Efficiency of recycled nitrogen from residues of maize (Zea mays), soybean (Glycine max) and moong (Vigna radiata) on wheat (Triticum aestivum) grain yield

Summary A laboratory incubation experiment followed by a greenhouse experiment was made in a silty clay loam at Pantnagar, India, to recycle plant utilizable N from crop residues such as maize stubble, soybean hay andmoong straw. The beneficial effect of recycled N was tested by a wheat crop. Soybean hay yielded the most NO₃–N upon mineralization and also gave the highest wheat grain yield. Maize stubble mineralized the least NO₃–N and gave the lowest grain yield.Moong straw occupied an intermediate position. An intervening period of 30–45 days would be required for the residues in question to release plant utilizable NO₃–N in sufficient quantities. From a practical view point, soybean hay appears to be an ideal choice of a residue capable of providing sufficient supplemental N for a succeding wheat crop and can be easily fitted into the prevalent cropping sequence.     

Determining When Bobolink Finish Breeding to Time Agricultural Activity in Nesting Refuges

Conservation actions are ongoing for the federally and provincially threatened bobolink (Dolichonyx oryzivorus) in Ontario, Canada because of population declines. One conservation action being implemented in agricultural grasslands is the delay of hay harvesting and livestock grazing until 15 July, a general guideline for when bobolink finish breeding. Efficient methods to assess when breeding ceases could benefit bobolink and farmers engaged in conservation by ensuring nesting is finished before agricultural activity occurs and enabling agricultural activity earlier when breeding is finished before 15 July. We conducted field surveys to assess if low-intensity surveys (i.e., transect surveys, point counts, roadside counts) could accurately detect when bobolink finish breeding compared to intensive monitoring (i.e., spot mapping and nest monitoring). We monitored 29 pastures in 2017 in eastern Ontario and 9 hay fields, 10 restored grasslands, and 6 fallow fields in 2018 in southern Ontario. The date breeding finished varied across fields in 2017 from 13 June to 29 July and in 2018 from 24 June to 30 July, based on spot mapping and nest monitoring. Transect surveys and point counts were good predictors of breeding in a field, as confirmed through spot mapping and nest monitoring, based on generalized linear mixed models. We recommend using transect surveys or point counts as an efficient field method to assess when bobolink finish breeding in a field targeted for bobolink conservation. Our results suggest that 2 consecutive visits that fail to detect evidence of breeding in early July are needed to reasonably infer that breeding has likely finished, leaving a small probability (i.e., <0.01) that breeding may still be occurring. Determining when bobolink finish breeding in fields intended to provide nesting refuges can help maximize conservation benefits and minimize negative effects on agricultural production. © 2020 The Wildlife Society.     

Study of airborne pollen composition and allergen spectrum of hay fever patients in South Hungary (1990–1999)

On the basis of their 10-year-longaeropalynological and allergological studies,the authors examined the changes in theallergen spectrum of hay fever patients inconnection with the seasonality of the symptomsand pollen count of this period of 10 years.The results of skin prick tests (SPT) and casehistories of patients examined in 1990/91 and1998/99 were compared. Pollen counting wasperformed with a Hirst-type pollen trap. By theend of the observed period, the ratio ofseverely polysensitized patients (4 or morepositive skin prick tests) increasedsignificantly according to the significantlyincreased amount of positive skin prick teststo trees, rye and plantain. As the seasonalityof the patients' symptoms did not change duringthis period, this increase in skin prick testpositivity means latent allergy. However, in afew years time, it may become manifest allergycausing symptoms in the early springtime.According to the results of pollen counting,the atmospheric pollen pollution of the regionwas markedly high during the possiblesensitization period of these patients.     

The life and death of barn beetles: faunas from manure and stored hay inside farm buildings in northern Iceland

1. Subfossil beetle remains from archaeological sites have proven invaluable for examining past living conditions, human activities, and their impacts on landscapes and ecosystems. 2. In Iceland, specific economic practices (e.g. land management and natural resource exploitation) and major historical events (i.e. colonisation, economic intensification and commercialisation, and urbanisation) have affected local environments and left recognisable traces in the beetle subfossil record. 3. Understanding the ecology of synanthropic beetles is crucial if they are to be employed in high‐resolution reconstructions of past lifeways and their ecological impacts, yet, because buildings' interiors are rarely the object of systematic entomological research, the ecological requirements of many such species are poorly understood. 4. A survey was conducted of live and dead beetle faunas from habitats that have so far been largely neglected by entomological research: stable manure and stored hay inside farm buildings, two key facets of a northern European pastoral economy. 5. The present results clarify the ecological requirements of some under‐studied synanthropic beetles and the processes by which their exoskeletons may become incorporated into the archaeological record while also producing new records of exotic species recently introduced to Iceland. 6. This paper provides crucial guidance for the interpretation of archaeological beetle assemblages and highlights the potential of further investigations of indoor insect faunas for clarifying the causes, processes, and ecological impacts of recent bio‐invasions.     

Microclimate and fluxes of water vapour, sensible heat and carbon dioxide in structurally differing subalpine plant communities in the Central Caucasus

Effects of canopy structure on microclimate, energy budget and CO₂ exchange were analysed in a pasture, two hay meadows, a tall herb community and a dwarf shrub community in the subalpine belt of the Central Caucasus. The results show that canopy structure exerts a marked influence on the distribution of photon flux density, temperature and canopy photosynthesis A_c. Three canopy types were distinguished. Type 1 (pasture) has a small LAI (leaf area index) and more than two-thirds of the phytomass is concentrated in the lowest few cm of the canopy, mainly as planophile leaves. This results in (1) a low degree of utilization of photosynthetic photon flux density (PPFD) by assimilatory plant components, (2) high leaf temperatures and a high soil heat flux during the phase of incoming radiation, and (3) a relatively low A_c/ LAI ratio. Type 2 (meadows), in spite of its erect leaves, which at high solar elevations permit light to penetrate to the lower canopy layers, is characterized by (1) marked effects of mutual shading in the lower canopy layers for most of the day, and thus (2) only slight variations in air and leaf temperatures and (3) a comparatively low A_c/LAI ratio. In canopies of type 3 (tall herb and dwarf shrub communities), there is a concentration of flat leaves in the upper layers. This results in (1) very good utilization of PPFD; (2) no strong fluctuations in canopy temperature as the flat leaves act as a buffer, reducing the amounts of incoming and outgoing radiation in lower canopy layers, and (3) high values of the A_c/LAI ratio. The energy budgets of the canopies investigated are governed not so much by their spatial structure, but rather indirectly by LAI and the degree of coupling of the canopy with the atmosphere.     

Transfer seeds,hay, or soil blocks? The importance of the completeness of biological inputs to address dispersal and establishment limitations during the restoration of plant assemblages in floodplain grasslands

This study investigated different techniques of grassland restoration to overcome dispersal or establishment limitation, which are key processes influencing early-successional plant community assembly. A fully randomized in situ experiment was set up in a former arable land in a floodplain along the Garonne river (south-western France) to test for the effect of (1) the type and completeness of the biological input (any biological material—seed, hay, and soil—transferred to the site under restoration), (2) soil disturbance by deep tillage, and (3) their interaction on plant community dynamics for 5 years. All inputs influenced the plant community structure and composition. The effects depended on the type of the input but not necessarily in link with its completeness. High density and diversity seed mixture led to high levels of richness and relative abundance of target species like soil blocks, the input considered as the most complete. During the first year, hay transfer mostly influenced community assembly through negative litter effects. Delayed germination of several species contributed to buffer these early effects. This study supports the importance of dispersal limitation during early succession in degraded grassland ecosystems whereas soil disturbance had only subtle effects on the seed bank and standing plant community, indicating that competition and establishment limitation were of secondary importance in our study system. Our results suggest that even low-frequency immigration events (e.g. when a few seeds are transferred within hay) can be of great importance providing that a sufficiently long time period is considered for grassland restoration.