Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. ...Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.展开更多
One of the objectives of the 1257/99 EU regulation was that rural populations should be able to gain an extra income. This regulation may not be any longer in force, but soon a new one will replace it. The plantations...One of the objectives of the 1257/99 EU regulation was that rural populations should be able to gain an extra income. This regulation may not be any longer in force, but soon a new one will replace it. The plantations that are created by Greek farmers more specifically the plantations of poplar trees-have a ten-year rotation at least. This means that the time between the establishment of the plantation and the harvest is high. As a consequence, during this time, the market environment （e.g. prices） may face substantial changes. Frequently, these changes are so immense that producers are driven in economic distress. This situation is also linked to the domestic timber supply and imports, and as a result to the product prices. Concerning the market prices of poplar trees, one additional factor that has probably deteriorated the situation is the E.U. expansion. This paper examines a case study in North Greece. Vital conclusions are made which may be useful for the Greek and E.U. decision makers regarding the process of dealing with current issues such as the 1257/99 regulation replacement （1698/2005）.展开更多
Jilin Province is one of the main grain-producing provinces of China,which has dominant position in maize production,by the view of its advantages in policy,location,breed and market. And after entering WTO,some measu...Jilin Province is one of the main grain-producing provinces of China,which has dominant position in maize production,by the view of its advantages in policy,location,breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize,analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages,carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province,cast the agricultural predicament off and promote the agricultural development into a new stage.展开更多
Willow species （Salix fragilis L. and S. alba L.） are important elements of cold desert agroforestry systems in the Lahaul valley, north- western Himalaya. Their ability to grow through shoot-cuttings plantations un...Willow species （Salix fragilis L. and S. alba L.） are important elements of cold desert agroforestry systems in the Lahaul valley, north- western Himalaya. Their ability to grow through shoot-cuttings plantations under extreme and xeric climatic conditions of cold deserts, makes them ecologically suited and socially accepted for forestry programmes. Willow species in cold deserts may combat desertification and can thrive well in these areas as compared to any other species. Salixfragilis L. and S. alba L. are under cultivation in the Lahaul valley. However, S. fragilis is widely cultivated under the agroforestry and plantation forestry systems. In the Lahaul valley, willow species are used as subsistence resources and for socio-religious purposes. The present study was carried out to examine the vegetation analysis, density, diversity and distribution of willow species, present status and potential willow plantation sites and uses. The results of present study revealed that a higher species density was recorded at middle altitude villages （Jahlma-3,ooo m asl and Hinsa-2,7oo m asl）, except, a higher density of S. fragilis was at Khoksar （3,200 m asl） in plantation forestry on south-facing slopes. In forests, S. fragilis was planted mainly along the water channels, resulted a low density. The shrubby willow species occurred naturally in the entire Lahaul valley up to an altitude of 3,850 m asl. 81% of households felt the scarcity of willow trees, whereas, 19% of households were satisfied with the willow trees they owned. The majority of willow species were planted in middle altitudes on privately owned irrigated lands. It was rated most potential prospective willow planting siteby the farmers. Small size of land-holdings was one of the main constraints for establishing a large number of willow plantations. Commercial aspects of willow species need to be investigated to encourage the farmers to plant more willows further.展开更多
基金Intercooperation,Agroforestry Improvement Project and Village and Farm Forestry Project (IC-VFFP, AFIP) Rajshahi (Funded by Swiss Agency for Development Cooperation,SDC)
文摘Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.
文摘One of the objectives of the 1257/99 EU regulation was that rural populations should be able to gain an extra income. This regulation may not be any longer in force, but soon a new one will replace it. The plantations that are created by Greek farmers more specifically the plantations of poplar trees-have a ten-year rotation at least. This means that the time between the establishment of the plantation and the harvest is high. As a consequence, during this time, the market environment （e.g. prices） may face substantial changes. Frequently, these changes are so immense that producers are driven in economic distress. This situation is also linked to the domestic timber supply and imports, and as a result to the product prices. Concerning the market prices of poplar trees, one additional factor that has probably deteriorated the situation is the E.U. expansion. This paper examines a case study in North Greece. Vital conclusions are made which may be useful for the Greek and E.U. decision makers regarding the process of dealing with current issues such as the 1257/99 regulation replacement （1698/2005）.
文摘Jilin Province is one of the main grain-producing provinces of China,which has dominant position in maize production,by the view of its advantages in policy,location,breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize,analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages,carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province,cast the agricultural predicament off and promote the agricultural development into a new stage.
基金financial support by the Ministry of Environment and Forests,Government of India,New Delhi,is gratefully acknowledged
文摘Willow species （Salix fragilis L. and S. alba L.） are important elements of cold desert agroforestry systems in the Lahaul valley, north- western Himalaya. Their ability to grow through shoot-cuttings plantations under extreme and xeric climatic conditions of cold deserts, makes them ecologically suited and socially accepted for forestry programmes. Willow species in cold deserts may combat desertification and can thrive well in these areas as compared to any other species. Salixfragilis L. and S. alba L. are under cultivation in the Lahaul valley. However, S. fragilis is widely cultivated under the agroforestry and plantation forestry systems. In the Lahaul valley, willow species are used as subsistence resources and for socio-religious purposes. The present study was carried out to examine the vegetation analysis, density, diversity and distribution of willow species, present status and potential willow plantation sites and uses. The results of present study revealed that a higher species density was recorded at middle altitude villages （Jahlma-3,ooo m asl and Hinsa-2,7oo m asl）, except, a higher density of S. fragilis was at Khoksar （3,200 m asl） in plantation forestry on south-facing slopes. In forests, S. fragilis was planted mainly along the water channels, resulted a low density. The shrubby willow species occurred naturally in the entire Lahaul valley up to an altitude of 3,850 m asl. 81% of households felt the scarcity of willow trees, whereas, 19% of households were satisfied with the willow trees they owned. The majority of willow species were planted in middle altitudes on privately owned irrigated lands. It was rated most potential prospective willow planting siteby the farmers. Small size of land-holdings was one of the main constraints for establishing a large number of willow plantations. Commercial aspects of willow species need to be investigated to encourage the farmers to plant more willows further.
