Investigating the effects of crop type, fertility management and crop protection on the activity of beneficial invertebrates in an extensive farm management comparison trial

The activity of 11 groups of invertebrates, mainly predators and parasites, was investigated in 2005 and 2006 in a plot trial system on a farm in northern England, where the effects of organic and conventional fertility and crop protection management were separated within different crop types. Invertebrate activity was assessed using pitfall traps and suction sampling. Mixed effects models indicated that crop type significantly affected activity in all 11 groups. Crop protection applications had only a limited impact on activity but fertility management had considerable effects in some crops. Most differences were in barley, wheat and grass/clover, with less in vegetable and bean plots. Carabidae, Lycosidae, Staphylinidae, Linyphiidae and Braconidae gave consistent responses to fertility management, with more activity of the first two groups in organic plots and more of the other three in conventional plots. However, Coccinellidae and Ichneumonidae were not consistent in their activity between crops. After the effects of crop type had been partialled out, a constrained ordination showed that the novel combination of organic fertility and conventional crop protection had the most influence on group activity, with the combination of organic fertility and organic crop protection also significant. Maximising the activity of beneficial invertebrates in organic and sustainable farming systems requires a basic understanding of the effects of both crop type and fertility management, as well as crop protection.     

Consumer preferences for agricultural products considering the value of biodiversity conservation in the Mekong Delta,Vietnam

Because biodiversity conservation is a crucial aspect of multifunctionality in agriculture, consumers may be willing to pay a higher premium for products with environmentally friendly farming techniques to preserve biodiversity. To analyze the effects of biodiversity on the market price of agricultural products, this study applied the choice experiment method to assess consumers’ preferences for environmentally certified rice (termed “crane-friendly farming”) proposed for growth in Tram Chim National Park, one of Vietnam's eight important bird areas. Our results indicate that the majority of Vietnamese Mekong Delta consumers agreed to buy the proposed environmentally certified rice. They were willing to pay a premium of VND 11 for one kilogram of environmentally certified rice to increase crane numbers and VND 1500 for a 100% increase in the biodiversity level. In addition, their implicit price for rice cultivation without chemical pesticides (organic rice) was VND 6200, a 62% premium over the price of normal rice.     

Effect of farming practices for greenhouse gas mitigation and subsequent alternative land use on environmental impacts of beef cattle production systems

This study evaluated effects of farming practice scenarios aiming to reduce greenhouse gas (GHG) emissions and subsequent alternative land use on environmental impacts of a beef cattle production system using the life cycle assessment approach. The baseline scenario includes a standard cow–calf herd with finishing heifers based on grazing, and a standard bull-fattening herd using a diet mainly based on maize silage, corresponding to current farm characteristics and management by beef farmers in France. Alternative scenarios were developed with changes in farming practices. Some scenarios modified grassland management (S1: decreasing mineral N fertiliser on permanent grassland; S2: decreasing grass losses during grazing) or herd management (S3: underfeeding of heifers in winter; S4: fattening female calves instead of being reared at a moderate growth rate; S5: increasing longevity of cows from 7 to 9 years; S6: advancing first calving age from 3 to 2 years). Other scenarios replaced protein sources (S7: partially replacing a protein supplement by lucerne hay for the cow–calf herd; S8: replacing soya bean meal with rapeseed meal for the fattening herd) or increased n-3 fatty acid content using extruded linseed (S9). The combination of compatible scenarios S1, S2, S5, S6 and S8 was also studied (S10). The impacts, such as climate change (CC, not including CO₂ emissions/sequestration of land use and land-use change, LULUC), CC/LULUC (including CO₂ emissions of LULUC), cumulative energy demand, eutrophication (EP), acidification and land occupation (LO) were expressed per kg of carcass mass and per ha of land occupied. Compared with the baseline, the most promising practice to reduce impacts per kg carcass mass was S10 (all reduced by 13% to 28%), followed by S6 (by 8% to 10%). For other scenarios, impact reduction did not exceed 5%, except for EP (up to 11%) and LO (up to 10%). Effects of changes in farming practices (the scenarios) on environmental impacts varied according to impact category and functional unit. For some scenarios (S2, S4, S6 and S10), permanent grassland area and LO per kg of carcass decreased by 12% to 23% and 9% to 19%, respectively. If the ‘excess’ permanent grassland was converted to fast-growing conifer forest to sequester carbon in tree and soil biomass, CC/LULUC per kg of carcass could be reduced by 20%, 25%, 27% and 48% for scenarios S2, S4, S6 and S10, respectively. These results illustrate the potential of farming practices and forest as an alternative land use to contribute to short- and mid-term GHG mitigation of beef cattle production systems.     

Management-induced changes in soil organic carbon and related crop yield dynamics in China's cropland

Enhancing soil organic carbon (SOC) sequestration and food supply are vital for human survival when facing climate change. Site-specific best management practices (BMPs) are being promoted for adoption globally as solutions. However, how SOC and crop yield are related to each other in responding to BMPs remains unknown. Here, path analysis based on meta-analysis and machine learning was conducted to identify the effects and potential mechanisms of how the relationship between SOC and crop yield responds to site-specific BMPs in China. The results showed that BMPs could significantly enhance SOC and maintain or increase crop yield. The maximum benefits in SOC (30.6%) and crop yield (79.8%) occurred in mineral fertilizer combined with organic inputs (MOF). Specifically, the optimal SOC and crop yield would be achieved when the areas were arid, soil pH was ≥7.3, initial SOC content was ≤10 g kg⁻¹, duration was >10 years, and the nitrogen (N) input level was 100–200 kg ha⁻¹. Further analysis revealed that the original SOC level and crop yield change showed an inverted V-shaped structure. The association between the changes in SOC and crop yield might be linked to the positive role of the nutrient-mediated effect. The results generally suggested that improving the SOC can strongly support better crop performance. Limitations in increasing crop yield still exist due to low original SOC level, and in regions where the excessive N inputs, inappropriate tillage or organic input is inadequate and could be diminished by optimizing BMPs in harmony with site-specific conditions.     

Comparison of microbial and transient expression (tobacco plants and plant-cell packs) for the production and purification of the anticancer mistletoe lectin viscumin

Cancer is the leading cause of death in industrialized countries. Cancer therapy often involves monoclonal antibodies or small-molecule drugs, but carbohydrate-binding lectins such as mistletoe (Viscum album) viscumin offer a potential alternative treatment strategy. Viscumin is toxic in mammalian cells, ruling them out as an efficient production system, and it forms inclusion bodies in Escherichia coli such that purification requires complex and lengthy refolding steps. We therefore investigated the transient expression of viscumin in intact Nicotiana benthamiana plants and Nicotiana tabacum Bright Yellow 2 plant-cell packs (PCPs), comparing a full-length viscumin gene construct to separate constructs for the A and B chains. As determined by capillary electrophoresis the maximum yield of purified heterodimeric viscumin in N. benthamiana was ~7 mg/kg fresh biomass with the full-length construct. The yield was about 50% higher in PCPs but reduced 10-fold when coexpressing A and B chains as individual polypeptides. Using a single-step lactosyl-Sepharose affinity resin, we purified viscumin to ~54%. The absence of refolding steps resulted in estimated cost savings of more than 80% when transient expression in tobacco was compared with E. coli. Furthermore, the plant-derived product was ~3-fold more toxic than the bacterially produced counterpart. We conclude that plants offer a suitable alternative for the production of complex biopharmaceutical proteins that are toxic to mammalian cells and that form inclusion bodies in bacteria.     

Unravelling the physical,technological and economic factors driving the intensification trajectories of livestock systems

Over the past 100 years, the French livestock sector has experienced significant intensification that has occurred in different ways across the country. Specifically, France has changed from a homogeneous state with most of the agricultural area covered by grasslands and a uniform distribution of animals, to a heterogeneous state characterised by an uneven distribution of grasslands, livestock numbers and livestock species. Studying the dynamics of this change is fundamental to the identification of drivers that shaped the various intensification trajectories and led to these different states, as well as to the prediction of future changes. Hence, the objective of this study was to characterise the trajectories undertaken by the French livestock sector to understand the intensification process and the role of socioeconomic, land use and production-related factors. A set of 10 indicators was employed to analyse the main changes between 1938 and 2010, using principal component analysis followed by a clustering of the 88 French departments. Between 1938 and 2010, significant increases in farm size, mechanisation, labour productivity and the stocking rates of monogastrics enabled the French livestock sector to double its production. The most important changes involved mechanisation (with the number of tractors per hectare (ha) rising from 0.0012 to 0.0053), labour productivity (improving from 8.6 to 35.9 ha/worker), livestock production (e.g. milk production increasing from 758 to 1856 l/ha of fodder area) and stocking rates (rising from 0.57 to 0.98 livestock units (LU) per ha). The increased heterogeneity apparent in the patterns of change throughout France’s departments was captured by clustering four trajectories. Two trajectories were formed by departments that experienced strong specialisation towards livestock production, with one type mainly orientated towards high-intensive dairy, poultry and pig landless production systems, and a second type orientated towards extensive beef grazing production systems. Another trajectory corresponded to departments that specialised in crop production with high labour productivity; mixed crop-livestock systems were still maintained at the margins of this group of departments. The fourth trajectory corresponded to the lowest livestock population and productivity levels. The increase in mechanisation during the period was important but uniform, with no significant differences between the trajectories. This typology of intensification trajectories will enable the targeting of specific areas in which the detrimental impacts of livestock intensification require mitigation and provide guidance for future livestock sector developments.     

Loss of Nitrogen,Phosphorus, and Potassium Through Crop Harvests in Agroecosystems of Qianjiang,Hubei Province,PR China

The level of chemical fertilization in China is considerably higher than that normally applied in Western countries. For example, in the last decade the use of N-P-K chemical fertilizers increased, within the province of our study, from about 300 kg/ha in 1980 to about 850 kg/ha in 1990. Data on total amounts on nitrogen, phosphorus, and potassium that are removed with the harvest are necessary in determining and optimizing the amount of chemical fertilizers to be applied to different crops and in different cropping patterns. In this article we report the results of analyses of N, P, and K content of soils and different parts of different plants (soybean, cotton, rice, peanut, radish, Chinese cabbage, sesame, pepper, eggplant, and ambary) typically grown in rural areas of Southern China and provide an estimate of the balance of these nutrients under the five cropping systems that are dominant in the studied area.     

Edge distributions of Ceutorhynchus assimilis and its parasitoid Trichomalus perfectus in a crop of winter oilseed rape (Brassica napus)

The edge distributions of Ceutorhynchusassimilis and its parasitoid Trichomalusperfectus within a crop of winter oilseed rape were investigated between May and July using yellow water-traps arranged on a grid system. A randomisation test, which compared the observed arrangement of trap counts with permuted arrangements, was used to quantify the observed tendency of C. assimilisto congregate at the edges as it migrated into the crop; this tendency declined during the season. Trichomalus perfectus were distributed at the edge of the crop only during the early phase of its immigration in May, which occurred later than immigration of its host. It is considered that this simple means of quantifying insect spatial distribution could prove a useful tool in precision targeting of insecticides. This revised version was published online in July 2006 with corrections to the Cover Date.     

High body condition score combined with a reduced lambing to ram introduction interval improves the short-term ovarian response of milking Lacaune ewes to the male effect

The male effect is an effective natural technique to induce off-season ovulation and ultimately mating or artificial insemination in small ruminants. It constitutes an alternative to hormonal treatments in conventional breeding systems and, to shift and organise the yearly production cycle, is currently the only solution complying with European organic standards. However, its associated performances are still heterogeneous, both in terms of the global response and the extent of reproductive synchronisation of the females, due to complex interactions with environmental factors that limit its use on commercial farms. This study was carried out on a French organic farm under commercial conditions to investigate, in the field and across five consecutive years, the main parameters affecting the early ovarian response to a ram effect on Lacaune dairy ewes. While the within-year binary logistic regressions yielded contrasting results, the cross-year mixed-effect binary logistic regression models clearly showed that parameters associated with the nutritional state of the animals have a profound influence on the ovarian response of the ewes. Indeed, the probabilities of a spontaneous resumption of ovarian activity before the ram effect and of an early ovarian response to the ram effect were positively associated with the body condition score, total milk production and the age of the animals, while being negatively associated with the milk production level at the 3rd milk recording. The probabilities of a spontaneous resumption of ovarian activity before the ram effect were positively associated with the interval between lambing and the introduction of the rams. Altogether, these results indicate that the ovarian performances in response to a male effect follow a bell-curve pattern with optimal performances depending upon a complex combination between photoperiodic and nutritional cues. Regarding these latter, this study highlights the major contribution of body reserves and energy balance dynamics.     

Family break-up in farmed silver foxes (Vulpes vulpes) housed in enlarged cage systems as families

We monitored the behaviour of farmed silver foxes housed in family units in enlarged cage systems from weaning until late October. Activity of family members, use of space available, and aggressive acts were recorded. Aggressiveness between family members increased from July until October, leading to a more scattered use of the available space. Furthermore, the mean activity level of family members increased, and the synchrony of activity decreased. We conclude that social tension in the fox families increased gradually during the autumn, leading to dispersion of the family members. Received in revised form: 22 October 2001 Electronic Publication