Previous Year Question
With reference to micro-irrigation, which of the following statements is/are correct ?
Fertilizer/nutrient loss can be reduced.
It is the only means of irrigation in dry land farming.
In some areas of farming, receding of ground water table can be checked.
Select the correct answer using the codes given below :
1 only
2 and 3 only
1 and 3 only
1, 2 and 3
Correct Answer: C
Detailed Solution
Micro-irrigation mainly includes drip and micro-sprinkler systems. Water is supplied in small quantities, at controlled rates, at or near the plant’s root zone.
1. Fertilizer/nutrient loss can be reduced — Correct
The application of soluble fertilizers through a drip-irrigation system is called fertigation.
Fertilizers can be supplied in small, controlled doses according to the crop’s requirements and delivered close to its roots.
This can reduce surface runoff, deep percolation below the root zone, evaporation-related losses and application to non-target areas.
Consequently, nutrient loss can decline while water- and fertilizer-use efficiency can improve.
2. It is the only means of irrigation in dry land farming — Incorrect
Rainfed or dryland farming depends primarily on rainfall and moisture stored in the soil.
Rainwater harvesting, moisture conservation, drought-tolerant crops and life-saving or supplemental irrigation can also be used.
Supplemental irrigation may be supplied through drip, sprinkler or other locally appropriate methods.
Micro-irrigation can therefore be beneficial, but it is not the “only” means of irrigation.
3. Receding of the groundwater table can be checked in some areas — Correct
Micro-irrigation supplies water at the required location and in controlled quantities, reducing conveyance, runoff and evaporation losses.
If less groundwater is extracted for the same agricultural output, pressure on the aquifer may decrease and groundwater-table decline can be slowed or checked in some areas.
The statement deliberately says “in some areas” and “can be checked”; it is not a universal claim.
If saved water is used to expand irrigation or grow more water-intensive crops, total groundwater extraction may not decline. Suitable crop planning and groundwater management are therefore also necessary.