Erratic impacts of climate change on crop cultivation

Bishnu Prasad Aryal

Lalitpur, April 17

The scientists and agronomists have pointed out erratic impacts on crop cultivation and recommended varieties, underlining the need to shift the crop zone in Nepal due to the worrisome climate change.

“Now, there is an urgent necessity to assess the crop zone shifting standards,” said Dr Anand Kumar Gautam, chief scientist at the National Agricultural Research Council (NARC). “Otherwise, it will result to dire consequences on the production, leading to food crisis if not timely addressed,” he warned.

A study of NARC on crop yielding trends has indicated an alteration in cultivation method. “Either we have to develop and recommend new varieties or choose a way to change plantation period but it will be problematic in relation to the irrigation,” Gautam added. “Rise in temperature has caused carbon emission from land and added the lifecycle of insects and bacteria, which is alarmingly harmful to the crops.”

Tarai falls under the sub-tropical zone and the varieties are recommended as per the climatic nature. “However, there is a need to apply tropical varieties in this region now,” said Hari Krishna Upreti, senior scientist, NARC.

Upreti said that early maturing varieties of paddy—Harinath-1, Sugandha-1, 2 and 3, and CNTRL85033, tested and recommended for Tarai—have been found cultivated in the Kathmandu valley during the period of last six years. “A few years ago, they were unproductive, failing to head here,” he said. “Even maturity period of rice has decreased by one to two weeks whereas the heading period has been adaptable to late period by two weeks in the hilly region.”

Annually, mercury is on rise by 0.06-degree Celsius. Positive and negative both results of climate change have been traced in crop cultivation in Nepal. “The production of crops in the fertile Tarai region, known as food bank, has been declining whereas it is increasing in the hilly region,” said Gautam. Tarai covers a big majority of the productive land.

The cultivation of wheat crops in western Tarai will be almost infertile in about a decade if this climate change ratio continues, according to the scientists. “Wheat production has drastically come down in Tarai during last few years whereas production in hilly region is increasing,” said Upreti.

According to Open Top Chamber field experiment, production of paddy and wheat has increased by 17-26 and 8-18 percent respectively due to the rise in temperature and carbon dioxide in Kathmandu. “Production of maize has decreased by 21 per cent in the low land as per the DSSAT model experiment based on temperature record of the Department of Hydrology and Metrology,” said Gautam. “It was found apples could not head this year where it was cultivated earlier.”

An extensive research is inevitable to quantify change and timely tackle the problem but financial crunch has become a big obstacle. “It is the government’s responsibility to think in time,” Gautam said.