Herbicide Toxicity to Soybean–Rhizobium Symbiosis as Affected by Soil pH
The current study examined whether soil pH could influence the toxicity of herbicides to soybean–rhizobium symbiosis. This can be useful for farmers to minimize the toxicity of them to crop–rhizobium symbiosis via applying their reduced doses. The toxicity of bentazon, metribuzin, and trifluralin to soybean–rhizobium symbiosis was investigated in pH 6.4, 7.2, and 8 soils. Seed inoculation decreased shoot:root (S:R) ratio but increased height, shoot dry weight (SDW), root dry weight (RDW), shoot nitrogen content (SNC), root nitrogen content (RNC), and nitrogen fixation effectiveness (NFE) in the pH 7.2 soil without herbicide application. All herbicides decreased NFE in all soil pH regimes except metribuzin in the pH 6.4 soil. Unlike trifluralin, the toxicity of bentazon and metribuzin to soybean–rhizobium symbiosis was influenced by the soil pH. It can be concluded that soil acidification and alkalization, which can rapidly occur in agroecosystems, can decrease and increase the toxicity of bentazon and metribuzin to soybean–rhizobium symbiosis, respectively.
KeywordsBradyrhizobium japonicum Lime Nitrogen fixation Nodulation Sulfur
The authors acknowledge the Nature Bio-Technology Company who provided the soybean inoculant. Appreciation is extended to Somayeh Ebrahimpoor Faraji, Zeineb Mirjani, and Zahra Ahmadi Joyandeh who provided invaluable assistance to conduct this study.
- AOAC (2016) Official methods of analysis of AOAC international, 20th edn. Latimer GW (ed). AOAC International, Washington, DCGoogle Scholar
- Belda KD (2014) Effect of liming on root nodulation and grain yield of soybean at Bako agricultural research center, Western Ethiopia. Dissertation. Haramaya University, EthiopiaGoogle Scholar
- Bohm GMB, Alves BJR, Urquiaga S, Boddey RM, Xavier GR, Hax F, Rombaldi CV (2009) Glyphosate- and imazethapyr-induced effects on yield, nodule mass and biological nitrogen fixation in field-grown glyphosate-resistant soybean. Soil Biol Biochem 41:420–422. https://doi.org/10.1016/j.soilbio.2008.11.002 CrossRefGoogle Scholar
- Marileo LG, Jorquera MA, Hernández M, Briceño G, de La Luz Mora M, Demanet R, Palma G (2016) Changes in bacterial communities by post-emergent herbicides in an Andisol fertilized with urea as revealed by DGGE. Appl Soil Ecol 101:141–151. https://doi.org/10.1016/j.apsoil.2016.02.003 CrossRefGoogle Scholar
- Monaco TJ, Weller SC, Ashton FM (2002) Weed science: principles and practices. Wiley, New York, p 137Google Scholar
- Zandstra B, Particka M, Masabni J (2004) Guide to tolerance of crops and susceptibility of weeds to herbicides. Michigan State University, Michigan. https://www.uky.edu/Ag/Horticulture/masabni/xreflist/E-2833.pdf