Micro Sprinkler Groundnut performance

Micro sprinkler in onion

DRIP FERTIGATION TO ANNUAL MORINGA

Drip irrigation in chillies

Drip irrigation to coconut

Drip irrigation in cotton – modified geometry

Drip irrigation in Typhonium

Sugarcane drip

Surface Irrigation Hydraulics Advance Advance – Movement of water from the inlet end to the downstream end – Curve of Time vs. Distance is NOT linear – Rule-of-Thumb: 1/3 of the total advance time is needed to reach midpoint of the furrow length

Surface Irrigation Hydraulics, Contd Recession Recession – Process of water leaving the surface (through infiltration and/or runoff) after the inflow has been cut off – Usually begins to recede at the upstream end – Can also be plotted as Time vs. Distance – Flatter" curve than the Advance Curve

Surface Irrigation Hydraulics, Contd Infiltration Infiltration – Opportunity Time: difference between Recession and Advance curves – Infiltration Depth: a function of the opportunity time and the infiltration class (rate) of the soil

Opportunity Time

Infiltration vs. Opportunity Time

Infiltration Profile

Uniformity Inherent non-uniformity because recession and advance curves are not parallel Inherent non-uniformity because recession and advance curves are not parallel Factors affecting Factors affecting – Inflow rate – Slope – Soil infiltration – Roughness – Channel shape – Inflow time – Length of run

Efficiency Volume balance Volume balance – V g = V z + V s + V r – g gross – z infiltration – s surface storage – r runoff (or depth basis): d g = d z + d s + d r (or depth basis): d g = d z + d s + d r Part of infiltration may go to deep percolation Part of infiltration may go to deep percolation

Improving Irrigation Efficiency Alternate furrow irrigation Alternate furrow irrigation – Increases advance time, but reduces average infiltration depth (twice the width) Cutback irrigation Cutback irrigation – Use large inflow rate during advance, and then reduce the inflow to match the soil's steady- state infiltration rate – Intensive management is required

Improving Irrigation Efficiency Contd Land smoothing and laser grading Land smoothing and laser grading – Helps to improve uniformity Surge irrigation Surge irrigation – Alternate on-off periods for applying water – Achieve higher efficiencies and uniformities in some soils – Lends itself to semi-automation

Treatments SI 1 - Surge irrigation with a stream size of 1.5 lps in 100 m long furrow SI 2 - Surge irrigation with a stream size of 2.0 lps in 100 m long furrow C 1 I 1 - Continuous irrigation in 100 m long furrows with a stream size of 1.5 lps C 1 I 2 - Continuous irrigation in 100 m long furrows with a stream size of 2.0 lps C 2 I 1 - Basin irrigation with a stream size of 1.5 lps C 2 I 2 - Basin irrigation with a stream size of 2.0 lps

SI 1 SI 2 C1I1C1I1 C1I2C1I2 C2I1C2I1 C2I2C2I2 Irrn. Eff. (%) Total cycle time Actual ON time Total cycle time Actual ON time Irrn. Time Irrn. No Actual supply time variation during advance phase between irrigations ( minutes )