Research Provides Case for Boron Application in Soybeans

:: Thursday, September 17, 2020 :: Posted By Fabiano Silvestrin
Soybeans, like all legumes, have a high boron requirement, necessitating pre- and in-season monitoring via both soil and foliar testing. Boron deficiency causes depression of growing points such as root tip and young leafs and deformity of organs, including bud flowers and fruits. Furthermore, plant stands experiencing boron deficiency may be difficult to identify due to the most prominent symptoms being exhibited below the soil’s surface.

Irreparable damage occurs to the soybean plant’s root tips, causing the subsequent death of the root shoot growing point and prolific development of lateral shoots with brittle petioles. Plants that do survive lack vigor and, most often, fail to reach variety yield potential. Maintaining adequate boron at critical growth and reproductive stages of soybean plant development is critical to both stand establishment and yield.

However, soybeans have been thought to be sensitive to boron toxicity, thus caution and, in some instances, reluctance to the application, especially foliar application, of boron exists. This reluctance continues to cost a producer both in terms of soil health and soybean cash-crop productivity.

Appropriate boron for higher yields

Today, it is known that that yield reductions do not necessarily accompany leaf spotting and marginal necrosis caused by excessive boron accumulation.

What’s more, multi-year research trials in Maracaju and Naviraí, Mato Grosso do Sul, Brazil, provide that, even in weather-compromised years, timely application of boron produces a higher yielding crop. The research conducted and led by Douglas Gitti, saw marked yield increases as a result of the application of Granubor®. The trials showed that over the course of the three-year study, more than 5 bags per hecatre could be attributed to the addition of Granubor.

The consistent yield improvement of soybean variety M 6410 IPRO, above the control-group hectares, was noted throughout the randomized complete block design that was used in both sites. Each location received five repetitions of soil-applied Granubor at 1.0 kg B/ha in October of each of the agricultural production years: 2017-2018; 2018-2019; 2019-2020, with much of the 2018-2019 growing season lost to extreme drought.

The results of the research show that boron should be a strong pre-plant, consideration for soybean acres. The micronutrient may be applied in dry of fluid blends. Granubor may be added to bulk blend fertilizer and broadcast prior to planting, at a rate of 1.0 kg B/ha to improve soybean stand resilience and yield.


Results graph from Maracaju soy trial

  Results graph from Naviraí soy trial




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U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 650 customers with more than 1,800 delivery locations globally. We supply around 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles northeast of Los Angeles. Learn more about Rio Tinto.

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