Nitrogen could help mitigate the impact of drought on soybeans, researchers find

In Argentina, Seed World reported that a team of INTA scientists is exploring strategies to optimize soybean production. The initiative, led by the Plant Ecophysiology Group at INTA’s Institute of Plant Physiology and Genetic Resources, focuses on whether improving nitrogen nutrition can mitigate the negative effects of water stress  on both yield and grain protein content.

Conducted through field trials in partnership with INTA’s Manfredi Agricultural Experimental Station, the research aims to better understand the physiological mechanisms behind enhanced protein accumulation in high-performing soybean genotypes, according to the report.

Previous studies have shown that drought conditions reduce the crop’s ability to fix atmospheric nitrogen, often resulting in earlier harvests, lower yields, and diminished grain quality. However, the underlying biological processes driving these outcomes remain under investigation.

One of the most outstanding findings of the study was that, “the drought during grain filling reduced the yield by 71%, with respect to the irrigation condition, regardless of the availability of nitrogen. However, it was interesting to observe that a greater availability of nitrogen under conditions of water deficit resulted in increases of 12% in the final weight of the grains, 5% in the concentration of protein in the grain and up to 30% in the harvest index, a key indicator of the amount of biomass that ends up in the grains,” explained Ve USDA rónica Ergo, a specialist at INTA.

The study explored the ecophysiological foundations of nitrogen uptake, remobilization, and partitioning, along with the key regulatory processes that enable simultaneous improvements in soybean yield and grain protein content—both under optimal conditions (with irrigation and nitrogen supply) and during water stress.

The report noted that the findings offer valuable insights for breeders aiming to develop soybean genotypes that not only deliver high yields and superior protein quality but are also resilient to drought conditions.

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