Abstract:
White corn is source of caloric energy, but to produce such energy also requires enormous energy in the form of direct energy input (DEI), indirect energy input (IEI) and embedded energy input (EEI) or call this the total energy input (TEI) calculated from the major farm activities such as pre-land operation (PLO), crop establishment (CE), crop care and maintenance (CCM), harvest and postharvest (HPH). The energy coefficients, calculations and its carbon emission equivalent were based from various literatures. All Mcal energy units were converted to liter diesel oil equivalent or LDOE, where 14.414 Mcal = 1.0 LDOE = 3.36 kg CO2e emission equivalent. A total of 20 white corn growers were interviewed using a structured questionnaire. The relationships of predictors such as the DEI, IEI and EEI ha-1 were tabulated and analyzed using a descriptive statistic. Means, percentages and sums were compared. The TEI to produce white corn grown in the upland-rainfed conditions of Barangay Vitali, Zamboanga City, Philippines was calculated at 2,398.6 Mcal ha-1 or this is equal to 210.1 LDOE ha-1 or a total of 0.83 tCO2e ha-1 emission equivalent, of this amount, the DEI, IEI and EEI contributed 8.4, 90.4 and 1.2% or this is 0.07, 0.75 and 0.01 tCO2e ha-1 emission equivalent, respectively. The high IEI was attributed largely to high inorganic fertilizer usage (32.2%), chemical pesticides (18.5%), animal and man labor (44.3%) or call these the ‘energy hotspots’. Despite the application of high dosage of inorganic fertilizers, yields are low (1.82 t ha-1). |
