Seasonal speedup along the western flank of the Greenland Ice Sheet

It has been widely hypothesized that a warmer climate in Greenland would increase the volume of lubricating surface meltwater reaching the ice-bedrock interface, accelerating ice flow and increasing mass loss. We have assembled a data set that provides a synoptic-scale view, spanning ice-sheet to outlet-glacier flow, with which to evaluate this hypothesis. On the ice sheet, these data reveal summer speedups (50 to 100%) consistent with, but somewhat larger than, earlier observations. The relative speedup of outlet glaciers, however, is far smaller (<15%). Furthermore, the dominant seasonal influence on Jakobshavn Isbrae's flow is the calving front's annual advance and retreat. With other effects producing outlet-glacier speedups an order of magnitude larger, seasonal melt's influence on ice flow is likely confined to those regions dominated by ice-sheet flow.     

Productivity and Sustainability of Cotton (Gossypium hirsutum L.)–Wheat (Triticum aestivum L.) Cropping System as Influenced by Prilled Urea, Farmyard Manure and Azotobacter

Field experiments were conducted at Indian Agricultural Research Institute, New Delhi, during 2001–2002 and 2002–2003, to study the effect of inorganic, organic and Azotobacter combined sources of N on cotton (Gossypium hirsutum L.) and their residual effect on succeeding wheat (Triticum aestivum L.) crop. The results indicated considerable increase in yield attributes and mean seed cotton yield (2.33 Mg ha^?1) with the combined application of 30 kg N and farmyard manure (FYM) at 12 Mg ha^?1 along with Azotobacter (M₄). The treatment in cotton that included FYM, especially when fertilizer N was also applied could either improve or maintain the soil fertility status in terms of available N, P and K. Distinct increase in yield attributes and grain yield of wheat was observed with the residual effect of integrated application of 30 kg N ha^?1 + FYM at 12 Mg ha^?1 + Azotobacter. Direct application of 120 kg N ha^?1 resulted 67.4 and 17.7 % increase in mean grain yield of wheat over no N and 60 kg N ha^?1, respectively. Integrated application of organic and inorganic fertilizer is therefore, recommended for higher productivity and sustainability of the cotton–wheat system.     

Stage Sensitivity of Mungbean (Vigna radiata L. Wilczek) to an Elevated Level of Carbon Dioxide

An experiment was undertaken using open‐top chambers to study the effect of CO₂ enrichment on crop growth and to assess the variation related to the time of CO₂ exposure. In general, enriched CO₂ conditions (600 ± 50 p.p.m.) in the chamber positively affected the growth and development of mungbean (Vigna radiata), a short‐duration (60–65 days) summer pulse crop. However, there was significant variability in the effect of the crop stage/time of CO₂ exposure. It was observed that high CO₂ exposure at an early growth stage [0–20 days after germination (DAG)] had a larger effect than that at a later growth stage (21–40 DAG). The experiment also provided a means of assessing the short‐ and long‐term effects of elevated CO₂ on the carbon exchange rate at both stages of exposure. The study revealed that the sensitivity of plants to high CO₂ was more pronounced with respect to net photosynthetic rate. The overall photosynthetic activity gave greater growth and development of plants under high CO₂.     

International society for horticultural science calendar of events 1979

A study was made to induce flowering in an “off-year” in the strictly irregularly-bearing mango cultivar ‘Langra’. Cycocel 3000 mg/l on ringed shoots produced the largest number of flower panicles (62.3%), whereas the control recorded the lowest number (8%). MH-1500 mg/l with ringing reduced the length of the shoot, increased the diameter of the shoots, and greatly reduced the vegetative growth. All the treatments produced quite good percentages of flower buds in comparison to the control, and enhanced the flowering-time. With CEPA 400 mg/l the flowering-time was enhanced by 16 days.     

Available Moisture in Relation to Water-stable Aggregates of Two Forest Soils

Available moisture release characteristics for two well aggregated clayey forest soils of West Bengal (INDIA) were determined with respect to different-sized water-stable aggregates. In situ determination of higher range of available moisture differed appreciably from classic 1/3 bar moisture retention, for the soils. Release of moisture at lower tensions (0.33 > bar) were mainly governed by the inter-aggregate pore size distribution while that at higher tension chiefly attributed to the texture of aggregates i.e. the intra-aggregate pore size distribution. The difference in moisture releasing capacity particularly in the range 0.33—15.0 bar amongst different sized aggregates, was due mainly to varying amount of clay and organic carbon in different-sized aggregates.     

Density and nitrogen effects on interference and economic threshold of common lambsquarters in wheat

Common lambsquarters (CL) constitutes about 50 % of the total weed population in many wheat fields of the northern and central India. It causes considerable wheat yield losses. Its interference is highly influenced by nitrogen (N). Information on its density effect in response to N, and economic threshold (ET) will be useful for its effective management. This experiment was designed to evaluate and compare the interference of CL in response to N with that of natural weed infestations; and to determine its ET in wheat. It was observed that the natural weed infestation including CL, and a pure stand of 128 CL plants/m² were more competitive, causing greater reductions in wheat growth and yield than other CL densities. In the absence of CL, the natural weed infestation was less competitive. The natural weed infestation including CL, and the pure stand densities of 128 and 64 CL/m² inflicted more yield losses at 120 than 60 kg N/ha. But, at lower densities up to 32 CL/m², increasing N levels favoured wheat more, resulting in greater crop-weed balance at 120 than at 60 kg N/ha. The ET, 6–7 CL/m², would help in making decisions for CL management and fitting models. It can be approximated for other similar locations. This ET takes several production factors into account and would be more economical than what was determined based on only yield losses. The ET-based control would reduce future CL/weed populations by preventing seed bank build-up in soil, and rationalize herbicide use through tailoring of doses.     

Studies on bacteriological quality of nainital lake water in different seasons

The total coliform and E. coli load of Nainital lake water in different seasons has been studied. The variation of these organisms with season, rainfall and human activities in the catchment area were observed.     

不同年代大豆品种(系)根系生长动态的比较研究

不同年代大豆品种根干重积累动态可以用Logistic曲线方程进行模拟。在不同施肥水平下,根干重最大增长速率及出现的时间和平均增长速率有所不同。根干重最大增长速率出现的时间,中国当代品种、美国当代品种及中国20世纪20年代的品种间差异不显著,各品种间差异及施肥处理间差异也不显著。根干重最大增长速率,中国当代、美国当代及中国20世纪20年代的品种间差异不显著,各品种间差异也不显著,施肥处理间差异显著。平均增长速率,中国当代、美国当代及中国20年代的品种间差异显著,各品种间及施肥处理间差异也显著。不同施肥水平、不同生育时期,中国当代品种与美国当代品种根干重都比中国20年代品种大。