The quantity of nitrogen derived from symbiotic N fixation but not the relative contribution of N fixation to total N uptake increased with breeding for greater soybean yields
| Autor: | Hussien Almtarfi, Janelle M. Donahue, Hossein Zakeri, Hua Bai, Felix B. Fritschi |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Fertigation fungi food and beverages Soil Science Sowing chemistry.chemical_element 04 agricultural and veterinary sciences Biology 01 natural sciences Nitrogen Fixation (population genetics) Animal science chemistry Shoot 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Mineral particles Dry matter Cultivar Agronomy and Crop Science 010606 plant biology & botany |
| Zdroj: | Field Crops Research. 259:107945 |
| ISSN: | 0378-4290 |
| DOI: | 10.1016/j.fcr.2020.107945 |
| Popis: | Long-term soybean [Glycine max (L) Merr.] breeding for yield has increased plant nitrogen (N) demands. On one hand, because N fertilizer application in soybean production systems continues to be insignificant, increased plant N demands over time may have been satisfied from greater biological N fixation (BNF). On the other hand, increased soil residual N over time may have affected the sensitivity of nodulation and BNF. To understand the impact of breeding for greater yield and the effect of soil residual N on nodulation and BNF, two field and a greenhouse study were conducted. Field studies were conducted with maturity group IV soybean cultivars released from 1930 to 2005 and included experiments in four environments. Total shoot N and N from BNF increased with cultivar year of release in two of the four environments. Simulation of different levels of residual soil mineral N by application of 0, 34, 67, and 101 kg N ha−1 shortly after planting resulted in linear increases in shoot N content and δ15N, and linear decreases in nodule number and nodule dry matter in the field. Consistent with these results, fertigation of greenhouse-grown soybean cultivars with different levels of NH4NO3 led to a reduction in nodule number, dry matter, and size. Overall, results from these studies indicate that increases in seed yields with cultivar year of release were associated with greater amounts of N derived from BNF as well as greater total shoot N accumulation, but the relative contribution of BNF to total shoot N did not change over time. Analysis also suggest that the sensitivity of nodulation and BNF to soil mineral N has not been altered over the course of soybean breeding. |
| Databáze: | OpenAIRE |
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