Read the following statements about drip irrigation
(A). Crops that are not too sensitive to salts can be drip-irrigated even with somewhat brackish water (1,000 mg /L of salts)
(B). Brackish water cannot be used with drip irrigation system at all as the salts clog the lateral pipes and emitters
(C). In drip irrigation, salts accumulate at the periphery of wetted circle
(D). Leaching of salts from drip irrigated fields is not required
(E). Irrigation efficiency of drip irrigation system is 80-85%
Choose the correct answer from the options given below:
Show Hint
Salt accumulation at the periphery of the wetted bulb is a key characteristic of drip irrigation. If a light rain occurs, it can wash these salts back into the root zone, which can cause sudden salt stress to the crop.
Step 1: Understanding the Concept:
Drip (or micro) irrigation delivers water directly to the plant root zone through emitters. This method provides precise water application, but also alters soil salt distribution and dynamics. Step 2: Detailed Explanation:
Let us analyze each statement to determine its validity:
Statement (A): Because drip irrigation keeps the soil root zone consistently moist, the soil water potential remains high, which dilutes salt concentrations. This allows salt-tolerant crops to be irrigated using moderately brackish water (up to 1,000 mg/L) without experiencing yield-reducing osmotic stress. Thus, Statement (A) istrue.
Statement (B): Brackish water can be used in drip systems if the water is properly filtered and appropriate emitter designs are used to prevent clogging. Thus, Statement (B) isfalse.
Statement (C): Water moves radially outward from the drip emitter.
As this water evaporates from the soil surface, dissolved salts are left behind and accumulate at the outer boundary of the wetted soil volume (the periphery of the wetted circle). Thus, Statement (C) istrue.
Statement (D): Over time, salt accumulation at the periphery of the wetted zone can build up and migrate back into the root zone during rain events.
Periodic leaching (applying excess water to flush salts down below the root zone) is necessary to maintain soil health. Thus, Statement (D) isfalse.
Statement (E): Drip irrigation is highly efficient, typically achieving an irrigation application efficiency of90% to 95%. Standard values of 80-85% are associated with sprinkler irrigation systems. Thus, Statement (E) isfalse.
Therefore, only statements (A) and (C) are correct. Step 2: Final Answer:
The correct option is (C), representing A and C only.
