The volcanic ash fall caused by the eruption of Kanlaon Volcano on Monday night has increased the level of acidity in both the sugar cane leaves and ground soil in affected areas, the Sugar Regulatory Administration reported on Wednesday, June 5.
The pH level which is used to indicate the level of acidity showed a 4.14 pH on sugar cane leaves and 5.06 pH in the soil the morning after the ash fall, both results indicating acidity as compared to the 6.48 pH of the ground testing last week, it said.
SRA Administrator Pablo Luis Azcona said “the pH level of 7 is neutral but years of tilling sugar fields has affected our soil and the 6.48 pH result last week should have been ideal. With the current results after the ash fall, if this will not be washed out by rains, we will need soil rejuvenation in affected sugar lands to bring it back to the ideal state and that is long term.”
Azcona added that as of now it is too early to tell whether the volcanic ash will cause much damage on crops as it has been raining on the affected places and so hopefully the acidity will be diluted.
In a report presented by the Research and Development arm of the agency that conducted testing in the La Granja Research Station in La Carlota City Tuesday, the immediate effects of volcanic ash can cause physical damage on the leaves, reducing its photosynthesis capability and biological and chemical disruption on the soil which can all lead to reduction of yield.
Its long term effects on sugar crops can cause nutrient imbalance on soil, compaction and erosion and chemical leaching that may reduce the soil pH level, it said.
The SRA team was accompanied by researchers of the Japan International Research Center for Agricultural Sciences (JIRCAS) who are in town for a long term research cooperation in collecting ash samples.
About 23,000 hectares in four sugar mill districts may have been affected by the volcanic eruption.
Azcona said that SRA will continue to monitor pH recovery and what needs to be done and has assigned field personnel, including SRA Board Member David Sanson to go around affected areas and coordinate with the farmers.
The research team said volcanic eruption cannot be ignored as there have been records that it can adversely affect agricultural productivity such as in the 1991 eruption of Mt. Pinatubo and the 2010 eruption of Eyjafjallajökul in Iceland that disrupted sugarcane farming in parts of Europe due to ash fallout and subsequent atmospheric changes.
Among the mitigating measures they recommend if ash fall continues is the use of cover crops, irrigation by washing off plants and soil, and applying lime or organic matter to neutralize soil pH changes caused by the ash fall, it said.
In the long run though, sugar farmers can benefit in due time from volcanic ash fall as it is rich in minerals and nutrients such as potassium, phosphorus, and trace elements, which can enhance soil fertility over time and improve crop yields, the report said.
The fine particles in volcanic ash can also improve soil texture and water retention, aiding root growth and reducing the need for frequent irrigation and can act as a natural pesticide by creating a physical barrier that deters pests and disrupts their life cycles, reducing the need for chemical interventions, the report said.
Meanwhile, SRA will also be assisting the Department of Environment and Natural Resources in ambient air monitoring in affected areas, Azcona said.
In its letter to SRA, DENR Assistant Division Chief, Cliff Jeffersonn Escobar, said they only have the capability and equipment to monitor the particulate matter in ambient air in two stations in La Carlota City and the town of La Castellana and asked SRA to monitor the ambient air in Bacolod where smells of sulfur were detected on the night the volcano erupted.*