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Soil,
water, vegetation and production systems are the most important natural
resources in any agro-ecosystem. For production systems to be sustainable,
they must be in harmony with the environment. The arid ecosystem covers
roughly 0.70 km2 in cold arid conditions and 0.32 million km2
in hot arid conditions. The entire arid region, which includes the states of
Rajasthan, Gujarat, Andhra Pradesh, Punjab, Haryana, Karnataka, and
Maharashtra, makes up around 12% of the nation's land area; however,
Rajasthan (62%) and Gujarat (20%) make up the majority of this region (Faroda
et al., 1998). The climate of the region is characterized by low and
erratic rainfall, extreme temperature variation (-5.7°C to 50°C), long
sunshine durations (6.6-10 hours), low relative humidity (30-80 %), high wind
velocity (9-13 km-1), and high evapotranspiration (1600-1800 mm)
(Rao, 2009). In addition to the above, other factors that inhibit
agricultural production in this region include poor soil fertility, high
rates of wind erosion, water scarcity, and poor quality irrigation water.
Water scarcity is one of the most pressing issue affecting agricultural
production sustainability in arid and semi-arid regions. It has resulted in
over-exploitation of groundwater for indiscriminate use of irrigation (Goyal
et al., 2007), and at the same time majority of this is saline with very poor
water quality. Excessive use of such water in saline/sodic degraded land
results in increased amounts of secondary soil salinization. Therefore
maintaining agricultural productivity and livelihoods in this fragile
environment will require efficient management of natural resources,
especially water and energy. Towards complementing low and erratic rainfall,
the region needs enhanced total water supply for irrigation to enable farmers
to produce. Water management techniques that can be used to enhance total
supply of water for irrigation include tillage, mulching, soil moisture
barriers, contour bunds and water harvesting. Hence, conservation and
efficient management of limited water is the need of the hour for achieving
sustainable production for longer period. Since per unit returns from
horticultural crops are higher, their inclusion in the production system
improves the net return of farm lands and would impart resilience to aberrant
weather. Arid fruit species have some special adoptive features viz. deep
tap root system, modified structures and lower water needs during their
critical growth phases (Chundawat, 1995). Integrating hardy and water
economizing fruit species like ber, pomegranate, fig, and other regional
horticultural crops into farming systems will allow better utilization of
harvested rainwater (Singh et al., 2017). Consequently, aligning water
availability and crop needs will play a large role in improving total water
productivity and ensuring sustainability in growing regions that have limited
amounts of water. It is also necessary to choose the type of crops and their
varieties according to the atmospheric moisture and rainfall. It requires the
integration of suitable technologies according to the potential water
availability, resource inventory, and available technologies, along with
activities related to sufficient runoff generation, its movement, and storage
in the reservoirs by means of better design and development of farm plan. At
present, the stored water is mainly utilized as an additional source for
irrigation in the kharif season and for growing post-monsoon crops (Meghwal et
al., 2022; Singh et al., 2017). Land configuration for field water
management for inter-row rain water harvesting is a very good approach to
increase the potential runoff generation in the field, even in light textured
sandy soil. This technique consists of land leveling, contour bunding,
mulching, and developing alternate ridge and furrows to minimize runoff
losses (Goyal and Sharma, 2000).
Micro-catchment
is one of the major forms of direct water conservation systems. They are
relatively effective growing trees and shrubs. In micro-catchment based
cropping, rainwater is concentrated in a small portion of the cultivable
area. Sandy soil have meagre water storage capacity so fruit crops are
prefered over seasonal field crop in this system owing to deep-rooted system,
fruit crop can utilize the moisture stored in the sub-stratum. Deep rooted
tree crops can utilize moisture stored in the sub-stratum forming a better
option for micro-catchment based farming in sandy soil. Circular
micro-catchments with inward slopes have been found effective for crops like
ber, lasora, bael, improving soil moisture by around twenty percent (Ojasvi et
al., 1999). Covering these catchments with plastic sheets can further
enhance water conservation by reducing infiltration losses and evaporation.
In fruit orchard, rows and inter rows may be mulched with polythene mulch
during rainy season to enhance runoff. In a study conducted by Singh et
al. (2017) at Central Arid Zone Research Institute, it was observed that
mulching had significantly enhanced the run off capacity of a field, which
was three times higher in row and inter row mulching compared to no mulching.
Rain water harvesting, in specialized
designed water harvesting structure, is an integrated approach in farm pond
lined with polyethylene and equipped with solar pumping system to operated
micro-irrigation system for enhancing water productivity vis-à-vis farm
productivity. One such innovative energy and water harvesting model has been
developed by the Central Arid Zone Research Institute, with solar PV based
ferti-drip system (Singh et al., 2017). The model has provision of
harvesting rain water of pomegranate field in low cost HDPE lined farm pond
having storage capacity of 4.5 lakh litre. For enhancing run off, proper
field levelling at around 1 percent slope followed by mulching of row and
inter rows with plastic mulch. Anti evaporative material (Thermocol balls of
two different sizes) are spread on the pond water surface to reduce water
loss from farm pond through evaporation. Harvested rain water is applied
through ferti-drip system operated by solar PV pumping system with regulated
deficit irrigation. There is also a provision of covering individual plant or
rows of plants with non-woven polypropylene sheet (17gsm) to reduce
transpiration loss from plant and also to create favorable micro-climate.
These coverings reduce transpiration losses, protect fruits from
environmental stress and pest damage, and improve fruit quality and
marketability (Kim et al., 2003).This system is able to irrigate
pomegranate trees spread across one acre land with 30% higher water
productivity without affecting crop productivity. Best quality pomegranate
fruits with minimum agrochemical residue are being harvested which enhanced
marketable yield. The system has proved its potential in non-traditional
areas where ground water quantity and quality are not much suitable for
cultivation of pomegranate. This model may also provide opportunities to
resource poor farmers of water scarce areas in cultivating high value crops
for enhancing their livelihood and net returns.
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