Planting under plastic-film mulches is widely used in spring maize production in arid-cold regions for water conservation and warming the soil.  To ameliorate the associated issues such as plastic-film residues and additional labor during the “seedling release” in spring maize production, we have developed a plastic-film-side seeding (PSS) technology with the supporting machinery.  In the semi-arid regions of Northwest China, a 7-year trial demonstrated that PSS increased plant number per hectare by 6 547 and maize yield by 1 686 kg ha^–1 compared with the traditional method of seeding under plastic-film mulch (PM).  Two-year experiments were conducted in two semi-arid regions to further understand the effects of PSS on three important aspects of production: (i) the moisture and temperature of soil, (ii) maize development, yield output, and water use efficiency (WUE), and (iii) the revenue and plastic-film residuals in comparison with that of flat planting (CK) and PM.  Continuous monitoring of the soil status demonstrated that, compared with CK, the PSS treatment significantly increased the temperature and moisture of the 0–20 cm soil in the seeding row at the early stage of maize development, and it also promoted grain yield (at 884–1 089 kg ha^–1) and WUE, achieving a similar effect as the PM treatment.  Economically, the labor inputs of PSS were equal to CK, whereas the PM cost an additional 960 CNY ha^–1 in labor for releasing the seedlings from below the film.  Overall, the PSS system increased profits by 5.83% (547 CNY ha^–1 yr^–1) and 8.16% (748 CNY ha^–1 yr^–1) compared with CK and PM, respectively.  Environmentally, PSS achieved a residual film recovery rate of nearly 100% and eliminated 96 to 130 kg ha^–1 of residual plastic-film in PM in 3–5 years of maize production.  Collectively, these results show that PSS is an eco-friendly technique for improving yield stability and incomes for the sustainable production of maize in semi-arid regions.

The basidiomycetous fungus Sporisorium scitamineum causes sugarcane smut that leads to severe economic losses in the major sugarcane growing areas in China, India and Brazil, etc.  Autophagy is a conserved pathway in eukaryotes for bulk degradation and cellular recycling, and was shown to be important for fungal cell growth, development, and pathogenicity.  However, physiological function of autophagy has not been studied in S. scitamineum.  In this study, we identified a conserved Atg8 protein, named as SsAtg8 and characterized its function. Our results showed that autophagy was blocked in the ssatg8Δ mutant, in nitrogen starvation.  The ssatg8Δ mutant formed pseudohypha frequently and was hypersensitive to oxidative stress.  However, mating or filamenation was unaffected in the ssatg8Δ mutant in vitro.  Overall we demonstrate that autophagy is dispensable for S. scitamineum mating/filamentation, while critical for oxidative stress tolerance and proper morphology in sporidial stage.   

Groundwater is a key component for water resources in Sanjiang and Songnen Plain, an important agriculture basement in China.  The quality and the renewability of irrigation groundwater are essential for the stock raising and agricultural production.  Shallow groundwater was sampled and analyzed for various variables.  The salinity sodium concentration and bicarbonate hazard, were examined with regard to the United States Department of Agriculture (USDA) irrigation water standards.  The concentration of chlorofluorocarbons (CFCs) was determined to analyze the age of groundwater.  Most groundwater samples labeled as excellent to good for irrigation with low salinity hazard or medium salinity hazard.  Four groundwater samples were good and suspected for irrigation with high salinity hazard.  Generally groundwater in Sanjiang Plain was younger than the groundwater in Songnen Plain.  Meanwhile, groundwater nearby river is younger than the groundwater further away inside the watershed.  The mean age of groundwater in Sanjiang Plain is in average of 44.1, 47.9 and 32.8 years by CFC-11 (CCl₃F), CFC-12 (CCl₂F₂) and CFC-113 (C₂Cl₃F₃),  respectively.  The mean ages of groundwater in Songnen Plain is in average of 46.1, 53.4, and 40.7 years by CFC-11, CFC-12 and CFC-113, respectively.  Thus, groundwater nearby rivers could be directly exploited as irrigation water.  Partial groundwater has to be processed to lower the salt concentration rather than directly utilized as irrigation water in Songnen Plain.  Both water quality and renewability should be put in mind for sustainable agricultural development and water resources management.

    Currently, insecticides are considered as the primary approach for controlling western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). However, the heavy use of insecticides resulted in high insect resistance and serious environmental pollution. Given its characteristics of ease of operation and environmental friendliness, insect control using high temperature is receiving considerable renewed research interest. However, although the combination of insecticides and high temperature to control F. occidentalis has been studied before, few studies have focused on the short-term effect of such treatment. In a laboratory study, F. occidentalis adults and second-instar nymphs were exposed to 45°C for 2 h. Then, their susceptibility to acetamiprid, spinosad, methomyl, and beta-cypermethrin was tested after different periods of recovery time (2–36 h). Additionally, the specific activity of three detoxification enzymes (esterase, glutathione S-transferase, and cytochrome p450 (CYP) monooxygenase) of the treated insects was determined. The results indicated that the fluctuation of susceptibility to insecticides and detoxification enzyme activity during F. occidentalis recovery from heat shock are related. Furthermore, several recovery time points (2, 30, and 36 h) of significant susceptibility to four tested insecticides compared with the control were found during the treatment of adults that were heat-shocked. Recovery time points of higher susceptibility compared with the control depended on different insecticides during the second-instar nymph recovery from heat shock. Interestingly, the fluctuation of CYP monooxygenase activity exhibited a trend that was similar to the fluctuation of susceptibility to insecticides (especially spinosad) during the recovery from heat shock of adults. In addition, the glutathione S-transferase and CYP monooxygenase activity trend was similar to the trend of susceptibility to spinosad during the recovery from heat shock of second-instar nymphs. Our results provide a new approach for controlling F. occidentalis using the combined heat shock and insecticide. This effectively enhances the control efficiency of heat shock and significantly reduces the application of insecticides

Changes in the soil nematode community induced by global warming may have a considerable influence on agro-ecosystem functioning. However, the impacts of predicted warming on nematode community in farmland (e.g., winter wheat field) have not been well documented. Therefore, a field experiment with free air temperature increase (FATI) was conducted to investigate the responses of the soil nematode community to nighttime warming in a winter wheat field of Yangtze Delta Plain, China, during 2007 to 2009. Nighttime warming (NW) by 1.8°C at 5-cm soil depth had no significant impact on the total nematode abundance compared to un-warmed control (CK). However, NW significantly affected the nematode community structure. Warming favored the bacterivores and fungivores, such as Acrobeles, Monhystera, Rhabditis, and Rhabdontolaimus in bacterivores, and Filenchus in fungivores, while the plant-parasites were hindered, such as Helicotylenchus and Psilenchus. Interestingly, the carnivores/ omnivores remained almost unchanged. Hence, the abundances of bacterivores and fungivores were significantly higher under NW than those under CK. Similarly, the abundances of plant-parasites were significantly lower under NW than under CK. Furthermore, Wasilewska index of the nematode community was significantly higher under NW than those under CK, indicating beneficial effect to the plant in the soil. Our results suggest that nighttime warming may improve soil fertility and decrease soil- borne diseases in winter wheat field through affecting the soil nematode community. It is also indicated that nighttime warming may promote the sustainability of the nematode community by altering genera-specific habitat suitability for soil biota.

To characterize the β-lactam resistance in veterinary clinical isolates of Haemophilus parasuis, 115 isolates were examined for the β-lactam resistance, the possession of β-lactamase, and the presence of β-lactamase genes. The genetic relationship among isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Overall, the commonly detected resistance phenotypes were resistant to ampicillin (26.09%), penicillin (22.61%), amoxicillin (21.74%), cefazolin (14.78%), cefaclor (12.17%), and cefotaxime (6.96%). These strains showed high minimal inhibitory concentration (MICs) to oxacillin. 20.87% strains produced β-lactamase, and 4.35% strains showed extended-spectrum b-lactamase (ESBL) phenotype. Moreover, 19 strains harboured bla genes including TEM-1 (n=5), TEM-116 (n=10), and ROB-1 (n=5). Significantly, one strain possessed both TEM-1 and ROB-1, and displayed resistance to cefotaxime (MIC=8 mg L-1). The epidemiological analysis of PFGE revealed high genetic diversity among bla-positive isolates. This work shows that TEM- and ROB-type β-lactamases are prevalent in H. parasuis isolates in China.

The beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), is an economically important pest of crops worldwide,attacking plants from over 20 families including trans-continental agricultural cotton, corn and citrus crops. In this study,performance and subsequent enzyme activity of beet armyworm reared on host plants from five families were investigated.Significant differences were found in development, fecundity and enzyme activity on different host plants. Survival ratewas the highest (42.8%) on asparagus lettuce (Lactuca sativar var. asparagina) and the lowest (17.0%) on sweet pepper(Capsicum annuum). Larval duration was the shortest on asparagus lettuce (12.0 d), and was 43.4% longer on sweetpeppers (21.2 d). The activity of acetylcholine esterase (AChE) and carboxylesterase (CarE) in 3rd instar larvae, andsoluble carbohydrate and crude protein contents in different host plants were determined. AChE activity was the highestin the larvae feeding on Chinese cabbage (Brassica rapa), but declined by nearly 60% on maize (Zea mays) seedlings. Theratio of soluble carbohydrate content to crude protein content in host plants was found to have a positive effect onoviposition and a negative correlation with larval duration and life time (from larval to adult stages) of the insect.

A field experiment with rice-rice rotation was conducted since 2002 in southeast China for investigating the response of soil microbial properties to intensive nitrogen fertilizer application. The tested soil was a subtropical paddy soil derived from Quaternary red clay. Differences between treatments existed in different application rates of urea when the experiment was designed. Urea was applied in five rates, i.e., 0, 0.5, 1, 1.5, and 2 U, equivalent to 0, 0.5, 1, 1.5, and 2 times the local average amount of urea application (900 kg urea ha-1 yr-1, equivalent to 414 kg N ha-1 yr-1). In 2007, soil total nitrogen, available nitrogen, and soil organic carbon contents were increased by 10.2-27.9, 8.0-16.0, and 10.2-30.6%, respectively, in treatments with urea application rates of 0.5 to 2 U compared to control (0 U). Microbial biomass carbon and nitrogen were also increased by 3.1-30.8 and 1.3-13.9%, respectively, in treatments with urea application. Basal respiration in treatments with urea input were 9.4-29.1% higher than that in control. However, changes of bacterial functional diversity had different trends. Urea fertilization enhanced bacterial functional diversity until treatment of 1 U, but re-decreased it from treatment of 1.5 U. Principal components analysis indicated that there were intimate relationships among soil organic matter, nitrogen nutrient, microbial biomass, and respiration. Nevertheless, microbial diversity was related to soil moisture contents after urea application. We conclude here that the application of N fertilizer improved soil microbial biomass and respiratory activity. But, microbial diversity was reduced when excessive urea was applied in the tested paddy soil.