Atmospheric Moisture Conditions Research Articles

Application of machine learning methods for crop rotation selection in organic farming system

This study demonstrates the possibility of crop rotation selection based on the assessment of productivity and sustainability of crop production under different atmospheric moisture conditions. The study considers 8 crop rotations oriented to grain production. The data obtained in long-term field experiments in the forest-steppe of the Novosibirsk region were used. As a result of the implementation of the decision tree (CART) and the use of ensemble algorithm (Random Forest) the construction of a model characterized by a fairly high predictive ability was performed. Standardized Precipitation Index was chosen as the main predictor characterizing atmospheric moistening in different periods of vegetation. The most stable from the point of view of stability of crop yield – grain-fallow with winter rye, grain-fallow with legumes (vetch-oats), in conditions of manifestation of atmospheric drought of different severity were selected. The possibility of using machine learning methods (CART, Random Forest) as effective tools in the selection of crop rotation for sustainable grain production without the use of chemicalization in soil and climatic conditions of Siberia, as well as the assessment of possible risks in the transition of crop production to organic technologies were scientifically substantiated.

Fast Beam Discovery and Adaptive Transmission Under Frequency Selective Attenuations in Sub-Terahertz Bands

Sub-THz-based communication needs ultra-large antenna arrays to generate pencil-like beams under the stringent requirements of line-of-sight (LoS) to overcome the effect of the rapid attenuation of signal strength, including atmospheric attenuation. In addition, the complexity of attaining narrower beamwidth, which also requires fast and perfect alignment between the TX-RX pair, makes the sector sweeping-based beam discovery approach no longer suitable. To solve these challenging problems, in this paper we propose a leaky waveguide (LWG)-assisted, high-resolution codebook-based beam discovery, precoding, and combining scheme together with an adaptive frequency hopping spread spectrum (FHSS) for a network with relays and small base stations (SBS). The proposed method can help the transmitter quickly determine a suitable beam pattern for an LoS path requiring only limited feedback information. In the beam discovery phase, we use LWG to attain valuable information about the angle of departure (AoD) and angle of arrival (AoA). LWG has also been used to identify frequency selective attenuated regions, which can change from time to time depending on the local atmospheric moisture conditions. To mitigate the impact of such attenuations, we opt for an adaptive Frequency Hopping Spread Spectrum (FHSS). The simulation results indicate that our beam discovery and FHSS based method can achieve a much higher performance than baseline methods.

Was Warming Amplified Under Drought Conditions Across China in Observations and Future Projections?

AbstractConcurrent hot extremes and droughts undoubtedly aggravate the impacts of droughts on agriculture, natural environment, and human society. Recent studies mainly focus on the trends and changes in frequency and severity of compound drought and hot extreme events. However, relatively little attention has been paid to the changes in mean temperature during drought conditions. In this study, we investigated the mean temperature changes during droughts in observed and projected periods across China on a century time‐scale and explored the possible contributions of land surface‐atmosphere interactions or atmospheric moisture conditions to these changes. China experienced reduced rather than amplified warming under droughts both in observations and future projections. A drier condition or a higher emission scenario was projected to result in a larger range of mean temperature changes under droughts in the future. We attributed the reduced mean temperatures under droughts to increasing winter droughts and higher atmospheric moisture conditions. This study provides a reference for water resource management, drought risk reduction, as well as mitigation of agricultural crop loss and public health damage.

Room-Temperature Synthesis of Air-Stable Near-Infrared Emission in FAPbI3 Nanoparticles Embedded in Silica.

Hybrid organic−inorganic and all-inorganic metal halide perovskite nanoparticles (PNPs) have shown their excellent characteristics for optoelectronic applications. We report an atmospheric process to embed formamidinium CH(NH2)2PbI3 (FAPbI3) PNPs in silica protective layer at room temperature (approximately 26 °C) employing (3-aminopropyl) triethoxysilane (APTES). The resulting perovskite nanocomposite (PNCs) achieved a high photoluminescence (PL) quantum yield of 58.0% and good stability under atmospheric moisture conditions. Moreover, the PNCs showed high PL intensity over 1 month of storage (approximately 26 °C) and more than 380 min of PNCs solutions in DI water. The studied near-infrared (NIR) light-emitting diode (LED) combined a NIR-emitting PNCs coating and a blue InGaN-based chip that exhibited a 788 nm electroluminescence spectrum of NIR-LEDs under 2.6 V. This may be a powerful tool to track of muscle and disabled patients in the detection of a blood vessel.

Features of water regime changes of steppe chernozem in the South-East of Central Chernozem zone in modern conditions

The article presents an analysis of the elements of the water regime of the steppe chernozems of the Stone Steppe of the Central Chernozem Region in the conditions of the dry period from the end of 2019 to the autumn of 2020. The objects of the study were: the mowed fallow land plowing in 1882, the old-growth forest strip of 1903 planting and arable land adjacent to fallow plots. The soil-hydrological constants were calculated (total water capacity, lowest field capacity, permanent wilting point) both in the time interval and down the soil profile to a depth of 2 m. The reserves of productive moisture during the growing season were also studied. The maximum values of productive moisture content was reached on the mowed fallow sites by the beginning of February, the minimum in the forest belt areas, the arable land plots had an intermediate value. By the middle of the growing season (June), 2020, the moisture reserves in the soils of the forest strip, fallow and arable land were 127, 123 and 109 mm, respectively, in the meter thickness. The highest amount of productive moisture in the upper soil horizon (0-20 cm) is observed under the forest belt – 39 mm. However, moisture content under the fallow land in the upper horizon had decreased to rate of the dead moisture reserve by early August. Similar values were found in soil under the forest belt and arable land. Otherwise, moisture profile was formed in underlying carbonate horizons. The forest belt soils in insufficient atmospheric moisture conditions in 2020 were more dried out than soil of fallow and arable land. The estimation was given for nature of soil profile changes of soil moisture profile due to influence of forest belt. The data of productive moisture reserves in soil at different distances from the forest belt were presented. In the meter layer at the edge of the forest belt, moisture reserves were at the level of 94.0 mm, sharply decreasing to 60.3 mm at a distance of 25 m from the forest strip, with a gradual decrease to 34 mm at a distance of 125 m. The results of observations showed a clear downward trend of productive moisture content due to distance from the old-growth forest belt.

УСТОЙЧИВОСТЬ КЛЕВЕРА ПОЛЗУЧЕГО (TRIFOLIUM REPENS L.) В СЕЯНЫХ ТРАВОСТОЯХ В ЗАВИСИМОСТИ ОТ ИХ СОСТАВА, КРАТНОСТИ СКАШИВАНИЯ И АЗОТНЫХ УДОБРЕНИЙ

The authors carried out studies at the experimental field station of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy in 2008–2020. The study aimed to determine the resistance of white clover in mixtures with various types of grasses with two- and three-cut clipping treatments. In the experiment with four to five-component mixtures, the proportion of white clover reached 36–53% in the botanical composition of swards with the content of perennial ryegrass in the fourth year of life. It did not exceed 22–23% in the mixtures with cock’s foot. With the application of nitrogen fertilizers at a dose of N180, the clover content in the second year of swards was only 1–27%. With the aging of the swards, the proportion of clover in the harvest decreased. In the ninth year of life, its amount in swards with the content of perennial ryegrass without nitrogen application decreased to 13–24%, and in agrophytocenoses with cock’s foot and with nitrogen application to 0–14%. The cock’s foot dominated in the four-component grass mixtures, but during the overwintering of 2015–2016, cock’s foot and perennial ryegrass almost entirely dropped out of agrophytocenoses. Tall fescue was a more resistant species. The yield of grass mixtures composed of grass varieties of Russian selection amounted to 4.16–5.52 t/ha of dry weight on average for eight years, and from varieties of Dutch selection, the yield equaled 4.07–5.24 t/ha. There were no significant differences in yield between grass-legume mixtures based on perennial ryegrass and cock’s foot. With the introduction of nitrogen in a dose of N180 on grass/legume herbage, the yield increased by only 31%, and the return on fertilizers by yield increases was low, making up 4.6–8.9 kg of dry matter per 1 kg of nitrogen. The aftereffect of nitrogen fertilizers on the yield of grass-legume mixtures without the additional introduction of phosphorus and potassium was insufficiently effective. In long-term three-component swards, used from the 14th to the 24th years of life, white clover was more stable in the composition of agrophytocenoses after three-fold mowing than with two-mowing. In years with favorable atmospheric moisture conditions, the proportion of white clover in two and three mows reached 20.1–34.7 and 2.2–24.3%, respectively, and with a moisture deficit, it decreased to 0–9%. For 26 years of growing grasses, there was a significant increase in soil acidity – pHKCl decreased from 6.3 to 4.91–5.36, which negatively affected the resistance of clover as the herbage was aging.

Estimation of 10-Hour Fuel Moisture Content Using Meteorological Data: A Model Inter-Comparison Study

Forest fire modeling often requires estimates of fuel moisture status. Among the various fuel variables used for fire modeling studies, the 10-h fuel moisture content (10-h FMC) is a promising predictor since it can be automatically measured in real time at study sites, yielding more information for fire models. Here, the performance of 10-h FMC models based on three different approaches, including regression (MREG), machine learning algorithms (MML) with random forest and support vector machine, and a process-based model (MFSMM), were compared. In addition, whole-year models of each type were compared with their respective seasonal models to explore whether the development of separate seasonal models yielded better estimates. Meteorological conditions and 10-h FMC were measured each minute for 18 months in and near a forest site and used for constructing and examining the 10-h FMC models. In the assessments, MML showed the best performance (R2 = 0.77–0.82 and root mean squared error [RMSE] = 2.05–2.84%). The introduction of the correction coefficient into MREG improved its estimates (R2 improved from 0.56–0.58 to 0.68–0.70 and RMSE improved from 3.13–3.85% to 2.64–3.27%) by reducing the errors associated with high 10-h FMC values. MFSMM showed the worst performance (R2 = 0.41–0.43 and RMSE = 3.70–4.39%), which could possibly be attributed to the lack of radiation input from the study sites as well as the particular fuel moisture stick sensor that was used. Whole-year models and seasonal models showed almost equal performance because 10-h FMC varied in response to atmospheric moisture conditions rather than specific seasonal patterns. The adoption of a hybrid modeling approach that blends machine-learning and process-based approaches may yield better predictability and interpretability. This study provides additional evidence of the lagged response of 10-h FMC after rainfall, and suggests a new way of accounting for this response in a regression model. Our approach using comparisons among models can be utilized for other fire modeling studies, including those involving fire danger ratings.

Distinct xylem responses to acute vs prolonged drought in pine trees.

Increasing dryness challenges trees' ability to maintain water transport to the leaves. Most plant hydraulics models use a static xylem response to water stress. Yet, in reality, lower soil moisture and warmer temperatures during growing seasons feed back onto xylem development. In turn, adjustments to water stress in the newly built xylem influence future physiological responses to droughts. In this study, we investigate the annual variation of anatomical traits in branch xylem in response to different soil and atmospheric moisture conditions and tree stress levels, as indicated by seasonal predawn leaf water potential (ΨL,pd). We used a 6-year field experiment in southwestern USA with three soil water treatments applied to Pinus edulis Engelm trees-ambient, drought (45% rain reduction) and irrigation (15-35% annual water addition). All trees were also subject to a natural 1-year acute drought (soil and atmospheric) that occurred during the experiment. The irrigated trees showed only moderate changes in anatomy-derived hydraulic traits compared with the ambient trees, suggesting a generally stable, well-balanced xylem structure under unstressed conditions. The artificial prolonged soil drought increased hydraulic efficiency but lowered xylem construction costs and decreased tracheid implosion safety ((t/b)2), suggesting that annual adjustments of xylem structure follow a safety-efficiency trade-off. The acute drought plunged hydraulic efficiency across all treatments. The combination of acute and prolonged drought resulted in vulnerable and inefficient new xylem, disrupting the stability of the anatomical trade-off observed in the rest of the years. The xylem hydraulic traits showed no consistent direct link to ΨL,pd. In the future, changes in seasonality of soil and atmospheric moisture are likely to have a critical impact on the ability of P. edulis to acclimate its xylem to warmer climate. Furthermore, the increasing frequency of acute droughts might reduce hydraulic resilience of P. edulis by repeatedly creating vulnerable and less efficient anatomical structure.

Effects of soil moisture on water transport, photosynthetic carbon gain and water use efficiency in tomato are influenced by evaporative demand

Although deficit irrigation has long been recognized as a water-saving practice, the beneficial effects on crop production and on water use efficiency under varying atmospheric evaporative demands has rarely been examined. In the present study, the coordinated effects of soil moisture and atmospheric vapor pressure deficit (VPD) on photosynthetic carbon gain versus water transport and water use efficiency in tomato were addressed. Experiments were designed with factorial combinations of two levels of VPD and two gradients of soil moisture. Low VPD (VPD < 1.0 kPa) compensated for the negative effect of soil water deficit on plant photosynthesis and productivity by reducing the resistance for CO2 transport. Moreover, low VPD moderated water stress by reducing the force driving passive water movement and preventing turgor loss, which sustained stomatal openness and reduced the resistance to CO2 uptake. In addition to stomatal conductance, the mesophyll conductance for CO2 transport from the substomatal cavities to the chloroplasts was increased synchronously in low-VPD-grown plants. The effect of water-use efficiency on the yields and plant biomass was substantially increased in the low-VPD treatment for both deficit irrigation and well-irrigated conditions. Water use efficiency was maximized in the combinatory treatment of deficit irrigation and low VPD. The present study demonstrated that the beneficial effect of deficit irrigation on tomato was amplified by decreasing VPD to the range of 0.5–1 kPa by decreasing the resistance for CO2 uptake from the atmosphere to the carboxylation site. Moreover, the adverse effects of deficit irrigation were pronounced with increased VPD when exceeding 1 kPa. Therefore, VPD plays significant roles in mediating the magnitudes of the beneficial or negative effects of deficit irrigation. The present study highlights the significance of the integrative regulation of soil and atmospheric moisture conditions, which provides novel insight for water-saving tomato production.

Trends in Persistent Seasonal-Scale Atmospheric Circulation Patterns Responsible for Seasonal Precipitation Totals and Occurrences of Precipitation Extremes over Canada

AbstractBoth large-scale atmospheric circulation and moisture content in the atmosphere govern regional precipitation. We partition recent changes in mean, heavy, and extreme precipitation for all seasons over Canada to changes in synoptic circulation patterns (dynamic changes) and in atmospheric moisture conditions (thermodynamic changes) using 500-hPa geopotential height and precipitation data over 1979–2014. Using the self-organizing map (SOM) cluster analysis, we identify statistically significant trends in occurrences of certain synoptic circulation patterns over the Canadian landmass, which have dynamically contributed to observed changes in precipitation totals and occurrence of heavy and extreme precipitation events over Canada. Occurrences of circulation patterns such as westerlies and ridges over western North America and the North Pacific have considerably affected regional precipitation over Canada. Precipitation intensity and occurrences of precipitation extremes associated with each SOM circulation pattern also showed statistically significant trends resulting from thermodynamic changes in the atmospheric moisture supply for precipitation events. A partition analysis based on the thermodynamic–dynamic partition method indicates that most (~90%) changes in mean and extreme precipitation over Canada resulted from changes in precipitation regimes occurring under each synoptic circulation pattern (thermodynamic changes). Other regional precipitation changes resulted from changes in occurrences of synoptic circulation patterns (dynamic changes). Because of the high spatial variability of precipitation response to changes in thermodynamic and dynamic conditions, dynamic contributions could offset thermodynamic contributions to precipitation changes over some regions if thermodynamic and dynamic contributions are in opposition to each other (negative or positive), which would result in minimal changes in precipitation intensity and occurrences of heavy and extreme precipitation events.

Management Implications of Snowpack Sensitivity to Temperature and Atmospheric Moisture Changes in Yosemite National Park, CA

AbstractIn order to investigate snowpack sensitivity to temperature increases and end‐member atmospheric moisture conditions, we applied a well‐constrained energy‐ and mass‐balance snow model across the full elevation range of seasonal snowpack using forcing data from recent wet and dry years. Humidity scenarios examined were constant relative humidity (high) and constant vapor pressure between storms (low). With minimum calibration, model results captured the observed magnitude and timing of snowmelt. April 1 snow water equivalent (SWE) losses of 38%, 73%, and 90% with temperature increases of 2, 4, and 6°C in a dry year centered on areas of greatest SWE accumulation. Each 2°C increment of warming also resulted in seasonal snowline moving upslope by 300 m. The zone of maximum melt was compressed upward 100–500 m with 6°C warming, with the range reflecting differences in basin hypsometry. Melt contribution by elevations below 2,000 m disappeared with 4°C warming. The constant‐relative‐humidity scenario resulted in 0–100 mm less snowpack in late spring vs. the constant‐vapor‐pressure scenario in a wet year, a difference driven by increased thermal radiation (+1.2 W/m2) and turbulent energy fluxes (+1.2 W/m2) to the snowpack for the constant‐relative‐humidity case. Loss of snowpack storage and potential increases in forest evapotranspiration due to warming will result in a substantial shift in forest water balance and present major challenges to land management in this mountainous region.

Estimating midday near-surface air temperature by weighted consideration of surface and atmospheric moisture conditions using COMS and SPOT satellite data

The measurement of near-surface air temperature (Ta) is critically important for understanding the Earth’s energy and water circulation system and for diverse modelling applications. Ta data obtained from meteological ground stations are basically available but not suitable for large-scale areas, because of their spatial limitation. Remote-sensing techniques can provide a spatially well-distributed Ta map. However, the current remote-sensing methodology for Ta mapping has accuracy inferior to common expectations in terms of the region of various terrestrial ecosystems and climatic conditions. Our aim was to develop a midday Ta retrieval algorithm with reasonable accuracy over Northeast Asia during one seasonal year. In consideration of the various environmental conditions in our study area, Ta was calculated using land surface temperature and the normalized difference vegetation index in the nine cases derived from the combination of surface and atmospheric moisture conditions, and a weighting factor was applied to reduce the bias error among Ta results from nine cases. The reasonable pixel window size was established as 13 × 13. The validation process yielded a coefficient of determination (R2), root mean square error, and bias values of 0.9401, 2.8865 K, and 0.4920 K, respectively. Although the study area includes diverse land-cover and climatic conditions, our satellite-derived Ta data provided better results compared with a previous study of only four cases with no weighting function in the Korean peninsula. Our suggested methodology will be useful in estimating Ta using satellite data, particularly over complex land surfaces.

Observations of Air–Sea Interaction and Intensity Change in Hurricanes

Abstract Recent enhancements to the tropical cyclone-buoy database (TCBD) have incorporated data from the Extended Best Track (EBT) and the Statistical Hurricane Intensity Prediction Scheme (SHIPS) archive for tropical cyclones between 1975 and 2007. This information is used to analyze the relationships between large-scale atmospheric parameters, radial and shear-relative air–sea structure, and intensity change in strengthening and weakening hurricanes. Observations from this research illustrate that the direction of the large-scale vertical wind shear at mid- to low levels can impact atmospheric moisture conditions found near the surface. Drier low-level environments were associated with northerly shear conditions. In a separate analysis comparing strengthening and weakening hurricanes, drier surface conditions were also found for the intensifying sample. Since SST conditions were similar for both groups of storms, it is likely that the atmosphere was primarily responsible for modifying the near-surface thermodynamic environment (and ultimately surface moisture flux conditions) for this particular analysis.

Variation of Hydrometeorological Conditions along a Topographic Transect in Northwestern Mexico during the North American Monsoon

Abstract Relatively little is currently known about the spatiotemporal variability of land surface conditions during the North American monsoon, in particular for regions of complex topography. As a result, the role played by land–atmosphere interactions in generating convective rainfall over steep terrain and sustaining monsoon conditions is still poorly understood. In this study, the variation of hydrometeorological conditions along a large-scale topographic transect in northwestern Mexico is described. The transect field experiment consisted of daily sampling at 30 sites selected to represent variations in elevation and ecosystem distribution. Simultaneous soil and atmospheric variables were measured during a 2-week period in early August 2004. Transect observations were supplemented by a network of continuous sampling sites used to analyze the regional hydrometeorological conditions prior to and during the field experiment. Results reveal the strong control exerted by topography on the spatial and temporal variability in soil moisture, with distinct landscape regions experiencing different hydrologic regimes. Reduced variations at the plot and transect scale during a drydown period indicate that homogenization of hydrologic conditions occurred over the landscape. Furthermore, atmospheric variables are clearly linked to surface conditions, indicating that heating and moistening of the boundary layer closely follow spatial and temporal changes in hydrologic properties. Land–atmosphere interactions at the basin scale (∼100 km2), obtained via a technique accounting for topographic variability, further reveal the role played by the land surface in sustaining high atmospheric moisture conditions, with implications toward rainfall generation during the North American monsoon.

Adequacy of using surface humidity to estimate atmospheric moisture availability for probable maximum precipitation

Because of limitations in sampling of atmospheric moisture, surface humidity is used to estimate atmospheric moisture availability for probable maximum precipitation (PMP) estimation. In practice, a pseudoadiabatic moisture profile is assumed to estimate precipitable water from surface 12‐hour persisting dew point. This assumption was evaluated for the central United States using surface and upper air observations. The results show that the pseudoadiabatic assumption systematically overestimates precipitable water for PMP estimation. The overestimation occurs for extreme rainstorms and for climatological maximum conditions because the surface humidity is high but the upper air is drier than predicted by a pseudoadiabatic profile. To better represent the moisture relationship for the central United States, an empirical power law moisture profile was derived from a 23‐year climatology of the monthly maximum precipitable water and monthly maximum 12‐hour persisting dew point. Moisture maximization concepts were then used to recompute PMP estimates for the Chicago area. The results suggest that the pseudoadiabatic assumption overestimates PMP by about 6.9% on average. An analysis of atmospheric conditions for extreme rainstorms also raises concerns regarding the PMP moisture maximization assumption that such storms could occur under maximum atmospheric moisture conditions.

Intense near-infrared luminescence of anhydrous lanthanide(III) iodides in an imidazolium ionic liquid

Anhydrous neodymium(III) iodide and erbium(III) iodide were dissolved in carefully dried batches of the ionic liquid 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C 12mim][Tf 2N]. Provided that the ionic liquid had a low water content, intense near-infrared emission could be observed for both the neodymium(III) ion and for the erbium(III) ion. Luminescence lifetimes have been measured, and the quantum yield of the neodymium(III) sample has been measured. Exposure of the hygroscopic samples to atmospheric moisture conditions caused a rapid decrease of the luminescence intensities.

Effects of Soil and Atmospheric Moisture Conditions on Ecophysiological Characteristics in Crop Plants

Effects of Soil and Atmospheric Moisture Conditions on Ecophysiological Characteristics in Crop Plants

Development of Foliar Diseases of Alfalfa in Relation to Microclimate, Host Growth, and Fertility

Foliar diseases of alfalfa in four fertility treatments and an untreated control were evaluated in relation to microclimate, host growth, and soil fertility during 1991 and 1992. Over the course of six growth periods, alfalfa growth and disease development varied significantly. Disease incidence and severity were greater on leaves from the lower half of shoots than on leaves from the upper half. Disease development depended on moisture conditions. The relationship of disease to moisture varied between the upper and lower halves of shoots. Disease on the lower half of shoots was correlated with leaf wetness duration as well as atmospheric moisture conditions; disease on the upper half of shoots was correlated only with cumulative rainfall

Verres fluores a base de metaux lourds. Etude de la corrosion par la vapeur d'eau atmospherique

Chemical durability of ThF 4 BaF 2 glasses has been investigated in atmospheric moisture conditions. Corrosion of the melt by the vapor contaminates all the vitreous bulk. The corrosion of OH free glass until T g is only a surface phenomenon depending on a diffusion process.

European Crane Fly: Larval Infestations in Grass Cultivars12

The effects of larvae of Tipula paludosa Meigen on 20 irrigated and unirrigated forage grass cultivars and 21 irrigated turfgrass cultivars were evaluated from 1973 to 1975 by determining numbers of larvae in soil cores and examining associations between agronomic characters of the grasses and numbers of larvae. Only minimum infestations of larvae developed in unirrigated forage grasses. Differences in numbers of larvae between irrigated forage grass cultivars were numerically large but not statistically significant, but there were some instances in which an inverse association between hay yields and numbers of larvae was statistically significant. Associations between numbers of larvae and broadleaf weeds in irrigated forage grasses were numerically moderate but had questionable biological significance, and no associations were apparent between stands of weedy grasses or irrigated forage grasses and numbers of larvae. Differences in numbers of larvae between individual turfgrass cultivars were statistically significant but not sharply defined. However, comparisons of turfgrass types showed well-defined differences in numbers of larvae. The number of larvae in ryegrass plots was less by an average factor of 2.4 than numbers in fescue, blue, or bentgrass plots. Differences in larval population levels between irrigated and unirrigated forage and turfgrasses were attributed to differences in soil and atmospheric moisture conditions during the oviposition periods of the European crane fly.