Irrigation and efficient use of water

Published on by in Technology

The growing water scarcity and the misuse of available water resources are nowadays major threats to sustainable development for most developing arid and semiarid countries of the Mediterranean. Important is reducing water losses and increasing the water use efficiency in the irrigation sector. LEts discuss how to increase the efficiency of irrigation water in agriculture.

1 Answer

  1. Perhaps a general outline of some basic strategies would be helpful. Some initial thoughts: 1. Apply water when it is most needed for yield and conserve it at other times. Yield is typically most sensitive to the adequacy of water during the reproductive (flowering) stage. 2. Limit losses downward through the soil and laterally across the soil surface. This can be done by controlling application rates (as with drip irrigation) and scheduling irrigation so that it does not take place before necessary. It can also be done by managing and amending the soil for greater moisture retention, and by contouring the soil surface appropriately. 3. Limit evaporation losses. This can be done by plastic sheeting, and by irrigating at night. It can also be helped by irrigation methods that do not result in water landing on leaves and evaporating from there. 4. Select or develop crops that require less water. 5. Control water withdrawals through strictly enforced permit systems. Where some research and development can be supported, (1) regression techniques and nonlinear modeling (such as neural nets) might be used to determine the crop phase that is most sensitive to drought, and (2) soil moisture can be observed and forecast using instrumentation and a simple model. (As an aside, I have often wondered whether it would be feasible to use an indicator plant that exhibits stress and signals a need for irrigation before the market crop itself is weakened. But I am not aware of any R&D to test that approach.) I look forward to hearing from other experts who can speak more specifically to issues and opportunities along the Mediterranean.