The short term effects of irrigation?

Question

The short term effects of irrigation?

Answer 1

sends animal waste downstream

Answer 2

Irrigation provides needed water to agriculture which is benefited by optimizing harvest. It needs to be kept, though, as a benign effect to that with respect to surroundings and environment. Problems arise when that is not a benign affair as in trying to irrigate where water is not available readily and used to the point that surrounding environment is adversely affected. Trying to irrigate arid regions into food production can disrupt the natural flow of the water cycle, in some places to the point where the course of rivers are reversed. Energy demand makes providing irrigation water so costly that food produced also bears a huge cost increase. The short term irrigation effect that is a benefit frequently can have a long term negative environmental effect.

Answer 3

This depends on how irrigation is done, and in what place.

If flood irrigation is used, there is strong risk that salts may either rise to the surface or be forced to leave the soil here, and show up downstream.

Very judicious use of water such that there is no soaking down to salt beds creates no overflow to move anything downstream, unless a heavy rain comes after application of irrigation.

If the irrigation water is reclaimed water from a sewage system, and used judiciously, almost all of the biological contaminants in the sewage water are left in the soil as fertilizer. This reuse of sewage water of course makes it important for users of the sewer system to be careful of what they send down the pipes.

Answer 4

It increases the amount of water held in the macropores of the soil (assuming it's not already at maximum water holding capacity).  The aim is to irrigate to reach "field capacity", where the pores are filled with adequate water, but drainage is still occurring so there is still adequate oxygen in the pores for plant growth as well.  Other short term effects really depend on the moisture level to start with, the amount of water (if it is water) being applied, the farm and pasture/crop type, and climatic conditions.