Effects of Nitrogen Application on Nitrogen Fixation in Common Bean Production

Abstract

The nitrogen fixing ability of common bean (Phaseolus vulgaris L.) in association with rhizobia is often characterized as poor compared to other legumes, and nitrogen fertilizers are commonly used in bean production to achieve high yields, which in general inhibits nitrogen fixation. In addition, plants cannot take up all the nitrogen applied to the soil as a fertilizer leading to runoff and groundwater contamination. The overall objective of this work is to reduce use of nitrogen fertilizer in common bean production. This would be a major advance in profitability for the common bean industry in Canada and would significantly improve the ecological footprint of the crop. In the current work, 22 bean genotypes [including recombinant inbred lines (RILs) from the Mist × Sanilac population and a non-nodulating mutant (R99)] were screened for their capacity to fix atmospheric nitrogen under four nitrogen regimes. The genotypes were evaluated in replicated field trials on N-poor soils over three years for the percent nitrogen derived from atmosphere (%Ndfa), yield, and a number of yield-related traits. Bean genotypes differed for all analyzed traits, and the level of nitrogen significantly affected most of the traits, including %Ndfa and yield in all three years. In contrast, application of rhizobia significantly affected only few traits, and the effect was inconsistent among the years. Nitrogen application reduced symbiotic nitrogen fixation (SNF) to various degrees in different bean genotypes. This variation suggests that SNF in common bean can be improved through breeding and selection for the ability of bean genotypes to fix nitrogen in the presence of reduced fertilizer levels. Moreover, genotypes like RIL_38, RIL_119, and RIL_131, being both high yielding and good nitrogen fixers, have potential for simultaneous improvement of both traits. However, breeding advancement might be slow due to an inconsistent correlation between these traits.

Response of Sugarcane Rhizosphere Bacterial Community to Drought Stress

“…In return, rhizobia obtain photosynthates from the plant. The activity of the rhizobia is affected by multiple factors such as drought resistance of the host plant, the amount of accumulated photosynthates, and levels of AP (Shen et al, 2019;Reinprecht et al, 2020). This is a good validation of the relationship between Rhizobiales and plant photosynthetic indicators in our SEM (Figure 5).…”

Arbuscular Mycorrhizal Fungi and Nutrition Determine the Outcome of Competition Between Lolium multiflorum and Trifolium subterraneum

“…N-fertilization was expected to increase photosynthetic capacity ( Evans, 1989 ) in both plant species and thus increase carbon input into the fungal network, resulting in higher colonization, particularly in the highly mycotrophic legume ( Unger et al, 2016 ), leading to a higher C–P trade benefit in the grass than in the clover. In addition, the presumed advantage of the rhizobial symbiosis of Trifolium would be diminished under these conditions ( Reinprecht et al, 2020 ). P-fertilization was expected to increase the competitive ability of the legume over the grass ( Ren et al, 2017 ; Mitran et al, 2018 ).…”

The effect of mineral fertilizers on the yield of vegetable beans, depending on the competition between plants in crops

“…Thus, in the fruit formation period, plants make maximum use of their own internal nitrogen reserves from the vegetative organs for seed formation. [13] In turn, as is noted by Reinprecht et al, the insufficient supply of nitrogen from the root system to the aboveground organs negatively affects photosynthesis, accelerates the leaves aging process, and reduces their active functioning time. Moreover, such a sequence of the pointed interdependent processes is subject to general ontogenetic patterns, regardless of the availability of plant nutrients [13].…”