Rice-wheat cropping system (RWCS) is one of the most important cropping systems in South Asia. However, sustainability of this system is under threat owing to several factors, of which deficiency of micronutrients par...Rice-wheat cropping system (RWCS) is one of the most important cropping systems in South Asia. However, sustainability of this system is under threat owing to several factors, of which deficiency of micronutrients particularly zinc (Zn), boron (B) and manganese (Mn) is one of the major problems. Continuous rotation of rice and wheat, imbalanced fertilizer use and little/no use of micronutrient-enriched fertilizers induce deficiencies of Zn, B and Mn in the RWCS of South Asia. Here we review that (i) imbalanced fertilizer use and organic matter depletion deteriorate soil structure resulting in low efficiency of applied macro- and micro-nutrients in RWCS.(ii) The micronutrients (Zn, B and Mn) are essentially involved in metabolism of rice and wheat plants, including chlorophyll synthesis, photosynthesis, enzyme activation and membrane integrity.(iii) Availability and uptake of Zn, B and Mn from rhizosphere depend on the physico-chemical soil properties (which differ under aerobic and anaerobic conditions) including soil pH, soil organic matter, soil moisture and interaction of these micronutrients with other nutrients.(iv) Plant ability to uptake and utilize the nutrients is affected by several plant factors such as root architecture, root hairs, transport kinetics parameter and root exudates.(v) Crop management and application of these microelements can help correct the micronutrients deficiency and enhance their grain concentration.展开更多
A 12-year cover crops study on the effects on SOC sequestration, storage, retention and loss and corn and soybean yields was conducted in southern Illinois. The use of cover crops for the maintenance and restoration o...A 12-year cover crops study on the effects on SOC sequestration, storage, retention and loss and corn and soybean yields was conducted in southern Illinois. The use of cover crops for the maintenance and restoration of soil organic carbon (SOC) and soil productivity of previously eroded soils were evaluated. No-till (NT), chisel plow (CP), and moldboard plow (MP) treatment plots with and without cover crops were established in 2001. The plot area was on sloping with a moderately well drained, eroded soil. The average annual corn and soybean yields were statistically the same for NT, CP, and MP systems with and without cover crops. By 2012, the cover crop treatments had more SOC stock than that without cover crops for the same soil layer and tillage treatment. The NT, CP, and MP treatments all sequestered SOC with cover crops. A pre-treatment SOC stock baseline for rooting zone was used to validate the finding that cover crops sequestered SOC in the topsoil, subsoil and root zone of the NT, CP and MP treatments during the 12-year study. Additional sequestered SOC was lost as a result of being transported off of the plots and retained in lower slopes, transported to the stream or released to atmosphere.展开更多
Farmers in the highlands of Ethiopia often plant Eucalyptus on their farmlands. However, growing Eucalyptus, especially on farm- lands suitable for crop production has become a great concern due to its alleged long-te...Farmers in the highlands of Ethiopia often plant Eucalyptus on their farmlands. However, growing Eucalyptus, especially on farm- lands suitable for crop production has become a great concern due to its alleged long-term site effects. Our study was conducted at Koga water- shed, Mecha District, northwestern Ethiopia to investigate whether crop- lands afforested with Eucalyptus camaldulensis Dehnh. can be restored for annual crop production after tree harvest. We compared growth and yield of two agricultural crops, barley （Hordeum vulgate L.） and finger millet （Eleusine coracana （L.） Gaertn.）, grown in clear-felled stands of E. camaldulensis and continuously cultivated croplands at twelve paired farmlands under a conventional farming system. Plant height and dry matter production were evaluated as indices of crop growth, while grain weight was evaluated as an index of crop yield. Crop growth and yield measurements averaged over all farmlands differed between land-use types. For both crops, plants grown on clear-felled stands were taller than on croplands. Dry matter production and yield were also significantly greater in crops cultivated on clear-felled stands. Cropland aboveground and belowground dry matter productions were lower by 31.8 and 25.4% for barley and 32.8% and 37% for finger millet, respectively. Clear-felled stands gave an average yield of 2.91 t.ha-1 for barley and 3.27 t.ha-1 for finger millet while cropland gave a yield of 1.97 and 2.31 t.ha-1 for barley and finger millet, respectively. Farmers also responded that farm plots on former eucalypt plantations showed greater crop growth and yield thandid continuously cultivated croplands. Farmers perceived that Eucalyptus plantations improved soil fertility and they preferred clear-felled stands for crop production and wished to plant Eucalyptus on their farmlands. Our results suggest that conversion of agricultural lands to Eucalyptus plantations can increase post-felling yields of cereal crops.展开更多
The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house...The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house field 2 UPM using the sand media to determine the adventitious roots initiation and development using the histological method. The cuttings were treated with different IBA concentrations (0, 500, 1000, 1500 and 2000 mg/L). The nodes explants were used in the development of a protocol for in vitro propagation of P. betle L., with different concentrations of Clorox with different times of immersion (20% Clorox 10 minutes, 30% Clorox 10 minutes, 20% Clorox 20 minutes, and 30% 20 minutes). In multiplication of the plantlets, Murashige and Skoog (MS) medium with different concentrations of BAP (0, 0.5, 1.0, 2.0 mg/L) were used to investigate the rooting of the explants. The results indicated that the types of the cuttings were different in the rooting capacity and the length of the roots. Moreover, it was found that in comparison with the control treatment, by a rise in the concentrations of the IBA, there was a significant upsurge in the rooting percentage, the root diameter, and the number of the roots. The results indicated that the types of cutting with 1000, 1500 and 2000 mg/L IBA perform better in the root percentage (100%) in the semi hardwood cuttings. The best results, however, were 2000 mg/L IBA in the semi hardwood cuttings, with the number of the roots to be 35.05, and the fresh weight of the roots to be 3.94 g, the dry weight of the roots to be 0.33 g, the length of the roots to be 391.88 cm, the roots diameter to be 1.21 mm, the surface area of the roots to be 121.83 cm2, and the root volume to be 2.99 cm3. Nonetheless, the optimal concentration of Clorox with the time immersion was 20% with the 20-minute immersion time, which produced a shoot induction percentage of 30% dead explants and a mean number of 70.00 shoots per explant and the optimal concentration of benzylaminopurine (BAP) at 1.0 mg/L. It is of note that a shoot induction percentage of 22.29% and a mean number of 4.1% number of auxiliary bud per treatment. P. betle shoots in MS medium without PGR MS (0.0) yielded a good rooting.展开更多
High tunnels have been used in the United States for more than 50 years, and growers are encouraged to use them more frequently through government cost-share programs. Research on fruits and vegetable production syste...High tunnels have been used in the United States for more than 50 years, and growers are encouraged to use them more frequently through government cost-share programs. Research on fruits and vegetable production systems has focused on high value crops such as tomato, salad greens, and several fruit crops. Maintaining soil quality and controlling insects and diseases are all issues that growers face. This review looks at current research on these issues as well as economic considerations addressed in the scientific literature. Global statistics and reports are also reviewed that complement the North American studies. Gaps in our understanding are identified, and directions for future research are suggested.展开更多
This study sought to establish the compatibility effects of biochar/vermin-compost application on growth and yield of maize and cabbages. Biochar application rate was at 3 to 4% of soil weight. Biochar was mixed in va...This study sought to establish the compatibility effects of biochar/vermin-compost application on growth and yield of maize and cabbages. Biochar application rate was at 3 to 4% of soil weight. Biochar was mixed in various proportions to come up with treatments which were 100% vermicompost, 50/50% biochar： vermicompost, 75/25% biochar： vermicompost and 100% biochar. The experiment was repeated twice and arranged as a completely randomized design and replicated five times. The study established that maize yield increased with application of biochar from 25% to 50%. In the cabbage trial, comparable results in plant height, leaf numbers and final yield was obtained with 100% vermicompost application, 50% and 75% biochar inclusion. When biochar was applied at 100%, noticeable reduction in plant performance was noted. It is recommended to use biochar as a bio-fertiliser at 50/50% biochar： vermicompost in maize and cabbage production.展开更多
This study was conducted to assess the incidence of seed-borne fungi on rice seeds sourced from the major rice growing areas of South-Eastern Nigeria. The rice seeds were collected during the dry seasons between 2009 ...This study was conducted to assess the incidence of seed-borne fungi on rice seeds sourced from the major rice growing areas of South-Eastern Nigeria. The rice seeds were collected during the dry seasons between 2009 and 2010. Four hundred rice seeds randomly collected and surface sterilized by washing in 3% sodium hypochlorite and rinsed two times with sterile distilled water were placed in three circular rings inside the Petri dishes. The incubation was done one after the other for each variety from all the locations. Ten fungi species from eight genera were isolated from the rice seeds in all the rice growing areas of South-Eastern Nigeria. The fungi pathogens vary from one locality to another, as well as the frequency of occurrence. The pathogens isolated include： Fusarium moniliforme, F. solani, F. oxysporium, Aspergillus spp., Botridiploidia spp., Helminthosporium spp., Penicillium spp., Trichoconis padwickii, Curvularia oryzae and Phoma oryzae. Though, there was the presence of some seed-borne fungi in the rice seeds from the areas studied, most of the cultivars experienced up to 90% germination. But some cultivars had very low germination. IR 1416 from Arochukwu and GB90 from Arondiuzogu had less than 1% germination. This study shows that seed-borne organisms are major constraint in rice production in the South-Eastern states of Nigeria as a result of low seed germination stemmed from infestation of fungi organisms in the seeds.展开更多
The emergence of novel phytopathogens and the accelerated spread of plant diseases to new regions,driven by global climate change,constitute significant threats to agricultural resources.Rice,a major tropical staple c...The emergence of novel phytopathogens and the accelerated spread of plant diseases to new regions,driven by global climate change,constitute significant threats to agricultural resources.Rice,a major tropical staple crucial for global food security,possesses six transcription factor superfamilies-AP2/ERF,bHLH,bZIP,MYB,NAC,and WRKY-that function in innate immunity against pathogens.We review their biological functions and regulatory mechanisms in rice immunity.展开更多
Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the p...Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.展开更多
To better understand the effects of ground-level ozone(O_(3))on nutrients and stoichiometry in different plant organs,urban tree species Celtis sinensis,Cyclocarya paliu-rus,Quercus acutissima,and Quercus nuttallii we...To better understand the effects of ground-level ozone(O_(3))on nutrients and stoichiometry in different plant organs,urban tree species Celtis sinensis,Cyclocarya paliu-rus,Quercus acutissima,and Quercus nuttallii were sub-jected to a constant exposure to charcoal-filtered air(CF),nonfiltered air(NF),or NF+40,60,or 80 nmol O_(3)mol^(-1)(NF40,NF60,and NF80)starting early in the summer of the growing season.At the end of summer,net CO_(2)assimila-tion rate(A),stomatal conductance(gs),leaf mass per area(LMA),and/or leaf greenness(SPAD)either were not sig-nificantly affected by elevated O_(3)or were even higher in some cases during the summer compared with the CF or NF controls.LMA was significantly lower in autumn only after the highest O_(3)exposures.Compared to NF,NF40 caused a large increase in gs across species in late summer and more K and Mn in stems.At the end of the growing season,nutri-ent status and stoichiometric ratios in different organs were variously altered under O_(3)stress;many changes were large and often species-specific.Across O_(3)treatments,LMA was primarily associated with C and Mg levels in leaves and Ca levels in leaves and stems.NF40 enriched K,P,Fe,and Mn in stems,relative to NF,and NF60 enhanced Ca in leaves relative to CF and NF40.Moreover,NF resulted in a higher Ca/Mg ratio in leaves of Q.acutissima only,relative to the other O_(3)regimes.Interestingly,across species,O_(3)stress led to different nutrient modifications in different organs(stems+branches vs leaves).Thus,ambient and/or elevated O_(3)exposures can alter the dynamics and distribution of nutrients and disrupt stoichiometry in different organs in a species-specific manner.Changes in stoichiometry reflect an important defense mechanism in plants under O_(3),and O_(3)pollution adds more risk to ecological stoichiometries in urban areas.展开更多
A pot experiment was conducted to investigate the action mechanisms phorus （P） uptake of Capsicum annuum L. in a sterilized fossil Oxisol of arbuscular mycorrhizal （AM） fungi in phos- Three P levels of 0, 10 and 2...A pot experiment was conducted to investigate the action mechanisms phorus （P） uptake of Capsicum annuum L. in a sterilized fossil Oxisol of arbuscular mycorrhizal （AM） fungi in phos- Three P levels of 0, 10 and 200 mg kg-1 soil （P0, P10 and P200, respectively） without and with AM fungal inoculation were applied as Ca（H2PO4）2-H20. Shoot dry matter yields and shoot P uptake increased significantly （P 〉 0.05） by the inoculation of AM fungi at P0 and P10. Root length and P concentration in soil solution increased with the inoculation of AM fungi but the root：shoot ratio decreased or remained constant. Around 50% roots of inoculated plants were infected by AM and the external hyphae amounted to 20 m g^-1 soil at P10 and P200. The hyphae surface area of the infected root cylinder amounted to 11 and 2 cm^2 cm^-2 root at P0 and P10, respectively. The increased P uptake of inoculated plants was mainly because of an up to 5 times higher P influx of the infected root. Model calculations showed that the root alone could not have achieved the measured P influx in both infected and non-infected roots. But the P influx for hyphae calculated by the model was even much higher than the measured one. The P uptake capacity of hyphae introduced in the model was too high. Model calculations further showed that the depletion zone around roots or hyphae was very narrow. In the case of the root only 7% of the soil volume would contribute P to the plant, while in the case of hyphae it would be 100%. The results together with the model calculations showed that the increased P uptake of AM inoculated plants could be explained partly by the increased P concentration in the soil solution and by the increased P absorbing surface area coming from the external hyphae.展开更多
Using a scheme of agricultural fields with progressively less intensive management (deintensification), different manage- ment practices in six agroecosystems located near Goldsboro, NC, USA were tested in a large-sca...Using a scheme of agricultural fields with progressively less intensive management (deintensification), different manage- ment practices in six agroecosystems located near Goldsboro, NC, USA were tested in a large-scale experiment, including two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT), an organic farming system (OR), an integrated cropping system with animals (IN), a successional field (SU), and a plantation woodlot (WO). Microbial phos- pholipid fatty acid (PLFA) profiles and substrate utilization patterns (BIOLOG ECO plates) were measured to examine the effects of deintensification on the structure and diversity of soil microbial communities. Principle component analyses of PLFA and BIOLOG data showed that the microbial community structure diverged among the soils of the six systems. Lower microbial diversity was found in lowly managed ecosystem than that in intensive and moderately managed agro- ecosystems, and both fungal contribution to the total identified PLFAs and the ratio of microbial biomass C/N increased along with agricultural deintensification. Significantly higher ratios of C/N (P < 0.05) were found in the WO and SU systems, and for fungal/bacterial PLFAs in the WO system (P < 0.05). There were also significant decreases (P < 0.05) along with agricultural deintensification for contributions of total bacterial and gram positive (G+) bacterial PLFAs. Agricultural deintensification could facilitate the development of microbial communities that favor soil fungi over bacteria.展开更多
Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bite...Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bites,lesions caused by herpes simplex virus,diabetes,and gout in Malaysia.Indonesia.Thailand and China.Phylochemieal investigations documented the varied contents of bioaclive compounds from litis plant namely flavonoids,glycosides,glycoglyeerolipids.cerebrosides and monoacylmonogalatosylglycerol.The pharmacological experiment proved that various types of extracts and pure compounds from this species exhibited a broad range of biological properties such as anti-inflammatory,antiviral,antioxidant,and anti-diabetic activities.The lindings of toxicity study showed that extracts from this plant did not show any toxicity thus it can be used as strong therapeutic agents for specific diseased conditions.However,further experiments on chemical components and their mode of action showing biological activities are required to elucidate the complete phytochemical profile and assess to confirm their suitability tor future drugs.This review summarizes the medicinal uses,phytochemistry and pharmacology of this plant in order to explore its therapeutic potential and gaps necessitating for prospected research work.展开更多
Water soluble organic carbon （WSOC） is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WS...Water soluble organic carbon （WSOC） is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils differently managed. WSOC was extracted from soil with water （soil/water ratio of 1：2, W/V） for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on the both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, and provided useful information to soil fertility.展开更多
As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and...As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions.展开更多
A large portion of the Loess Plateau of China is characterized as “marginal” with serious land degradation and desertification problems. Consequently, two policies, Grain for Green and Western Development Action wer...A large portion of the Loess Plateau of China is characterized as “marginal” with serious land degradation and desertification problems. Consequently, two policies, Grain for Green and Western Development Action were established by the Chinese government in response to the demand for ecological protection and economic development in the Loess Plateau. These policies are designed to increase forest cover, expand farmlands, and enhance soil and water conservation, while creating sustainable vegetation restoration. Perennial grasses have gained attention as bioenergy feedstocks due to their high biomass yields, low inputs, and greater ecosystem services compared to annual crops. Moreover, perennial grasses limit nutrient runoff and reduce greenhouse gas emissions and soil losses while sequestering carbon. Additionally, perennial grasses can generate economic returns for local farmers through producing bioenergy feedstock or forage on marginal lands. Here, we suggest a United States model energy crop, switchgrass（Panicum virgatum L.） as a model crop to minimize land degradation and desertification and to generate biomass for energy on the Loess Plateau.展开更多
Low temperature and drought stress are the major constraints in rice productivity worldwide. This study investigated the influence of low soil temperature and/or drought stress on physiology and pollen traits of two r...Low temperature and drought stress are the major constraints in rice productivity worldwide. This study investigated the influence of low soil temperature and/or drought stress on physiology and pollen traits of two rice genotypes viz., Guinongzhan and Yueza 763 at flowering stage. The experiment included four treatments, i.e., under the greenhouse natural growth conditions (UC) taken as control, drought stress (DS), the soil water potential was kept at ?0.035 to ?0.045 MPa (DS), low soil temperature (LT) maintained at 19 to 21℃, combined LT and DS (LT+DS, LD). Results showed that LT, DS, and LD substantially reduced net photosynthetic rate (Pn) and the maximal photochemical efficiency of PSII (Fv/Fm), whilst transpiration rate (Tr) was markedly enhanced by under LT in both rice genotypes. The malondialdehyde (MDA) contents were enhanced under LT, DS, and LD in Guinongzhan, whilst the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were regulated by LT, DS, and LD in both rice genotypes. Furthermore, anther dehiscence rate, pollen numbers on stigma, pollen viability and pollen germination rate, and anther starch contents were obviously reduced under LT and DS of both rice genotypes. Stress conditions substantially reduced the yield and yield components, i.e., effective panicles, seed set percentage, grain/panicles, 1000-grain weight, and grain yield of both genotypes and the effects were more apparent in Guinongzhan than those in Yueza 763 whilst combined LT and DS proved more damaging than individual stress.展开更多
The effects of protein characteristics and the proportion of gluten on end-use quality in 13 Korean wheat cultivars for three years were verified in this study. Year, cultivar, and the interaction between the year and...The effects of protein characteristics and the proportion of gluten on end-use quality in 13 Korean wheat cultivars for three years were verified in this study. Year, cultivar, and the interaction between the year and the cultivar influenced protein characteristics, the proportion of gluten except for γ-and ω-gliadin using RP-HPLC(reversed-phase high-performance liquid chromatography), and end-use quality. Protein characteristics and the proportion of gluten in Korean wheat cultivars were between those of Australian standard white(ASW) and hard wheat(AH). Korean wheat cultivars exhibited a higher average α+β gliadin proportion than imported wheat, a γ-gliadin proportion similar to that of dark northern spring wheat, and the same ω-gliadin proportion as AH. They showed a bread-loaf volume intermediate between those of ASW and AH and a texture of cooked noodles similar to that of soft white wheat, but less springiness than imported wheat. The cookie diameter of Korean wheat cultivars was similar to that of hard red winter wheat. There was a correlation between bread-loaf volume and protein characteristics, except for the protein content in Korean wheat cultivars. Springiness and cohesiveness of cooked noodles were not correlated with protein characteristics, while hardness was correlated with the protein content and water absorption of a mixograph. Cookie diameter was negatively correlated with the sodium dodecyl sulfate(SDS) sedimentation volume and water absorption of a mixograph. The end-use quality was not correlated with any proportion of gluten composition. Principal component analysis(PCA) showed that the proportion of gluten was not related to the quality of the bread(both PCs, 81.3%), noodle(77.7%), and cookie(82.4%). PCA explained that Keumkang is suitable for superior bread, while Uri is good for cooked noodles and cookies.展开更多
Unintended effects of genetic modification on chemical composition of Bt maize leaf litter may have impacts on its decomposition. In most agricultural systems in South Africa, maize litter is either left on the soil s...Unintended effects of genetic modification on chemical composition of Bt maize leaf litter may have impacts on its decomposition. In most agricultural systems in South Africa, maize litter is either left on the soil surface or incorporated into the soil during tillage. A litterbag experiment, using leaf litter of three maize hybrids （DKC80-12B, DKC80-10 and DKC6-125）, was carried out at the University of Fort Hare Research Farm, South Africa, to determine the effects of genetic modification on decomposition of maize leaf litter when left on the soil surface under field conditions between July and November, the normal fallow period, in 2008. Another litterbag experiment was conducted at the University of Fort Hare Research Farm and Zanyokwe Irrigation Scheme, South Africa, using leaf ~itter of two maize hybrids genetically modified with the erylAb gene （MONS10）, DKC75-15B and PAN6Q-3OSB, and their corresponding near isolines, CRN3505 and PAN6Q-121. The degradation of CrylAb protein in the litter, both surface-applied and soil-incorporated, was also investigated. Decomposition of Bt maize litter was similar to that of non-Bt maize litter both when applied on the surface and when incorporated into soil. Soil-incorporated litter, as well as its CrylAb protein, decomposed faster than that applied on the surface. The leaf litter C：N ratios of PAN6Q-308B and PAN6Q-121 were similar throughout the study, whereas those of DKC75-15B and CRN3505 declined by similar amounts during a 12-week period. These findings suggested that decomposition of leaf litter of Bt maize, with the MON810 event, was not affected by maize genetic modification, and that the CrylAb protein broke down together with plant leaf litter during the winter fallow regardless of whether the litter was applied on the soil surface or incorporated into soil.展开更多
Chloramines,in practice,are formed onsite by adding ammonia to chlorinated drinking water to achieve the required disinfection.While regulated disinfection byproducts(DBPs)are reduced during chloramine disinfection,ot...Chloramines,in practice,are formed onsite by adding ammonia to chlorinated drinking water to achieve the required disinfection.While regulated disinfection byproducts(DBPs)are reduced during chloramine disinfection,other DBPs such as iodinated(iodo-)DBPs,that elicit greater toxicity are formed.The objective of this study was to investigate the impact of prechlorination time on the formation of both halogen-specific total organic halogen(TOX)and iodo/chlorinated(chloro-)DBPs during prechlorination/chloramination in source waters(SWs)containing iopamidol,an X-ray contrast medium.Barberton SW(BSW)and Cleveland SW(CSW)containing iopamidol were prechlorinated for 5–60 min and afterwards chloraminated for 72 hr with ammonium chloride.Chlorine contact time(CCT)did not significantly impact total organic iodine(TOI)concentrations after prechlorination or chloramination.Concentrations of total organic chlorine(TOCl)formed during prechlorination did not significantly change regardless of pH and prechlorination time,whileTOClappearedtodecreaseafter 72 hrchloraminationperiod.Dichloroiodomethane(CHCl_2I)formation during prechlorination did not exhibit any significant trends as a function of p H or CCT,but after chloramination,significant increases were observed at pHs 6.5 and 7.5 with respect to CCT.Iodo-HAAs were not formed during prechlorination but were detected after chloramination.Significant quantities of chloroform(CHCl_3)and trichloroacetic acid(TCAA)were formed during prechlorination but formation ceased upon ammonia addition.Therefore,prechlorination studies should measure TOX and DBP concentrations prior to ammonia addition to obtain data regarding the initial conditions.展开更多
文摘Rice-wheat cropping system (RWCS) is one of the most important cropping systems in South Asia. However, sustainability of this system is under threat owing to several factors, of which deficiency of micronutrients particularly zinc (Zn), boron (B) and manganese (Mn) is one of the major problems. Continuous rotation of rice and wheat, imbalanced fertilizer use and little/no use of micronutrient-enriched fertilizers induce deficiencies of Zn, B and Mn in the RWCS of South Asia. Here we review that (i) imbalanced fertilizer use and organic matter depletion deteriorate soil structure resulting in low efficiency of applied macro- and micro-nutrients in RWCS.(ii) The micronutrients (Zn, B and Mn) are essentially involved in metabolism of rice and wheat plants, including chlorophyll synthesis, photosynthesis, enzyme activation and membrane integrity.(iii) Availability and uptake of Zn, B and Mn from rhizosphere depend on the physico-chemical soil properties (which differ under aerobic and anaerobic conditions) including soil pH, soil organic matter, soil moisture and interaction of these micronutrients with other nutrients.(iv) Plant ability to uptake and utilize the nutrients is affected by several plant factors such as root architecture, root hairs, transport kinetics parameter and root exudates.(v) Crop management and application of these microelements can help correct the micronutrients deficiency and enhance their grain concentration.
文摘A 12-year cover crops study on the effects on SOC sequestration, storage, retention and loss and corn and soybean yields was conducted in southern Illinois. The use of cover crops for the maintenance and restoration of soil organic carbon (SOC) and soil productivity of previously eroded soils were evaluated. No-till (NT), chisel plow (CP), and moldboard plow (MP) treatment plots with and without cover crops were established in 2001. The plot area was on sloping with a moderately well drained, eroded soil. The average annual corn and soybean yields were statistically the same for NT, CP, and MP systems with and without cover crops. By 2012, the cover crop treatments had more SOC stock than that without cover crops for the same soil layer and tillage treatment. The NT, CP, and MP treatments all sequestered SOC with cover crops. A pre-treatment SOC stock baseline for rooting zone was used to validate the finding that cover crops sequestered SOC in the topsoil, subsoil and root zone of the NT, CP and MP treatments during the 12-year study. Additional sequestered SOC was lost as a result of being transported off of the plots and retained in lower slopes, transported to the stream or released to atmosphere.
基金financially supported by Bahir Dar University Research and Community Service
文摘Farmers in the highlands of Ethiopia often plant Eucalyptus on their farmlands. However, growing Eucalyptus, especially on farm- lands suitable for crop production has become a great concern due to its alleged long-term site effects. Our study was conducted at Koga water- shed, Mecha District, northwestern Ethiopia to investigate whether crop- lands afforested with Eucalyptus camaldulensis Dehnh. can be restored for annual crop production after tree harvest. We compared growth and yield of two agricultural crops, barley （Hordeum vulgate L.） and finger millet （Eleusine coracana （L.） Gaertn.）, grown in clear-felled stands of E. camaldulensis and continuously cultivated croplands at twelve paired farmlands under a conventional farming system. Plant height and dry matter production were evaluated as indices of crop growth, while grain weight was evaluated as an index of crop yield. Crop growth and yield measurements averaged over all farmlands differed between land-use types. For both crops, plants grown on clear-felled stands were taller than on croplands. Dry matter production and yield were also significantly greater in crops cultivated on clear-felled stands. Cropland aboveground and belowground dry matter productions were lower by 31.8 and 25.4% for barley and 32.8% and 37% for finger millet, respectively. Clear-felled stands gave an average yield of 2.91 t.ha-1 for barley and 3.27 t.ha-1 for finger millet while cropland gave a yield of 1.97 and 2.31 t.ha-1 for barley and finger millet, respectively. Farmers also responded that farm plots on former eucalypt plantations showed greater crop growth and yield thandid continuously cultivated croplands. Farmers perceived that Eucalyptus plantations improved soil fertility and they preferred clear-felled stands for crop production and wished to plant Eucalyptus on their farmlands. Our results suggest that conversion of agricultural lands to Eucalyptus plantations can increase post-felling yields of cereal crops.
文摘The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house field 2 UPM using the sand media to determine the adventitious roots initiation and development using the histological method. The cuttings were treated with different IBA concentrations (0, 500, 1000, 1500 and 2000 mg/L). The nodes explants were used in the development of a protocol for in vitro propagation of P. betle L., with different concentrations of Clorox with different times of immersion (20% Clorox 10 minutes, 30% Clorox 10 minutes, 20% Clorox 20 minutes, and 30% 20 minutes). In multiplication of the plantlets, Murashige and Skoog (MS) medium with different concentrations of BAP (0, 0.5, 1.0, 2.0 mg/L) were used to investigate the rooting of the explants. The results indicated that the types of the cuttings were different in the rooting capacity and the length of the roots. Moreover, it was found that in comparison with the control treatment, by a rise in the concentrations of the IBA, there was a significant upsurge in the rooting percentage, the root diameter, and the number of the roots. The results indicated that the types of cutting with 1000, 1500 and 2000 mg/L IBA perform better in the root percentage (100%) in the semi hardwood cuttings. The best results, however, were 2000 mg/L IBA in the semi hardwood cuttings, with the number of the roots to be 35.05, and the fresh weight of the roots to be 3.94 g, the dry weight of the roots to be 0.33 g, the length of the roots to be 391.88 cm, the roots diameter to be 1.21 mm, the surface area of the roots to be 121.83 cm2, and the root volume to be 2.99 cm3. Nonetheless, the optimal concentration of Clorox with the time immersion was 20% with the 20-minute immersion time, which produced a shoot induction percentage of 30% dead explants and a mean number of 70.00 shoots per explant and the optimal concentration of benzylaminopurine (BAP) at 1.0 mg/L. It is of note that a shoot induction percentage of 22.29% and a mean number of 4.1% number of auxiliary bud per treatment. P. betle shoots in MS medium without PGR MS (0.0) yielded a good rooting.
文摘High tunnels have been used in the United States for more than 50 years, and growers are encouraged to use them more frequently through government cost-share programs. Research on fruits and vegetable production systems has focused on high value crops such as tomato, salad greens, and several fruit crops. Maintaining soil quality and controlling insects and diseases are all issues that growers face. This review looks at current research on these issues as well as economic considerations addressed in the scientific literature. Global statistics and reports are also reviewed that complement the North American studies. Gaps in our understanding are identified, and directions for future research are suggested.
文摘This study sought to establish the compatibility effects of biochar/vermin-compost application on growth and yield of maize and cabbages. Biochar application rate was at 3 to 4% of soil weight. Biochar was mixed in various proportions to come up with treatments which were 100% vermicompost, 50/50% biochar： vermicompost, 75/25% biochar： vermicompost and 100% biochar. The experiment was repeated twice and arranged as a completely randomized design and replicated five times. The study established that maize yield increased with application of biochar from 25% to 50%. In the cabbage trial, comparable results in plant height, leaf numbers and final yield was obtained with 100% vermicompost application, 50% and 75% biochar inclusion. When biochar was applied at 100%, noticeable reduction in plant performance was noted. It is recommended to use biochar as a bio-fertiliser at 50/50% biochar： vermicompost in maize and cabbage production.
文摘This study was conducted to assess the incidence of seed-borne fungi on rice seeds sourced from the major rice growing areas of South-Eastern Nigeria. The rice seeds were collected during the dry seasons between 2009 and 2010. Four hundred rice seeds randomly collected and surface sterilized by washing in 3% sodium hypochlorite and rinsed two times with sterile distilled water were placed in three circular rings inside the Petri dishes. The incubation was done one after the other for each variety from all the locations. Ten fungi species from eight genera were isolated from the rice seeds in all the rice growing areas of South-Eastern Nigeria. The fungi pathogens vary from one locality to another, as well as the frequency of occurrence. The pathogens isolated include： Fusarium moniliforme, F. solani, F. oxysporium, Aspergillus spp., Botridiploidia spp., Helminthosporium spp., Penicillium spp., Trichoconis padwickii, Curvularia oryzae and Phoma oryzae. Though, there was the presence of some seed-borne fungi in the rice seeds from the areas studied, most of the cultivars experienced up to 90% germination. But some cultivars had very low germination. IR 1416 from Arochukwu and GB90 from Arondiuzogu had less than 1% germination. This study shows that seed-borne organisms are major constraint in rice production in the South-Eastern states of Nigeria as a result of low seed germination stemmed from infestation of fungi organisms in the seeds.
基金supported by Research Program for Agricultural Science and Technology Development,Republic of Korea(PJ01570601)the Fellowship Program(PJ01661001)of the National Institute of Agricultural Sciences,Republic of KoreaRural Development Administration,Republic of Korea.
文摘The emergence of novel phytopathogens and the accelerated spread of plant diseases to new regions,driven by global climate change,constitute significant threats to agricultural resources.Rice,a major tropical staple crucial for global food security,possesses six transcription factor superfamilies-AP2/ERF,bHLH,bZIP,MYB,NAC,and WRKY-that function in innate immunity against pathogens.We review their biological functions and regulatory mechanisms in rice immunity.
文摘Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.
基金supported by the National Natural Science Foundation of China(NSFC)(No.42107299).
文摘To better understand the effects of ground-level ozone(O_(3))on nutrients and stoichiometry in different plant organs,urban tree species Celtis sinensis,Cyclocarya paliu-rus,Quercus acutissima,and Quercus nuttallii were sub-jected to a constant exposure to charcoal-filtered air(CF),nonfiltered air(NF),or NF+40,60,or 80 nmol O_(3)mol^(-1)(NF40,NF60,and NF80)starting early in the summer of the growing season.At the end of summer,net CO_(2)assimila-tion rate(A),stomatal conductance(gs),leaf mass per area(LMA),and/or leaf greenness(SPAD)either were not sig-nificantly affected by elevated O_(3)or were even higher in some cases during the summer compared with the CF or NF controls.LMA was significantly lower in autumn only after the highest O_(3)exposures.Compared to NF,NF40 caused a large increase in gs across species in late summer and more K and Mn in stems.At the end of the growing season,nutri-ent status and stoichiometric ratios in different organs were variously altered under O_(3)stress;many changes were large and often species-specific.Across O_(3)treatments,LMA was primarily associated with C and Mg levels in leaves and Ca levels in leaves and stems.NF40 enriched K,P,Fe,and Mn in stems,relative to NF,and NF60 enhanced Ca in leaves relative to CF and NF40.Moreover,NF resulted in a higher Ca/Mg ratio in leaves of Q.acutissima only,relative to the other O_(3)regimes.Interestingly,across species,O_(3)stress led to different nutrient modifications in different organs(stems+branches vs leaves).Thus,ambient and/or elevated O_(3)exposures can alter the dynamics and distribution of nutrients and disrupt stoichiometry in different organs in a species-specific manner.Changes in stoichiometry reflect an important defense mechanism in plants under O_(3),and O_(3)pollution adds more risk to ecological stoichiometries in urban areas.
基金Supported by the Higher Education Commission of Pakistan
文摘A pot experiment was conducted to investigate the action mechanisms phorus （P） uptake of Capsicum annuum L. in a sterilized fossil Oxisol of arbuscular mycorrhizal （AM） fungi in phos- Three P levels of 0, 10 and 200 mg kg-1 soil （P0, P10 and P200, respectively） without and with AM fungal inoculation were applied as Ca（H2PO4）2-H20. Shoot dry matter yields and shoot P uptake increased significantly （P 〉 0.05） by the inoculation of AM fungi at P0 and P10. Root length and P concentration in soil solution increased with the inoculation of AM fungi but the root：shoot ratio decreased or remained constant. Around 50% roots of inoculated plants were infected by AM and the external hyphae amounted to 20 m g^-1 soil at P10 and P200. The hyphae surface area of the infected root cylinder amounted to 11 and 2 cm^2 cm^-2 root at P0 and P10, respectively. The increased P uptake of inoculated plants was mainly because of an up to 5 times higher P influx of the infected root. Model calculations showed that the root alone could not have achieved the measured P influx in both infected and non-infected roots. But the P influx for hyphae calculated by the model was even much higher than the measured one. The P uptake capacity of hyphae introduced in the model was too high. Model calculations further showed that the depletion zone around roots or hyphae was very narrow. In the case of the root only 7% of the soil volume would contribute P to the plant, while in the case of hyphae it would be 100%. The results together with the model calculations showed that the increased P uptake of AM inoculated plants could be explained partly by the increased P concentration in the soil solution and by the increased P absorbing surface area coming from the external hyphae.
基金Project supported by the grants from the US Department of Agriculture, USA (Nos. NRI-1999-35108-8101, NRI-2000-00531, and S-IPM-00-34103-9023), and the Key Projects of the 10th Five-Year Plan of China (No. 2004BA520A14) andScience Foundation of Jiangsu Province, China (No. BK2004002).
文摘Using a scheme of agricultural fields with progressively less intensive management (deintensification), different manage- ment practices in six agroecosystems located near Goldsboro, NC, USA were tested in a large-scale experiment, including two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT), an organic farming system (OR), an integrated cropping system with animals (IN), a successional field (SU), and a plantation woodlot (WO). Microbial phos- pholipid fatty acid (PLFA) profiles and substrate utilization patterns (BIOLOG ECO plates) were measured to examine the effects of deintensification on the structure and diversity of soil microbial communities. Principle component analyses of PLFA and BIOLOG data showed that the microbial community structure diverged among the soils of the six systems. Lower microbial diversity was found in lowly managed ecosystem than that in intensive and moderately managed agro- ecosystems, and both fungal contribution to the total identified PLFAs and the ratio of microbial biomass C/N increased along with agricultural deintensification. Significantly higher ratios of C/N (P < 0.05) were found in the WO and SU systems, and for fungal/bacterial PLFAs in the WO system (P < 0.05). There were also significant decreases (P < 0.05) along with agricultural deintensification for contributions of total bacterial and gram positive (G+) bacterial PLFAs. Agricultural deintensification could facilitate the development of microbial communities that favor soil fungi over bacteria.
文摘Clinacanthus nutans Lindau is known as snake grass belonging to the Acanlhaceae family.This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes,insects and snake bites,lesions caused by herpes simplex virus,diabetes,and gout in Malaysia.Indonesia.Thailand and China.Phylochemieal investigations documented the varied contents of bioaclive compounds from litis plant namely flavonoids,glycosides,glycoglyeerolipids.cerebrosides and monoacylmonogalatosylglycerol.The pharmacological experiment proved that various types of extracts and pure compounds from this species exhibited a broad range of biological properties such as anti-inflammatory,antiviral,antioxidant,and anti-diabetic activities.The lindings of toxicity study showed that extracts from this plant did not show any toxicity thus it can be used as strong therapeutic agents for specific diseased conditions.However,further experiments on chemical components and their mode of action showing biological activities are required to elucidate the complete phytochemical profile and assess to confirm their suitability tor future drugs.This review summarizes the medicinal uses,phytochemistry and pharmacology of this plant in order to explore its therapeutic potential and gaps necessitating for prospected research work.
文摘Water soluble organic carbon （WSOC） is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils differently managed. WSOC was extracted from soil with water （soil/water ratio of 1：2, W/V） for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on the both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, and provided useful information to soil fertility.
基金partially funded by the Greek General Secretariat of Research and Technologythe Greek Scholarship FoundationThe ’Empirikion’ Foundation
文摘As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions.
基金supported by the USDA National Institute of Food and Agriculture, Hatch Project (1001878)
文摘A large portion of the Loess Plateau of China is characterized as “marginal” with serious land degradation and desertification problems. Consequently, two policies, Grain for Green and Western Development Action were established by the Chinese government in response to the demand for ecological protection and economic development in the Loess Plateau. These policies are designed to increase forest cover, expand farmlands, and enhance soil and water conservation, while creating sustainable vegetation restoration. Perennial grasses have gained attention as bioenergy feedstocks due to their high biomass yields, low inputs, and greater ecosystem services compared to annual crops. Moreover, perennial grasses limit nutrient runoff and reduce greenhouse gas emissions and soil losses while sequestering carbon. Additionally, perennial grasses can generate economic returns for local farmers through producing bioenergy feedstock or forage on marginal lands. Here, we suggest a United States model energy crop, switchgrass（Panicum virgatum L.） as a model crop to minimize land degradation and desertification and to generate biomass for energy on the Loess Plateau.
基金supported by the National Natural Science Foundation of China (31271646)the Natural Science Foundation of Guangdong Province, China (8151064201000017)+1 种基金the Agricultural Research Projects of Guangdong Province, China (2011AO20202001)the Agricultural Standardization Project of Guangdong Province, China (4100 F10003)
文摘Low temperature and drought stress are the major constraints in rice productivity worldwide. This study investigated the influence of low soil temperature and/or drought stress on physiology and pollen traits of two rice genotypes viz., Guinongzhan and Yueza 763 at flowering stage. The experiment included four treatments, i.e., under the greenhouse natural growth conditions (UC) taken as control, drought stress (DS), the soil water potential was kept at ?0.035 to ?0.045 MPa (DS), low soil temperature (LT) maintained at 19 to 21℃, combined LT and DS (LT+DS, LD). Results showed that LT, DS, and LD substantially reduced net photosynthetic rate (Pn) and the maximal photochemical efficiency of PSII (Fv/Fm), whilst transpiration rate (Tr) was markedly enhanced by under LT in both rice genotypes. The malondialdehyde (MDA) contents were enhanced under LT, DS, and LD in Guinongzhan, whilst the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were regulated by LT, DS, and LD in both rice genotypes. Furthermore, anther dehiscence rate, pollen numbers on stigma, pollen viability and pollen germination rate, and anther starch contents were obviously reduced under LT and DS of both rice genotypes. Stress conditions substantially reduced the yield and yield components, i.e., effective panicles, seed set percentage, grain/panicles, 1000-grain weight, and grain yield of both genotypes and the effects were more apparent in Guinongzhan than those in Yueza 763 whilst combined LT and DS proved more damaging than individual stress.
基金the support of Cooperative Research Program for Agriculture Science & Technology Development (Project title: Establishment of quality criteria for high uniformity in end-use of Korean wheat cultivars, PJ011009), Rural Development Administration, Republic of Korea
文摘The effects of protein characteristics and the proportion of gluten on end-use quality in 13 Korean wheat cultivars for three years were verified in this study. Year, cultivar, and the interaction between the year and the cultivar influenced protein characteristics, the proportion of gluten except for γ-and ω-gliadin using RP-HPLC(reversed-phase high-performance liquid chromatography), and end-use quality. Protein characteristics and the proportion of gluten in Korean wheat cultivars were between those of Australian standard white(ASW) and hard wheat(AH). Korean wheat cultivars exhibited a higher average α+β gliadin proportion than imported wheat, a γ-gliadin proportion similar to that of dark northern spring wheat, and the same ω-gliadin proportion as AH. They showed a bread-loaf volume intermediate between those of ASW and AH and a texture of cooked noodles similar to that of soft white wheat, but less springiness than imported wheat. The cookie diameter of Korean wheat cultivars was similar to that of hard red winter wheat. There was a correlation between bread-loaf volume and protein characteristics, except for the protein content in Korean wheat cultivars. Springiness and cohesiveness of cooked noodles were not correlated with protein characteristics, while hardness was correlated with the protein content and water absorption of a mixograph. Cookie diameter was negatively correlated with the sodium dodecyl sulfate(SDS) sedimentation volume and water absorption of a mixograph. The end-use quality was not correlated with any proportion of gluten composition. Principal component analysis(PCA) showed that the proportion of gluten was not related to the quality of the bread(both PCs, 81.3%), noodle(77.7%), and cookie(82.4%). PCA explained that Keumkang is suitable for superior bread, while Uri is good for cooked noodles and cookies.
基金Supported by the National Research Foundation of South Africa(NRF)the Govan Mbeki Research and Development Center(GMRDC)of the University of Fort Hare(No.GUN62299)
文摘Unintended effects of genetic modification on chemical composition of Bt maize leaf litter may have impacts on its decomposition. In most agricultural systems in South Africa, maize litter is either left on the soil surface or incorporated into the soil during tillage. A litterbag experiment, using leaf litter of three maize hybrids （DKC80-12B, DKC80-10 and DKC6-125）, was carried out at the University of Fort Hare Research Farm, South Africa, to determine the effects of genetic modification on decomposition of maize leaf litter when left on the soil surface under field conditions between July and November, the normal fallow period, in 2008. Another litterbag experiment was conducted at the University of Fort Hare Research Farm and Zanyokwe Irrigation Scheme, South Africa, using leaf ~itter of two maize hybrids genetically modified with the erylAb gene （MONS10）, DKC75-15B and PAN6Q-3OSB, and their corresponding near isolines, CRN3505 and PAN6Q-121. The degradation of CrylAb protein in the litter, both surface-applied and soil-incorporated, was also investigated. Decomposition of Bt maize litter was similar to that of non-Bt maize litter both when applied on the surface and when incorporated into soil. Soil-incorporated litter, as well as its CrylAb protein, decomposed faster than that applied on the surface. The leaf litter C：N ratios of PAN6Q-308B and PAN6Q-121 were similar throughout the study, whereas those of DKC75-15B and CRN3505 declined by similar amounts during a 12-week period. These findings suggested that decomposition of leaf litter of Bt maize, with the MON810 event, was not affected by maize genetic modification, and that the CrylAb protein broke down together with plant leaf litter during the winter fallow regardless of whether the litter was applied on the soil surface or incorporated into soil.
基金supported by the National Science Founda-tion (NSF, project numbers NSF1124865 and NSF1124844)the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG, project number TE 533/4-1)
文摘Chloramines,in practice,are formed onsite by adding ammonia to chlorinated drinking water to achieve the required disinfection.While regulated disinfection byproducts(DBPs)are reduced during chloramine disinfection,other DBPs such as iodinated(iodo-)DBPs,that elicit greater toxicity are formed.The objective of this study was to investigate the impact of prechlorination time on the formation of both halogen-specific total organic halogen(TOX)and iodo/chlorinated(chloro-)DBPs during prechlorination/chloramination in source waters(SWs)containing iopamidol,an X-ray contrast medium.Barberton SW(BSW)and Cleveland SW(CSW)containing iopamidol were prechlorinated for 5–60 min and afterwards chloraminated for 72 hr with ammonium chloride.Chlorine contact time(CCT)did not significantly impact total organic iodine(TOI)concentrations after prechlorination or chloramination.Concentrations of total organic chlorine(TOCl)formed during prechlorination did not significantly change regardless of pH and prechlorination time,whileTOClappearedtodecreaseafter 72 hrchloraminationperiod.Dichloroiodomethane(CHCl_2I)formation during prechlorination did not exhibit any significant trends as a function of p H or CCT,but after chloramination,significant increases were observed at pHs 6.5 and 7.5 with respect to CCT.Iodo-HAAs were not formed during prechlorination but were detected after chloramination.Significant quantities of chloroform(CHCl_3)and trichloroacetic acid(TCAA)were formed during prechlorination but formation ceased upon ammonia addition.Therefore,prechlorination studies should measure TOX and DBP concentrations prior to ammonia addition to obtain data regarding the initial conditions.
