Weather phenomenon is beyond technology’s control but it is possible to adapt to or mitigate its effects if information is available on time
Weather and agriculture are two interrelated components of nature. Weather has profound influence on crop, development and productivity. Growth of fish, for example, is closely linked to temperature of water. Hot or cold weather can adversely affect livestock. So understanding of weather issues is crucial for those involved in agriculture.
The cropping pattern, selection of crops, cultural operations, application of farm inputs, harvesting and even storage and transportation is decided by prevailing weather conditions.
Sunshine, wind movement and temperature have direct relationship with photosynthesis, transpiration and respiration activities. Even flowering is influenced by duration of sunlight and darkness. This is known as photoperiodism—the response of an organism to seasonal changes in day length. Whatever advanced agriculture technology we have, without good weather, it is not possible to expect a good return. Extreme weather events cause significant decline in reductions of agriculture production.
Nepal heavily relies on agriculture, which has more than 36 percent contribution to Nepal’s GDP. Nepal’s agriculture is mainly based on monsoon, which does not always favor the farmers. For instance, floods and landslides triggered by heavy monsoon rainfall in Tarai districts last year swept away crops worth over eight billion rupees. The floods had also swept away more than 60 percent of fisheries in 31 districts.
Weather phenomenon is beyond the control of technology. However, it is possible to adapt to or mitigate the effects of adverse weather to a large extent if the information is available on time. Some farmers have keen sense of predicting weather.
The weather forecasts must be timely and accurate to help enhance agriculture production. They are helpful in devising agronomic strategies to cope with changing weather. Delays in the start of crop season can be countered by using short-duration varieties or crops. In this context, medium-range weather forecasts with a validity period that enables farmers to organize and carry out appropriate cultural operations to cope with or take advantage of the weather forecast will be very useful.
The rapid advancement in information technology and its expansion in rural areas provide better opportunities to meet rising demand among farmers for timely and accurate weather forecasts so that they can move ahead for timely plantation and harvest.
A weather forecast includes various parameters including the amount and type of cloud cover, rainfall and snow, maximum and minimum temperatures, and relative humidity. Besides, wind speed and direction, extreme events, such as heat waves and cold waves, fog, frost, hail, and low-pressure areas are some of the important components of weather.
An agricultural weather forecast contains various information including bright hours of sunshine, solar radiation, dew, and evaporation, soil moisture conditions, and microclimate in specific cases. In Nepal, field preparation for rain fed crops is weather dependent. Seed germination is dependent upon proper light and moisture, as well as soil temperature. In dry land areas, the amount of rainfall is very meager and farmers should rely on even minimum showers.
The prediction of the exact time of occurrence of rainfall in a particular location helps to initiate field preparation. Weather forecasts are also needed for controlling insect-pests, diseases and weeds. It can not only help minimize the volume of agrochemicals applied, but also make the applications more effective. The forecast for post-harvest activities should ensure that whatever yield can be saved on the field can be saved after harvest as well.
Therefore, the general agricultural weather should supply the meteorological information necessary for harvest and post-harvest operations. The primary weather factors for crop harvest are rainfall and atmospheric temperature, while for post-harvest operations, in addition to the above, sunshine, wind, relative humidity and dew are also important components to be taken into account. The minimum temperature forecast is essential in hilly and temperate regions. These regions need a special minimum temperature forecast system particularly during the cropping season.
This critical information helps farmers in judicious allocation of their resources, such as labor and other agricultural inputs, so as to avoid crop losses. The forecast should include the minimum temperature expected in the next 24 hours. This may be location-specific or for a particular region as a whole.
The agricultural information management system tailored for farmers should include weather forecast programs so that we can make our farmers better prepared with the help of timely information through an efficient communication system. The Nepal Agricultural Research Council (NARC) and the Department of Hydrology and Meteorology (DHM) should work in collaboration for such programs. Even the World Meteorological Organization, established in 1950, could play a critical role in LDCs like Nepal.