A field experiment to determine the available bensulfuron-methyl (BSM) in the upper soil layer was conducted in an agricultural area in the South of Spain. To facilitate herbicide analysis, two application rates were employed, 200 g ha(-1) and 5 kg ha(-1). Samples of upper soil and soil solution were collected. Soil solution was sampled by means of metallic samplers, placed at a depth of 35 cm. In the plots receiving the lower dose ceramic suction, porous cups were also installed. Results from soil solution samples showed that the maximum BSM concentration was found after 8-10 days for the high irrigation supply (945 mm) and after 18-25 days for the lower irrigation regime (405 mm). The mathematical model FOCUSPELMO 1.1.1 was applied to interpret the data obtained in the field experiments. In general, there was a reasonable agreement between experimental and simulated data for soil samples, although the model did not acceptably predict herbicide concentrations in water soil samples. Ceramic cups sampled a higher soil water volume and more frequently than did the metallic samplers. However some variable results were attributed to preferential flow.

Native vegetation has been destroyed or dramatically modified throughout agricultural regions of southern Australia. Extensive restoration of native perennial vegetation is likely to be crucial in these areas for the persistence of native plant and animal species, to ameliorate dryland salinity and soil degradation, and to maintain long-term agricultural production. The long-term resilience of these systems will be dependent on the ability of key functional taxa, such as perennial shrubs, to recruit and persist. In this study, we examine the factors limiting establishment of two perennial shrubs in formerly cropped land, the rare Maireana rohrlachii and the common Maireana decalvans. Field and laboratory observations suggest that establishment of both species is not limited by life-history traits following cultivation. Both species established and persisted under varying levels of plant competition. Similarities existed between species in their initial germination rates. Weak differences were found between species in the growth and survival rates under different levels of competition. The main difference between the two species was in the decline of germinability of fruits with increasing fruit age. From the data, it is difficult to determine what factors limit the establishment of perennial shrubs in these landscapes. The main hypothesis that can be advanced is that establishment of shrub species appears to be limited by propagule availability and this is likely to be a function of past and present grazing management rather than cultivation per se. Further investigation of these land-use practices may give greater insight into the factors affecting the establishment of this life form across these landscapes.

A field experiment to determine the available bensulfuron-methyl (BSM) in the upper soil layer was conducted in an agricultural area in the South of Spain. To facilitate herbicide analysis, two application rates were employed, 200 g ha(-1) and 5 kg ha(-1). Samples of upper soil and soil solution were collected. Soil solution was sampled by means of metallic samplers, placed at a depth of 35 cm. In the plots receiving the lower dose ceramic suction, porous cups were also installed. Results from soil solution samples showed that the maximum BSM concentration was found after 8-10 days for the high irrigation supply (945 mm) and after 18-25 days for the lower irrigation regime (405 mm). The mathematical model FOCUSPELMO 1.1.1 was applied to interpret the data obtained in the field experiments. In general, there was a reasonable agreement between experimental and simulated data for soil samples, although the model did not acceptably predict herbicide concentrations in water soil samples. Ceramic cups sampled a higher soil water volume and more frequently than did the metallic samplers. However some variable results were attributed to preferential flow.

Although agriculture dominates much of Central America, little is known about the bat assemblages that occur within agricultural landscapes and how bats use different types of tree cover within these landscapes. Using mist-nets and a mark-recapture protocol, we compared bat diversity and movement across six types of tree cover within an agricultural landscape in central Nicaragua. The tree cover types surveyed included secondary forests, riparian forests, forest fallows, live fences, pastures with high tree cover and pastures with low tree cover. We captured a total of 3084 bats of 39 species, including two new species records for the country (Lonchorhina aurita and Molossops greenhalli). Of these, 2970 bats and 27 species were in the Phyllostomidae family. There were significant differences in mean species density, abundance and evenness of phyllostomid bats across the different types of tree cover, but not in bat diversity. Riparian forests had the highest mean species density and bat abundance per plot. In contrast, mean bat abundance and species density were lowest in pastures with low tree cover. Of the 1947 phyllostomid bats marked, a total of 64 bats of eight species were recaptured. The average linear distance between extra-site recaptures was 2227 m (± 228 SE) and the maximum distance was 10.6 km. Bats were recorded moving between almost all types of tree cover, and especially to and from riparian forests. Our study suggests that agricultural landscapes retaining a heterogeneous tree cover may maintain a diverse bat assemblage, and that bats visit and use a variety of tree cover types within the agricultural matrix.

To explicate the dynamics of nitrogen and phosphorus in an agricultural pond, numerical simulations were conducted for their temporal fluctuation in pond water by using an ecosystem model, and the developed model was applied to a scenario analysis for the improvement and preservation of water environment by the reduction of nitrogen and phosphorus. In this study, the model was composed of 5 water quality indices-nitrogen oxides, ammonia-nitrogen, organic nitrogen, phosphate-phosphorus and organic phosphorus-and was adapted to the Toishigawara agricultural pond in Fukuoka Prefecture, Japan, where concentrations of total nitrogen and total phosphorous were extraordinarily high. A comparison between the calculated results and the observed data showed that the ecosystem model used in this study could reproduce the dynamics of nitrogen and phosphorus in Toishigawara pond. According to the scenario analysis, 80% reduction of current nutrient inflow load resulted in the remarkable decrease of total nitrogen and total phosphorous concentrations. As a result, total nitrogen fulfilled the water quality standard of irrigation water in Japan.

International audience | We propose a new method for estimating and testing the zones where a variable has discontinuities or sharp changes in the mean. Such zones are called Zones of Abrupt Change (ZACs). Our method is based on the statistical properties of the estimated gradient of the variable. The local gradient is first interpolated by kriging. Then we test whether the estimated local gradient exceeds some critical threshold computed under the null hypothesis of a constant mean. The locations where the local test is rejected define the potential ZACs, which are then tested globally. Using this method, we analysed soil data from an agricultural field. The analysis of the main soil components of the ploughed layer (clay, silt and sand particles and calcium carbonate content) reveals the structural variations in the field, linked to boundaries between soil types. Its application to non-permanent variables (soil water and mineral nitrogen content of the soil profile to 120 cm taken at several dates) shows that water content has the same ZACs for all dates, whereas mineral nitrogen has none

Effects of agricultural intensification and a naturally occurring landslide of asbestos material upon water and sediment quality in a transboundary watershed were investigated. The water and sediments of the Sumas River watershed were analyzed for copper (Cu), zinc (Zn), chromium (Cr), and nickel (Ni) concentrations in 1993/1994 and 2003/2004 and differences within sites over time were examined. Based upon a review of the literature, Cu and Zn were used as indicators of agricultural impacts while Cr and Ni were used as indicators of impacts from an asbestos landslide. Animal unit equivalents (AUEs) were calculated on a per area basis as an indicator of livestock density using detailed statistical census data. Whatman #42 filtered metals, bioavailable metals, and sediment-bound metals (in the <63 μm fraction) were determined at 22 sites along the mainstem and tributaries, including two reference sites. Temperature, pH, and dissolved organic carbon (DOC) were also measured. The bioavailable metal fraction was determined using the diffusive gradient thin film technique (DGT). Sediment-bound results were compared with British Columbia's Interim Sediment Quality Guidelines (ISQGs) and Severe Effects Levels (SELs). A Wilcoxon signed rank test was used to determine if the concentrations of metals changed significantly within sites between 1993/1994 and 2003/2004. Spearman rank correlation analysis was used to determine relationships between trace metals, water quality parameters, and AUEs/hectare. The results indicate that Cu and Zn levels in sediments increased significantly to concentrations above the ISQGs of 35.7 mg/kg and 123 mg/kg, respectively from 1993/1994 to 2003/2004 in streams, where associated land use was dominated by intensive agriculture. Higher AUEs/hectare were significantly correlated with greater bioavailable levels of Zn as well as higher sediment-bound Zn concentrations. Neither Cu nor Cr were detected by the DGTs on any of the sampling occasions. The Cr and Ni sediment concentrations were highest in Swift Creek, the headwater tributary affected by the natural landslide of asbestos material, and decreased in the Sumas River downstream from the point of input. Cr and Ni concentrations have increased in the mid-region of the Sumas River since 1993/1994, suggesting downstream movement of the asbestos material over time. DGT results indicated that bioavailable Zn is significantly positively correlated to sediment-bound Zn and livestock density, and bioavailable Ni is significantly correlated to sediment-bound Ni.

The article examines formation of the system of controlling in agricultural-production cooperative Ovsyanka of Gorki district of Mogilev region. Mechanism of individual business plan, as well as a programme for organizing controlling system in agriculture on the basis of platform IC: Company 7.7 has been developed and tested. Special attention has been given to the process of tuning and creating automated forms of input and output of information for analysis of economic activity of a company and making managerial decisions