The Philippines is a sugar-producing country, growing it mainly on the islands of Negros, Luzon, Panay and Mindanao. Recently, the Philippine government passed the Biofuel Act of 2006 (or Republic Act 9367) which created a certain market for ethanol investors in the Philippines and paved the way for the development of a new industry: fuel ethanol production.
Sugarcane is expected to be the predominant source of feedstock for ethanol production. Commercial production of ethanol from sugarcane will help the country diversify its fuel portfolio and ensure its energy security.
Presently, sugarcane farmers produce an average of only 65 tons of cane/ha potentially yielding only 70 liters (18.5 gallons) or 4550 liters/ha/year (145 gallons/ha/year) of ethanol per metric ton using sugarcane as feedstock.
This ratio is very low when compared to the potential cane yields (120 to 150 tons/ha) achieved in Brazil, India, South Africa and other regions growing sugarcane with drip irrigation and fertigation. Therefore, new and innovative sustainable technologies are needed, not only to raise and sustain sugarcane productivity per hectare, but also to enable the consistent supply of feedstock to bio-refineries at lower costs and to meet domestic sugar demands.
As both the food and energy industries use scarce and expensive resources such as water and fertilizers, a solution is required to ensure a more competitive position, especially within the global market.
Food and agro-industrial crop Climatic change and water scarcity concerns Rising fertilizer and labor costs Leaching and washing away of nutrients by runoff Low water and fertilizer use efficiency Low cane productivity/ha Favorable biofuel policy
Why is drip needed?
Economic importance of sugarcane in meeting sugar and fuel ethanol demands and to generate employment. To conserve water, increase water and fertilizer use efficiency.
To optimize cane yields.
Sugar mill name
San Carlos Bio Energy Incorporated
Location: San Carlos Bio Energy Incorporated, Hacienda vasconia, brgy. Palampas (09° 30′ 0″ N-latitude, 122° 40′ 0″ E-longitude), San Carlos City, Negros Occidental, Philippines
Area: 7.2 ha
Crop varieties: 88-39, 84524, 87599
Crop spacing: Row to row – 1.5 m and plant to plant – 0.15 m
Seed rate: 50000 number of three-bud setts/ha
Plant population at harvest: 130,000 millable canes/ha
Crop season: Sowing March 28, 2007 & April 3, 2007
Climate: Equatorial humid climate with dry winter, frost free
Maximum temperature: 32.9°C
Minimum temperature: 24.2°C
Mean vapor pressure: 29 hPa
Mean wind speed: 3.7 km/hour
Rainfall: 2608 mm/year; effective rainfall: 1278 mm/year
Reference crop evapotranspiration: 1478 mm/year
Moisture availability index: 1.76
Other climate-related indicators:
Day length: 12.1 hours; sunshine duration: 6.0 hours
Soil physical properties: Clayey soil texture Soil pH: 6.6
Bulk density: 1.3 g/cm3
Water table: below 6 m
Soil chemical properties: N (0.05%), P (6 mg/kg), K (0.4 meq/100 soil), Ca (39.0 meq/100 soil), Na (0.5 meq/100 soil)
Soil salinity (ECe): 0.45 dS/m
Water source: Canal water
Power source: Diesel pump
Agro-solution: What has been done?
Subsurface drip irrigation (SDI) system Head control unit, main and sub-main pipes besides DripNet PC integral dripline 16 mm diameter, with a lateral spacing of 1.5 m, emitter spacing of 0.5 m and emitter flow rate 1.0 Liters/hour. Each crop row was irrigated with one dripline installed at 0.3 m below the soil.
Year of drip system installation: 2007
Agronomic and technical support
Crop water requirement and irrigation scheduling: Depth and frequency of water application; water quality consideration, measurement of applied water. Fertigation scheduling: Soil and water analysis, estimation of nutrient dose, selection of fertilizers and compatibility, application skill via drip system and foliar diagnosis for nutrient deficiencies. System operation and maintenance: Pressure reading and maintenance, valves operation, measurement of applied water. Cleaning of filters, fertilizer tank, acid treatment, chlorination, etc.
Training and capacity building: Soil water plant relationships, drip irrigation and fertigation principles, benefits, limitations and utility; water quality and herbicide usage.
Improved cane yield: Conventional overhead sprinkler irrigation – 70.0 tons/ha and with subsurface drip yield increased by 90% (133.5 tons/ha). Improved cane quality: Increase in sucrose content by 5.2% in comparison to overhead sprinkler irrigation.
Water requirement and saving: Conventional overhead sprinkler irrigation – 13000 m3/ha (1300 mm/ha) and with subsurface drip – 3000 m3/ha (300 mm/ha). The water saving by drip over center pivot sprinkler is 70% or 10000 m3/year/ha. As an illustration, the saved water can irrigate 3.3 ha.
Economic indices: Higher net returns by subsurface drip (919 US$/ha) in comparison to overhead sprinkler irrigation.
Other benefits: Savings in fuel expenses, uniform intermodal length, higher cane diameter, improvement in fertilizer use efficiency, management flexibility, less weed growth, uniform irrigation of sugarcane on undulated terrains.
Drip irrigation of sugarcane in Philippines is a feasible eco-technological and economically viable technology. Sustainable use of scarce water resources in sugarcane cultivation in order to bring a larger area under cane cultivation near the sugar mill. Higher productivity and sucrose content, food security and increased income for farmers. Farmers and ethanol bio-refineries are willing to expand drip irrigation to remaining cane areas. Approximately 217 ha of the sugarcane area is being brought under subsurface drip irrigation during 2008. Sugarcane best management practices: Subsurface drip irrigation (SDI) and fertigation scheduling.
Grow More: 90% cane yield
With Less: Water conservation 70%