Traditional Knowledge for Sustainable Management of Soils - Principles of Sustainable Soil Management in Agroecosystems - page 322

social system is the result of people's action to survive and their attempts to optimize the
use of available resources (i.e., soil, water, and vegetation).
13.5.1 l oCation -S peCiFiC r unoFF C ontrol p raCtiCeS
Quite early, farmers realized the need for protection of land from erosion, landslides,
and floods. In most agricultural fields across the country, farmers protect their land
from erosion through traditional methods such as by using bamboo culms, stones,
and gunny bags filled with soil (NIC 2001). In the Meghalaya state of northeast
India, a primitive form of bench terraces was in vogue even while practicing shifting
cultivation. The vertical slope between the terraces is not usually more than a meter.
It prevents soil erosion and retains maximum rainwater within the slopes and safely
disposes of the excess runoff to the foothills.
In Peninsular India and the central plains, farmers in India followed the concept
of watershed while delineating village boundaries. Village boundaries were decided
upon on a watershed basis by the expert farmers in the villages. Such boundaries
were socially acceptable to all the members of the system. Such age-old village
boundaries are fixed at the common point of the drainage system in between two
villages. It is still in vogue, and people do not go beyond the limits of their hydrologi-
cal boundaries. In the western Himalayas, farmers used to carry water to their fields
through small irrigation channels known as gula s ( Figure 13.7 ) . These go from the
source of water along the slopes to the fields. In order to avoid seepage losses, pipes
made of bamboos and tree trunks were also used (Sharma and Sinha 1993). In the
Garhwal Himalayas, traditionally, rainwater was harvested in small dug-out ponds.
Such ponds were dug at several places along the slope. Natural streams in the hills
were the source of drinking water. Villagers planted vegetation all along the stream
bunds in order to prevent sediment entry and pollution of water.
13.5.2 F laSh F lood C ontrol in h iMalayaS
In the entire Himalayas, flash floods cause landslides, and silt carried by water fills up
the water bodies. Ancient Indian farmers have indicated three strategies to deal with
this problem. They are mechanical, agricultural, and vegetative. The main occupa-
tion of the hill farmers is agriculture. They usually construct terraces for cultivation
known as nala , with risers known as pusata . These terraces are small, but there are
many. In 1 acre of land, a farmer possesses 50 nalas . In these, it is possible to man-
age rainwater. The farmers, with their expertise, are able to prepare fields for crop
production in hills. Though cultivation is allowed on up to a 33% slope, hill farmers
are able to make terraces from top to bottom of the mountain terrain with indig-
enous practices. With terraces, they construct loose boulder retention walls (risers)
and grass them. These grasses keep both stones and the land intact. In making these
risers, farmers simply arrange boulders of the proper size along the terrace wall. They
retain the soil perfectly and gradually become stabilized. Farmers of the hill region
used to make brushwood or long wood check dams across the drainage channels for
controlling soil loss by means of local materials. In the Doon Valley, Ipomea carnea
and Arando donex plant species are used as vegetative spurs in order to train torrents.