Satellite data plus conservation equals better crop yields

[NEW DELHI] Combining remote sensing technology with water and soil conservation techniques can help raise crop yields in South Asia, scientists have reported.

Satellite data can help identify specific problems on farmlands such as moisture shortage, excessive soil wetness and flood occurrence.

Using the data along with appropriate resource conserving technology (RCT) will increase productivity, a study team of researchers reported this month (8 September) in Applied Geography.

The study team included researchers from the International Rice Research Institute (IRRI), Manila, International Maize and Wheat Improvement Centre, Banaras Hindu University, Jawaharlal Nehru University, Delhi, and Punjab state’s department of agriculture.

Applied in the Balia district of northern Uttar Pradesh state, the method showed significant increase in annual per hectare incomes — US$ 63 by raising beds in saline soils, US$ 140 by introducing deep-water rice varieties, and US$ 147 through timely wheat planting.

"Our remote sensing studies show that wheat is generally sown late in more than half of the eastern Gangetic plains," Parvesh Chandna, scientist at the IRRI and one of the authors of the study, told SciDev.Net.

"Zero tillage, a method of growing crops without disturbing the soil — thereby increasing water and organic matter and decreasing erosion — increases yield by advancing planting dates of winter wheat," said Chandna.

"RCTs reduce cost of crop establishment, conserve natural resources and increase productivity. High-resolution remote sensing and improved classification techniques can precisely identify lands most suitable for these technologies," Chandna added.

The Rice Wheat Consortium for the Indo-Gangetic Plain, an alliance of the national agricultural research systems of Bangladesh, India, Nepal and Pakistan, developed the RCTs.

RCTs are also being promoted by the Cereal Systems Initiative for South Asia, a project which applies science and technologies to cereal production in South Asia.

The authors said that this method can help increase agricultural production in 15 million hectares of underutilised land in the Indo-Gangetic plains where productivity has decreased due to natural resource degradation.

Chandna said technologies like zero tillage and the use of deep-water rice varieties have become popular with farmers in mid and upland areas, as also has boro (summer) rice cultivation in riverside areas.

Other scientists emphasised the importance of combining 'ground truthing' along with remote sensing to pinpoint problems.

"For a method to succeed remote sensing should be accompanied by ground truthing," said Rajeshwari Raina, agricultural scientist at the New Delhi-based National Institute of Science Technology and Development Studies.

"This can help in application of the RCTs because it informs the researchers about the socioeconomic characteristics of the place, the farmer profile and other information that help identify the right technologies," she said.