Quaking aspen (Populus tremuloides Michx.) is being stressed across the America West from a variety of sources including drought, herbivory, fire suppression, development, and past management practices. Rich assemblages of plants and animals that utilize aspen forests, as well as economic values of tourism, grazing, hunting, and water conservation, make aspen ecosystems among the most valuable vegetation types in this region. The 43‐ha Pando clone near Fish Lake, Utah, is an iconic example of an aspen community undergoing rapid decline due to overstory mortality and chronic recruitment failure. As part of a larger project to restore Pando, we fenced, treated, and monitored a portion of this famous grove with the intent of documenting regeneration responses and using such practices at larger scales. Twenty‐seven randomly stratified monitoring plots were placed across this landscape in order to better understand herbivory and regeneration responses to distinct treatment categories: protected and unprotected, and passive (fenced only) and active (burning, shrub removal, selective overstory cutting) treatments. At each site, we measured basal area and mortality on mature trees, made counts of juvenile and intermediate suckers, documented browse levels and herbivore scat presence, and characterized environmental conditions in terms of aspen and common juniper cover, treatment type, elevation, slope, and aspect. Our results confirmed a positive regeneration response to browsing cessation after fencing, whereas non‐fenced areas showed no improvement. Within the fence, there was a significantly better response of active treatment vs. passive and there was no significant difference between treatment types in terms of level of regeneration. Both active and passive management produced regeneration levels that were sufficient to replace dying canopy trees if managers continue to protect suckers until they exceed the reach of browsers. These results support a growing body of research suggesting managers need to invest in continuous protection from herbivory in stable aspen forests, as well as targeting additional post‐treatment protection, to ensure adequate regeneration. We examine ramifications of these results for broader restoration purposes in the remainder of Pando, as well as other aspen communities regionally, with the ultimate goal of restoring ecological process toward greater ecosystem resilience.

Water culture methods for commercial crop production are now under research and development. Experiments have been performed primarily to investigate methods for preparing nutrient solutions. The objective of this study, however, was to develop a physical model for a water culture system. A study of nutrient uptake by egg plant (Solanum melanogena L. var. esculentum) as a function of both the solution and the root system properties in a soiless culture system is presented. The soiless culture system. is mathematically modelled with a one‐dimensional continuity equation for mass flow. The kinetics of nutrient uptake in the root system are treated in analogy with the kinetics of enzyme catalyzed processes. The system parameters are determined from experimental data for the two limiting cases of negligible and near‐total nutrient depletion from the solution. An experimental procedure which is intended both to test the validity of the mathematical model and to investigate better techniques for water culture systems is described. Both experimental anl theoretical results showed a rapid depletion in the system of the nutrient O2, and a more moderate depletion of other nutrients such as nitrate and K ions. The theoretical results can also be used to predict possible combinations of nutrient concentration, length of rows, and rate of water flow which afford optimal operation of the system.

Growers have many ideas for improving their farming operations, but there is always a certain amount of risk involved in implementing any change. A great way to minimize this risk is to test changes on a smaller scale by carrying out on‐farm experiments. Earn 0.5 CEUs in Nutrient Management by reading this article and taking the quiz at http://www.certifiedcropadviser.org/education/classroom/classes/700.

Small grain forages are commonly grown following alfalfa (Medicago sativa L.) in Utah and the Intermountain West, especially during drought years as small grains require less irrigation than corn (Zea mays L.). Several studies have shown that corn following alfalfa rarely needs nitrogen (N) fertilizer, yet few have evaluated N needs of small grains grown for forage. Objectives of this research were to determine whether N fertilizer is needed to economically optimize the yield and quality of first-year small grain forages following alfalfa, and whether spring soil nitrate tests can predict N responsiveness. Fertilizer trials (four replications of six N rates) were conducted on 11 first-year small grain forage sites in Utah during 2018 and 2019.Results indicated that N fertilizer was not needed to economically increase small grain forage yield at most (91%) site-years. The one responsive site-year followed an old and thinning alfalfa stand (9-yr old) and required only 67 kg N ha −1 . In contrast, forage quality improved with average N fertilizer applications ranging from 101 to 142 kg N ha −1 at all but one site-year. Soil nitrate concentration was able to separate yield and forage quality response to N in 73 and 53% of the cases, respectively, suggesting it may be a viable prediction test for yield and some aspects of quality response in this rotation. Results indicate that growers often do not need to apply fertilizer N to first-year small grain forages unless compensation for forage quality improvement outweighs fertilizer costs.

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