Potential Applicability of a Low-Cost Drip Irrigation System as a Water-Saving, Water Use-Efficient and
Cost-Effective Technology for Sustainable Upland Crop Production in the Philippines
Victor B. Ella
Land and Water Resources Division, Institute of Agricultural Engineering, College of Engineering and Agroindustrial Technology, University of the Philippines Los Baños
Materials and Methods
Both laboratory and field experiments were performed using a
low-cost drip system developed by the International
Development Enterprises (IDE), which makes use of either
microtube or button-type emitters inserted in lay-flat-whenempty plastic pipes connected to polyethylene submain which in
turn is attached to an elevated drum or tank water reservoir.
Laboratory tests of the drip systems were performed to
evaluate the water distribution uniformity under sloping
conditions at various operating pressures and consequently
determine optimum operating conditions. The use of adjustable
pressure regulators to improve system performance was also
evaluated. All laboratory tests were performed at the facilities
of the College of Engineering and Agro-industrial Technology
(CEAT) at University of the Philippines Los Baños . Field
experiments were performed in Lantapan, Bukidnon, Philippines
to evaluate the yield of selected vegetable crops and the
water productivity with and without the low-cost drip system.
CU with and without AV Adjustment
at h = 0.5 m
80
60
40
20
With AV adj
Without AV adj
10% Slope
85
78
20 % Slope
90
67
30% Slope
87
53
With AV adj
Without AV adj
60
40
20
10% Slope
92
88
20 % Slope
87
79
30% Slope
82
72
80
60
40
20
0
With AV adj
Without AV adj
10% Slope
89
80
20 % Slope
78
67
30% Slope
75
55
CU with and without AV Adjustment
at h = 1.5 m
DU with and without AV Adjustment
at h = 1.5 m
100
100
80
60
40
20
With AV adj
Without AV adj
a. Cabbage and Chinese cabbage
Binahon farm
Lucbo farm
Quidlat farm
Average
b. Tomato and pepper
Binahon farm
Lucbo farm
Padla farm
Average
30% Slope
79
25
100
80
0
Figure 2. Field experiments on the low-cost drip system.
20 % Slope
84
47
10% Slope
94
91
20 % Slope
78
85
30% Slope
76
79
80
60
40
20
0
With AV adj
Without AV adj
10% Slope
91
87
20 % Slope
65
77
30% Slope
64
68
Figure 3. Results of laboratory experiments on the use of
adjustable valve pressure regulator for improving water
distribution uniformity of the low-cost drip system under
sloping conditions.
With Drip
(kg/m3)
7.84
8.72
3.62
0.90
Crop/ Farm
Without drip
(kg/m3)
8.24
8.71
3.46
0.67
Benefit-Cost
Ratio*
Payback Period
(year)
1.06
1.04
1.44
1.18
2.32
2.47
2.04
2.28
1.37
1.05
1.12
1.18
1.00
2.34
1.82
1.72
Conclusion
DU with and without AV Adjustment
at h = 1.0 m
Average DU (%)
Average CU (%)
.
10% Slope
80
68
Without drip
(tons/ha)
33.8
34.1
39.3
7.6
Table 3. Financial profitability with the low-cost
drip system for selected crops
20
Average DU (%)
Average CU (%)
Figure 1. Laboratory experiments on the low-cost drip system.
Cabbage
Chinese cabbage
Tomato
Pepper
40
100
With AV adj
Without AV adj
Crop
60
0
With Drip
(tons/ha)
44.5
50.4
47.8
11.4
Table 2. Comparison of water productivity with and
without low-cost drip irrigation
80
CU with and without AV Adjustment
at h = 1.0 m
0
Cabbage
Chinese cabbage
Tomato
Pepper
100
100
0
Crop
DU with and without AV Adjustment
at h = 0.5 m
Average DU (%)
be used to address the issue of sustainable upland crop
production in the Philippines. However, its prohibitive initial cost
particularly the conventional type makes it unsuitable for small
farmers in the country. This study aimed to assess the potential
applicability of a low-cost drip irrigation system as a watersaving, water use-efficient and cost-effective technology for
sustainable upland crop production in the Philippines. To
variability of
Results of the laboratory experiments showed that both the
Christiansen’s Uniformity Coefficient (CU) and Merriam-Keller
Distribution Uniformity (DU) generally increase with increasing
head and decreasing slope. Results also showed that installation
of adjustable valve pressure regulators at the head of each
lateral could improve the CU and DU to as high as 94% and
91%, respectively for low slopes and high heads, consequently
indicating higher irrigation efficiencies and minimal application
losses and hence, water savings. Field testing of the low-cost
drip technology in selected upland vegetable farms in the
Philippines demonstrated its applicability and feasibility. Field
trials showed that actual crop yield could reach its potential
yield and is generally higher in drip-irrigated farms than in
unirrigated farms. The
as
weight
a water productivity measured
b
of produce per unit volume of water used, which is a measure
of water use efficiency, also proved to be higher in drip
irrigated farms than in farms without drip irrigation. Moreover,
a rough financial analysis showed that the benefit-cost ratio is
greater than 1.0 for all farms and crops and indicated a
relatively short payback period ranging from 1 to 2.5 years.
Average CU (%)
Drip irrigation is one of the technology interventions that can
Table 1. Comparison of crop yield with and without
low-cost drip irrigation
Results
Introduction
All results of this study suggest that the low-cost drip
irrigation technology has a great potential for wider
application in upland crop production areas in the
Philippines. It is a water-saving, water use-efficient and
cost-effective irrigation engineering technology that can
potentially address the issue of sustainability of upland
crop production systems in the Philippines from both
environmental and economic standpoints. It can also
potentially address the issues of food security, climate
change and poverty alleviation in the country. Continued
research and development should be given the necessary
institutional and financial support to maximize its potential
benefits. Government, NGOs and other institutions should
consider pouring resources on drip irrigation technology
research, development and extension in the Philippines as
part of food security, poverty alleviation and climate
change adaptation programs in the country.
.
This project was made possible through support provided by the United States Department of Agriculture and United States
Environmental Protection Agency in partnership with the United States Agency for International Development Sustainable
Agriculture and Natural Resources Management Collaborative Research Support Program under the Office of International
Research and Development at Virginia Tech.