The brown gold : a reappraisal of medieval peat marshes in Northern Flanders (Belgium)

Although the importance of peat as energy supplier in the medieval and early modern North Sea Area is well known, the location, extent and nature of the peat-producing areas—peat marshes or mires—remains amongst the major problems in the landscape history of the coastal wetlands. This is especially true for areas like Northern Flanders, where peat marshes have since completely disappeared. This article reconsiders the ‘peat debate’ between geoscientists, who rely on ‘positive’ soil evidence, and historians, who accept ‘circumstantial’ historical data so as to reconstruct former peat marshes. Based on a systematic comparison of the arguments of both geoscientists and historians, we argue that recent methodological advances, such as integration of historical and geophysical data in a GIS, allow for bridging the gap between the two approaches and to reconcile contrasting opinions on historical peat marshes. This is tested in a case study for two villages - Moerbeke and Wachtebeke - in Northern Flanders, where re-evaluation of both geophysical features (soil, elevation models, hydrology) and archaeological and historical data (maps, documentary evidence on landed property and peat extraction and toponyms) leads to a completely new model for the presence of (Holocene) peat marshes

Effect of beta-hydroxybutyric acid, parity, and body condition score on phenotype and proliferative capacity of colostral mononuclear leukocytes of high-yielding dairy cows

In neonatal calves, the ingestion of colostrum is imperative for preventing infectious diseases. Investigations into the transfer of passive immunity of cattle have primarily focused on the importance of colostral immunoglobulins, with a recent increase in focus on understanding the role of colostral leukocytes. The main objective of the present study was to measure the influence of parity, body condition score, serum nonesterified fatty acids, and serum β-hydroxybutyrate concentrations of periparturient cows on phenotype and mitogen- and antigen-induced proliferative capacity of bovine colostral leukocytes. Holstein-Friesian cows (n=141) were intramuscularly vaccinated at 60 and 30 d before the expected parturition date with a tetanus toxoid vaccine. Of these 141 animals, 28 primiparous and 72 multiparous cows were sampled immediately after parturition. Colostrum mononuclear cell populations were identified by flow cytometry using bovine cluster of differentiation markers, and the proliferative capacity of these cells was determined using a (3)H-thymidine proliferation assay. Under-conditioned cows had a significantly higher percentage of colostral macrophages than normal-conditioned animals, whereas over-conditioned cows had significantly more colostral B-lymphocytes. Serum β-hydroxybutyrate was significantly associated with higher numbers of colostral T-lymphocytes and macrophages. Heifers had significantly higher mitogen- and antigen-induced proliferation of their colostral leukocytes than third parity or older cows. In conclusion, body condition score, parity, and serum β-hydroxybutyrate concentration of periparturient high-yielding dairy cows were shown to influence the number of colostral macrophages or the mitogen- and antigen-induced proliferation of colostral leukocytes, possibly influencing the cellular immunity of the newborn calf.status: publishe

Geographical determinants of inorganic fertiliser sales and of resale prices in north Ethiopia

Low mineral fertiliser use received much attention in Africa over the last decades. As fertiliser sales have exponentially grown in Ethiopia, and evidence exists of a supply that is beyond the demand in the drier northern parts of the country, we investigated the geographical determinants of inorganic fertiliser sales and its resale prices in north Ethiopia. Quantitative data on fertiliser provision and prices on the black market in 2016 were obtained from official statistics and from key informants in each of the 35 studied districts and in all municipalities of the Raya area. Environmental variables were collected from spatial databases. To promote inorganic fertiliser, agricultural experts use incentives, and also barter the purchase of fertiliser by a farmer against food aid or other advantages from the authorities. The high application rate that is aimed at (200kgha−1) contrasts with the dominance of less-responsive soils in the study area, for which inorganic fertiliser application does not result in higher crop yields, or even leads to root burn. The quantitative analysis shows that 40.7 103 Mg of fertiliser were officially sold in the study area in 2016, which corresponds to 52kgha−1. This is notably different from the application rate, as reselling widely occurs, at 50% of the official price for diammonium phosphate (DAP) and 54% for urea, mostly to users outside the community. By accepting the opportunity offered by agricultural companies and traders, smallholders save themselves from greater losses. The black market rate is strongly and positively correlated to monthly rainfall at sowing time (July 2016) (R2=0.44; n=31; p<0.01). In the four districts with spate irrigation, black market prices for inorganic fertiliser are low (35% of the official rate) and small quantities are sold officially (32kgha−1). This corresponds to the farmers’ saying that there “nobody needs inorganic fertiliser since the spate irrigation adds organic and inorganic nutrients yearly”. We found similarities to the ‘Green Revolution’ in Mexico: the forced delivery of high-cost fertiliser, and the reselling at half price in the black market. Inorganic fertilisers are one of the elements that have allowed boosting agricultural production in Ethiopia; our findings indicate however that in the study area, the fertiliser policy needs to be much fine-tuned so that it is led by agronomic needs, rather than by statistics of inorganic fertiliser consumption, that hide complex environmental variability and socio-political relations.status: publishe