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Garma
Garam
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Agriculture |
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V.
Agricultural Diversification and Natural Resources
In this section we look at
various aspects of natural resources’ degradation and
over-exploitation, and examine how diversification of agriculture
would affect these resources and environment. Land degradation: Progress of green revolution technology, till early 1990s,
rather than causing increase in waterlogged and saline soils, has
been associated with steady decline in the degraded land. Area under
barren and unculturable lands has decreased from 208,000 hectares in
pre-green revolution period to 72,000 hectares in post-green
revolution period. Between 1965-66 and 1991-92, saline and
water-logged area has been reduced to 1/4th and culturable wastes
declined from 83,000 to 36,000 hectares. According to Chopra (1990)
installation of a large number of tubewells in the 1970s and early
1980s provided vertical drainage which helped in limiting the extent
of waterlogging and salinity. The second factor for decrease in land
degradation is the profitability of green revolution crops which
made it economically attractive to reclaim degraded land. Of late, the situation has
changed dramatically. The south-west region, particularly Faridkot
district, where cotton was the major crop, has been worst affected
by rising water-table, and thousands hectares of land have become
waterlogged. Other kind of land degradation attributed to intensive
cultivation of wheat and paddy is nitrate pollution and excessive
chemicalisation of soils and rising deficiency of micro nutrients
[Chopra 1990, 1993]. Since soil is a living matter, increase in
application of chemicals beyond certain level is injurious to soil
micro-organisms which are very essential for maintaining soil
structure and basic fertility. This problem is not irreversible and
the remedy lies in increasing organic matter in the soil. This can
be done through increased use of animal dung, green manuring and
alike measures. Agricultural diversification
through dairying or pulse crops are some of the options which can
check soil degradation and restore soil health and fertility of
degraded lands. Expansion of dairy would be helpful in two ways.
One, it would result in shift in some area from wheat and paddy,
which are considered problem creating crops, to fodder crops, some
of which are legume. Two, it would increase availability of organic
manures (animal dung) for crop production. Environment pollution: Burning of crop residues and application of
insecticides/pesticides are the major source of environment
pollution by agricultural activities. Burning of crop residues of
paddy and wheat generates smoke which makes the atmosphere
suffocating in the months of April and October. To quote one such
incidence, due to burning of paddy straw, a thick fog engulfed
Ludhiana town and large area in its surroundings around October 15
this year causing a panic due to very poor visibility during
otherwise bright season and irritation to eyes. The untimely rain
came to the rescue of the people by settling the smog. Each year more than 5 million
tonnes of paddy straw5 is destroyed by burning and
only a small fraction is used for industrial production.6
Rice straw is not used as feed for animals because there is
sufficient availability of green fodder and wheat straw in the state
which are superior feed compared to paddy straw. Air pollution caused by burning
of rice straw can be checked by promoting industrial demand for
straw as it can be used to manufacture products like straw-board,
paper, alcohol, mats and ropes. It is a pity that despite lot of
concern about biomass scarcity in the country there is reckless
wastage of millions of tonnes of biomass, that too at a cost to
environment. Some of the wheat straw is also
burnt in the fields harvested by harvest combines but the problem is
confined to limited area. Coming to the use of
insecticides/pesticides, the results of our study show that use of
plant protection chemicals was nil in wheat and very little in
paddy, whereas the crops which have potential to compete with wheat
and paddy are applied heavy doses of plant protection chemicals. The
only alternative which does not involve use of plant protection
chemicals is production of fodder crops, ie, diversification through
dairy activity. Water resource depletion and degradation:
Studies on groundwater balance in Punjab have observed that the
water-table has been receding in many parts of the state due to
excess of draft over the recharge [Baldev Singh 1992; Surender Singh
1991 and Prihar et al 1993]. Severity of over-exploitation of
groundwater can be judged from the fact that withdrawal of
groundwater exceeded recharge in half of the state’s
districts and in 58 per cent of the blocks (termed as grey) during
1991-92, the latest year for which information is available. The
extent of over-exploitation in these districts varied between 7 and
159 per cent with average at 40 per cent [Dhawan 1995]. A study conducted
by PAU [Prihar et al 1993] indicates that water-table in the
state is declining at the rate of 0.11 metre every year. Though many factors are
responsible for over-exploitation of groundwater, the problem is
being largely attributed to rice-wheat production system, which has
come to dominate crop pattern in the state during the post-green
revolution period. Second, it is said that paddy, which is a crop of
wet-land areas, is basically not suitable for large scale
cultivation in the state. In order to understand the role of various
factors in groundwater depletion and to evolve remedial measures to
mitigate the problem we have estimated to what extent wheat-paddy
rotation is responsible for the water depletion. It is also explored
whether diversification through other crops and activities would
rectify the situation. As there is close coincidence
between expansion of area under paddy cultivation and incidence of
water depletion, it is strongly believed that paddy is the main
culprit for the problem. This impression is reinforced by the fact
that paddy requires many times more irrigation compared to the crops
it has substituted – as it is generally believed that water
consumption by a crop is proportional to its irrigation requirement.
However, a study conducted by PAU, Ludhiana, [Prihar et al 1993]
shows that this is not entirely true. This study provides estimates
of actual water used by important crops, (transpiration plus
evaporation) net of seepage water, ie, part of irrigation water that
percolates back to water-table, which show that paddy consumes only
22 per cent higher water compared to maize and 12 per cent higher
water compared to cotton. Whereas, irrigation needs of paddy are 4
and 4.5 times the irrigation needs of maize and cotton (Table
5). The study also shows that sugarcane draws more heavily on
water than the sum of net water actually consumed in wheat and paddy
cultivation. The next question now is, does
the difference in water requirement due to shift in crop pattern, ie,
the difference in actual water consumption between paddy and other
kharif crops and wheat and other rabi crops, explain the negative
water balance in the recent years. To find answer to this question
we have estimated incremental water requirement between early 1970s
and early 1990s attributable to: (i) shift in crop pattern, (ii)
expansion of net sown area, and (iii) increase in cropping intensity
(vide Table 6).
The exercise reveals that the
shift in crop pattern in favour of paddy is responsible for 4.65 and
shift in favour of wheat for 2.29 per cent of the over-exploitation
of water. The main factor has been additional area brought under
cultivation during the last two decades through (i) expansion of net
sown area, which witnessed an increase of 3.44 per cent, and (ii)
increase in crop intensity, which recorded a jump of 25 per cent
during this period. These two changes resulted in expansion of gross
cultivated area by 29.3 per cent. Additional area brought under
paddy and wheat cultivation accounted for about 43 per cent and 15
per cent of the deficit respectively. The combined impact of change
in crop pattern and area expansion on account of paddy is about 47
per cent while wheat is responsible for 17 per cent of water
depletion. Increase in water use by other sources (non-agricultural
uses) is responsible for about 31 per cent of the present water
deficit in the state. Thus, increase in agricultural as well as
non-agricultural uses of water are responsible for declining
water-table in the state though contribution of former is almost
double the latter. The increase in water use for agricultural
purposes has resulted mainly due to additional area brought under
crop cultivation,7 and profitability of green
revolution crops, namely, wheat and paddy is the underlying factor
for this. This area was previously put to land uses like fallow,
unculturable waste, barren land, saline or waterlogged area. Apart from the factors discussed
above, the policy on water pricing is also aggravating the problem.
Electric motor operated tubewells have come to dominate the
irrigation sector in the state for which fixed nominal tariff was
paid till recently; the present state government has waived even the
nominal tariff and declared free supply of electricity to
agricultural sector. This leaves no incentive with the farmers to
economise on water and encourages indiscriminate and excessive water
use. This assertion is supported by the PAU study which shows that
irrigation treatment to paddy with 2 days drainage, between complete
infiltration of ponded water and subsequent irrigation, provides
higher yield compared to the farmers’ practice of continuous
submergence of paddy (Table
7). Similarly, in wheat crop, the
studies in rainfed area show that with judicious use of inputs, only
2 irrigations can result in 40 quintals yield per hectare which is
at par with the yield obtained with five-six irrigations. Excessive
irrigation in most of the cases causes damages like leaching of
nutrients causing economic losses, pollution of groundwater due to
leaching of chemicals, cost of energy to lift excessive water and
wastage of scarce water resource. Can Crop Diversification Check Groundwater Exploitation?
We have discussed in the previous
section that the most important factor underlying over-exploitation
of groundwater in Punjab is increase in crop intensity and net sown
area. Increase in cultivated area on account of both these factors
has gone mainly to paddy and wheat crops. Now the issue of interest
is that if some of the area under wheat and paddy is replaced by
some other crops how would it affect strain on water resources? Though it would be of interest to
see how diversification through vegetables, floriculture and fodder
crops, which hold the potential to replace some area under wheat and
paddy, would affect water resource, the information on net water
consumption (ET demand) of these crops is not so far available.
Therefore, we have examined the likely impact on water demand
resulting from diversification through only those crops for which
data on ET demand is available (the results are presented in Table
8). The exercise reveals that, if the
estimates of net water demand provided by PAU study for various
crops are considered as reliable, the change in crop pattern away
from paddy or wheat in favour of less water intensive crops would be
of small help in reducing water depletion. When paddy crop is
totally withdrawn from the state, the gap between water use and
availability reduces by about 15 per cent. Another scenario in which
share of paddy and wheat in GCA is reduced to the level prevailing
in early 1970s, when there was no strain on water resources,
existing water deficit decreases by about 12 per cent (10.43 per
cent on account of paddy and 1.13 per cent on account of wheat). Based on these findings we
conclude that if the challenge of over-exploitation of water is to
be tackled, following measures need to be adopted: 1 Indiscriminate
and excessive use of irrigation should be checked through volumetric
pricing of water, which in the case of electric tubewells means
levying energy (electricity) used for irrigation based on actual
use. 2 In the areas with serious
water depletion problems (known as dark blocks) some incentive for
keeping a part of land fallow should be considered. 3 Diversification of
existing crop pattern with suitable crops would result in some,
though small, savings of water. Since no single measure can result
in large reduction in water use, the strategy should be to make use
of such small savings wherever possible. 4 Incentive should be
provided for installation of water saving devices like drip and
sprinkler, etc. 5 Cultivation of crops like
sunflower during peak summer season8 should be
discouraged. Similarly, cultivation of sugarcane in areas facing
declining water-table should be discouraged. 6 Serious efforts need to be
made on supply side to conserve and harvest maximum of rain water
during the monsoon season.
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