Maize is one of the major agricultural commodities in the world, and a source of food in Africa, representing more than 40 million ha currently harvested on the continent. Despite sub-Saharan Africa's dependence on grain, the maize actual yield (Ya) of the crop is low when compared to its potential yield. In Brazil, the yield-gap between Ya and water-limited yield (Yw) is approximately 50% of Yw. The objective of this study was to carry out a case study, using upland maize as a reference to identify a set of agricultural areas with similar soil and climate in Brazil and sub-Saharan Africa (SSA). The climatic similarity between Brazil and SSA countries was verified, seeking homogeneous climatic zones that occur in both regions. The Ya was determined including the data of at least the last three years of cultivation and were taken from the database of the national institutes of agricultural statistics. The climatic data showed that the SSA had well-distributed rainfall throughout the crop season, being higher than in Brazil, as well as the average air temperature. The average Yw was 11.3 and 7.4 Mg/ha for Brazil and SSA, respectively. Maize Ya in SSA was 1.4 Mg/ha, while in Brazil Ya was 5.2 Mg/ha. Ya represented approximately 9% of Yw in the SSA. The low Ya shows the large yield-gap found in SSA. With this, it is evident that the technologies used and the crop management are largely responsible for the yield differences between Brazil and SSA.

Farmland biodiversity is declining worldwide, and especially in Western countries largely owing to the large-scale intensification of agricultural practices. The Little Bustard Tetrax tetrax is a steppe bird adapted to agro-pastoral ecosystems in Western Europe, and is one of those many farmland species declining due to changes in agricultural production systems. In the EU, the majority of the extant population of this species is concentrated in the Iberian Peninsula. In Italy, the species has now disappeared from the mainland and is currently present only in Sardinia, where two populations, in the central-western areas, hold about two-thirds of the whole island’s numbers, with the rest scattered across numerous smaller nuclei. While there are indications and anecdotal information suggesting a possible population decline during recent decades, robust monitoring across different time periods that would allow a comparison of numbers is lacking in Sardinia. Here we repeated a Little Bustard survey performed in 2008 in two areas of western Sardinia: Abbasanta, which is one of the two strongholds for the species in Sardinia, and Campeda, which holds a small population (about 10 territorial males). Using the same methodology as in the past survey, we assessed current population size and density, and quantified changes over time. We found alarming declines, at a rate of around 30% in 14 years in both areas, with an estimated current population of 87 males in Abbasanta and 8 males in Campeda. We highlight current and emerging threats, such as the downsizing of the Special Protection Area of Abbasanta, and the encroachment of solar power plants within the same area.

Over the last decades, European farmland birds have strongly declined, mainly driven by agricultural intensification. The Ortolan Bunting Emberiza hortulana has suffered one of the most severe declines among farmland specialists. In order to maintain viable populations of the species in the long run, there is a vital need for evidence-based conservation measures. The main goal of this study was to detect the key drivers of breeding-territory selection and mating success of the species in an agricultural landscape in central Europe. We found that the landscape structure within the territories of Ortolan Bunting breeding pairs strongly varied from the overall habitat availability in the study area on both the territory and home-range scales. However, the environmental conditions also differed between the territories of breeding pairs and those of unpaired males. While landscape structure played an important role in breeding-territory selection, it had only weak effects on mating success. In contrast, crop type and vegetation height at potential nesting sites were important drivers of mating success. Overall, our study revealed that Ortolan Bunting has very complex breeding-habitat requirements. Only heterogeneous agricultural landscapes where (1) suitable song posts, (2) appropriate nesting sites, and (3) sufficient foraging habitats occur in close proximity are suitable for breeding. According to the findings of our study, agri-environmental schemes should primarily facilitate low-intensity farming practices that promote landscape heterogeneity, provide suitable nesting sites, and sustain a high abundance of invertebrate prey in farmlands.

In this study, we compared the richness of ground-dwelling ants among three different sugarcane management systems (with the application of the insecticide fipronil and the addition of vinasse; with fipronil and no vinasse; and with vinasse and no fipronil, i.e., an organic production system) to evaluate whether the feeding/foraging types vary according to the management system. We tested the hypothesis that organic management increases species diversity because there is no use of chemical inputs. Estimated species richness was significantly higher in the organic management system than in the systems that used fipronil with vinasse. Generalists species were prevalent in all sugarcane fields, regardless of the production system, whereas predatory and fungivorous species were infrequent. However, the organically managed field had many predatory species. Our results suggest that fipronil with vinasse in sugarcane cultivation alters the ant community, possibly disrupting the functions performed by the edaphic fauna, such as control of arthropod crop pests, due to reduced predator species richness.

Farmland bird populations in Germany are declining at a higher speed than species inhabiting other habitats. We studied potential causes for bird population changes based on data from standardised German breeding bird monitoring schemes. We related population trends to covariates describing the changes in the agricultural landscape in Germany, weather conditions during the breeding season and for some migratory species, conditions at stopover and wintering sites. Linear mixed effect models were used to analyse effect strength at species level and conclusions are drawn for the overall group of farmland bird species. The area of grassland and fallow land was shown to have the strongest positive effects and the area of maize and rapeseed the strongest negative effects on farmland bird population trends. The results obtained also indicate that despite the consistent influence of weather conditions during the breeding season, land-use changes had a stronger impact on bird populations than weather. Conditions at Sahel wintering sites did not show a consistent effect on population trends. Based on these findings the study quantitatively underpins and ranks key factors shaping farmland bird populations in Germany.

New evidence from archaeological investigations in north-east Thailand shows a transition in rice farming towards wetland cultivation that would have facilitated greater yields and surpluses. This evidence, combined with new dates and palaeoclimatic data, suggests that this transition took place in the Iron Age, at a time of increasingly arid climate, and when a number of broader societal changes become apparent in the archaeological record. For the first time, it is possible to relate changes in subsistence economy to shifts in regional climate and water-management strategies, and to the emergence of state societies in Southeast Asia.

The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grasslands into agriculture, represents an interesting scenario to understand the early stages of weed community assembly and its relationship with crop identity and management. Our aim was to characterize the weed communities in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.], the main crops of the Espinal region, under the dominant rainfed conditions. Weed surveys were carried out in 53 fields, and farmers were interviewed to collect information about crop management. Floristic composition was compared within and between crops by calculating the additive partition of the abundance-based Bray-Curtis dissimilarity. We compared the frequency and mean cover of functional groups between crops through generalized linear models. Finally, canonical correspondence analysis was carried out to analyze the associations between floristic composition and agronomic variables. Mean alpha and gamma diversity was greater in corn (10.0 and 80 species, respectively) than in soybean (7.6 and 46 species, respectively). Furthermore, species composition of weed communities was more similar among soybean fields than among either cornfields or fields of both crops. Hence, floristic differences between crops are potentially the result of different microenvironmental heterogeneity above- and belowground, with corn likely to be more permissive to weed establishment compared with soybean. The higher frequency of annual, dicotyledonous, and native species, and the high proportion of rare species, mostly native, suggest a strong legacy of the original vegetation that thrived in these recently cultivated systems. The functional composition was also affected by agronomic management, with sulfur, nitrogen, and grass herbicide application being the most important factors related to the floristic composition of weed communities. This early description can be used as a starting point for studies concerning trajectories, mechanisms, and processes of weed communities related to environment and management.

Agriculture threatens biodiversity across the tropics, particularly in semi-natural grassland landscapes, where human populations are high, habitat is easily converted and agriculture is prone to intensification. Over the last 20 years intensive, commercial dry season rice cultivation has emerged as the dominant threat to the Bengal florican Houbaropsis bengalensis, a globally threatened bustard that breeds in the seasonally inundated grasslands of central Cambodia. Although floricans have been extensively monitored for 10 years, no socioeconomic research has been undertaken to examine how local livelihood activities interact with the florican. We conducted household questionnaires and focus groups in 21 villages in the Northern Tonle Sap Conservation Landscape to gather information on household demographics, rice farming and bird hunting in protected and unprotected areas of florican breeding habitat. We identified a significant increase in dry season rice adoption by local communities since 2005. Dry season rice cultivation was strongly associated with agrochemical use and rice fields directly overlapped with florican breeding habitat, reducing habitat availability throughout the breeding season. We identified a low but significant level of bird hunting in grassland households (8%) and revealed a demand for wild bird meat amongst local communities. Our findings suggest an urgent need for conservation interventions in unprotected farmland and emphasize the role of enforcement and community engagement in improving protection within protected areas. We highlight the potential of private sector initiatives such as the Sustainable Rice Platform in reconciling conservation and development for impoverished rural communities.

The intensification of agriculture as farming communities grew in size did not always produce a successful and sustainable economic base. At Ras an-Numayra on the Dead Sea Plain, a small farming community of the late fourth millennium BC developed a specialised plant economy dependent on cereals, grapes and flax. Irrigation in this arid environment led to increased soil salinity while recurrent cultivation of flax may have introduced the fungal pathogen responsible for flax wilt. Faced with declining yields, the farmers may have further intensified their irrigation and cultivation schedules, only to exacerbate the underlying problems. Thus specialised crop production increased both agricultural risk and vulnerability to catastrophe, and Ras an-Numayra, unlike other sites in the region, was abandoned after a relatively short occupation.

Forests are an important source of environmental services and livelihoods in Africa, thus it is important to determine potential drivers of forest loss. Over recent decades, forest cover has been declining steadily in Malawi. This paper attempts to evaluate the influence of agricultural input subsidies on forest conversion in Malawi. A two-stage regression model analysis of 2009 farm survey data from Chimaliro and Liwonde Forest reserves in Kasungu and Machinga districts, respectively, did not reveal direct evidence of policy-induced forest clearing for agricultural expansion. Instead, subsidy-induced agricultural intensification of food crops, especially maize, appeared to have reduced the rate and extent of forest clearing among households in Malawi compared with households not benefiting from subsidies. However, indirect negative impacts on forests arose due to offtake of trees to construct drying sheds for tobacco, a local cash crop. These findings have implications for designing strategies for simultaneously conserving forests while promoting food security in rural areas, and shed light on the direct and indirect effects of input subsidies.

In recent decades there has been a marked decline in most ortolan bunting Emberiza hortulana populations in temperate Europe, with many regional populations now extinct or on the brink of extinction. In contrast, Mediterranean and, as far as we know, eastern European popula-tions seem to have remained relatively stable. The causes of decline remain unclear but include: habitat loss and degradation, and related reduction in prey availability; climate change on the breeding grounds; altered population dynamics; illegal captures during migration; and environmental change in wintering areas. We review the current knowledge of the biology of the ortolan bunting and discuss the proposed causes of decline in relation to the different population trends in temperate and Mediterranean Europe. We suggest new avenues of research to identify the factors limiting ortolan bunting populations. The main evidence-based conservation measure that is likely to enhance habitat quality is the creation of patches of bare ground to produce sparsely vegetated foraging grounds in invertebrate-rich grassy habitats close to breeding areas.

European rabbits (Oryctolagus cuniculus), a multifunctional keystone species in the Iberian Peninsula, have drastically declined over past decades. Rabbit decline has been frequently attributed to the arrival of two viral diseases. However, decline was apparently ongoing before the arrival of the diseases, as a consequence of habitat loss and fragmentation. In this paper, the effect on rabbit populations of land-use changes during recent decades in Andalusia (southern Spain) is analysed. Areas favourable for rabbits both at present and during the 1960s are identified, and the environmental and land-use factors that determine these areas established. In areas where the favourability for rabbits has changed during recent decades, main land use changes are assessed to identify possible factors explaining rabbit favourability in these areas. Areas favourable to rabbits are currently determined by factors similar to those during the 1960s; these areas have undergone geographic changes in recent decades, apparently as a consequence of land-use changes in Andalusia. The percentages of the variables that were positively associated with rabbit favourability in both models (current and 1960s) have declined in Andalusia as a whole, and in areas where rabbit favourability has decreased; hence environments suitable for rabbits have become impoverished. Conversely, in both models, environments suitable for rabbits increased in municipalities, where rabbit favourability also increased. The preservation of rabbit-friendly habitats should be a priority for the conservation of this key species in the western Mediterranean.

In Spain, it is estimated that 60% of wetlands have disappeared in the last 50 years. The present study aimed to describe the relationships between loss of wetlands and land-use change in Azuaga County, Central-western Iberian Peninsula where during the period 1896-1996, 94% of the original wetlands disappeared. Forest, scrub, holm oak dehesas and olive groves have become fragmented or disappeared completely, having been substituted by eucalyptus plantations in areas of low productivity and by dry cultivation of herbaceous crops, mainly cereals, in more productive areas. These substitutions have resulted in a homogeneous, coarse-grained landscape with low diversity and high dominance. The type of land-use has depended on the evolution of demographic processes, with high human immigration rates toward the end of the nineteenth century and beginning of the twentieth century, and high emigration rates during the 1960s and 1970s. The mechanization of agriculture and transition from closed to market economy in the second half of the twentieth century also played an essential role in the landscape changes described.