Water Management in Horticultural Crops

Water requirements of India

• Traditionally, India has been an agriculture based economy.
  
• Hence, development of irrigation to increase agricultural production for making the country self sustained and for poverty alleviation has been of crucial importance for the planners.
  
• Accordingly, the irrigation sector was assigned a very high priority in the five year plans. Long-term planning has to account for the growth of population.
  
• Table 2.1. provides details of the population of India and per capita water availability as well as utilizable surface water for some of the years from 1951 to 2050 (projected).
  
• The availability of water in India shows wide spatial and temporal variations.
Table 2.1. Per capita per year availability and utilizable surface water in India (in m³)


S. No.	Year	Population (millions)	Per-capita surface water availability	Per-capita utilizable surface water
1.	1951	361	5410	1911
2.	1955	395	4944	1746
3.	1991	846	2309	816
4.	2001	1027	1902	672
5.	2025 (projected)	a. 1286 (low growth)	1519	495
		b. 1333 (high growth)	1495
6.	2050 (projected)	a. 1346 (low growth)	1451	421
		b. 1581 (high growth)	1235


a) Domestic use

• Community water supply is the most important requirement and it is about 5 per cent of the total water use.
  
• About 7 km³ of surface water and 18 km3 of groundwater are being used for community water supply in urban and rural areas.
  
• Along with the increase in population, another important change from the point of view of water supply is higher rate of urbanization.
  
• According to the projections, the higher is the economic growth, the higher would be urbanization. It is expected that nearly 61 per cent of the population will be living in urban areas by the year 2050 in high-growth scenario as against 48% in low growth scenario.
  
• Based on these norms and projection of population, it is estimated that by 2050, water requirements per year for domestic use will be 90 km³ for low demand scenario and 111 km³ for high demand scenario.
  
• It is expected that about 70 per cent of urban water requirement and 30 per cent of rural water requirement will be met by surface water sources and the remaining from groundwater.
b)Irrigation

• The irrigated area in the country was only 22.6 million hectare (Mha) in 1950–51.
  
• Since the food production was much below the requirement of the country, due attention was paid for expansion of irrigation.
  
• The ultimate irrigation potential of India has been estimated as 140 Mha.
  
• Out of this, 76 Mha would come from surface water and 64 Mha from groundwater sources. The quantum of water used for irrigation by the last century was of the order of 300 km3 of surface water and 128 km³ of groundwater, total 428 km3.
  
• The estimates indicate that by the year 2025, the water requirement for irrigation would be 561 km³ for low-demand scenario and 611 km³ for high-demand scenario.
  
• These requirements are likely to further increase to 628 km³ for low-demand scenario and 807 km³ for high-demand scenario by 2050.
• The net area sown during 2007-08 was 140.9 mha out of which 62.2 mha was under irrigation.
  
• This area includes 20.66 mha under horticultural crops which may be taken as raised under irrigated condition.
  
• The area under horticultural crop is slowly expanding.
c)Hydroelectric power

• The hydropower potential of India has been estimated at 84,044 MW at 60 per cent load factor.
  
• At the time of independence, the installed capacity of hydropower projects was 508 MW.
  
• By the end of 1998, the installed hydropower capacity was about 22,000 MW.
  
• India has plans to develop 60,000 MW additional hydropower by the twelfth five year plan.
  
• It includes 14,393 MW during the tenth five-year plan (2002–2007); 20,000 MW during eleventh (2007–2012) and 26,000 MW during the twelfth (2012–2017) five-year plans.
d)Industrial water requirement

• The present water use in the industrial sector is of the order of 15 km³.
  
• The water use by thermal and nuclear power plants with installed capacities of 40,000 MW and 1500 MW (1990 figures) respectively, is estimated to be about 19 km³.
  
• In view of shortage of water, the industries are expected to switch over to water efficient technologies.
  
• If the present rate of water use continues, the water requirement for industries in 2050 would be 10³ km³; this is likely to be nearly 81 km³ if water saving technologies is adopted on a large scale.