Oilseed rape characteristically has high N uptake efficiency and low N utilization efficiency (NUtE, seed yield/shoot N accumulation). Determining the NUtE phenotype of various genotypes in different growth conditions is a way of finding target traits to improve oilseed rape NUtE. The aim of this study was to compare oilseed rape genotypes grown on contrasting N supply rates in pot and field experiments to investigate the genotypic variations of NUtE and to identify indicators of N efficient genotypes. For 50 oilseed rape genotypes, NUtE, dry matter and N partitioning, morphological characteristics, and the yield components were investigated under high and low N supplies in a greenhouse pot experiment and a field trial. Although the genotype rankings of NUtE were different between the pot experiment and the field trial, some genotypes performed consistently in both two environments. N-responder, N-nonresponder, N-efficient and N-inefficient genotypes were identified from these genotypes with consistent NUtE. The correlations between the pot experiment and the field trial in NUtE were only 0.34 at high N supplies and no significant correlations were found at low N supplies. However, Pearson coefficient correlation (r) and principal component analysis showed NUtE had similar genetic correlations with other traits across the pot and field experiment. Among the yield components, only seeds per silique showed strong and positive correlations with NUtE under varying N supply in both experiments (r=0.47**; 0.49**; 0.47**; 0.54**). At high and low N supply, NUtE was positively correlated with seed yield (r=0.45**; 0.53**; 0.39**; 0.87**), nitrogen harvest index ( r=0.68**; 0.82**; 0.99**; 0.89**), and harvest index (r=0.79**; 0.83**; 0.90**; 0.78**) and negatively correlated with biomass distribution to stem and leaf ( r=-0.34**; -0.45**; -0.37**; 0.62**), all aboveground plant section N concentration (r from-0.30* to -0.80**), N distribution to the vegetative parts (silique husk, stem and leaf) (r from-0.40** to -0.83**). N-efficient (N-responder) genotypes produced more seeds per silique and had significantly higher NHI and HI than did N-inefficient (N-nonresponder) genotypes. In conclusion, across the pot and field experiments, the 50 genotypes had similar underlying traits correlated with NUtE and seeds per silique may be a good indicator of NUtE.

Spent coffee ground (SCG) is a main byproduct of the coffee industry and has been revalorized as a source of value-added products. The direct application of SCG as a soil amendment has drawn much attention in recent years as a more environmentally sustainable option. In this work, a comprehensive review of studies on the agricultural application of SCG is presented. The aims of this review were (1) to summarize the impacts of raw SCG on soil health and to identify the factors limiting its direct soil use, (2) to outline methods that are often used to upgrade SCG for soil application, and (3) to highlight the potential of SCG and its derivatives as a biocontrol agent and biofertilizer. The results indicate that raw SCG could improve certain soil health attributes, but plant growth is often limited owing to its phytotoxicity and induced N immobilization. To eliminate phytotoxicity, composting, vermicomposting, and thermochemical treatments have been employed but to a limited extent. SCG and its derivatives may be used as biocontrol agents for weeds, soil-borne pathogens, and pests. Novel bio-organic fertilizers based on SCG have also been developed. Future research should focus on the long-term effects of SCG and its derivatives as soil amendments under real scenarios and the underlying mechanisms, particularly the soil–plant–microorganism interactions.

Wheat (Triticum aestivum L.) grain quality is determined by multiple physical and chemical attributes. However, previous studies mainly focused on protein quantity and composition, which may not be adequate for understanding grain quality, especially end-use quality. Field experiments were conducted at two locations for two years to better understand how and to what extent water and nitrogen (N) availability affect flour end-use quality. Four drought stress levels (i.e., mild, moderate, severe, and well-watered) and four N rates (i.e., zero, low, medium, and high) were applied to two spring wheat cultivars (i.e., Dayn and Egan). Evaluated end-use quality traits, including milling quality, mixograph parameters, flour protein and gluten contents, solvent retention capacity (SRC), and baking quality. Most end-use quality parameters were not significantly different between the well-watered treatment and mild drought stress in both cultivars. Nitrogen availability above the low rate (168 kg N ha⁻¹) failed to further improve most end-use quality traits in either cultivar. Among all the end-use quality traits, lactic acid SRC may be a reliable indicator of flour end-use quality. These results indicate that mild drought stress (i.e., a 25% reduction in irrigation throughout the growing season) may not negatively affect end-use quality and excessive N fertilization offers minimal improvement in end-use quality. Such information could facilitate the development of irrigation and fertilization guidelines targeting at grain quality.

Background: In 2018, the Farm Bill mandated the United States Department of Agriculture to develop regulations governing the cultivation, processing, and marketing of industrial hemp. Industrial hemp is defined as Cannabis sativa L. with a total Δ-9-tetrahydrocannabinol (Δ-9-THC) content ≤0.3%. Therefore, for hemp to become an agricultural commodity, it is important to regulate production by developing standard methods for sampling and testing of the plant material. Methods: An ultra-performance liquid chromatography-tandem mass spectrometry analytical method for the quantification of twelve cannabinoids was developed. The method was applied to a regulatory sampling trial of three hemp varieties cultivated for cannabidiol (CBD) production. Two samples were taken from 28 plants with one sample being flower only while the other was a composite sample that included flowers, leaves, and stems. Results: The assay method was validated for specificity, range, repeatability, reproducibility, and recovery in accordance with all applicable standards for analytical methods. The results of the regulatory study indicated a significant decrease in the concentration of total Δ-9-THC and total CBD of 0.09% and 1.32%, respectively, between a flower only and a composite sample. Conclusions: There are many factors that may influence reported total Δ-9-THC content in industrial hemp. A robust analytical method was developed to analyze hemp samples in a trial regulatory study. The results indicate that the way hemp is sampled and analyzed may influence the legality of a crop, which could have negative economic and legal consequences.