Drought induced changes in growth, leaf gas exchange and biomass production in Albizia lebbeck and Cassia siamea seedlings

Diurnal trends in net photosynthesis rate (P(N)), stomatal conductance (g(s)), water use efficiency (WUE) and biomass were compared in six-month-old seedlings of Albizia lebbeck and Cassia siamea, under different levels of drought stress. The potted plants were subjected to four varying drought treatment by withholding watering for 7 (D1), 14(D2) and 25 (D3) days. The fourth group (C) was watered daily and treated as unstressed (control). Species differed significantly (p < 0.001) in their physiological performance under varying stress conditions. Higher P(N) of 11.6 +/- 0.05 in control followed by 4.35 +/- 0.4 in D1 and 2.83 +/- 0.18 micromol m(-2) s(-1) in D2 was observed in A. lebbeck. A significant (p < 0.001) reduction in P(N) was observed in C. siamea (C 7.65 +/- 0.5 micromol m(-2) s(-1), D1, 2.56 +/- 0.33 micromol m(-2) s(-1) and D2, 1.4 +/- 0.01 micromol m(-2) s(-1)) at 9 hr. A positive correlation was seen between P(N) and g(s) (A. lebbeck, r2 = 0.84; C. siamea, r2 = 0.82). Higher WUE was observed in C. siamea (D2, 7.1 +/- 0.18 micromol m(-2) s(-1); D3, 8.39 +/- 0.11 micromol m(-2) s(-1)) than A. lebbeck, (control, 7.58 +/- 0.3 micromol m(-2) s(-1) and D3, 8.12 +/- 0.15 micromol m(-2) s(-1)). The chlorophyll and relative water content (RWC) was more in A. lebbeck than C. siamea. Maximum biomass was produced by A. lebbeckthan C. siamea. From the study, one could conclude that A. lebbeckis better than C. siamea in adopting suitable resource management strategy and be best suited for the plantation programs in the semi-arid dry lands.     

Diurnal photosynthesis, water use efficiency and light use efficiency of wheat under Mediterranean field conditions

Photosynthesis and transpiration rates of wheat leaves (Triticum aestivum L.) were measured at 30 min intervals under Mediterranean field conditions, using Photosynthesis Monitor system (PM-48M). The dynamics of net photosynthetic rate (P(N)), transpiration rate (E(T)), water use efficiency (WUE), light use efficiency (LUE), stomatal conductance (g(s)), photosynthetically active radiation (PAR), air temperature (T), relative humidity (RH), and atmospheric CO2 concentration (Catm) were quantified at five rainfed wheat sites with the same stages of development (midflowering) along south-to-north and east-to-west transects for eight days in April. Diurnal P(N) (3.6 to 6.6 micromol m(-2) s(-1)), PAR (392 to 564 micromol m2 sec(-1)), LUE (0.006 to 0.015) and WUE (0.0001 to 0.011) did not vary significantly across all five wheat sites (p > 0.05). P(N) and E(T) were strongly coupled and highly correlated with PAR (p < 0.001). Best multiple linear regression (MLR) models accounted for 92% of variations in P(N) as a function of PAR and E(T), and 90% in E(T) as a function of PAR and RH (p < 0.001). P(N) exhibited a peak at mid-morning, and a photosynthetic midday depression under the limiting effects of high evaporative demand. Diurnal variations in WUE and LUE showed a bimodal behavior with the maximum values in early morning and late afternoon. As the impacts of global climate change become increasingly felt, continuous measurements of climate-crop-soil-managementinteractions under natural conditions play a pivotal role not only in exploring changes in ecophysiological properties of strategic crops for food security such as wheat but also in devising preventive and mitigative management practices to ensure sustained agricultural productivity.     

根修剪对冬小麦根系效率、水分利用及产量的影响

通过盆栽试验研究了根修剪对冬小麦根系效率、水分利用及产量形成的影响.结果表明,在不同水分条件下,根修剪均减少了小麦的根量及根呼吸速率,但对根冠比没有显著影响.在湿润和中度干旱条件下,根修剪提高了小麦花期的光合速率和根系效率;在严重干旱胁迫条件下,根修剪小麦的光合速率显著下降,但根系效率与对照相比没有显著差异.在湿润条件下,小剪根处理对籽粒产量并没有显著的影响,而大剪根处理小麦的籽粒产量显著下降;在中度干旱胁迫条件下,小剪根处理小麦的产量(25.18 g pot-1)显著高于对照(22.31 g par-1),但大剪根处理小麦的产量(18.34 g pot-1)显著下降;在严重干旱条件下,两个剪根处理小麦的产量均显著下降.在湿润和中度干旱胁迫条件下,小剪根处理籽粒产量水平的水分利用效率(分别为1.57 g kg-1和1.85 g kg-1)显著大于相应的对照处理(分别为1.46 g kg-1和1.55 g kg-1),但大剪根处理水分利用效率和对照相比没有显著差异;在严重干旱条件下,各剪根处理的水分利用效率和对照相比没有显著差异.可见,在湿润和中度干旱条件下进行的适当根修剪根对作物生产是有利的.图1表3参15     

Effects of nitrogen treatments and harvesting stages on the aconitic acid, invert sugar and fiber in sweet sorghum cultivars

Sweet sorghum is adapted to the hot and dry climatic conditions and its tolerance to slat is moderately. It can be used for different products such as food, feed, fiber and fuel. This study was carried out to evaluate the effects, three nitrogen treatments, and three harvesting stages on the aconitic acid, fiber and invert sugar of three sweet sorghum cultivars in the experimental station and the results showed that the effects were significant. Among nitrogen treatments, application of 100 kg ha(-1) urea at planting and 200 kg ha(-1) urea at 4 leaf stage had the highest aconitic acid (0.26%) and invert sugar (3.44%). Among sweet sorghum cultivars, IS2325 and Vespa had the highest aconitic acid (0.26%) and invert sugar (3.86%), respectively Plant harvested at 4 leaf stage had the highest aconitic acid (0.26%) and the highest invert sugar (3.85%). Rio had higher fiber content than Vespa and IS2325 and all cultivars had the highest fiber content before chilling harvesting stage. In general, since high invert sugar and high aconitic acid interfere crystallization of sugar so, it is suggested that to plant Vespa, apply urea 100 kg ha(-1) urea at planting, 100 kg ha' urea at 4 leaf stage and 100 kg ha(-1) urea at booting and harvested before chilling that had lowest aconitic acid and invert sugar. Thereby, it is recommended to plant Vespa, apply urea 100 kg ha(-1) urea at planting, 100 kg ha(-1) urea at 4 leaf stage and 100 kg ha(-1) urea at booting and harvested at 4 leaf stage that had the highest aconitic acid.     

Studies on antimicrobial activities of solvent extracts of different spices

The antimicrobial activities of the ethyl acetate, acetone and methanol extract of 12 plant species were studied. The extract of Capsicum annuum (red pepper) (fruit) Zingiber officinale (ginger) (root), Cuminum cyminum (cumin), Alpinia ficinarum (galingale), Coriandrum sativum (coriander), Cinnamomun zeylanicum Nees (cinnamomun), Origanum onites L. (thyme), Folium sennae (senna), Eugenia caryophyllata (cloves), Flos tiliae (lime), Folium menthae crispae (peppermint) and Piper nigrum (blackpepper) were tested in vitro against 2 fungi and 8 bacterial species by the disc diffusion method. Klebsiella pneumonia 13883, Bacillus megaterium NRS, Pseudomonas aeroginosa ATCC 27859, Staphylococcus aureus 6538 P, Escherichia coil ATCC 8739, Enterobacter cloaca ATCC 13047, Corynebacterium xerosis UC 9165, Streptococcus faecalis DC 74, Kluyveromyces marxianus, Rhodotorula rubra were used in this investigation. The results indicated that extracts of different spices has shown antibacterial activity in the range of 7-24 mm 30 microl(-1) inhibition zone Eugenia caryophyllata (clove), 7-20 mm 30microl(-1) inhibition zone Capsicum annum (red pepper) and Cinnamomun zeylanicum (cinnamon) bark, 7-18 mm 30microl(-1) inhibition zone Folium sennae (senna) leaves, 7-16 mm 30 microl(-1) inhibition zone Zingiber officinale (ginger) root, 7-15 mm 30microl(-1) inhibition zone Cuminum cyminum (cumin) seed, 7-14 mm 30 microl(-1) inhibition zone Folium menthae crispae (peppermint), Origanum onites (thyme) leaves and Alpinia ficinarum (galingale) root, 7-12 mm 30 microl(-1) inhibiton zone Piper nigrum (blackpepper), 7-11 mm 30microl(-1) inhibition zone Flos tiliae (lime) leaves, 7-8 mm 30microl(-1) inhibition zone Coriandrum sativum (coriander) to the microorganisms tested.     

Root biomass and carbon storage in oriental spruce and beech stands in Artvin, Turkey

In this study, influence of slope position (south-facing vs. north-facing), species type and sampling time on fine (0-2 mm), small (2-5 mm) and coarse (5-10 mm) root biomass and carbon storage of oriental spruce (Picea orientalis) and oriental beech (Fagus orientalis) were investigated. Mean total root biomass of oriental spruce was 20160 kg ha(-1) in south-facing slopes and 17140 kg ha(-1) in north-facing slopes. Mean total belowground C storage of oriental spruce was 7861 kg ha(-1) in south-facing slopes and 6840 kg ha(-1) in north-facing slopes. Similarly, biomass and C storage of oriental beech were 17190 and 6690 kg ha(-1) in south-facing slopes, and 13260 and 5200 kg ha(-1) in north-facing slopes, respectively. Oriental spruce had significantly higher fine root biomass than did oriental beech in south-facing slopes. Fine root biomass was significantly higher in fall than in spring in south-facing slopes.     

Role of water hyacinth in the health of a tropical urban lake

The paper assesses health of the tropical urban Robertson Lake, Jabalpur which receives domestic sewage from neighboring human inhabitation and is infested with water hyacinth. Peak density of this macrophyte was 12.5 t dw ha(-1). The water-column was anaerobic (0.6 to 1.9 mg O2 L(-1)), neutral in pH, and enriched with inorganic carbon (23.5 to 37.1 mg L(-1)), NH4-N (0.48 to 2.96 mg L(-1)), and organic nitrogen and phosphorus. Density of heterotrophic bacteria was high (6.8 to 15x10(5) cfu ml(-1)) along with that of total coliforms and fecal bacteria. Species diversity of phytoplankton and submerged macrophytes was very low. Growing stands of water hyacinth could store up to 613 g C m(-2), 23.5 g N m(-2) and 5.5 g P m(-2) and released them during decomposition. The release of nutrients was 3-4 times faster than the uptake. Water hyacinth stabilized water quality and provided substantial support to bacterial density, which in turn contributed significantly to its growth and nutrient dynamics. Turnover of water hyacinth was only 70-80%, adding approximately 175 t humus in the lake. The results denote poor health of the lake, characterized by low species diversity, fast shallowing, dominance of detritus food--webs, and the water unsuitable for human consumption.     

胡椒养分含量状况的研究

胡椒大、中量元素的含量在不同树龄中有所不同，幼龄期以氮最高，其Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１５：０．５３－０．９：０．２２－０．３８：０．１５－０．３０；成年龄则以Ｋ２Ｏ最高，Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１３：１．３２：０．４４：０．１６．在不施微肥的情况下，胡椒叶片缺Ｂ、Ｍｏ、Ｚｎ．成年龄胡椒各养分含量都是从萌芽期（收获后）开始，随生育期的进展而增加，到果实成熟期下降．一株中产胡椒Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ总吸收量为２８２．４ｇ，其比例为１：０．１９：０．９．     

Porphyrobacter sp.D22F的降解特性及其在石油降解菌群中的生态位

为揭示多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)降解微生物资源的多样性和石油降解菌群的优势菌,研究了从南海沉积物中分离得到的一株PAHs降解菌D22F的降解特性及其在石油降解菌群D22-1中的生态位.对菌株D22F进行16S rRNA基因同源性分析及透射电镜观察以初步确定其种属,通过培养法、气相色谱质谱联用(GC-MS)测定其多环芳烃降解范围和降解率,通过简并引物PCR扩增其PAHs双加氧酶大亚基基因片段并进行系统发育分析,采用变性梯度凝胶电泳(DGGE)监测石油降解菌群中的优势菌.结果表明,与菌株D22F的16S rRNA基因相似度最高的模式株为产卟啉杆菌属Porphyrobacter tepidarius DSM 10594T(AF465839;98.55%).该菌株能降解萘、甲基萘、苊、硫芴、菲、蒽等;对初始浓度为0.2 g/L菲10 d后的降解率可达90%以上.从其基因组DNA中克隆到的PAHs起始双加氧酶大亚基基因phnAc与Novosphingobium aromaticivorans DSM 12444中的质粒pNL1(CP000676)上的bphA1f基因相似度最高,达到99.41%.DGGE谱图显示,菌株D22F是石油降解菌群中的3种优势菌之一,在传代菌群中可稳定存在.Porphyrobacter sp.D22F为产卟啉杆菌属(Porphyrobacter)中首株以低分子量PAHs为唯一碳源和能源的菌株,是石油降解菌群的优势菌.     

Effect of organic materials and rice cultivars on methane emission from rice field

A field experiment was conducted for two years on a sandy loam (Typic Ustochrept) soil of Punjab to study the effect of organic materials and rice cultivars on methane emission from rice fields. The methane flux varied between 0.04 and 0.93 mg m(-2) hr(-1) in bare soil and transplanting of rice crop doubled the methane flux (0.07 to 2.06 mg m(-2) hr(-1)). Among rice cultivars, significantly (p < 0.05) higher amount of methane was emitted from Pusa 44 compared to PR 118 and PR 111. Application of organic materials enhanced methane emission from rice fields and resulted in increased soil organic carbon content. The greatest seasonal methane flux was observed in wheat straw amended plots (229.6 kg ha(-1)) followed by farmyard manure (111.6 kg ha(-1)), green manure (85.4 kg ha(-1)) and the least from rice straw compost amended plots (36.9 kg ha(-1)) as compared to control (21.5 kg ha(-1)). The differential effect of organic materials in enhancing methane flux was related to total carbon or C:N ratio of the material. The results showed that incorporation of humified organic matter such as rice straw compost could minimize methane emission from rice fields with co-benefits of increased soil fertility and crop productivity.     

Effect of sulphur and phosphorus on yield, quality and nutrient status of pigeonpea (Cajanus cajan)

A field experiment was conducted to study the impact of Sulphur(S) and Phosphorus (P) on yield, nutrient status of soil and their contents in pigeonpea (Cajanus cajan) during the year 2008-2009. Seven treatments were studied in Factorial Randomized Block Design with three replications. The treatment combinations were derived from three levels of sulphur (0, 20 and 40 kg S ha(-1)) and four levels of phosphorus (0, 25, 50 and 75 kg ha(-1)). The experimental soil was medium black, slightly calcareous, clay in texture and slightly alkaline in reaction. The results indicated a significant increase in grain yield (14.81 q ha(-1)) and straw yield (41.26 q ha(-1)) of pigeonpea after 20 kg S ha(-1) and 50 kg P2O5 ha(-1) treatment with common dose of nitrogen @ 30 kg ha(-1). The increase in grain and straw yield was 102.77 and 52.87% as compare to higher over control. Maximum number of pods plant(-1), maximum number of grains pod and test weight by this treatment was also observed as compared to control. Application of S and P improved soil fertility status and S alone did not influence P availability. Hence, in order to maintain the fertility status of the soil at high level, combine application of 20 kg S ha(-1) with 50 kg P2O5 ha(-1) is essential. The residual fertility status of soil is advocated for rainfed pigeonpea crop grown on vertisol in Vidarbha region.     

Flow of chemical energy in Alwar jheel of Yamuna basin near Allahabad

The water quality, rate of energy transformation, chemical composition of producers and flow of chemical energy were studied in both feeding river Yamuna and Alwar jheel near Allahabad. As the river Yamuna had high value of alkalinity (210.0 mgl(-1)), conductance (518.0 micromhos), dissolved solids (260.0 mgl(-1)), hardness (162.0 mgl(-1)) and chloride (54.6 mgl(-1)) jheel also showed high values of these parameters. The rate of energy transformation from kinetic radiant energy to chemical energy was very high in the jheel 32,315 Cal m(-2) day(-1) of which 25,620 Cal m(-2) day(-1) was contributed by aquatic plants. Out of 11,764 x 10(4) Kcal ha(-1) yr(-1) total energy fixed in the system, producers stored 7,154 x 10(4) Kcal ha(-1) yr(-1) and the rest was lost as heat of respiration. The pattern of storage of energy was different in two groups of producers and thus most of the energy fixed by phytoplankton was stored as protein (56.2%) and less as carbohydrate (11.7%) while aquatic plants stored more energy as carbohydrate (40.8%) than protein (23.2%). The chemical energy obtained from the system was 1,85,000 Kcal ha(-1) yr(-1) and thus only 0.260% of the chemical energy stored by producers was harvested. The potential chemical energy resource in the jheel was 81.4 x 10(4) Kcal ha(-1) yr(-1) of which only 22.6% was harvested in the jheel and there is enough scope for further enhancement.     

Sulphur management in onion (Allium cepa) cultivation in hills of Himachal Pradesh

Field experiment were conducted at CSK HPKV Research Farm, Palampur during Rabi seasons of 2000-01 and 2001-02, to study the response of onion (Allium cepa var Patna red) at four sulphur levels (0, 15, 30 and 60 kg ha(-1)) applied through Gypsum and S95. The analysis was done to allocate the limited availability of sulphur for maximizing net profit over fertilizer cost. The results show that the dose of sulphur under its full availability is 43.02 kg ha(-1). But under its scarce availability the maximum benefit would occur when it is applied up to 32.11 kg ha(-1) followed by even distribution of fertilizer i.e. 20 kg ha(-1). The returns following sulphur application at these rates, would be Rs 69340, 73092 and 68700 ha(-1) respectively.     

Nitrogen and phosphorus cycling in shrimp ponds and the measures for sustainable management

Six ponds of age 3 were selected 45 km north from Suzhou in the Tailake region, and research conducted on nitrogen and phosphorus cycling in P. vannanmei (Penaeus vannanme) ponds and M. nipponense (Macrobrachium nipponense) hatchery ponds under normal management. Two treatments each had three replications. The results confirmed that feed was the major path of nitrogen and phosphorus input, each accounted for 61.24% (193.81 kg ha(-1)) and 81.08% (45.20 kg ha(-1)) of the total nitrogen and phosphorus input for P. vannanme ponds; the values for M. nipponense ponds were 43.93% (86.31 kg ha(-1)) and 57.67% (14.61 kg ha(-1)), respectively. Water pumped into ponds contributed on average 83.57 kg ha(-1) nitrogen and 8.48 kg ha(-1) phosphorus for P. vannanmei ponds, and 87.48 kg ha(-1) nitrogen and 7.00 kg ha(-1) phosphorus for M. nipponense hatchery ponds. Shrimp harvest recovered 102.81 kg ha(-1) nitrogen (32.94% of the total nitrogen input) and 7.94 kg ha(-1) phosphorus (14.23% of the total phosphorus input) for P. vannanme ponds; and 43.94 kg ha(-1) nitrogen and 4.46 kg ha(-1) phosphorus for M. nipponense hatchery ponds. The sum of nitrogen losses through volatilization, denitrification and sedimentation was 173.62 and 122.39 kg ha(-1), 54.86% and 62.29% of the total nitrogen input for P. vannanme ponds and M. nipponense hatchery ponds, respectively. Sediment accumulated 41.46 and 14.63 kg ha(-1) phosphorus, 74.37% and 64.85% of the total phosphorus input for P. vannanm ponds and M. nipponense hatchery ponds. Draining and seeping caused 40.06 kg ha(-1) nitrogen (12.66% of total nitrogen input) and 6.36 kg ha(-1) phosphorus (11.40% of total phosphorus input) loss to the surrounding water from P. vannanme ponds in 114 days; 30.14 kg ha(-1) nitrogen (15.34% of the total input) and 4.45 kg ha(-1) phosphorus (17.57% of the total input) to channel water from M. nipponense hatchery ponds in 87 days, respectively. Countermeasures for sustainable pond management include improving feeds and feeding, sediment treatments, machine aerating, chemicals with no pollution, and integrated fish-shrimp cultivation. Management of water resources for pond and methods to reduce nitrogen and phosphorus loading into surrounding water from drainage are elucidated.     

Characterization in the archaeological excavation site of heterotrophic bacteria and fungi of deteriorated wall painting of Herculaneum in Italy

Microbiological characterization of frescos in four different locations (Collegio degli Augustali, Casa del Colonnato Tuscanico, Casa dello Scheletro and Casa del Gran Portale) of excavation sites of Herculaneum was carried out. The use of infrared thermography allowed detecting sample points on frescos with greatest moisture not visible to the naked eye, resulting in structural damage. The microclimatic conditions provided perfect habitat for bacteria and fungi, particularly of spore forming and mould. In fact, heterotrophic bacteria were prevalent in all wall paintings monitored (ranging from 18 +/- 2 CFU 100 cm(-2) to 68 +/- 4 CFU 100 cm(-2)), whereas fungi were also detected but at lower levels (ranging from 9 +/- 2 CFU 100 cm(-2) to 45 +/- 3 CFU 100 cm(-2)). Cultural-based method allow us to identify by 16S and 26S rRNA partial sequence analysis heterotrophic microorganisms belonging to different genera of Bacillus and Aspergillus, Penicillium and Fusarium together with the unusual genera as Microascus and Coprinus. By using this approach, Bacillus-related species (B. cereus/B. thuringiensis group, B. simplex/B. muralis group, B. megaterium and B. subtilis) were isolated in all sample points analysed with the exception of the Casa dello Scheletro in which Micrococcus luteus/Arthrobactersp. group and Streptomyces fragilis were found. DGGE analysis of PCR amplified V3 region of rDNA from DNA directly recovered from frescos samples, enabled identification of bacterial species not identified using culturable technology asthose closest related to Microbacterium group, often associated with Brevibacterium, Streptomyces and Stenotrophomonas. Combination of culture-dependent and independent methods provided better microbiology characterization of heterotrophic microbiota present on the surface of ancient frescos of this important archaeological site.     

杠板归的化学成分

采用柱层析方法从蓼科药用植物杠板归(Polygonum Perfoliatum)分离了21个化合物(1～21),通过MS与NMR数据鉴定这些化合物为α-tocopherolquinone (1), 7'-dihydroxymatairesinol (2), (24S)-24-ethylcholesta-3β,5α,6α-triol (3), 4-dihydroxy-5,7-dihydroxy-4-(4-hydroxyphenyl) coumarin (4), quercetin (5), cucurbitacin Ⅱa (6), cucurbitacin U (7), iotroridoside A (8), pokeweedcerebroside 5 (9), bonaroside (10), helonioside A (11), helonioside B (12), lapathoside D (13), vanicoside B (14), vanicoside C (15), vanicoside F (16), asteryunnanoside F (17), saikosaponin M (18), hydropiperoside (19), quercetin-3-O-β-D-glucuronide-6"-butyl ester (20), quercetin-3-O-β-D-glucuronide-6"-methyl ester (21). 化合物1～19(除4,5,12)为首次从该植物中分离得到,化合物1～11(除4,5)和17～19为首次从该属植物中分离得到.图1参22     

Evaluating the effects of future climate change and elevated CO2 on the water use efficiency in terrestrial ecosystems of China

Water use efficiency (WUE) is an important variable used in climate change and hydrological studies in relation to how it links ecosystem carbon cycles and hydrological cycles together. However, obtaining reliable WUE results based on site-level flux data remains a great challenge when scaling up to larger regional zones. Biophysical, process-based ecosystem models are powerful tools to study WUE at large spatial and temporal scales. The Integrated BIosphere Simulator (IBIS) was used to evaluate the effects of climate change and elevated CO₂ concentrations on ecosystem-level WUE (defined as the ratio of gross primary production (GPP) to evapotranspiration (ET)) in relation to terrestrial ecosystems in China for 2009-2099. Climate scenario data (IPCC SRES A2 and SRES B1) generated from the Third Generation Coupled Global Climate Model (CGCM3) was used in the simulations. Seven simulations were implemented according to the assemblage of different elevated CO₂ concentrations scenarios and different climate change scenarios. Analysis suggests that (1) further elevated CO₂ concentrations will significantly enhance the WUE over China by the end of the twenty-first century, especially in forest areas; (2) effects of climate change on WUE will vary for different geographical regions in China with negative effects occurring primarily in southern regions and positive effects occurring primarily in high latitude and altitude regions (Tibetan Plateau); (3) WUE will maintain the current levels for 2009-2099 under the constant climate scenario (i.e. using mean climate condition of 1951-2006 and CO₂ concentrations of the 2008 level); and (4) WUE will decrease with the increase of water resource restriction (expressed as evaporation ratio) among different ecosystems.     

生物炭早期植物毒性评估培养方法研究

为更加科学地评估生物炭潜在植物毒性,采用生物炭(B)、生物炭+土壤(B+S)、生物炭水浸提液+土壤(AE+S)、生物炭+石英砂(B+Q)、生物炭水浸提液+石英砂(AE+Q)5种不同的培养方法进行早期植物毒性效应实验。比较分析不同培养方法中西红柿种子发芽率、根长、芽长对生物炭的响应。结果表明:在5种培养方法中,随生物炭剂量增加,西红柿种子发芽率、根长、芽长呈现先增后降的变化趋势。虽在低剂量生物炭处理下(10.0 g·kg~(-1)),种子萌发表现出促进作用。但随剂量增加,除B+S和AE+S外,均表现出一定的抑制作用,且当剂量为160.0 g·kg~(-1)时,抑制作用达到最大。对比有土和无土培养方法中种子萌发情况发现,在高剂量下,无土培养方法中种子发芽率,根、芽生长所受抑制作用显著高于有土培养方法。无土方法中,尤其AE+Q方法中,高剂量生物炭对种子发芽率、根长、芽长表现出最大的抑制作用,其中发芽率抑制率为91.1%,根长抑制率为77.7%,芽长抑制率为93.7%。综合比较分析,生物炭水浸提液+石英砂(AE+Q)的培养方法干扰因子少,可提高毒性响应灵敏度。因此,在生物炭早期植物毒性效应评估中,该法可作为推荐的培养方法。     

Impact of distillery effluent on germination behaviour of Brassica napus L

The study has been focused on effect of untreated distillery effluent (Devans Breweries Ltd., Jammu) on germination of gobi sarson (Brassica napus. L. var. Punjabi Special). Six treatments (E0.... E100) each having three replicates were made. E0 was taken as control in which tap water was used for irrigation of the plants. For E20, E40, E60, E80 and E100, different concentrations i.e. 20, 40, 60, 80 and 100% of effluent were used for irrigation, respectively. The 100% sample of distillery effluent analyzed for various physicochemical parameters showed acidic nature (pH 4.0) and higher values of COD (2496 mg l(-1)), TDS (799.7 mg l(-1)) and chlorides (1408 mg l(-1)). The parameters e.g. percent germination, germination index, speed of germination, and peak value were highest in treatment receiving 20% effluent concentration which also showed minimum values for percent inhibition, germination period, and delay index.     

Direct, residual and direct + residual effects of sulphur in garlic (Allium sativum)-maize (Zea mays) cropping sequence

Significant positive effects of 30 kg/ha of sulphur as manifested on yield and yield parameters of garlic were further carried over to following maize crop. Garlic bulb and foliage yield (6.3 and 0.8 t/ha respectively) obtained at 30 kg/ha of sulphur dose was significantly higher over without sulphur (3.7 and 0.5 t/ha respectively) as revealed from two years' pooled data. Similarly number of leaves/plant, weight of cloves/5bulbs and weight/100 cloves at the said sulphur dose significantly increased over without sulphur from 10.5 to 11.9, 98.3 to 141.2 g and from 159 to 217 g in respective manner Increase in grain yield of maize (residual effect) and in the economic yield of the whole cropping sequence (Bulb yield of garlic and grain yield of maize) i.e. direct plus residual effect at 30 kg/ha of sulphur dose over without sulphur was from 28.3 to 47.2 and from 71 to 116 q/ha in respective manner i.e. with significant differences. Sulphur use efficiencies (kg yield/kg sulphur) of these crops at 15, 30 and 45 kg/ha over no sulphur were 57, 43 and 32; 53, 63 and 6 and 160, 150 and 67, all in respective order An optimum sulphur dose of 44.3 kg/ha produced increased bulb yield (over no S) worth Rs 34892 over fertilizer cost giving B:C ratio of 31.5:1. Utilization of sulphur added at 15, 30 and 45 kg/ha rates was 24.1, 19.3 and 15.7% by the garlic crop; and 29.6. 24.5 and 9.02% by the following maize crop, thus, adding up to 54.1, 43.8 and 24.9% by the cropping sequence, all in respective order.