Comparative growth responses of range grasses to varying
watering schedules in the rangelands of Kenya
KOECH OSCAR KIPCHIRCHIR
Prof. Robinson Kinuthia Ngugi
Dr. George Karuku
Dr. Raphael Wanjogu
NIB RESEARCH AND PROPOSAL PRESENTATION, KSMS
13TH TO 14TH JUNE 2013
okkoech@yahoo.com
INTRODUCTION




African dry lands have been facing challenges of food insecurity due to
frequent droughts and other extreme climatic events
L/s production is the main activity in the D/L of Kenya
Plays crucial role in Kenyan economy, contributing ~10% of NGDP and 40%
of AGDP (GoK, 2004)
In ASALS, L/s contributes ~90% of employment opportunities and ~ 95% of
family incomes




Potential productivity KSh212.5 billion
annually
The main constraint is loss of livestock
due to high annual mortality (Serna,
2011)
Estimated value of losses is KES 2 billion
annually (ILRI 2011)
This is due to low Q and Q of feed, high
disease incidences, poor management
Pastoralism/irrigated agriculture complex
LIVESTOCK
Manure, draft power, capital for inputs in crop lands
Nutrients flow from feeds
HUMAN
Nutrients flow/manure,
urine, dispersal
Water for crop growth,
nutrients cycling
CROP LAND
PASTURE LANDS
WATER
RESOURCE/IRRIGATION
Control of siltation, hydrological flow maintenance
Water for growth, nutrients
My study



This study seeks to evaluate irrigated pasture
species production in the drylands of Kenya, and
how scarce water resource can be optimized
Currently during dry seasons, fodder is sourced
from far and at higher price due to transportation
costs and is of poor quality
This calls for local fodder production within the
dry lands of Kenya, to ensure timely supply and
of good quality
Objectives
The main objective of this study is to increase feed availability for livestock in pastoral
areas through integration of crop and pasture production under irrigation.
Specific objectives
1.
To determine the growth responses (aboveground biomass yield, tiller density, leafstem ratio, seed quantity/quality) of six range grasses growing singly, to different
watering schedules.
2.
To determine the interspecific competition growth responses of five range grasses
growing in mixtures, to different watering schedules.
3.
To determine the effect of different watering schedules on forage quality, curability
and storability of forage from the six grass species.
4.
To estimate water use efficiency and water stress tolerance of the six grass species.
MATERIALS AND METHODS
Study area

This study is being conducted in Tana river county-Bura and Katilu
Methodology


Field experiments were set up in 6x4 factorial experiments in Completely
Randomized Design.
There are two treatments: One; watering schedules at 80%, 50% and 30% Field
Capacity), and two; six range grass species.
Data collection

Data collection on primary productivity, forage quality and seed yield and quality,
water stress tolerance and calc8ulation of WUE using evapotranspiration.
Preliminary Results-Yields
ABOVE GROUND BIOMASS
Biomass yields on dry matter basis (Kg/ha) of six grass species
growing singly, 80% FC
16000
14000
Yield Kg/Ha DM
12000
Chr rox
Ersu
Enma
Ce ci
Ch ga
Sobi
10000
8000
6000
4000
2000
0
Week 8
Week 10
Week 12
Week 14
Week 16
Biomass yields on dry matter basis (Kg/ha) of six grass
species growing singly, 50% FC
14000
Yields kg/ha DM
12000
Chr rox
Ersu
Enma
Ce ci
Ch ga
Sobi
10000
8000
6000
4000
2000
0
Week 8
Week 10
Week 12
Week 14
Week 16
Biomass yields on dry matter basis (Kg/ha) of six
grass species growing singly, 30% FC
12000
Yields Kg/ha DM
10000
Chr rox
Ersu
Enma
Ce ci
Ch ga
Sobi
8000
6000
4000
2000
0
Week 8
Week 10
Week 12
Week 14
Week 16
Results on yields of the six species

Ch ga shows continued production >10000kg/ha at all irrigation levels; no significant
differences on yields (P>0.05)

So bi produces high biomass at 80% FC irrigation level, and lowest at 30% FC
(13664kg/ha) and 7664kg/ha respectively (P<0.05) . No sig diff btw 80 and 50 % Irrigation
level

Ce ci and En ma produced least biomass yield at 80%, does best at 50 % (9132kg/ha,
10464kg/ha) respectively. Significant diff btw 80 %, FC 50% FC and 30% FC

Er su does better at 80%FC (5600kg/ha) than all the two levels (P<0.05)

Chl rox has no significant differences (P<0.05) in yields at all irrigation levels (btw 20003500kg/ha)
QUALITY- CP %
Species
Week 8
Week 10
Week 12
Week 14
Week 16
CR
14.6a ±3.1
13.1a ±4.1
13.1a ±2.1
11.4c ±1.8
10.6c ±2.1
ES
13.2a ±2.4
12.8a ±2.2
12.6a ±3.3
12.4a ±1.6
12.1a ±1.6
EM
12.6a ±1.5
12.7a ±3.1
12.3a ±1.6
12.1a ±2.3
11.6a ±3.4
CC
12.1b ±2.3
11.8b ±2.3
12.1a ±4.2
11.4c±2.7
10.7b ±3.2
CG
13.3a ±3.4
12.6a ±4.1
12.5a ±2.1
12.6a ±4.5
11.6b ±3.3
SB
10.4c ±2.1
9.6c ±2.6
8.7b ±3.1
7.1c ±2.4
6.8c ±1.9
All the forages had above minimum CP at wk 14.
So bi had below 7% cp at wk 16
Insacco DMD %
Species
Week 8
Week 10
Week 12
Week 14
Week 16
CR
65.0a ±8.1
64.3a ±4.1
65.0a ±8.7
65.0a ±1.8
62.4a ±2.1
ES
69.0a ±2.4
65.2a ±2.2
61.0a±3 .3
61.2a ±1.6
60.3a ±1.6
EM
57. 6b ±11.5
57.0b ±3.1
52.0c±1.6
51.6c ±2.3
53.2c ±3.4
CC
68.1a ±2.5
69.0a ±2.3
65.0a ±4.2
63.5a ±2.7
61.3b ±3.2
CG
68.3a ±6.1
65.0a ±4.1
63.2a ±6.1
59.8b ±4.5
54.6b ±3.3
SB
59.4b ±7.1
57.8b ±2.6
57.2b ±7.5
52.1c ±2.4
47.3c ±1.9
IVDMD decreased with growth stages of the spp
SB and CG declined faster with maturity
CR, ES and CC showed higher D even at wk 16
Seed yields on dry matter basis (Kg/ha) of six range grass species at 80, 50, 30 % FC
1400
1200
1000
chr rox
Er su
800
Enma
600
ceci
chga
400
sobi
200
0
80% FC
50% FC
30% FC
-So bi showed significant decline in seed yields at lower moisture levels
-Ch ga and Ch rox showed higher seed yields at lower moisture levels
-Ce ci had lowest yield with no significant diff in both irrigation schedules
-Er su and enma had no significant difference in seed yields across the irrigation levels
Returns from biomass
So bi
Ch ga
No. of
bales
Sale at KES
150/bale
Kg/ha No. of bales
Sale at KES
150/bale
556.705
83,505.88
7932
466.588
69,988.23
Harvest at
week 16 13664 803.764
120,564.70
10864
639.058
95,858.82
Kg/ha
Harvest at
week 12 9464
COSTS
PLOUGHING 3000/HA
FERTILIZER 4500/LABOUR ?
TOTAL ?
Returns from seed yields
Kg/ha
KES 600/kg
SOBI
1250
750000
CHR GA
1066
639600
Number of Animal (TLU’s) to be sustained for 3 months
So bi
Kg/ha No. of bales
Harvest
at week
12
9464
Harvest
at week
16
13664
Ch ga
No. of animals 3
months
Kg/ha No. of bales
No. of animals 3
months
556.705
16 animals
7932
466.588
14 animals
803.764
24 animal
10864
639.058
19 animals
Animal sustainance in a year and sales
Animals kept after 3
months harvest for 3
months considering yields
from 1 ha
One year, productivity
under irrigation-3 months
harvests…. One can keep
14 animals for whole year
Sales @20,000/head
1 ha=14 animals
14 animals
280,000/-
250,000 ha=3,500,000
animals
3,500,000 animals
20,000,000,000
20,000*14
Conclusion




Soil moisture levels affects range grass species
primary productivity differently, either
positively, negatively and others not affected
Seed yields of the six range grasses are also
influenced by soil moisture levels
There is potential for cultivation of range
grasses as source of L/S feed and income. The
final results out of this study will provide more
insights into pragmatism of this.
The range grass seeds production from
irrigated pastures can also be used for
rangeland rehabilitation in pastoral grazing
lands to enhance sustainability of livestock
production.
Recommendations




Irrigated pasture production should be up-scaled and
establishment of fodder banks for use during harsh
climatic conditions.
From the preliminary results, a few species can be
piloted on large scale production. These are Sorghum
bicolor, Chloris gayana and Eragrostis superba.
There is need for increased awareness and training on
irrigated pasture cultivation in the study areas.
The communities are not used to pasture production,
grass seed bulking, hay baling and pasture sales and
marketing.