Text and Photos by Henrylito D. Tacio
“One of the scientific success stories of the late 20th century was the ability to predict El Niño events up to a year ahead.” — Michael Jarraud, secretary general of the UN World Meteorological Organization
It rose out of the tropical Pacific in late 1997, bearing more energy than a million Hiroshima bombs. By the time it had run its course eight months later, the giant El Niño of 1997-98 had deranged weather patterns around the world, killed an estimated 24,000 people, displaced six million and affected some 111 million. The guesstimated cost of property damage worldwide: US$34 billion.
“The 1997-98 event was a wake-up call,” Dr. Michael Glantz of the National Center for Atmospheric Research in Boulder, Colorado was quoted as saying. “Awareness of El Niño can do to societies and economies are now high.”
No one knows precisely when El Niño first struck. Historians are dating the phenomenon at least as far back as the early 1500s, when the Spanish conquistadores entered South America amid raging storms. Some 400 years before that, there were some records of terrible sweeping through pre-Columbian communities.
Originally, Spanish fishermen named the event as “Corriente del Niño.” The word “corriente” describes the appearance of warm ocean current flowing from time to time in the eastern equatorial Pacific region along the South American coasts. The word “Niño” was traditionally associated with the birth of Baby Jesus, as it was observed around Christmas. It was used to be considered a local event along the coasts of Peru and Ecuador. Through the years, “corriente” was dropped out, leaving only “El Niño.”
According to the Global Environmental Outlook 2000, El Niños are not natural disasters but natural variations in climate. They normally occur every three to five years, lasting 6-18 months. Between El Niños, there are often periods marked by a cooling of the surface waters of the same area of the Pacific, a phenomenon called La Niña (“the girl”). The whole cycle is called the El Niño Southern Oscillation (ENSO).
The ocean current is characterized as “a mysterious, massive pond of warm, nutrient-poor seawater” which produces a periodic shift in ocean temperatures and atmospheric conditions in the tropical Pacific. El Niño varies the surface temperature of the central eastern part of the tropical Pacific by up to 4 degrees Centigrade, with associated changes in the wind and rainfall patterns. This condition disrupts weather around the world leading to nasty extremes.
In its August 5 advisory, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said the moderate El Niño the country is currently experiencing will intensify in the last quarter of the year.
PAGASA added that, based on leading climate models, the weather event will linger up to the first months of 2016. There are predictions that this current El Niño will be identical with what the country experienced in 1997-1998 — or it may even be worse.
“This year’s El Niño began in March and is forecast to last about a year. Authorities in Australia have already predicted it would be ‘strong’ and ‘substantial,’” the Agence-France Presse reported.
The Philippines Recommends for Water-Saving Technologies for Rice and Other Crops, published by the Department of Science and Technology (DOST), said farmers can still vegetable crops even in times of drought and/or dry spells. “Vegetable cropping after rice usually coincides with the dry season,” it noted. “This crop may use residual soil moisture, supplemented by irrigation, underground supplies, or tank storage. Farmers may also take advantage of the drop in river levels to cultivate riverbanks.”
In water-scarce areas, farmers can make the most efficient use of available water. “To do this, the growers decide how much and which crops to plant, or whether to plant at all,” the book said. “However, it is unwise to plant crops that cannot be properly irrigated because there are no drought-tolerant or -resistant vegetable varieties in the market.”
The DOST publication said that irrigation and water use in vegetable farming varies with the production system and ecoregion. “Vegetables are known as succulent products,” it explained. “In general, these consist of more than 90% water.”
As such, vegetables require good water supply for optimal productivity. “They are able to produce a crop during short periods of high moisture availability and respond well to controlled delivery of water, which enhances water use efficiency,” the book said. “On the contrary, drought conditions drastically reduce vegetable productivity.”
Here are more tips from the book on how to grow vegetable crops when water is scarce:
· Proper water management planning must consider all uses of water, from the source of irrigation water to plant water use. It is very important to differentiate between crop water requirements and irrigation or production water system requirements.
· Irrigation systems are rated with respect to application efficiency, which is the fraction of water that has been applied to the irrigation system and that is available for plant use. Applied water that is not available for plant use may have been lost from the crop root zone through evaporation.
· For good crop production, there is a need for an appropriate match between the soil physical properties controlling water movement and retention and the irrigation system. This affects the amount of water that can be stored in the soil after irrigation, the depth of wetting, wetting pattern, and aeration status.
· The characteristics of the irrigation system, crop needs, soil properties and atmospheric conditions must all be considered to properly schedule irrigations. Poor timing or insufficient water applications can result to crop stress and reduced yields.
· Various crop management practices such as mulching, using shelters, and planting in raised beds help conserve soil moisture; and prevent or reduce soil runoff, erosion, and degradation. The use of organic materials as mulch can help enhance soil fertility, structure, and other properties.
· Crop selection if important where water is expected to be in short supply. Plants with shallow root system will require more frequent irrigation to maintain a healthy growth rate. Shallow-rooted plants include lettuce, pechay, onions, and most other bulb/root/tuber crops, celery, and cabbage family plants. Deep-rooted crops include tomato, corn, sweet potato, and melons. Those with intermediate root depth are beans, peppers, squash, and cucumbers.
On the other hand, the Philippine Rice Research Institute (PhilRice) encourages farmers to plant drought-tolerant varieties and use El Niño-ready technologies on rice production. In a press release, it names the recommended varieties:
For irrigated lowland, farmers may consider planting several early-maturing varieties such as PSB Rc10 (Pagsanjan), NSIC Rc130 (Tubigan 3) and NSIC Rc152 (Tubigan 10). Pagsanjan matures in 106 days with a maximum yield of 7.5 tons per hectare (t/ha). Tubigan 3 matures in 108 days with a maximum yield of 7.6vt/ha while Tubigan 10 matures in 109 days with a maximum yield of 8.7vt/ha.
Farmers may also plant NSIC Rc134 (Tubigan 4), an early-maturing variety (107 days) with a maximum yield of 9.8vt/ha and NSIC Rc160 (Tubigan 14) also an early-maturing variety (107 days) with a maximum yield of 8.2 t/ha.
For rainfed lowland, farmers may choose from NSIC Rc192 (Sahod Ulan 1), PSB Rc14 (Rio Grande), and PSB Rc68 (Sacobia). Sahod Ulan 1 matures in 106 days with a maximum yield of 5.5 t/ha. Rio Grande matures in 110 days with a maximum yield of 6.1 t/ha. Sacobia matures in 116 days with a maximum yield of 4.4 t/ha. These varieties are also known for their drought-tolerant properties preferable in areas where El Niño is expected to hit worst.
Drought-tolerant varieties for the uplands include PSB Rc80 (Pasig), PSB Rc9 (Apo), and NSIC Rc23 (Katihan 1). Pasig can yield up to 8.7 t/ha and matures in 112 days. Apo matures in 119 days with a maximum yield of 5.6 t/ha while Katihan 1 matures in 108 days with a maximum yield of 7.6 t/ha.
