Stubble Fields Research Articles

Niektóre cechy biologiczne Agrostemma githago L. i Centaurea cyanus L. w różnych siedliskach Wysoczyzny Siedleckiej

The analysis of biological features of Centaurea cyanus and Agrostemma githago as well as their variability and diversity, depending on the occupied habitats, is presented in the paper. For this purpose, 30 specimens were randomly collected from each studied habitat – stubblefields, winter cereals and spring cereals and put to the morphological analysis with respect of the height of plant, number of ramifications of 1st and 2nd categories, length of the ramifications, number of inflorescences, number of seeds at one plant, a thousand-seed weight and aerial dry mass of plant. The values of features were used for statistic calculations. Centaurea cyanus and Agrostemma githago populations collected in Siedlecka Upland habitats revealed internal variability in respect to all analyzed features. Specimens of Centaurea cyanus differed from each other with regard to the above mentioned features, depending on habitat type. Significant differences between populations occurring in winter cereals, depending on the soil conditions as well as between individuals originating from rye cultivations and stubble-fields in identical soil conditions, were demonstrated. Moreover, no significant differences between populations developing in winter and spring cereals on the analogical soil type were found. 
 No significant differences between the majority of the investigated features of Agrostemma githago specimens, developing in rye cultivations and in stubble fields in the same soil conditions were noted. There were also no significant differences in features of the studied species between 2005 and 2006 – no interactions between year of studies and habitat type were observed.

Habitat use by Carrion CrowsCorvus corone coroneand Hooded CrowsC. c. cornixand Their Hybrids in Eastern Germany

The habitat use of crow phenotypes (Carrion Crow, Hooded Crow, hybrids) was studied in the hybrid zone between Magdeburg and Dresden in eastern Germany. 1326 individuals (n = 293 hybrids, 417 Hooded Crows, 616 Carrion Crows) were sampled between 8 April and 12 July 2006. The study area was divided into eleven grid rectangles, 20 geographical minutes latitude by 32 minutes longitude in size. Carrion Crows, Hooded Crows and hybrids differed significantly in their habitat use. Carrion Crows avoided stubble fields with stubble taller than 15 cm, whereas the Hooded Crows were found significantly more frequently on those fields. Even when the stubble field data was pooled into one category, differences remained, with the Hooded Crows preferring maize stubble and the Carrion Crows avoiding it.

Classification of weed vegetation of arable land in the Czech Republic and Slovakia

Numerical classification of 2653 geographically stratified releves of weed vegetation from the Czech and Slovak Republics was performed with cluster analysis. Diagnostic species were determined for each of the seven main clusters using statistical measures of fidelity. The classification reflected clear distinctions between lowland (mostly calcicole) and highland (mostly calcifuge) sites, spring and summer phenological stages, and cereals and root crops. The results of the cluster analysis were compared with traditional phytosociological units. Two clusters corresponded to calcifuge weed vegetation of the Scleranthion annui alliance; one cluster represented the vegetation of root crops on moist soils of the Oxalidion europaeae alliance; one cluster contained thermophilous weed vegetation of the Caucalidion lappulae alliance; two clusters included weed vegetation of root crops and of stubble fields, which can be assigned to the Caucalidion, Panico-Setarion, Veronico-Euphorbion and Eragrostion alliances; one cluster included vernal weed vegetation in little disturbed habitats of the Caucalidion lappulae and Scleranthion annui alliances. Our analysis did not support the concept of the Sherardion and Veronico-Taraxacion alliances, which were included in earlier overviews of the vegetation units of the Czech Republic and Slovakia.

Winter diet of reed bunting Emberiza schoeniclus in fallow and stubble fields

An analysis of droppings collected in winter on unused fields in SW Poland (fallow, stubble of root crop, vegetable and cereal) showed that the base of the reed bunting Emberiza schoeniclus diet were seeds of annual weed species: Chenopodium album (74.06% of all recorded seed species), Amaranthus retroflexus (16.05%), Setaria viridis (9.50%), Stellaria media (0.21%), Fumaria officinalis (0.01%). The share of dominant weed species in the diet of reed bunting wintering on particular types of fields varied markedly. In the droppings from fallows and cereal stubbles, C. album clearly dominated (respectively, 88.60 and 66.12%). The highest proportion of A. retroflexus and S. viridis was detected in the diet of birds staying on root crop stubbles (respectively, 45.56 and 23.90%). The most diverse food composition was found in the case of birds feeding on root crops and the least diverse on fallows.

Altering perceived predation risk and food availability: management prescriptions to benefit farmland birds on stubble fields

Summary European farmland bird populations have fallen dramatically and sympathetic management of key habitats is one crucial way to help boost these populations. Maximizing the value of habitats for foraging birds has largely focused on practical measures to increase food abundance, but energy intake, the key determinant of habitat quality, is also affected by food accessibility and perceived predation risk. We tested the importance of manipulating perceived predation risk and access to food on the distribution of birds on stubble fields, a key wintering habitat for many UK species and used by many species in different parts of the world. Recent evidence suggests simple reductions in vegetation height alter perceived predation risk for some species. Light cultivation, by scarification of the soil surface, could potentially alter both perceived predation risk (via changes in vegetation structure) and food availability (by opening up the soil and bringing seeds to the surface) and so be a single solution to enhancing suitability of stubble fields for birds. In experiment 1, we investigated the effects of changing vegetation height (via topping) and scarification on vegetation structure, seed density and distribution of farmland birds, using a 2 × 2 factorial within‐field design. In experiment 2, we tested the temporal effects of scarification on bird distribution, using a similar within‐field design. Scarified plots supported higher abundances of invertebrate feeders (e.g. thrushes). Plots that were scarified within the last 1–13 days were used more by invertebrate feeders and granivores (e.g. yellowhammer) than plots scarified 2–4 months ago. Both results were probably a consequence of food availability being temporarily increased by scarification making prey more accessible. Granivorous passerines and invertebrate feeders preferred plots with shorter stubble while the abundance of skylarks, partridges, pigeons and meadow pipits was higher on plots with taller stubble. This was probably the result of differing anti‐predation strategies. Synthesis and applications. Prescriptions that generate fine‐scale heterogeneity should benefit a range of species. Although our work was confined to stubble fields, the importance of simultaneous consideration of predation risk and access to food is likely to apply across European farmland landscapes and elsewhere, and could apply to other arable crops and potentially to grassland systems. On stubble fields specifically, topping of part of the field in the autumn could be combined with successive strip scarification treatments throughout the winter, to provide optimal conditions for a range of species. This could be incorporated as a management option in agri‐environment schemes such as the English Environmental Stewardship Scheme.

Incorporating sheep into dryland grain production systems: I. Impact on over-wintering larva populations of wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae)

Wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae) is the most damaging insect pest to Montana's $ 1 billion dollar per year grain industry. Current WSS control methods are either expensive, reduce wheat yields, or are not effective. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on over-wintering WSS larval populations. Treatments were evaluated in three experiments using a randomized complete block design and four replications at each site. Eight, six, and two sites were used for Experiments 1, 2, and 3, respectively. Contrast statements were used to make pre-planned comparisons among treatments. For Experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. Five mature ewes were confined with electric fence to 111 m 2 plot for 24 h in the fall and spring grazed treatments resulting in a stocking rate of 452 sheep d/ha. For Fall/Spr, the stocking rate was 904 sheep d/ha. For Experiment 2, treatments were fall grazed, fall burned, fall tilled, and an untreated control. In Experiment 3, treatments were fall trampled, spring trampled, Fall/Spr trampled, hand clipped to a stubble height of 4.5 cm, and an untreated control. Trampled treatments were done at the same stocking rates as grazing treatments but sheep were muzzled to prevent intake. Wheat stem sawfly larval numbers were collected in the fall and spring, pre- and post-treatment, respectively, by collecting all plant material from three, 0.46 m lengths of row and counting the number of live larvae present. In Experiment 1, WSS mortality was greater ( P < 0.01) for the mean of all grazed treatments (68.4%) than either control (43%) or tilled (47%) plots. Mortality did not differ ( P = 0.75) between fall (67%) and spring (64%) grazed plots but was greater ( P = 0.02) for Fall/Spr (74%). In Experiment 2, larva mortality was greater ( P < 0.01) for fall grazed (63%) than burned plots (52%). In Experiment 3, WSS mortality was greater ( P < 0.01) for the mean of all trampling treatments (57%) than either control (33%) or clipped (32%) plots. Mortality did not differ ( P > 0.25) between fall (54%) and spring trampling (47%) but was greater ( P = 0.01) for Fall/Spr (70.6%). No differences ( P > 0.25) were detected for WSS mortality when grazing was compared to trampling. These results indicate the potential for using grazing sheep to control wheat stem sawfly infestations in cereal grain production systems.

Incorporating sheep into dryland grain production systems: II. Impact on changes in biomass and weed density

Weed control in fallow management to conserve soil moisture and nutrients is the largest variable cost to dryland grain production. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on changes in total aboveground biomass and weed density. Treatments were evaluated in three experiments using a randomized complete block design for each experiment with four replications at each site. Contrasts statements were used to make pre-planned comparisons. For experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. For grazing treatments, five mature ewes were confined with electric fence to 111 m 2 plot for 24 h for fall and spring resulting in a stocking rate of 452 sheep day/ha. For Fall/Spr the stocking rate was 904 sheep day/ha. For experiment 2, treatments were fall grazed, fall burned, fall tilled, and an untreated control. In experiment 3, treatments were fall trampling by sheep, spring trampling by sheep, fall and spring combined (Fall/Spr) trampling by sheep, stubble hand clipped to a height of 4.5 cm, and an untreated control. Trampling treatments were applied at the same stocking rates as grazing treatments but sheep were muzzled to prevent intake. Data were collected in the fall, prior to treatment imposition, and spring, after treatments had been removed. Post treatment biomass and weed density were greater ( P < 0.05) in either control or tilled plots when compared to grazed plots. Post treatment biomass and weed density were greater ( P < 0.01) for control than burned plots. Post treatment biomass, weed density, and percent change in these variables, did not differ ( P > 0.08) between burned and tilled, and burned and grazed treatments. These results indicate the potential for using grazing sheep as a component in fallow management to reduce biomass and control weeds.

Incorporating sheep into dryland grain production systems: III. Impact on changes in soil bulk density and soil nutrient profiles

Changes in soil bulk density and soil nutrient profiles are a major concern of dryland grain producers considering grazing sheep on cereal stubble fields. Our objective was to compare burned, grazed, tilled, trampled and clipped wheat stubble fields on changes in soil bulk density and soil nutrient profiles. Treatments were evaluated in a series of three experiments using a randomized complete block design and four replications at each site. Contrast statements were used to make pre-planned comparisons among treatments. For Experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined ( Fall/ Spr) grazed, and an untreated control. Five mature ewes were confined with electric fence to a 111 m 2 plot for 24 h for fall and spring grazed plots resulting in a stocking rate of 452 sheeps d/ha. For Fall/Spr, the stocking rate was 904 sheeps d/ha. For Experiment 2, treatments were fall grazed, fall burned, fall tilled, and an untreated control. In Experiment 3, treatments were fall trampling by sheep, spring trampling by sheep, fall and spring combined (Fall/ Spr) trampling by sheep, hand clipping to a stubble height of 4.5 cm, and an untreated control. Trampling treatments were done at the same stocking rates as grazing treatments but sheep were muzzled to prevent intake. In Experiment 1, post-treatment organic matter tended to be greater ( P = 0.09) in the mean of the grazed treatments than control plots. In all of the experiments, change in soil bulk density, and soil nutrient profiles did not consistently differ ( P > 0.07) among treatments in any manner that would suggest a detrimental impact of grazing sheep on small grain residue. These results indicate a strong potential for grazing sheep on grain stubble without adversely impacting soil bulk density or nutrient profiles.

Stubble height affects the use of stubble fields by farmland birds

Summary In the UK, over‐wintered stubbles are an important foraging habitat for farmland birds, many of which are of current conservation concern. Maximizing the value of stubbles for farmland birds has largely focused on increasing food abundance but has ignored other aspects of foraging behaviour, such as predator avoidance and vigilance. In this study we investigated the effects of stubble height reduction on seed depletion and the within‐field distribution of farmland birds. Stubble on one half of each of 20 fields was topped to lower vegetation height, while the other half was left untouched to act as a control area. The abundance of granivorous passerines and invertebrate feeders was higher on treatment plots, which had undergone stubble height reduction, while the abundance of skylark and partridges was higher on control plots. Topping had no effect on the within‐field distribution of either corvids or pigeons. Seed densities on both plot types fell between November and March, but there was no significant difference in levels of depletion between treatment and control plots. For many species, food accessibility and detectability are likely to have been higher, and thermo‐energetic and mobility costs lower, on treatment plots. Stubble height reduction could have led to either an increase or a decrease in associated predation risk, depending on the predator escape strategy of a species. Granivorous passerines, which flee to cover, are likely to have benefited from the reduced visual obstruction on treatment plots, while partridges, which rely on crypsis, will have benefited from the greater protection offered by the longer vegetation in control plots. Synthesis and applications. Increasing the structural heterogeneity of over‐wintered stubble is likely to increase its value as a foraging habitat, making it better suited to the foraging requirements and predator escape strategies of a greater diversity of species. Incorporating explicit management options into agri‐environment schemes, such as the new Environmental Stewardship Scheme, may represent a cost‐effective strategy to achieve this.

The roost-feeding area complex of Taiga Bean Goose Anser f. fabalis in the Ume River Delta Plains, Sweden—foraging patterns in comparison with Greylag Goose Anser anser, Whooper Swan Cygnus cygnus and Eurasian Crane Grus grus

In spring 2004, numbers of staging Taiga Bean Goose Anser f. fabalis, Greylag Goose Anser anser, Whooper Swan Cygnus Cygnus, and Eurasian Crane Grus grus were counted at the roost and at feeding grounds in and adjacent to the NATURA 2000 site Ume River Delta and Plains, Umeå, Sweden (SE0810475). For the Taiga Bean Goose a significant, negative relationship was found between total feeding time and the distance to the only roost. The most attractive feeding sites were stubble and non-harvested fields on moist or inundated soil within 2 km from the roost. The geese chose fields to minimize flight distances and disturbances from human activities. The Whooper Swan showed similar preferences as the Taiga Bean Goose, but it showed even a higher preference for inundated fields close to the roost. The Eurasian Crane showed a higher preference for the large central area of the plains, likely because of its sensitivity to disturbance. The Greylag Goose showed a very different foraging pattern with a greater preference for dryer uplands with cut hay fields.

Effects of field management and landscape context on grassland wintering birds in Southern Portugal

This study examined the multi-scale effects of farmland management on the assemblages of grassland wintering birds in Southern Portugal, evaluating the potential influences on bird conservation of ongoing transformations in agricultural landscapes. The bird assemblages of 42 grassland fields were characterised and related to three sets of variables reflecting field management, landscape context and large-scale spatial trends. Birds showed responses to the three sets of variables, with variation partitioning indicating that species richness was primarily influenced by landscape context, whereas abundances were mostly determined by field management. In general, high species richness was associated with small patches of arable land, diverse landscapes, high stream density and forest and shrub cover, which probably acted as sources of non-agricultural species to grassland fields. In contrast, fields located in homogenous arable landscapes tended to be species poor, though they were the most favourable for open farmland species of conservation concern (e.g. skylark, calandra lark and little bustard). Old grazed fallows were generally associated with the highest abundances of both invertebrate and seed-eating birds, particularly that of winter visitors. Seed-eating winter visitors were also associated with stubble fields. The results indicated that conservation of Iberian grasslands for wintering birds requires management at both the landscape and field scales. At the landscape level, large blocks of open farmland habitat need to be maintained. At the field level, conservation management should strive to maintain both stubble fields and old grazed fallows. The application of such prescriptions would require a combination of agri-environmental programs and land planning policies, whereby the financial support to individual farmers should be conditional on the maintenance of adequate landscape contexts at larger spatial scales.

Plant diversity and storage at Mandalo, Macedonia, Greece: archaeobotanical evidence from the Final Neolithic and Early Bronze Age

The charred plant remains from Final Neolithic and Early Bronze Age levels at Mandalo, Macedonia, Greece provide evidence for a broad range of crops and wild plant resources. There is clear evidence for the storage of some of these, in particular emmer, lentils and bitter vetch, but also barley, einkorn, Celtic bean, grass pea and acorns. There is also evidence for the possible storage and use of animal dung fuel, which has not previously been reported for Greece, and for the cultivation of flax dating back to the 5th millennium BC. The diversity of plant resources will have provided a ‘buffering mechanism’ against occasional crop failure, and the relationship of this to the proposed ‘marginal colonization’ of Greece is discussed. On the basis of the species found in animal dung, it is suggested that the arable and pastoral sectors were integrated, with relatively small numbers of animals grazed locally on stubble or fallow fields.

Rice yellow mottle virus Is Transmitted by Cows, Donkeys, and Grass Rats in Irrigated Rice Crops.

Rice yellow mottle virus (RYMV), endemic in Africa, is believed to be spread by chrysomelid beetles, although the infections in a field often cannot be explained by the prevailing number of beetles. We show that the grass rat Arvicanthis niloticus, domestic cows (Bos spp.), and donkeys (Asinus spp.) are potent and efficient transmitters of RYMV. Spread of RYMV by rats was demonstrated in cage experiments wherein individual rats transmitted the virus from healthy to infected rice plants and confirmed in a field experiment. Experiments with cows and donkeys showed that they could transmit the virus in plots with healthy and infected plants and to plots with healthy plants. A high percentage of seedlings became infected when a cow grazed in a seedbed after being fed with infected rice plants. Transmission also was observed when cows were allowed to graze on the stubble of infected fields. The disease incidence increased at least fourfold over time to approximately 36% of the plants infected in the experimental plots of two stubble fields. The results obtained in these stubble fields suggest that cattle-mediated spread will enhance the size of the virus load in the contraseason and the infection potential to infect the next crop.

Survey of Winter Wheat (Triticum aestivum) Stubble Fields Sprayed with Herbicides in 1998: Cultural Practices1

A survey of 174 fields was conducted during August and September of 1998 to investigate effects of cultural and herbicide practices on postharvest weed control in winter wheat stubble fields across western and southern Nebraska. Seventy-four percent of the fields were seeded at rates of 67 to 100 kg/ha, with 60% of the wheat seeded in rows spaced 25 cm apart. Wheat seeded in east–west rows contained 98% more stinkgrass and 82% more tumble pigweed than wheat seeded in north–south rows. Sixty-nine percent of winter wheat stubble fields were rated excellent for weed control. Postharvest weed control with herbicides was not affected by row spacing. In western Nebraska, density of tumble pigweed and Russian thistle was greater when wheat seeding rate was 50 kg/ha than at higher seeding rates. Short-stature winter wheat cultivars had greater densities of Pennsylvania smartweed and toothed spurge than taller cultivars. The most common winter wheat cultivars were ‘Arapahoe’ (34%) and ‘Alliance’ (17%). Weed control was positively correlated with number of winter wheat stems per square meter (r = 0.22**). Density of several weed species was greater in fields seeded with a disk than with a hoe drill. The most common crop rotations sampled were winter wheat–corn–fallow (50%), winter wheat–fallow (18%), and winter wheat–corn–soybean (13%). Winter wheat yields and wheat stem densities were greater and weed density was less when winter wheat was seeded after an 11- to 14-mo fallow period rather than a 0- to 5-mo period.Nomenclature: Green foxtail, Setaria viridis (L.) Beauv. #3 SETVI; kochia, Kochia scoparia (L.) Schrad. # KCHSC; Pennsylvania smartweed, Polygoncum pensylvanicum P. # POLPY; Russian thistle, Salsola iberica Sennen & Pau # SASKR; stinkgrass, Eragrostis cilianensis (All.) E. Mosher # ERACN; toothed spurge, Euphorbia dentata Michx. # EPHDE; tumble pigweed, Amaranthus albus L. # AMAAL; corn, Zea mays L.; soybean, Glycine max (L.) Merr.; winter wheat, Triticum aestivum L.Additional index words: Atrazine, crop rotations, ecofallow, ecofarming, glyphosate, no-till, weed management.Abbreviations: W–C or Sor, winter wheat–corn or sorghum; W–C–F, winter wheat–corn–fallow; W–C–Soy, winter wheat–corn–soybean; W–C–Spgr, winter wheat–corn–spring grains; W–F, winter wheat–fallow; W–W, winter wheat–winter wheat.

Herders and the Amelioration of Range: A Report from the Desert Frontier of Gujarat and Rajasthan - Complementarity of Basic and Applied Desert Research in India and Israel

I spent 29 March to 16 April (2003) in India, as the guest of BAIF. I, Mr P.K. Shirsath and Mr A. Bidhe were also the guests of three other NGOs. The four NGOs are: * BAIF--Bharatiya Agro-Industries Foundation is a development/research foundation committed to sustainable rural development, food security and clean environment. Pune, Mahrashtra. * GIDE--Gujarat Institute of Desert Ecology is an organisation for the conservation of Banni, Grasslands. Bhuj (Kachchh), Gujarat. * KALA RAKSHA--'Society and Trust' is a grassroots organisation to preserve and protect traditional arts; to enhance (after re-accommodations) the use of the Bhonga (the traditional round-shaped adobe house, once the prevalent residential form in the Kachchh district), Sumrasar Sheikh, Gujarat. * LPPS--Lokhit Pashu Palak Sansthan ('The Camel in India') is an organisation to enhance the breeding of camels--a threatened livestock in India. Sadri, Rajasthan. Scholarly Effort to Reinforce Village Communities The four aforementioned organisations share a commitment to better the future of India's rural communities by improving the quality of production, which would raise their standard of living, thus improving quality of life. All four NGOs acknowledge the key role that rural development plays in the general effort to secure the nation's future and restore dignity to village life, as in Gandhi's vision of the 'royal village': gram rajya (Howard 2000). All four share the opinion that stabilisation of the rural community is necessary to staunch the flow of migration from village to town. As a result, the phenomenon of neighbourhood's of poverty forming on the outskirts of towns might decline. Gandhi's disciple Mr. Manibhai Desai, the founder of BAIF, set the tone of the organisation's objectives--to improve life for those living in rural, rather than, urban areas. If one views India's economic burden as being tied mainly to what transpires in its rural sector, then one must call for a mobilisation of the resources of government and NGOs. In addition, mission-driven, devoted teams of academicians should volunteer to work hand-in-hand with India's villagers to help them prosper. Science's newest offerings to improve agriculture and facilitate agricultural work, should be made available to the rural sector. Our work tour was planned, with the assistance of Mr P.K. Shirsath of BAIF, so that I could learn about BAIF's state of the art program. Escorted by BAIF experts, I visited various farming communities, and we were able to sense at firsthand, the concerns and the difficulties encountered by herding communities along India's desert frontier. We discussed how the formation of better rural communities comprised of agriculturists and shepherds, who would benefit from reciprocal cooperation, could be encouraged. For example, herders can clean the stubble fields by grazing their animals on them after the harvest, or by exchange of agricultural and animal produce. Our itinerary included areas where stubble fields were grazed by herds not owned by the farmers. The herders had either been invited by the farmers or had, upon their own initiative, brought the livestock to these fields to forage on village land. Supporting Rural Communities--Objectives BAIF acts to encourage and support traditional farming, side-by-side with development, i.e., modernisation of agricultural methods, as long as they are congruent with the farmers' views. In order to ensure a positive reception in the villages, BAIF experts try to avoid altercations relating to the villagers' culture, tenets of creed or ideational views. For example, nourishment traditions, unequal division of arable lands, anti-social regulation of entitlement to real estate, caste prohibitions that limit integration of Others, family planning, etc. Land reform (Vinoba Bahave's campaign of the 1950-1960s) and the concerns of demography (Indira Gandhi's campaign of the 1970s) all remain relevant for India's future, but, as of yet, are beyond the scope of BAIF staff. …

University of Saskatchewan

I arrived in Saskatoon in September, not entirely sure what it would be like to do medieval studies in the stubble fields of Saskatchewan. After less than a year at the University of Saskatchewan, I am still not entirely sure, but have benefited greatly from informative chats with kindly colleagues (none of whom, of course, bears any responsibility for the cheerful ignorance here displayed in my opinions). This institution is perhaps better known for its biotech research, its programs in veterinary medicine, or its synchrotron, but being a medievalist here can be a source of some unexpected pleasures.

Comparing the hydrology of grassed and cultivated catchments in the semi‐arid Canadian prairies

AbstractAt the St Denis National Wildlife Area in the prairie region of southern Saskatchewan, Canada, water levels in wetlands have been monitored since 1968. In 1980 and 1983 a total of about one‐third of the 4 km2 area was converted from cultivation to an undisturbed cover of brome grass. A few years after this conversion all the wetlands within the area of grass dried out; they have remained dry since, whereas wetlands in adjacent cultivated lands have held water as before. Field measurements show that introduction of undisturbed grass reduces water input to the wetlands mainly through a combination of efficient snow trapping and enhanced infiltration into frozen soil. In winter, the tall brome grass traps most of the snowfall, whereas in the cultivated fields more wind transport of snow occurs, especially for short stubble and fallow fields. Single‐ring infiltration tests were conducted during snowmelt, while the soil was still frozen, and again in summer. The infiltrability of the frozen soil in the grassland is high enough to absorb most or all of the snowmelt, whereas in the cultivated fields the infiltration into the frozen soil is limited and significant runoff occurs. In summer, the infiltrability increases for the cultivated fields, but the grassland retains a much higher infiltrability than the cultivated land. The development of enhanced infiltrability takes several years after the conversion from cultivation to grass, and is likely due to the gradual development of macropores, such as root holes, desiccation cracks, and animal burrows. Copyright ©2002 Crown in the right of Canada. Published by John Wiley &amp; Sons, Ltd.

Daily Activity Pattern and Habitat Use of Greater White-fronted Geese Wintering in Japan: Factors of the Population Increase

Abstract During 20 years, numbers of Greater White-fronted Geese (Anser albifrons) wintering in Japan have increased 5.6 times (ca. 46,000 in 1999), with over 80% of the geese concentrated around Lake Izunuma-Uchinuma, in northern Japan. Detailed information on the wintering ecology of the geese had not been investigated in Japan and the daily activity pattern and habitat use of the geese were studied around the lake in three winters (October-February), 1996/97, 1997/98 and 1998/99. The daily activity pattern, i.e., flight timing and behavior relating to environmental factors (light intensity, snowfall, temperature and wind speed), was similar to that for several other geese species in temperate areas. The geese wintering in Japan depended exclusively on rice in fields; they foraged in stubble fields, where the density of rice grains was much higher than that in plowed fields. However, the area of stubble fields around the lake has decreased from 1980 to 2000, while combine harvesters replaced machinery, ...

The selection of stubble fields by wintering granivorous birds reflects vegetation cover and food abundance

Summary Fields left fallow after harvest (i.e. stubble fields) support high wintering densities of many species of granivorous bird. We examined correlates of use by eight such species of different types of intensively managed wheat and barley stubble fields, organic wheat fields and set‐aside fields on mixed lowland farmland in central England. Field occupancy was studied in relation to the physical characteristics of fields and seed abundance. Higher seed abundance was associated with greater occupancy by linnet Carduelis cannabina, grey partridge Perdix perdix, chaffinch Fringilla coelebs, yellowhammer Emberiza citrinella, reed bunting Emberiza schoeniclus and corn bunting Miliaria calandra. Larger areas of bare earth within stubble fields were associated with greater occupancy by linnet, yellowhammer, reed bunting and corn bunting, but lower occupancy by woodpigeon Columba palumbus. On conventional intensively farmed sites, seed abundance and area of bare earth were significantly greater on barley stubbles than on wheat stubbles. Seed numbers fell throughout the winter in all stubble types, although reductions were greatest on intensive barley stubbles, intermediate on intensive wheat stubble and lowest on undersown organic wheat stubbles. Within fields occupied by linnets, areas used for feeding had significantly greater quantities of seeds known to be important in their diet. Feeding areas also had a greater area of bare earth than randomly selected ‘non‐feeding areas’. Linnets and reed buntings were rarely found on fields where densities of weed seeds important in their diets fell below 250 seeds m−2. In autumn, yellowhammers and grey partridges rarely fed on fields where cereal grain density was below 50 m−2. However, in spring, both species fed on these fields irrespective of grain density, perhaps indicating a switch to other food sources. We suggest that land managers wishing to maximize the value of overwinter stubble fields for granivorous birds locate such fields where there is a substantial natural regeneration of weed flora and where previous cropping (e.g. barley) is likely to offer a sparse stubble with substantial areas of bare ground.

Baiting blackbirds (Icteridae) in stubble grain fields during spring migration in South Dakota

Blackbirds (Icteridae) annually damage US$5–8 million of ripening sunflower in the northern Great Plains. Baiting blackbirds with avicide-treated rice during spring migration might reduce the regional breeding population. In March and April 1996–1997, we simulated a baiting program in eastern South Dakota to compare attractiveness of rice-baited plots placed in fields of corn and soybean stubble. Blackbirds used plots in corn stubble more often than plots in soybean stubble and chose rice-baited plots over unbaited reference plots. We conclude that blackbirds can be successfully baited with avicide-treated rice placed in corn stubble.