Nitrogen efficiency indexes association with nitrogen recovery, utilization, and use efficiency in spring barley at various nitrogen application rates

Abstract

The nitrogen use efficiency (NUE) is the ratio of the N uptake by the plant to the total amount of applied N fertilizer. The optimization of NUE is essential for sustainable agriculture, especially in the breeding programs to improve the yield of barley (Hordeum vulgare L.). We investigated the NUE variation in 32 barley genotypes and to examine the response relationship between phenotypic traits and N level to determine the traits essential for the selection of breeding programs to optimize the NUE. The NUE was investigated in 32 barley genotypes for 2 yr under field conditions using three N levels (60, 120, and 180 kg N ha −1 ). Growth, physiological and agronomic traits, and N efficiency-related parameters were determined. The parameters investigated were significantly affected by N application and its interactions with traits. Plant height, biological yield, spike length, and grain number (GN) were increased at higher N levels, but the 1,000-grain weight decreased. The lowest grain yield was 2,000.7 kg ha −1 at 60 kg N ha −1 , and the highest was 8,607.9 kg ha −1 at 120 kg N ha −1 . An increase in the N rate from 60 to 120 kg N ha −1 was associated with a higher total chlorophyll content (CHL SPAD ) (from 19.04 to 23.13), but no significant change in CHL was seen at 180 kg N ha −1 . The agronomic nitrogen use efficiency (ANUE), fertilizer N recovery efficiency and the nitrogen utilization efficiency were both reduced with an increase of the N application rate. A path analysis revealed that GN was the most essential trait for NUE breeding program selection due to its high direct effect (0.72) on ANUE. A linear discriminant analysis showed that CHL at 60 d after sowing was the best trait for distinguishing low from high N levels.

Molecular and agro-morphological characterization of new barley genotypes in arid environments

“…On January 1, 1992, in the early winter, the five parents and their 10 F 2 segregating generations were seeded (Tables S1 and S2) [ 19 ]. Advanced promising lines were obtained from barley breeding programs for dual purposes (i.e., high grain yield as well as biological yield for animal feed) [ 20 ]. The selected genotypes were obtained from ICARDA, KSU, and ARC, Egypt (Table 1 ).…”

Comprehensive evaluation of growth characteristics, nitrogen removal capacity, and nutritional properties of three diet microalgae

“…The filtered water was further analyzed using an automated spectrophotometer (Smart-Chem 450 Discrete Analyzer, Westco Scientific Instruments, Brookfield, USA). Referring to the description of Xu et al (2012) and Ali et al (2022), the nitrate-N absorption efficiency (pg•cell -1 •d -1 ) was defined as the average amount (pg) of nitrate-N absorbed by each cell daily in this study. Nitrate-N removal rate was calculated with the equation given by Messer et al (2022).…”

Impact of nitrogen fertilizer sustainability on corn crop yield: the role of beneficial microbial inoculation interactions

“…Corn, along with wheat ( Triticum aestivum L.), accounts for roughly 30% of all synthetic nitrogen (N) fertilizers consumed globally in crop production [ 2 ]. Inadequate application rates, broadcasting without incorporation, or excessively high rates on poorly drained soils are common examples of poor fertilizer management practices that frequently lead to low nitrogen use efficiency (NUE) and apparent fertilizer recovery (AFR) [ 3 , 4 ]. The excessive use of fertilizers and other organic and inorganic amendments has been reported to present detrimental effects on water and soil quality on a global scale [ 5 ].…”