Fjölrit RALA - 05.12.1999, Blaðsíða 120

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Desertificaticn and rangeland management in India
shrubs like Aerva tomentosa, Zizyphus spinachristi, Calligonum polygonoides were
found to be very effective for Thar desert. In the Bikaner region rows of Eucalyptus
cameldulensis and Dalbergia sissoo have also worked as effective shelterbelts and
tree screens for creation of ‘micro-climates’ (Sinha 1993). Shelterbelts reduced the
wind velocity by 20-46% on the leeward side for 2H-10H during the monsoon period
(H= height of shelterbelt). Soil loss was also considerably reduced. Rajasthan State
Forest Department has so far covered about 38,000 row km area under shelterbelt,
road side, railway line and canal side plantations since 1978 by adopting the technol-
ogy developed at CAZRI, Jodhpur (Kaul 1969).
Ecological regeneration through aerial seeding
Aerial seeding of seed pellets of Cenchrus ciliaris, Acacia tortilis and Colophosper-
mum mopane was done in 56 ha of military range areas in Barmer district of Rajasthan
at two sites: the duny sandy plain of Jalipa and the rocky hill ranges of Jasai village.
The programme was undertaken in collaboration with the military. Two methods of
seeding, i.e., seeding by helicopter and manual broadcasting of pellets were used. Data
on establishment and growth were recorded twice, i.e., at sowing and maturity stages.
The manual broadcasting of pellets was found better than aerial seeding by helicopter.
Under controlled conditions in the Jasai area, the plant population at sandy and rocky
area were 6 and 3 individuals per m2, respectively. The controlled sites were seeded
manually (Anonymous 1995).
Aerial seeding was also done in Bikaner on the left bank of the IG Canal in Sardar-
pura (300 ha) and Motigarh (400 ha). The seed mixture consisted of seeds of Acacia
tortilis, Colophospermum mopane, Dichrostachys nutans, Prosopis cineraria, Zizy-
phus rotandifolia, Citrullus colocynthis and Lasiurus sindicus at the rate of 14 kg/ha.
A. tortilis recorded highest germination and seedling density followed by C. colo-
cynthis (Anonymous 1995).
Ecological restoration and regeneration of the mined wastelands
Two mined wastelands, one of gypsum and the other of limestone were selected for
ecological regeneration. Four plots of one hectare each were demarcated to have four
treatments, i.e., control, development of micro-catchment area, half moon structure
development and ridge and furrow system, so that the planting pits (60 cm) might re-
ceive additional rain water as run-off. Seven indigenous and exotic species of trees
and four of shrubs were selected for plantation. In general, 5 m x 5 m spacing in plant
to plant and row to row was adopted. Plant species included Salvadora oleoides, S.
persica, Acacia tortilis. Azadirachta indica, Prosopis juliflora, Tamarix articulata,
Pithecelobium dulca, Dichrostachys nutan, Cassia stnitii, Cercidium floridun and
Caesalpinnea ceraria (Anonymous 1995).
The rooted slips of grasses like Cenchrus ciliaris, C. setigerus and Cymbopogon
jwarancusa were also transplanted as a single row in the ridge and furrow system. 1.5
ha of mining muck heaps and the rocky substrata were used for plantation. The muck
heaps were reshaped to create slopes and inverted terraces for rainwater harvesting. At
the rocky site ‘half-moon’ structures were developed with 3 m and 5 m spacing. More
than 90% of the plants survived. Live hedges and biofences of Prosopis juliflora were
raised at both the sites with 1 m x 1 m spacing to protect the plantation.