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Several short‐term studies have investigated 4R (right source, rate, time, and place) N management for dryland wheat (Triticum aestivum L.) production and profitability, but few long‐term studies exist in the United States or abroad. This study evaluated long‐term impacts of several aspects of 4R N management on dryland hard red wheat yield, protein, and return to N. Experiments were conducted at Nephi and Blue Creek, UT, during 1995–2007. Fourteen N treatments evaluated performance of starter fertilizer, fall applications of anhydrous ammonia (AA) with and without nitrapyrin (AA‐Nitrapyrin and AA, respectively), and several split applications in the fall and spring. Across years, winter wheat required N to increase yield, protein, and returns at both sites. Applying 56 kg N ha−1 as AA in the fall usually produced the best return to N compared to other N treatments. Starter N (6 kg N ha−1) at fall planting rarely increased yield, protein, or returns at either site. Across both sites, nitrapyrin increased mean annual yield by 0.6 Mg ha−1 and mean return to N by $150 ha−1. Spring application of N was rarely required and only increased yield in 13% of the years. Results indicate that nitrapryin is often needed with fall AA applications to optimize yield and returns and that starter N or extra N in the spring are rarely economical in dryland wheat in Utah and possibly the greater Intermountain West. Further, N rate had the most influence among 4Rs on wheat production and should be the focus of future efforts to improve 4R stewardship. Core Ideas: Few long‐term studies have compared various 4R (right source, rate, time, and place) nitrogen aspects for dryland wheat–fallow systems.Across 13 years, fall fertilizer N was needed to optimize production and economics in dryland wheat–fallow system.Starter N and spring N applications rarely improved wheat yield, protein, or return to N.Nitrapyrin added to anhydrous ammonia increased mean annual yield by 0.6 Mg ha−1 and mean return to N by $150 ha−1.N rate had the most influence among 4Rs on wheat production and should be focus of future 4R stewardship efforts. [ABSTRACT FROM AUTHOR]

The host‐generalist two‐spotted spider mite [Tetranychus urticae (Acari: Tetranychidae); TSM] and host‐specialist Banks grass mite [Oligonychus pratensis (Acari: Tetranychidae); BGM] are common pests of corn (Zea mays L.) in the arid western United States. Climate warming and decreased precipitation may promote conditions favoured by these spider mites. However, rapid evolution of spider mite resistance to commercially available acaricides is driving the need for alternative solutions for managing outbreaks. Planting of drought‐tolerant corn hybrids has been proposed to be a dual‐purpose strategy for mitigating water deficits for irrigation and reducing leaf conditions favourable for BGM outbreaks. However, understanding of the mechanisms responsible for reducing the BGM in the field is lacking and determining whether outbreaks of the TSM can also be averted using drought‐tolerant corn is a pressing concern. We conducted a 2‐year field study testing a drought‐tolerant corn hybrid and an analogous drought‐susceptible hybrid under water‐stress, with artificially infested spider mite populations. Drought‐tolerant corn had larger stem diameter, more massive cobs, and greater leaf water mass compared to the drought‐susceptible corn under water stress. We also found that the BGM populations were reduced on drought‐tolerant plants under water‐stress, as expected, but we found an opposite trend in the TSM. Lastly, water‐stressed leaves were warmer, transpired less, and had higher carbon concentration, which contributed to larger investment in eggs and growth in the BGM. We anticipate that further evaluation of irrigation and crop drought‐tolerance in management of agriculture systems for multiple pest species will be increasingly impactful in arid regions. [ABSTRACT FROM AUTHOR]

Irrigation is a critical resource in meeting the global demand for food, feed, fiber, and fuel. One water optimization method with high potential and interest is the use of more efficient irrigation systems. In many areas where pivots are used, the most common sprinkler package is mid‐elevation sprinkler application (MESA), which typically has application efficiencies near 80%. Low‐energy precision application (LEPA) and mobile drip irrigation (MDI) can have greater than 95% application efficiency. The objective of this research was to evaluate the ability of LEPA and MDI to maintain crop yield and quality in alfalfa (Medicago sativa L.) and silage corn (Zea mays L.), at similar and reduced irrigation rates as MESA. The intent of the reduced rate was to determine if the decreased application losses with LEPA and MDI could result in sustained crop production with a 20% irrigation rate reduction. Actual reductions ranged from 5% to 55% depending on system and site due to equipment constraints. Data from two farms in Utah during 2018–2020 provided evidence that these systems can often maintain yield and forage quality with 5%–55% less applied water. However, there were also many instances where yield was reduced by LEPA and MDI, even with similar application rates to MESA. This indicates that the two higher efficiency systems will not save water in all cases and that the application system must be carefully evaluated in small on‐farm trials over multiple years for its ability to succeed in specific field conditions. Core Ideas: Low‐energy precision application (LEPA) and mobile drip irrigation (MDI) have high but inconsistent potential to maintain yield with less water than mid‐elevation sprinkler application.Low‐elevation sprinklers did not consistently benefit alfalfa and corn production with full or reduced irrigation.MDI often had severe rate reductions due to tubing flaws and thereby severed reduced alfalfa–corn production.Growers considering LEPA and MDI should test in small areas over multiple seasons to validate performance. [ABSTRACT FROM AUTHOR]

This research evaluated several methods to help reduce pivot ruts or wheel tracks on pivots. On-farm trials were established at nine site-years with corn (Zea mays L.), alfalfa (Medicago sativa L.) and wheat (Triticum aestivum L.) during 2020–2022 in Utah and Idaho. The eight-boom design (i.e., Advantage booms) had mostly positive crop responses but did not reduce wheel track depth. The part circle (PC) method provided much shallower tracks at one site, but it also lowered crop yield. At other sites there were minimal effects to yield and quality with the PC method, but the early-season, shallow wheel tracks did not usually last through the heaviest time of irrigating. The low energy precision application (LEPA) method was the most reliable method for maintaining crop yield and quality, while improving wheel tracks. The single boom method often maintained crop quality, but it also often reduced yield, and did not improve wheel tracks compared with the nontreated controls. The polyacrylamide had few effects on crop yield and quality, or wheel track depth. There was no approach in the study that maintained yield and reduced pivot track depth compared with no treatment in every scenario, but the LEPA method displayed the greatest potential for uniformly irrigating the area near the wheel track to maintain crop yield and quality, while minimizing water entering the track, to help reduce burdensome pivot ruts. Thus, LEPA may be one of the most effective sprinkler modifications for reducing pivot tracks and adequately irrigating the area around the track. This research evaluated how several sprinkler modifications and a soil conditioner help reduce pivot ruts or wheel tracks on pivot irrigation systems. On-farm research trials were established at six fields with corn, alfalfa, and wheat during 2020–2022 in Utah and Idaho. The eight-boom sprinkler modification had mostly positive crop responses but did not reduce wheel track depth. The part circle (PC) sprinkler method sometimes reduced wheel rut depth but came at the expense of lost crop production. The low energy precision application (LEPA) sprinkler method was the most reliable method for maintaining crop yield and quality, while improving wheel tracks. The single boom method often reduced yield and did not improve wheel tracks compared with the nontreated tracks. The polyacrylamide soil conditioner had few effects on crop yield and quality, or wheel track depth. There was no approach in the study that maintained yield and reduced pivot track depth compared with no treatment in every scenario, but the LEPA method displayed the greatest potential for uniformly irrigating the area near the wheel track and maintaining crop yield and quality. Thus, LEPA may be one of the most effective tools for reducing pivot tracks and adequately irrigating the area around the track. [ABSTRACT FROM AUTHOR]

Many breeds of dairy cattle exist, but questions remain about their relative performance within exclusively forage-based systems in the United States. This paucity of data is especially apparent in relation to heifer development, which is the second largest expense on most dairy farms. We evaluated the performance of prepubertal heifers from four different genetic backgrounds ("breeds") within a rotational grazing system in the Intermountain West. For each of two 105-day grazing seasons, 24 dairy heifers from each of four different breeds [Holstein (HO), Jersey (JE), Holstein/Jersey crossbred (HJ), and Swedish Red/Holstein/Montbeliarde crossbred (SHM)] were randomly assigned to one of two pasture treatments that consisted of either grass only (MONO) or grass interseeded with the legume birdsfoot trefoil (BFT; MIX). Main effects of treatment and breed (and potential interactions) on heifer average daily gain (ADG), change in percent mature body weight (CPMBW), fecal egg count (FEC), rumen volatile fatty acids (VFA), and body condition scores (BCS) were evaluated. There was a significant effect of pasture treatment on ADG, with MIX heifers averaging 0.48 kg of gain/day, whereas MONO heifers averaged 0.29 kg/day (P < 0.0001). Change in BCS was significantly affected by treatment (P = 0.0012) and breed (P < 0.0001). Significant effects of treatment (P < 0.0001), breed (P = 0.0005), and treatment*breed (P = 0.0005) on CPMBW were also found. Treatment and breed had no effect on FEC or total rumen VFA content (P > 0.05). Overall, we found that Jerseys were able to gain a higher percentage of their mature body weight and lose less body condition while on pasture than heifers of other breeds. We also found that grazing BFT can have significant positive effects on ADG, BCS, and CPMBW. Further research is needed to more thoroughly evaluate the influence of heifer genetics (breed) on metrics of growth, health, reproductive performance, and production in pasture settings. [ABSTRACT FROM AUTHOR]