Agriculture.ph Blog

Salt Technology

PERHAPS one of the most well-known organic farming technologies developed for the uplands today is the Sloping Agricultural Land Technology (Salt) which the Mindanao Baptist Rural Life Center (MBRLC) Foundation Inc. is heavily promoting.

The uplands are rolling to steep areas where both agriculture and forestry are practiced on slopes ranging upward from 18 percent. The sloping uplands occupy about 55 percent of the country’s total land area of 30 million hectares.

“Salt is basically a method of growing field and permanent crops in three meter to five-meter wide bands between contoured rows of nitrogen fixing trees and shrubs (NFT/S),” explained Roy C. Alimoane, the MBRLC director.

In Salt farming, the use of commercial fertilizer is no longer needed. The NFT/S is thickly planted in double rows to make hedgerows. When a hedge is 1.5 to two meters tall, it is cut down to about 40 centimeters and the cuttings (tops) are placed in alleyways to serve as organic fertilizers.

When the technology was still in its developing stage, the MBRLC used the leaves of ipil-ipil (Leucaena leucocephala) as its main source of fertilizer for the crops grown in the farm. Every year, ipil-ipil produced 36,080 kilograms of green leaves and stem per hectare with the following NPK equivalents: 258.5, 120.2, and 90.1.

But in the late 1980s, ipil-ipil suffered from the attack of psyllid (Heteropsylla cubana). With this infestation, the MBRLC started intensive testing for the different nitrogen-fixing species they had collected through the years. Among those that have the same as that of ipil-ipil are Flemingia macrophylla, Desmodium rensonii, and Indigofera anil.

Alimoane recommends planting all three instead of just one species. “As in organic concept, the more species, the better,” he said.

If the recommended species are not available, farmers can still use ipil-ipil but should be planted with other local species available in their area like kakawate.

Salt is sort of a diversified farming system. Rows of permanent crops like cacao, coffee, citrus and other fruit trees are dispersed throughout the farm. The strips not occupied by permanent crops are planted alternately to cereals (corn, upland rice, sorghum, etc.) or other crops (sweet potato, melon, pineapple, etc.) and legumes (soybean, mung bean, peanut, pigeon pea, and winged bean, among others).

“This cyclical cropping provides the farmer some harvest throughout the year,” Alimoane said. In addition, the practice also discourages pest infestations. As crops are healthier and sturdy, they don’t use pesticides in their Salt farm.

The thin layer of earth we call topsoil is essential to land’s fertility. Typically, only some 15 centimeters deep, topsoil is a rich medium containing organic matter, minerals, nutrients, insects, microbes, worms and other elements needed to provide a nurturing environment for plants.

“It takes thousands of years to build one inch of topsoil but only good strong rain to remove one inch from unprotected soil on the slopes of mountains,” Alimoane claims.

A six-year study conducted at the MBRLC farm showed that an upland farm tilled in the traditional manner erodes at the rate of 1,163.4 metric tons per hectare per year. A Salt farm erodes at the rate of only 20.2 metric tons per hectare per year in the same period.

Computed, the rate of soil loss in a Salt farm is 3.4 metric tons per hectare per year, which is within the tolerable range. Most soil scientists place acceptable soil loss limits for tropical countries like the Philippines range of 10 to 12 metric tons per hectare per year.

In comparison, the non-Salt farm has an annual soil loss rate of 194.3 metric tons per hectare per year.

“As a sustainable farming system, SALT replaces ugly eroded and denuded slopes with the luxuriant beauty of abundant vegetation,” pointed out
Alimoane.

Written by: Henrylito D. Tacio

Source: www.sunstar.com.ph