Intensive organic vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated management

Intensive vegetable production in greenhouses has rapidly expanded in China since the 1990s and increased to 1.3 million ha of farmland by 2016, which is the highest in the world. We conducted an 11‐year greenhouse vegetable production experiment from 2002 to 2013 to observe soil organic carbon (SOC) dynamics under three management systems, i.e., conventional (CON), integrated (ING), and intensive organic (ORG) farming. Soil samples (0–20 and 20–40 cm depth) were collected in 2002 and 2013 and separated into four particle‐size fractions, i.e., coarse sand (> 250 µm), fine sand (250–53 µm), silt (53–2 µm), and clay (< 2 µm). The SOC contents and δ¹³C values of the whole soil and the four particle‐size fractions were analyzed. After 11 years of vegetable farming, ORG and ING significantly increased SOC stocks (0–20 cm) by 4008 ± 36.6 and 2880 ± 365 kg C ha^?1 y^?1, respectively, 8.1‐ and 5.8‐times that of CON (494 ± 42.6 kg C ha^?1 y^?1). The SOC stock increase in ORG at 20–40 cm depth was 245 ± 66.4 kg C ha^?1 y^?1, significantly higher than in ING (66 ± 13.4 kg C ha^?1 y^?1) and CON (109 ± 44.8 kg C ha^?1 y^?1). Analyses of ¹³C revealed a significant increase in newly produced SOC in both soil layers in ORG. However, the carbon conversion efficiency (CE: increased organic carbon in soil divided by organic carbon input) was lower in ORG (14.4%–21.7%) than in ING (18.2%–27.4%). Among the four particle‐sizes in the 0–20 cm layer, the silt fraction exhibited the largest proportion of increase in SOC content (57.8% and 55.4% of the SOC increase in ORG and ING, respectively). A similar trend was detected in the 20–40 cm soil layer. Over all, intensive organic (ORG) vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated (ING) management.     

Rickettsial infection in farmed Atlantic salmon in eastern Canada

The cause of death in a postsmolt, Atlantic salmon population with elevated levels of mortalities was investigated. Diagnosis of a rickettsia-like organism was based on gross pathology, histopathology, differential staining, electron microscopy and fluorescent antibody tests. The course of the infection and response to treatment are discussed. This is the first reported occurrence of salmon rickettsias in the Atlantic coast of North or South America.     

Absorption,Distribution and Elimination of Carnosic Acid,A Natural Antioxidant from <Emphasis Type="Italic">Rosmarinus officinalis</Emphasis>, in Rats

The absorption, distribution and elimination of carnosic acid, the main antioxidant found in rosemary was studied, in vivo, in rats. Therefore, carnosic acid was administrated in a single dose, intravenously (20.5 ± 4.2 mg/kg) and orally (64.3 ± 5.8 mg/kg), to four and nine rats, respectively. Blood samples were collected at different time points, and plasma concentrations of carnosic acid were determined using LC-MS. Furthermore, total collection of urine and feces was done during 4 h and 24 h for the intravenous and oral administrations, respectively. After euthanizing the rats, intestinal content, liver and muscle tissue were sampled to determine carnosic acid concentrations. The bioavailability of carnosic acid, after 360 min, was 40.1%. Traces of carnosic acid were found in the rats intestinal content, liver and muscle tissue of abdomen and legs. The recovery of carnosic acid in the feces, 24 h after oral administration, was 15.6 ± 8.2%. Carnosic acid is absorbed into the bloodstream after oral administration in rats and is therefore bioavailable. It was found that carnosic acid in vivo is present in its free form and that its main elimination route is the fecal route.     

Effects of Land‐Related Policies on Land Development during a Real Estate Boom and a Recession

Our research evaluates and compares the effects of three land‐related policies on land development in a sprawling metropolitan area during a real estate boom and a recession. Our findings suggest that during a real estate boom 1) the urban growth boundary (UGB) serves its purpose of attracting urban development inside the given boundary during a boom while its effectiveness diminishes with increased development pressure from lower‐valued land outside of the UGB during a recession period, 2) the agricultural zone works well for restraining new development during a boom period while agriculture zoned parcels are more likely developed during a recession period, and 3) an increase in the land‐value tax bill increases the incentive for development during a recession period while higher tax bills do not affect development during a boom period. In anticipation of a re‐emergence of urban sprawl with the recovery of the real estate market, our findings imply that land planners and others concerned with sprawling development should pay more attention to development in sprawl‐prone areas during recession periods.     

Energy capture from thermolytic solutions in microbial reverse-electrodialysis cells

Reverse electrodialysis allows for the capture of energy from salinity gradients between salt and fresh waters, but potential applications are currently limited to coastal areas and the need for a large number of membrane pairs. Using salt solutions that could be continuously regenerated with waste heat (≥40°C) and conventional technologies would allow much wider applications of salinity-gradient power production. We used reverse electrodialysis ion-exchange membrane stacks in microbial reverse-electrodialysis cells to efficiently capture salinity-gradient energy from ammonium bicarbonate salt solutions. The maximum power density using acetate reached 5.6 watts per square meter of cathode surface area, which was five times that produced without the dialysis stack, and 3.0 ± 0.05 watts per square meter with domestic wastewater. Maximum energy recovery with acetate reached 30 ± 0.5%.     

The Economic Impact of Site-Specific Weed Control

In order to evaluate economic and ecological benefits, site-specific weed control was realised in a 4-year experiment on five fields with a GPS-guided sprayer. An average of 54% of the herbicides could be saved. Savings were strongly dependent on crop and year. For grass weed herbicides, the savings were 90% in winter cereals, 78% in maize, and 36% in sugar beet. For herbicides against broadleaf weeds, 60% were saved in winter cereals, 11% in maize, and 41% in sugar beet. The monetary savings resulting from the reduction in herbicide use varied between the crops, depending on the amount of herbicides saved and the price of the herbicides. In maize, savings of 42euro/ha were realised, in winter wheat of 32euro/ha, in winter barley of 27euro/ha and in sugar beet of 20euro/ha. Large sections of the fields needed herbicide treatment significantly less frequently. In those areas where weed density remained below the weed control threshold, flora and fauna were allowed to establish largely without disturbance.     

A Review of Sooty Blotch and Flyspeck Disease in German Organic Apple Production

Sooty blotch and flyspeck (SBFS) fungi colonise the surface of a range of fruits, especially apple, without penetrating the cuticle. Economic damage results from the exclusion of severely affected fruit batches from being marketed as table apples. A study of SBFS was conducted in 2007–2012 in the two largest German apple production areas, i.e. the Lake Constance and Lower Elbe regions. The absence of this disease complex from orchards under integrated pest management in both regions in all years was explained by the collateral effects of scab and storage-rot sprays with captan and quinone-outside inhibitors (QoI) such as trifloxystrobin. However, SBFS was economically relevant in organically managed orchards, being generally more severe in Southern Germany than in the North. In both regions, Peltaster cerophilus was the most frequently isolated SBFS fungus and was chiefly responsible for crop losses. Cyphellophora sessilis, Microcyclosporella mali and Schizothyrium pomi also contributed to SBFS in some organic orchards, whereas a diversity of additional species was confined to untreated orchards. Evidence was obtained that P. cerophilus overwinters within orchards, fruit mummies being one of presumably several colonised plant organs. Infections of young apple fruits were initiated at any time following the end of flowering, and P. cerophilus was capable of causing several infection cycles per season by means of conidial inoculum. The colonisation of sheets of waxed paper by P. cerophilus indicated that this species does not require fruit leachates for growth. No further expansion of colonies was observed during cold storage; instead, P. cerophilus was gradually displaced by other fungi. Differences in the susceptibility of apple varieties to P. cerophilus were due to fruit ripening, late-maturing cultivars being most heavily colonised, and to surface properties, varieties with a waxy bloom being conspicuously less strongly colonised than others. This fungus was unable to colonise russeted fruit areas. Repeated spray treatments with lime-sulphur and potassium bicarbonate throughout the season were effective and necessary to control SBFS in organic production. This strategy threatens the fungicide-saving potential offered by scab-resistant apple varieties. Cultural measures against SBFS include summer pruning as well as the manual removal of fruit mummies in winter.     

Involvement of mammalian Mus81 in genome integrity and tumor suppression

Mus81-Eme1 endonuclease has been implicated in the rescue of stalled replication forks and the resolution of meiotic recombination intermediates in yeast. We used gene targeting to study the physiological requirements of Mus81 in mammals. Mus81-/- mice are viable and fertile, which indicates that mammalian Mus81 is not essential for recombination processes associated with meiosis. Mus81-deficient mice and cells were hypersensitive to the DNA cross-linking agent mitomycin C but not to gamma-irradiation. Remarkably, both homozygous Mus81-/- and heterozygous Mus81+/- mice exhibited a similar susceptibility to spontaneous chromosomal damage and a profound and equivalent predisposition to lymphomas and other cancers. These studies demonstrate a critical role for the proper biallelic expression of the mammalian Mus81 in the maintenance of genomic integrity and tumor suppression.