Agriculture Reference
In-Depth Information
requires correct timing, for which constant watch should be kept on the progress of
germination of the first sowing, and after allowing sufficient time from the estimated
time of germination, resowing should be done. Resowing may have to be done in
the subsequent year(s) also, if a particular year proves to be a drought year.
Pelleting of seeds is required in case of grass seeds where wind can blow away
the seeds in sandy areas. Pelleting involves mixing of seeds with a semimoist matrix
of sand, clay, and manure, and making the mixture into balls, lumps, or disks.
Moisture in the mixture should be low to prevent the seeds from germinating within
the mixture itself. The pellets should be kept ready, and should be sown in field—on
bunds, furrows, and mulch lines—just before the estimated time of the rains.
Transplanting seedlings on the bunds of contour-based linear structures can be
considered in case of certain species. Species like Lawsonia inermis and Prosopis
juliflora will get a chance of advance growth in mother beds, and thus have a greater
chance of success if transplanted on bunds after 1 or 2 months of growth in a nursery.
To transplant, a sharp implement is used to create a deep narrow hole in soil on the
bund, roots of the uprooted seedling are inserted into the hole, and the hole is closed.
Transplanting should be carried out at a spacing of 0.50 m, in one or two lines. The
operation has to be timed immediately after the rains.
Planting of cuttings, of species like Euphorbia , Jatropha , and Ipomea , along the
dike-cum-terrace or on the lower edge of the bund of contour trench can also be
effective in establishing vegetative barriers. This should be considered when soil is
poor, terrain is rocky, and climate too dry and harsh.
The plants forming vegetative barriers must be looked after and maintained.
Timely hoeing, weeding, and cleaning will be required in most cases. If gaps are
seen in the hedge, these should be filled up by planting additional seedlings or by
resowing from time to time.
5.9
Loose-Stone Check Dams
The alignment for a loose stone check dam should clearly mark out its basal boundary.
Beginning at the lower edge of such alignment, dry stone masonry work is carried
out in such a manner that a given course of stone-laying is always horizontal. Earlier
courses will then occupy smaller basal area, and the courses will grow larger as the
height of the check dam rises. Interlocking of stones should be carefully ensured,
otherwise the structure may get carried away by the force of water. There should be
no slope either in transverse or in longitudinal direction—except a little reverse slope
against the direction of flow of the stream—because slope will make the structure
unstable (Fig. 5.5 ).
The topmost layer of stones may be heaped with mulch and brushwood and
overdumped with some more stones. A still better practice is to have a couple of
courses of brush-wood or mulch topped by a 10 cm thick layer of soil. This will
give some quality of impermeability to the stone masonry, and will delay flow of
water more effectively. It will also be effective in intercepting the soil particles in
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