governmental organizations and manpower (managers, engineers, technicians, an irrigation company (Jain Irrigation Ltd.) social scientists) that should be adequately evaluated the WIC by conducting farmer compensated. participatory field trials between 2010 and 2014 at different sites in India (e.g. Mota c. Facilities and procedures: Vadala in Jamnagar, Gujarat; Kothapally in Ranga Reddy, Telangana; Parasai-Sindh Water authorities at all levels of management watershed, Jhansi; Dharola Tonk, Rajasthan should be equipped with technologically and the ICRISAT research station). advanced devices and programs e.g. computers and software for the application of Irrigation was scheduled using WIC new techniques such as GIS, remote sensing calculations and an exact quantity of water etc. These advanced techniques facilitate the was applied as per the recommendations. multi-sectoral information availability and use and help water managers in their The gravimetric soil moisture content was decision- making. measured at 0–15 cm, 15–30 cm, 30–45 cm and 45–60 cm soil depths at weekly intervals. d. Legislative changes to the fragmented and Crop grain yield and above-ground biomass antiquated legislation should be promoted. yield were estimated at the end of the crop Responsibility of water resources planning harvest. WIC-simulated soil moisture was and operation, especially at the overall compared with measured data at different national level, should be under one institution soils and rainfall regions. for proper organization and non-conflicting actions by the various authorities.

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Table.1 Adaptation management strategies to combat climate change

Agriculture adaptation strategies Irrigation adaptation strategies 1.Assisting farmers in coping with current 1. Increasing the availability of useable climatic risk water  Improving collection and  Improving collection and dissemination of weather dissemination of weather information information  Establishment of a regional early  Water harvesting and storage warning system of climatic risks  Increasing groundwater  Promoting insurance for climatic recharge risk management  Recycling waste water 2.Intensifying food production systems 2. Increasing the efficiency of water use  Bridging yield gaps in crops  Laser levelling of irrigated area  Enhancing livestock productivity  Micro-irrigation  Enhancing fisheries  Adjusting crop agronomy 3.Improving land and water management 3. Groundwater management  Implementing strategies for more  Managing coastal ecosystems efficient water conservation and use  Rationing electrical power supply  Managed aquifer recharge Integration of surface and  Exploiting the irrigation and nutrient groundwater resource supply potential of treated wastewaters.  Increasing the dissemination of resource conserving technologies

4. Enabling policies and regional 4. Water transfer between basins cooperation  Integrating adaptation in current policy considerations  Providing incentives for resource conservation  Securing finances and technologies for adaptation 5.Strengthening research for enhancing 5. Trans-boundary cooperation between adaptive capacity. different states.  Evolving adverse climate tolerant genotypes  Evaluating the biophysical and economic potential of various adaptation strategies 6.Use of information and communication technology in water resource management.

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Figure.1 Water losses in agriculture

Figure.2 Plant yield response to water

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Figure.3 Irrigation scheduling components

Figure.4 Rain water harvesting

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Figure.5 Furrow irrigated raised bed system.

Figure.6 Greenhouse crops

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In general, simulated soil moisture was References found to be in good agreement with observed data. Based on minimum WIC Abdelraouf, R. E. 2016 Effect of partial root inputs on soil type, soil depth, date of zone drying and deficit irrigation sowing and climatic data, the exact amount techniques for saving water and of water on specific dates was recommended improving productivity of potato. in drip and flood/furrow irrigated fields. International Journal of Chemtech Crop yields were compared among WIC and Research 9 (8) pp 170–177. traditionally managed fields. Farmers at Alrajhi, A., Beecham, S., Bolan, N. S. and pilot sites could save nearly 30% water due Hassanli, A. 2017Evaluation of soil to need-based irrigation application (Garg et chemical properties irrigated with al., 2016). recycled wastewater under partial root-zone drying irrigation for In conclusion, decreasing water availability, sustainable tomato production. higher input costs and growing Agricultural Water Management environmental concerns are issues that water (161), pp 127–135. resources managers will not be able to Anantha, K. H. and S. P. Wani 2016. ignore in the future. Solutions will not be Evaluation of cropping activities in the easy and are likely to be multifaceted. Adarsha watershed project, southern Managing water properly is certainly one of India. Food Security 8(5) pp 885–97. the major challenges of the 21st century. Bangsund, D. and Leistritz, F. L. 2009 Water use in the agriculture sector has to Economic Impacts of Cloud Seeding reform to conserve water and other on Agricultural Crops in North resources so that non-agricultural demand Dakota. Report for North Dakota for water can be sustained. Efficient use of Atmospheric Resource Board, agricultural water can be ensured through Bismarck, ND, USA, pp 1–37. different water-smart technologies to Campbell, J., Cheong, S., McCormick, M., optimise productivity. There is a need to Pulwarty, S., Supratid, R. S. and develop a policy framework for Ziervogel, G. 2012 Managing the implementing the adaptation and mitigation Risks from Climate Extremes at the options so that farmers are saved from the Local Level. Managing the Risks of adverse impacts of climate change. To Extreme Events and Disasters to promote the adoption of climate-resilient Advance Climate Change Adaptation. strategies, we need to facilitate the transfer A special Report of Working Groups I of climate water-smart technologies from and II of the IPCC, Cambridge developed to developing countries. Future University Press, Cambridge, UK and agriculture has to be carried out smartly so New York, USA. that not only water but also other key input CGWB 2014 Dynamic groundwater resources like labour, chemicals, etc. can be resources of India. MoWR, River sustainably managed. Along with Development and Ganga Rejuvenation technological innovations, increased farmer Govt. of India. PG 299. awareness and the necessary policy support www.cgwb.gov.in/documents/Dynami (e.g., water pricing and changes in water c-GWResources-2011.pdf entitlements, etc. Will be essential to Challinor, A. J., Watson, J., Lobell, D. B., achieving the objectives. Howden, S. M. and Smith, D. R. (2014) A meta-analysis of crop yield

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