Prof (Dr) R D Gupta
Climate may be defined “as the processes of exchange of heat and moisture between the Earth and atmosphere over a long period of time (months, years) related to large areas (zone, state. Country, continent)”. It is an aggregate of atmospheric conditions involving heat moisture and air movement. The science which describes and explains the nature of climate, how it differs from place to place and how it is related to human activities, is called climatology. Climatology is closely related to meteorology which deals with day-to-day atmospheric conditions and their causes.
Climate, one of the major environmental factors, as stated above, largely determines the productivity of crops which has been described in details in the preceding paragraphs.
Climate and crop production : Productivity of all agricultural crops varies according to an ideal climatic conditions for their growth and development. Infact, weather and climate are the most pervasive (influential) factors of crop environment, and their knowledge is beneficial in a number of aspects of practical agriculture. Some of them which are very important, are as follows:
(a) They have practical utility in performing various agricultural operations timely so as to make the best use of favourable weather conditions and make suitable adjustments in case of adverse climatic situations.
(b) The risks of crop production due to insect attack and disease incidence, occurrence of prolonged drought, soil erosion, frost and other weather hazards can be minimised or controlled well in time.
(c) Weather and climate reports provide guidelines for long range or seasonal planning and selection of crops/cultivars most suitable to anticipated climatic conditions.
(d) Agrometeorological information can be utilized in soil classification and land use planning also.
(e) Weather forecasts can give an indication about the rainfall, thunder storms, wind blowing etc. Prior to sowing and harvesting of crops. Accordingly, necessary action can be taken in time.
Change of climate and its impact in agriculture
The most determinant factor in agricultural (food) production is climate (set of weathers). But weather instability and change of climate due to “Global Warming” has started affecting agricultural production The recent joint study conducted by the Research Institute of United Kingdom and India indicated that in the years to come grain yield of various crops will be hit badly due to climate change. (Anonymous, 2005). It has been found that rise in two degrees Celsius temperature would reduce grain yield potential. Areas with low productivity will be much more affected than those having higher productivity. Further, it has been found that warmer areas will have higher crop loss. Rice yield would be likely to fall in the eastern region of the country. In the northern India, including Jammu and Kashmir, the potential reduction in yield of various crops would be offset by higher radiation.
Occurrence of drought: Like other States of in Jammu & Kashmir Himalayas for the last two decades. Its most obvious effect was, however, noticed during 1998 especially in Kashmir valley, when there were no seasonal rains (April-May). Owing to this reason, the water of the river Jhelum and its tributaries was reduced badly. What to talk of transplanting the paddy, the farmers even could not sow the seeds for nursery (gardens for raising young plants). This resulted in heavy loss of rice production in the valley.
In the Karewas (lacustrine deposits), where already scarcity of topography, rainfed maize crop is mostly grown during Kharif. Due to lack of rains the production of this crop was very much affected. Like crops, the fruit production particularly of walnut, almond and apple suffered too.
Weather instability: Although the rainfall was normal in the country yet it remained below normal in the northern region including Jammu and Kashmir State during Kharif 2002. Weather instability in Kashmir valley was further noticed during winter, 2002-2003. While the people of Jammu region, dwelling in plains had been shivering due to cold wave since three to four weeks during January and February, 2003 the inhabitants of Kashmir valley were virtually basking in the sunshine those days (Gupta, 2003). It was quite amazing that in picturesque hill stations of Jammu and those of Kashmir, which previously used to be covered with heavy snow during November to January, there was not any snow during those days on the hill stations. Even there were no rains, no fog and no piercing or chilling cold. Kashmir were still rejoicing the sunshine in the core of winter though “Chil-e-Kalan” was in full swing. The Srinagar city was yet to receive the first snowfall of the season.
These changed weather conditions had been a big disappointment for orchardists of Kashmir. They proclaimed that if there is no snow, the fruit industry of Kashmir will be in doldrums and suffer an economic setback under the prevailing circumstances. But thanks God, there were good rains during March to April, 2003 and fruit production was not affected during that year.
Unexpected and unscheduled snowfall/rainfall: The unexpected and unscheduled snowfall on 30th April, 2004 has caused devastation. Thousands of trees had been broken and felled. (Anonymous, 2004a) The apple production, the backbone of economy for the people in vast area of south and north Kashmir is bound to get adversely affected. The production of cherry has very much affected. Reports said, the entire Pir Panjal range of mountains between Jammu and Kashmir, and Himachal Pradesh had 30 to 40 cm snowfall (Anonymous, 2004a). One and half metre (m) of snow was recorded in Sadana Top, about 1 m in Kera. The Jawahar Tunnel area on Banihal side recorded 7 cm snowfall while in and around Qazikund on the valley side 4 cm. Gulmarg recorded 24 cm fresh snowfall while Dras (Kargil) had 6 cm. This unexpected heavy snowfall would affect the production of almond walnut, cherry and apple. However, the people related with the farming and other agricultural activities have been encouraged by this snowfall / rainfall. They say, “Going by the rainfall, which has occurred during the winter and the subsequent months, it is quite possible that we would be able to reap a rich harvest this time, especially of paddy and maize”.
Unseasonal rainfall during the year 2004 was the hallmark as far as the farming community of Jammu division is concerned (Kaul and Wani, 2005). The disastrous track for the peasants was started in the second quarter of 2004 when in April they suffered a loss of nearly Rs.50-60 crore due to unseasonal rains. It might be pertinent to mention that Jammu district had topped in the damages caused due to heavy rains in the month of April, 2004 in wheat crop. In Jammu district alone, 44000 ha area of harvested wheat was destroyed due to heavy and unseasonal rains. In other districts destruction of such an area was to the extent of 6000 ha in Rajouri, 5000 ha in each in Kathua and Udhampur, 4000ha in Doda and 8000 ha in Poonch.
Failure of monsoon: The failure of monsoon in the midway of the season in the Indian subcontinent during 2004 has spread lot of panic among the farmers of Jammu region, Jammu & Kashmir State also.
South-west monsoon season (July-September): The period from last week of June to September is the period in which south-west monsoon cause intense precipitation at higher elevations. During this period the atmosphere becomes hot and humid. The rainfall comes in sharp showers and downpours are heavier and restricted in time. They cause soil erosion and their contribution towards the run-off can be as high as 80-90 per cent. There is frequent occurrence of thunder and storms. The maximum rainfall has been recorded in areas having 2600 m altitude.
Retreating south-west monsoon season (October-December): By October the intensity of rainfall becomes much less. The south-western monsoon winds gradually retreat, and the sky clears and temperature increases. The land is still moist and due to prevalent temperature, humidity is comparatively high. In the later half of October the temperature, however, begins to drop rapidly and by middle of December, the winter sets in. The months of October and November in this way, constitute a transitional period between rainy and winter seasons.
(The author is Ex-Associate Dean Cum Chief Scientist KVK-Jammu, SKUAST-J)
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