EVALUATION OF IRRIGATION WATER PRODUCTIVITY FOR NERICA RICE AND SOYABEAN UNDER DIFFERENT IRRIGATION TECHNOLOGIES IN MWEA IRRIGATION SCHEME

Dr. Wanjogu R.K., Owilla B.P.O., Okinyi D.M.

Kenya is expanding irrigation (vertically/horizontally) rapidly rising under water scarcity

Inefficient water management practices aggravate water scarcity and threatens irrigation sustainability

Sustainable irrigation expansion requires application of right quantity of water when the crop needs it

Limited research has been carried out to determine the appropriate quantity of water for irrigating non-flooded crops in Mwea

INTRODUCTION

To determine irrigation water productivity for rice and soyabean in Mwea irrigation scheme under different irrigation technologies

To evaluate water-use efficiency for rice and soyabean in Mwea irrigation scheme under different irrigationtechnologies

OBJECTIVE

Trial site MIAD (latitudes 37°13’E and 37°30’E, longitudes 0°32’S and 0°46’S and altitude of 1195 m a.s.l.)

RCBD with three treatments (drip, sprinkler, furrow) with three replications

Plot size: 7mx6m Spacing: hill spacing 20cmx20cm for rice, plant

to row 20cmx30cm for soyabean Crops: NERICA 4 rice and soyabean

METHODOLOGY

Rice growth data: plant height, total tillers Soya growth data: plant height Water applied to crop Water used by crop Rice yield data Soya yield data

DATA COLLECTION

Analysis using SAS program (SAS institute,2002)

DATA ANALYSIS

28 DAT 56DAT 84 DAT0

102030405060708090

DRIP FURROW SPRINKLER

DAYS AFTER TRANSPLANTING

PLAN

T H

EIG

HT

(CM

)RESULTS –plant height

There was no significant difference in plant height in all irrigation technologies

28 DAT 56DAT 84 DAT0

10

20

30

40

50

60DRIP FURROW SPRINKLER

DAYS AFTER TRANSPLANTINGPL

ANT

HEI

GH

T

NERICA rice Soya beans

28 DAT 56DAT 84 DAT0

2

4

6

8

10

12

14

16

18DRIP FURROW SPRINKLER

DAYS AFTER TRANSPLANTING

TILL

ER N

UM

BER

RESULTS – total tillers

No significant difference in number of total tillers under different irrigation

technologies

Rice

DRIP FURROW SPRINKLER0

500

1000

1500

2000

2500

3000

3500

4000

4500NERICA SOYA

IRRIGATION METHOD

WAT

ER A

PPLI

ED (

M3/

HA)

RESULTS -quantity of water applied

•Significant difference in quantity of water applied among the three irrigation technologies in all crops•Furrow had highest volume of water applied followed by sprinkler, the lowest was recorded in drip

SOYA RICE0

500

1000

1500

2000

2500

3000

3500

DRIPSPRINKLERFURROW

CROP

CRO

P W

ATER

USE

(M

3/H

A)

RESULTS-quantity of water used by crop

No significant difference in the quantity of water used by crop under the three irrigation technologies

DRIP FURROW SPRINKLER0

10

20

30

40

50

60

70

80

90

100NERICA SOYA

IRRIGATION METHOD

WAT

ER U

SE E

FFIC

IEN

CY (

%)

RESULTS - water use efficiency

•There was significant difference in water use efficiency among the three irrigation technologies in all crops•Drip had highest efficiency followed by sprinkler then furrow

DRIP FURROW SPRINKLER0

1000

2000

3000

4000

5000

6000

7000

8000NERICA SOYA

IRRIGATION METHOD

YIEL

D (

KG/H

A)RESULTS - yields

There was no significant difference in yield for both crops under the three irrigation

technologies

DRIP FURROW SPRINKLER0

0.5

1

1.5

2

2.5

NERICASOYA

IRRIGATION METHOD

WAT

ER P

ROD

UCT

IVIT

Y (K

G/M

3)

RESULTS – crop water productivity

No significant difference in crop water productivity in the two crops under furrow and sprinkler irrigation methods. On the other hand, drip revealed highest among the three irrigation technologies in both crops

In the three technologies which were under investigation, there was no significant different on plant height, total tillers, crop water use, yield in both crops

There emerged significant differences in quantity of water applied, crop water use efficiency and productivity among the three irrigation technologies. Furrow had highest quantity of water applied followed by sprinkler then drip. WUE was highest and least in drip and furrow irrigation technologies respectively. Crop water productivity was highest in both crops which were under drip irrigation method, but no significant difference realized between crops which were either under sprinkler or furrow irrigation technology

Water applied: drip delivers water directly to the base of plant and saturates root zone only, sprinkler deliver water to open ground surface and plant canopy leading to greater but non-uniform soil saturation beyond root zone, furrow uniformly saturate entire field.

DISCUSION

It can be concluded that among the three irrigation technologies which were under test, drip was the most effective method in terms of water application, water use efficiency and crop water productivity,

However, comparative economic evaluation of the systems is necessary to inform the choice of irrigation technology to adopt

CONCLUSION AND RECOMMENDATIONS