Abiotic and Biotic Limitations to Nodulation by Leguminous Cover Crops in South Texas

Authors

Stephanie Kasper, The University of Texas Rio Grande Valley
Bradley O. Christoffersen, The University of Texas Rio Grande ValleyFollow
Pushpa Soti, The University of Texas Rio Grande ValleyFollow
Alexis Racelis, The University of Texas Rio Grande ValleyFollow

Document Type

Article

Publication Date

9-23-2019

Abstract

Many farms use leguminous cover crops as a nutrient management strategy to reduce their need for nitrogen fertilizer. When they are effective, leguminous cover crops are a valuable tool for sustainable nutrient management. However, the symbiotic partnership between legumes and nitrogen fixing rhizobia is vulnerable to several abiotic and biotic stressors that reduce nitrogen fixation efficiency in real world contexts. Sometimes, despite inoculation with rhizobial strains, this symbiosis fails to form. Such failure was observed in a 14-acre winter cover crop trial in the Rio Grande Valley (RGV) of Texas when three legume species produced no signs of nodulation or nitrogen fixation. This study examined the role of nitrogen, phosphorus, moisture, micronutrients, and native microbial communities in the nodulation of cowpea (Vigna unguiculata L. Walp) and assessed arbuscular mycorrhizal fungi as an intervention to improve nodulation. Results from two controlled studies confirm moisture and native microbial communities as major factors in nodulation success. Micronutrients showed mixed impacts on nodulation depending on plant stress conditions. Nitrogen and phosphorus deficiencies, however, were not likely causes, nor was mycorrhizal inoculation an effective intervention to improve nodulation. Inoculation method also had a major impact on nodulation rates. Continued research on improved inoculation practices and other ways to maximize nitrogen fixation efficiency will be required to increase successful on-farm implementation.

Comments

Original published version available at https://doi.org/10.3390/agriculture9100209

Recommended Citation

Kasper, Stephanie, Bradley Christoffersen, Pushpa Soti, and Alexis Racelis. 2019. “Abiotic and Biotic Limitations to Nodulation by Leguminous Cover Crops in South Texas.” Agriculture 9 (10): 209. https://doi.org/10.3390/agriculture9100209.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Agriculture

DOI

10.3390/agriculture9100209