Researchers combat slowing yields with targeted fertilizer applications

December 10, 2007

Scientists at Punjab Agricultural University, the International Rice Research Institute, and Virginia Tech have been successful in increasing average rice yields in northwest India using site-specific nutrient management strategies.

The Punjab province, which accounts for 10 percent of the Indian rice production, is currently witnessing a slower rice grain yield growth rate as compared to the yield growth rate during the green revolution phase (1960-1986). To meet the expected food demand in the next 30 years, rough estimates for India suggest the need to increase average farm productivity of the system, which is currently at 45 to 60% of the attainable yield potential, to 70 to 80% of the attainable potential.

The researchers hypothesized that decreased nutrient supply capacity of soil and improper nutrient management approaches were key factors in the slower growth rate. By analyzing the existing soil nutrient composition and applying site-specific nutrient management (SSNM) the scientists were able to increase average rice grain yields by 17 percent compared with current farmers’ fertilizer practice. Similarly, profits rose about 14 percent using SSNM.

Over a two year period the scientists applied calculated amounts of nutrients at 56 sites in six key irrigated rice-wheat regions to evaluate the effectiveness of SSNM in increasing yield growth rates. Using the ‘Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS)’ model, which predicts crop yields from chemical soil characteristics, the scientists refined their nutrient applications and schedules on a site-specific basis.

In addition to yield and profit increases, improved timing of fertilizer applications led to a measured 13 to 15 percent increases in plant accumulations of nitrogen, phosphorous and potassium.

While further yield increases are likely to occur in small, incremental steps that involve gradual buildup of soil fertility and fine-tuning of crop management, the authors conclude that the agronomic and economic successes of SSNM are due to its site-specific and dynamic nature which take soil variability into account. They suggest that the major challenges for SSNM will be to reduce the complexity of the technology as it is disseminated to farmers and to combat environmental pollution stemming from nutrient leaching and runoff from rice fields.

“Site-specific nutrient management, as defined in our study, has potential for improving yields, profit, and nitrogen use efficiency in irrigated, transplanted rice,” explained the study’s author Harmandeep Singh Khurana.

“Future research needs to build on the present SSNM approach to develop a more practical approach for achieving similar benefits across large areas without farm-specific modeling and with minimum crop monitoring.”

Source: American Society of Agronomy

Explore further: Has the green revolution really succeeded?

Related Stories

Has the green revolution really succeeded?

July 20, 2015

Over the past 50 years, human population has more than doubled, but cereal-crop production has grown even faster. Mechanization, synthetic fertilizers, new high-yield seeds and other advances in intensified agriculture have ...

Scientists find new research models to study food crops

July 10, 2015

Farmers often are required to apply nitrogen fertilizers to their crops to maintain quality and improve yields. Worldwide, farmers used more than 100 million tons of nitrogen in 2011, according to the United Nations Food ...

Reducing agriculture's greenhouse gas emissions

June 23, 2015

The overwhelming scientific consensus is that gases produced by human activity are affecting the global climate. But even if you don't believe the current warming of the global climate is caused by humans, it's only common ...

Algae from wastewater solves two problems

April 2, 2015

In one of the first studies to examine the potential for using municipal wastewater as a feedstock for algae-based biofuels, Rice University scientists found they could easily grow high-value strains of oil-rich algae while ...

Recommended for you

Earliest evidence of reproduction in a complex organism

August 3, 2015

Researchers led by the University of Cambridge have found the earliest example of reproduction in a complex organism. Their new study has found that some organisms known as rangeomorphs, which lived 565 million years ago, ...

Model shows how surge in wealth inequality may be reversed

July 30, 2015

(Phys.org)—For many Americans, the single biggest problem facing the country is the growing wealth inequality. Based on income tax data, wealth inequality in the US has steadily increased since the mid-1980s, with the top ...

French teen finds 560,000 year-old tooth (Update)

July 28, 2015

A 16-year-old French volunteer archaeologist has found an adult tooth dating back around 560,000 years in southwestern France, in what researchers hailed as a "major discovery" Tuesday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.