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Bees play key roles in savannah ecosystems but face myriad threats. A combination of flower sweep netting and visual observations was used to determine bee-species diversity and preferred nesting sites in five villages in Nyamakate communal area, northern Zimbabwe. Almost 2000 bees were collected comprising two bee families and five species with diversity of Shannon-Weiner index (H') = 0.45 (0.19). Apis mellifera scutellata was widely distributed and the dominant bee species; it has a wide choice of nesting sites and high adaptation ability. Effective conservation of nesting habitats such as forest, woody vegetation, and riverine water sources is required to maintain bee-species diversity in an agro-based savannah ecosystem. [ABSTRACT FROM AUTHOR]

Sporadic rainfall and limited surface water sources have increased dependency on groundwater in semi-arid region of Punjab. The present paper is comprehensive study carried out in an intensive agricultural region of southwest Punjab to examine the quality and extent of contamination due to trace elements and nitrate in the aquifer system. Total 15 toxic elements are analyzed in groundwater samples (N = 129) covering both the shallow (<60 m) and deeper aquifers (>60 m). Elements such as As, B, Cd, Li, Mn, Pb, Sr, and Se exceed the prescribed limits. Overall, 68 and 13% of samples exceed the NO3− permissible limit (45 ppm) in shallow and deep aquifers, respectively. Contaminants concentration increases toward groundwater flow direction, that is, from northeast to southwest possibly due to arid climatic conditions. Relatively, shallow aquifer is more contaminated than deeper aquifer due to fertilizers input and irrigation return flow. Drinking water quality indices (DWQI) reveal that groundwater is unfit for drinking at most locations. Further, health risk indicate that comparatively, children are at higher risk in terms of non-carcinogenic risk posed by nitrate, and higher carcinogenic risk for As, Cr, and Cd is seen in all age groups. Multivariate analysis reveals the influence of anthropogenic activities on NO3−, Mn, Ni, and Zn levels, while geogenic factors control the, As and Mo concentrations. Present findings suggest regular monitoring of wells to lower the public health risk. [ABSTRACT FROM AUTHOR]

Apple orchards constitute an important agro-ecosystem across Kashmir Himalayan Region (KHR), but estimates of their soil organic carbon (SOC) are unavailable. We investigated 174 apple orchards for estimating SOC spatial distribution across KHR at regional scale and evaluate accuracy of five interpolation methods. The selected orchards were representative of varied size, age, and management practices prevalent across KHR. Soil samples were collected from both tree rows and alleys between tree rows by digging pits at three depth intervals of 0–10; 10–20 and 20–30 cm. A total of 1044 soil samples were collected. The interpolation methods used included, ordinary kriging (OK), inverse distance weighing, empirical bayesian kriging, radial basis functions and local polynomial interpolation. Cross validation was used to assess the comparative performance of each method by measuring interpolation bias and accuracy. The soils were structurally less stony, with weak granular to moderate crumb at surface and sub-angular to angular blocky structure at sub-surface. The soils exhibited lowest co-efficient of variation for soil acidity and highest for soil electrical conductivity. With mean value of 12.33 ± 3.98 g kg−1 on concentration basis and 48.45 Mg C ha−1 on stock basis, the SOC declined with increasing soil depth, so much that near surface (0–10 cm) SOC content could explain well over 64% and 35% of second (20–30 cm) and third layer (20–30 cm) variation respectively. Exponential model best described SOC content across all depths. Semi-variograms of SOC at topsoil exhibited larger nugget effect while nugget sill ratios of 43% suggested moderate SOC spatial dependence. Cross validation exhibited better accuracy for OK in terms of indicating good match between observed and predicted SOC. This study exemplifies that apple orchards across KHR are significant carbon pool, improves our understanding of spatial distribution of SOC and help in evaluating soil health by providing site specific maps. [ABSTRACT FROM AUTHOR]

We described herein the colonisation dynamics of trap-nests by females of the giant carpenter bee Xylocopa frontalis (Olivier). The behaviours performed by emerging females, such as philopatry and dispersal, were quantified in different environments and conditions of nest supply. Two artificial shelters containing high and low provision of trap-nests were installed in two areas to attract nesting females. It was detected a higher number of new foundations compared to nest reuse regardless the number of trap-nests provided. Full use of the available nests in shelters was not detected. Most of the emerging females dispersed from artificial shelter and the colonisation was made by both philopatric and vicinity females. No differences in the number of offspring produced by nesting females was observed among shelters but the number of brood cells in the newly founded nests was higher than that of the reused nests. The maximum span that a female remained in the shelter was 290 days. For dispersing females, the minimum permanence time in the shelter was 12 days ( x ˉ = 45 days). We conclude that the differences on availability of artificial substrates between the shelters was not sufficient to affect the number of constructed nests and the behaviours performed by nesting females. Additionally, it can be suggested that the higher number of dispersing females associated with the attraction of vicinity females can contribute to maximise the genetic variability of X. frontalis populations maintained in artificial shelters, aiming the management of this important pollinator in agro-ecosystems. [ABSTRACT FROM AUTHOR]

The encroachment of agricultural landscapes on natural ecosystems poses a significant threat to native wildlife persistence. In the Boland Mountain Complex (BMC), the presence of mammals was well documented in the 20th century, but an updated account is lacking. This study relied on Local Ecological Knowledge (LEK) to elucidate perceived medium- to large-sized (>300 g) mammal occurrences, distribution ranges, and relative abundance on private agricultural properties adjacent to protected areas in the BMC. In total, 30 mammal species were reported to be present, and inverse distance weighted (IDW) interpolations were created for species that had more than five independent citations (n = 24), to display reported relative abundance-distributions beyond the scope of the sampled locations. Species with severely isolated relative abundance-distribution profiles (e.g. leopard, Panthera pardus, Cape clawless otter, Aonyx capensis and honey badger, Mellivora capensis), species with low overall incidence (e.g. aardwolf, Proteles cristata and Smith's red rock rabbit, Pronolagus rupestris), and non-native species with high incidences (e.g. feral dog, Canis familiaris and feral pig, Sus scrofa) were identified, and can now be prioritised further for future research and conservation efforts within the BMC region. [ABSTRACT FROM AUTHOR]

The present study was conducted in climatically vulnerable villages in Western India to evaluate the impact of climate resilient management practices such as improved agronomic practices, nutrient management, water management and residue management on carbon balance using the Ex-ante Appraisal of Carbon balance Tool (EX-ACT) developed by FAO. This model predicts the changes in the carbon emissions (source capacity) and sinks (sink capacity) using default emission coefficients for a time period of 20 years. The results revealed increase in sink capacity across the villages ranging from 16.4 (Chomakot) to 96.9% (Khuntil) in annual crops, and 4.8 (Bhalot) to 63.8% (Khuntil) in perennials. The fertilizer management increased the sink capacity varying from 3.1 (Chomakot) to 39% (Magharvada). However, the emissions ranged from 17 (Magharvada) to 93.2% (Bharu) in livestock and 6.8 (Bharu) to 83% (Magharvada) due to non-forest land-use change in majority of the villages. In irrigated rice, an increase in sink of 4.6% (Khuntil) and emission of 12.8% (Chomakot) was observed. However, interestingly, based on balance sheet of all the sources and sinks, a sink varying from 1621 to 10410 Mg CO2-eq was observed across the villages, indicating the significant impact of management practices on reducing the GHG emissions. [ABSTRACT FROM PUBLISHER]

Biodiversity within European semi-natural biotopes in agro-ecosystem is declining, and herbicide drift from neighbouring fields is considered as an important factor for the decline. The aim of the present study was to investigate whether the growth and competitive interactions in a model system of two perennial grass species,Festuca ovinaandAgrostis capillaris, are affected by sub-lethal doses of glyphosate in field margins. In a glasshouse experiment with ample nitrogen, the interspecific competitive interactions were found to be significantly affected by glyphosate; the competitive effect ofF. ovinaonA. capillarisincreased and the competitive effect ofA. capillarisonF. ovinadecreased with increasing doses of glyphosate. Furthermore, the importance of interspecific competition increased with the glyphosate dose. The results of the study of competitive interactions are in agreement with the observed plant community dynamics at the field site whereF. ovinawas found to be more dominant in plots treated with a relatively high dose of glyphosate. Importantly, the effects of glyphosate on the plant community dynamics critically depended on the effect of glyphosate on the plant competitive interactions. The study concludes that the current practice in the environmental risk assessment of non-target effects of herbicides, where single species are tested in the greenhouse, may be inadequate for assessing the effect of herbicides in semi-natural plant communities. The presented methods can be used for assessing the importance of competitive interactions for the sensitivity of non-target plants to herbicides in risk assessment. [ABSTRACT FROM PUBLISHER]

Cypermethrin and carbaryl are both used to control pests of rice paddy crops but the two insecticides have different modes of action. In some areas or climates, the breeding of frogs living in rice paddy fields and the application of the insecticides coincide. The effects of the acetylcholinesterase (AChE) inhibitor carbaryl and the sodium channel blocker cypermethrin, both individually and in combination, were investigated on the survival and emergence of froglets ofFejervarya limnocharisusing a 3 × 3 concentration factorial design (0, 25, and 50 μg L−1). Compared to controls, carbaryl showed no effect on survival and froglet emergence. Exposure to cypermethrin reduced the survival and froglet emergence in a concentration-dependent manner. When tadpoles were exposed to combinations of carbaryl and cypermethrin, the influence of carbaryl on survival and froglet emergence is less significant than that of cypermethrin. [ABSTRACT FROM PUBLISHER]

Participatory approaches have emerged in developing countries as an integrated and holistic system approach for assessing the agro-ecosystem sustainability. The aim is to integrate and apply knowledge about natural and social aspects of agro-ecosystems, taking into account their long-term, uncertain and non-linear relationships. The purpose of the study described in this paper was to assess the sustainability of the agro-ecosystem of Abesard in Tehran Province. A participatory landscape/lifescape appraisal (PLLA) method was used within an agro-ecological framework to assess the farmers’ sense of agricultural sustainability based on different categories of sustainability (better-off, average and poor). Results indicated that a majority of farmers think of sustainability solely as an economic issue, followed by sustainability being a combination of ecological and social concerns. Regarding the indicators of sustainability, results revealed that for farmers in the poor group, resilience and stability were critical criteria, whereas for better-off farmers, stability, reliability and resilience were generally important. However, the average group of the farmers was placed between the two groups. Overall, it was concluded that the economic status of households has an influence on the sustainability of their agro-ecosystems and that improvement of their economic situation promotes agricultural sustainability. It could also be concluded that PLLA has the potential to integrate socio-economic (lifescape) and environmental (landscape) dimensions for analysing the sustainability of agro-ecosystems. [ABSTRACT FROM AUTHOR]

This study assesses the use of pesticides and attitude to pest management strategies among rice and rice-fish farmers in Cn Th and Tin Giang provinces of the Mekong Delta, Vietnam, in 2007. A comparison is made to a similar study in 1999, in order to identify changes in patterns of pesticide use and possible influences of integrated pest management (IPM) programmes and brown planthopper (a major pest) outbreaks. One hundred and twenty farmers used 66 different pesticides, similar to the 64 pesticides recorded as being used in the 1999 survey. Nine of the 10 most popular pesticides in 2007 were the same as those found to be popular in 1999. Insecticides are used by 73–95% of the farmers, which is the most commonly employed type of pesticide. The number of applications of both herbicides and fungicides has more than halved since 1999 for all farmers, while insecticide applications has doubled for IPM farmers (those with prior training in IPM methodology). Similarly, the average dose of active ingredient (a.i.) of insecticides per crop has decreased slightly for non-IPM rice farmers, while it has more than doubled among IPM farmers, resulting in almost the same amount of a.i. per crop for all groups of farmers (insecticides 0.6, fungicides 0.5, and herbicides 0.3 kg a.i. ha−1 crop−1). Overall, the results indicate a temporal trend for more selective use of pesticides and an increased awareness among non-IPM farmers of the negative side effects of pesticide use. [ABSTRACT FROM PUBLISHER]

Serious resource depletion has made sustainable agriculture an important and pressing issue for scientists, policy makers, and stakeholders worldwide, particularly in developing countries. Researchers have focused on methods to assess agriculture correctly, and to introduce sound solutions for sustainability, but have reached no agreement. In this paper, we introduce the theoretical framework of the agro-ecosystem health model, a new holistic approach, and apply it at a regional scale using four aspects (4S): sound structure, stable function, safe service, and sustainable development. We examine how 12 indicators of an agro-ecosystem health assessment (AHA) were selected using three dimensions based on this theoretical framework. In an AHA, we used an amoeba approach to examine a high-yield agro-ecosystem in Huantai County, Shandong Province, China. The results indicate that this model of ecosystem health can reflect the complex ecological, economic, and human conditions of an agro-ecosystem and evaluate these conditions using perspectives pertinent to system structure, function, and responses (services). [ABSTRACT FROM AUTHOR]

The Free Air Carbon dioxide Enrichment (FACE) experiment conducted at the Federal Agricultural Research Centre (FAL) in Braunschweig in an arable crop rotation (total duration six years) allowed us to trace carbon (C) input in the soil C pool, as the CO2, used in the experiment to increase the atmospheric CO2 concentration, was depleted in 13C. Accurate assessment of the C input by means of stable C isotope analysis requires detailed knowledge on the spatial distribution of both the C isotopic composition and the C content in the soil C. Assumed changes in these parameters were examined. CO2 enrichment treatment over a six year period resulted in a clear trend towards an increase of soil C content in the uppermost 10 cm of soil. About 4.9% of the soil C present under ambient air conditions, and 10.7% present under elevated CO2 conditions were determined as new input. However, the results are not statistically significant yet. [ABSTRACT FROM AUTHOR]

Soil is believed to be file most important sink for sequestering atmospheric carbon. Hence, estimating soil carbon sequestration potential has been carried out for different regions and agricultural practices. However, soil carbon saturation (SCS), a fundamental concept for estimating soil carbon sequestration potential, has not been estimated for countries or regions. In this study, we estimated SCS of agricultural land for most provinces in China for 1990 by the DNDC model, a carbon and nitrogen biogeochemical cycle model, in order to provide a basis for farmers to select the land use, tillage and fertilization regimes to sequester more carbon. The result showed that SCS was as low as 0.48% in Tianjin and up to 5.14% in Tibet. There was a positive correlation between SCS and the proportion of paddy field in a province. In 1990, cropland soil carbon sequestration potential (SCSP) in China was-0.969 Gt C (-2.706 to 0.767 Gt C). This suggests that agricultural soil will be a carbon source to the atmosphere if agricultural practices are not altered. However, SCSP differed between provinces in China. SCSP was highest in Tibet (7.9 t C ha-¹) and lowest in Heilongdiang Province (-60.8 t C ha-¹), with a gradual decrease from south to north in China. [ABSTRACT FROM AUTHOR]

Urease activity (by buffer and non-buffer method) of soils of different agro-ecosystems in alluvial soil was studied. Urease activity by buffer method records a higher value than the non-buffer method. Both the methods showed significant positive correlation (0.99**) between each other. Urease activity by both methods showed positive correlation with organic matter (0.88** and 0.89**, buffer method) and clay content (0.91** and 0.83*, non-buffer method)) of the soils. Multiple regression analysis showed that the stabilization of urease activity in the soils studied was due to an organic matter-enzyme complex. Among the organic matter humus C plays a dominating role to control the urease activity of the soils. [ABSTRACT FROM AUTHOR]

Intensive agricultural production leads to degradation of the environment and consequently to decrease of quality of agricultural products. Therefore, there is a need to develop a universal environmental index, which could give information about the 'environmental quality' of agricultural products. From the physical point of view environmental degradation can be linked with the concept of entropy and therefore the main goal of the project is: to develop a new method, based on thermodynamics theory of ecosystems, for evaluation of the environmental degradation caused by the intensification of agriculture and to support and ensure ecological and sustainable public policies for agricultural land use. In this project the Pimental theory of eco-energetic analysis of ecosystems will be used. For the analysis and balance of entropy of agricultural ecosystems in relation to the referenced (natural) ecosystem, the concept of 'entropy pump' will be used. The overproduction of entropy (not balanced by the 'entropy pump' and caused by additional anthropogenic energy added into the ecosystem) causes the environmental changes (mainly soil degradation). Thus, the entropy can be used as a parameter to develop an index of both environmental degradation or environmental sustainability. [ABSTRACT FROM AUTHOR]

A system for simulation of crop dynamics is described. It includes a dynamic crop model for several cultures and a model shell. The model permits to simulate crop dynamics on the second level of plant productivity. The model shell serves for organization and implementation of series of computer experiments in dialogue regime. As it is known, soil and climatic conditions in the majority of Russia's regions differ from that in West Europe in a principal way. It especially concerns the continental Russia regions where deep droughts regularly occur, or Northwest regions, which are subjected to excess of water. So a special attention in model development was paid on account of the influence of water stress on plant production process. [ABSTRACT FROM AUTHOR]