EXERCISE 13

EXERCISE 13: WATER MANAGEMENT IN FRUIT ORCHARDS

Aim: To make judicious use of available water for proper growth and production of fruit crops in rainfed areas.

Water is an important essential natural land resource affecting growth and production of fruit crops. Fruit trees require irrigation water for maintaining adequate growth, fruit quality and yield, particularly in dry months. However, availability of water is always a limiting factor in fruit cultivation, particularly in arid and semi arid conditions. Even in high rainfall (>1500 mm) areas, sufficient moisture may not be available in the root zone during the dry months and crops may suffer from drought at any stage due to erratic rainfall pattern and for the want of irrigation water. In order to ensure the supply of requisite quantity of water at critical stages of growth and development of fruit crops, efficient management of water is required. In rain fed areas, three essential components of water management are:

  • In situ moisture conservation
  • Water harvesting
  • Efficient utilization of conserved/harvested water through improved cultural practices

In situ soil moisture conservation: Mulching is known to conserve soil moisture, be it mulching with organic (Plate 13.1) or inorganic material.

13.113.2
Plate 13.1. Grass mulching in pomegranate Plate 13.2. Construction of pond for irrigation

Water harvesting: Two natural water resources that can effectively be harvested are rainfall and low (as low as 1 to 30 l/min) water springs and rivulets. About 10 to 14 per cent of total rainfall, depending on soil and rainfall characteristics may be lost as surface runoff. Water harvesting can be done through in situ rainwater harvesting and water harvesting in farm ponds (Plate 13.2).

In situ rainwater harvesting: In fruit plantations, rain water can be harvested in the tree basin areas by certain soil working techniques such as:
  • Preparation of tree basins: Well prepared tree basins prior to rains aid in water infiltration, and subsequent frequent shallow hoeing not only remove the competitive weeds but also prevent evaporation losses of moisture from the soil by forming dry soil mulch over the sub soil.
  • For arid and semi-arid regions, soil working techniques like ‘Crescent Bund with Open Catchments Pits’ (Plate 13.1), ‘Trench Systems’, ‘V-ditch’ (Plate 13.2) etc. provide satisfactory in-situ harvest of rain water. These techniques are found to be useful for conserving soil moisture in the root zone of trees for the dry months.

15.115.2
Water harvesting through farm ponds:
The run-off water from orchards and water flowing from other sources like spring and small streams that though cannot serve as water source for irrigating crops due to their meagre flow rates but, can be effectively stored in suitable small or big reservoirs. Small ponds may also be used as auxiliary water reservoirs in which water is stored during lean period and used when required by crops. The provision of a small pond in one corner of the orchard to collect runoff water during high intensity rains and its utilization as life saving irrigation or during critical periods of the crop is an age old practice (Plate 13.2).

Small ponds are ideal for growers who have scattered land holdings. In addition, they do not require elaborate management skills and resources. Ponds, however, vary in shape, size and mode of construction. Orchard ponds can be divided in to three categories:
  • Dugout small ponds on flat lands
  • Ponds constructed by making barriers constructed in low lying areas or natural depressions or small streams
  • Dugout ponds constructed by making barriers constructed on lands with mixed topography

Suitable sealants may be used to check/reduce seepage losses in ponds. Ponds may be lined with polyethylene sheet (covered with soil or bricks or round boulders to protect it against UV sun light), silpauline sheet (UV resistant), bitumen, cement and concrete lining, RCC, etc. The cost and longevity of structure will depend upon the lining material used.

Larger ponds can be made by damming the upper catchment area of a creek. Water harvesting in larger ponds is practiced on community basis. It involves proper planning and sincere participation of the inhabitants of the catchment and command areas. It may form a part of integrated watershed management involving participatory approach.

Efficient Utilization of Conserved/Harvested Water:

The water conserved/harvested from natural resources must be used very efficiently for fruit crops. The water should be possibly be used through pressurized irrigation system e.g. drip irrigation (Fig. 15.1). Drip irrigation system is ideal for fruit crops, because it enable to achieve higher water use efficiency and also help in maximizing crop production within limited water resource.

Observations to be recorded:
Record periodic observations on soil moisture contents under different systems of in-situ moisture conservation techniques and draw inference.
Last modified: Saturday, 7 January 2012, 7:34 AM