Irrigation practices can greatly influence greenhouse gas (GHG) emissions because of their control on soil microbial activity and substrate supply. However, the effects of different irrigation management practices, such as flood irrigations versus reduced volume methods, including drip and sprinkler irrigation, on GHG emissions are still poorly understood. Therefore, this review was performed to investigate the effects of different irrigation management strategies on the emission of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) by synthesizing existing research that either directly or indirectly examined the effects of at least two irrigation rates on GHG emissions within a single field-based study. Out of thirty-two articles selected for review, reduced irrigation was found to be effective in lowering the rate of CH4 emissions, while flood irrigation had the highest CH4 emission. The rate of CO2 emission increased mostly under low irrigation, and the effect of irrigation strategies on N2O emissions were inconsistent, though a majority of studies reported low N2O emissions in continuously flooded field treatments. The global warming potential (GWP) demonstrated that reduced or water-saving irrigation strategies have the potential to decrease the effect of GHG emissions. In general, GWP was higher for the field that was continuously flooded. The major finding from this review is that optimizing irrigation may help to reduce CH4 emissions and net GWP. However, more field research assessing the effect of varying rates of irrigation on the emission of GHGs from the agricultural field is warranted.

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No inverse relation existed between grain yield and protein when N > 100 kg ha -1 for Egan.• An inverse relationship between grain yield and protein in Egan was only evident at a very low N level.• An inverse relationship between Egan grain yield and protein was also evident with year, but grain protein remained at a premium level as long as N > 100 kg ha -1 .• Grain yield was limited via reduced productive tillers and grain number on a drought year.

High wheat (Triticum aestivum L.) grain yield and desirable quality must be considered to avoid market price penalty. Wheat classes and genotypes may respond differently to agronomic management and environmental conditions. Our goal was to characterize the yield, protein, test weight, and falling number of four hard red and four soft white spring wheat cultivars randomized within the five N levels over contrasting environments (rainfed and irrigated) in northwestern Montana. One‐third yield reduction from 2016 to 2017 was attributed to heat stress. Irrigation increased both grain yield and test weight. However, falling number was generally higher under rainfed environment, but was also cultivar dependent. ‘Egan,’ ‘McNeal,’ and ‘Alpowa’ falling number values were more resilient to environmental differences than other cultivars. Overall, soft whites had higher yields than hard reds, but with a stronger negative yield to protein relationship. Achieving high yield in hard reds via irrigation did not reduce grain protein in relation to rainfed, except at very low N (2017 control). The cultivar Egan, with Gpc‐B1 gene for higher grain protein, had similar yield to its parent material and to other hard red, though inferior to ‘Vida’ (characterized by extended green leaf duration after heading) under hot and dry conditions. During the less limiting year (2016), the maximum protein was achieved with much less N under irrigated environment compared with rainfed. Soft whites, due to lower grain protein requirement and lack of yield response to N in our study, can be grown with lower N input than hard reds. Core Ideas Egan (Gpc‐B1 gene cultivar) had superior grain protein with relatively no yield penalty Vida (stay‐green trait cultivar), Alturas, and UI Stone are more resilient under varied growing conditions and management Soft white market class had higher grain yield and stronger protein dilution than hard red

Core Ideas Boron (B) application increased petiole B in irrigated alfalfa but did not impact yield and quality. Low initial soil B is not a reliable measure of the need to amend with B using foliar application of irrigated alfalfa in Montana. Diagnosing signs of B deficiency coupled with in‐season petiole B analysis may be of better value to the producers. A boron (B) deficient soil may negatively impact irrigated alfalfa (Medicago sativa L.) plant tissue sufficiency, thereby compromising yield and quality in a short‐season environment such as Montana. The objective was to determine the impacts of B fertilization on irrigated alfalfa yield and quality in 2015 and 2016 at Creston and Dillon, MT on fine sandy loam and silt loam soils, respectively. The initial soil B levels at the Creston and Dillon sites were 0.2 and 0.8 ppm, respectively. The study was conducted as a randomized complete block design with five B levels: (1) 0; split applications of (2) 0.50, (3) 1.00, (4) 2.00; and a one‐time application of (5) 2.00 lb/ac in four replications. Full doses of Treatment 5 and half the dose of Treatments 2–4 were applied in early spring at a 3‐inch regrowth height. The other half dosage of Treatments 2–4 was re‐applied at a 3‐inch plant height after the first cutting. A liquid 10% B AgriSolutions was foliar‐applied as B fertilizer. All the cuttings were performed at 10% bloom. Application of B increased (P < 0.05) plant B concentration at both locations. Boron fertilization increased (P < 0.05) crop yield for the second cutting in 2015 at Dillon but did not influence all of the other seasonal cuttings nor total yields for either year or location. No significant effect of B on forage quality was observed. This research suggests foliar B fertilization based on a low B soil test is not beneficial for irrigated alfalfa producers in Montana.