Introduction
Proper irrigation water management is an important strategy
in addressing potential nonpoint source pollution, both on and off the
farm. Properly managed irrigation water will reduce deep percolation and
excess runoff. When deep percolation and excess runoff are allowed, salts,
selenium, and other elements are mobilized and transported along with the
water into drainage areas, causing excessive accumulation of nutrients
and minerals.
Guidance Principle
Manage irrigation water to minimize transport of chemicals,
nutrients, or sediment to protect water quality.
General BMPs for Irrigation Water Management
1.1 Schedule irrigations
according to soil water depletion and projected crop evapotranspiration
(ET). Evapotranspiration is a combination of two words -evaporation and
transpiration - and refers to the water loss from the crops due to these
two factors combined. Apply only enough irrigation water to meet
the growing crop’s needs. |
1.2 Monitor soil moisture
by the feel and appearance method, and/or tensiometers, resistance blocks,
moisture probes, or other acceptable methods to schedule irrigation timing
and amount.
Figure 3: Source and fate of water in the crop
system
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