119 research outputs found
Dry matter accumulation, nutrient uptake and nutrient use efficiency of two improved cultivars of taro (Colocasia esculenta) under screen house conditions in Samoa
Taro (Colocasia esculenta (L.) Schott) is a staple crop of many of the South Pacific nations with an ever increasing export demand. In recent years, yields of taro have in creased dramatically through breeding and selection. However, selections of improved lines are often entirely based on final yield. There are many physiological pathways by which increased potential yield may be achieved.
Factors such as the accumulation of dry matter and nutrient use efficiency, merit investigation. Two improved (blight resistant) taro cultivars were planted and harvested for biomass measurements on a monthly basis for a total of eight months (30-240 days after planting) through destructive sampling. At each harvest, plants were separated into various plant parts and their dry matter
accumulation and nutrient content were determined. Comparatively, cultivar Samoa 2 showed significantly higher uptake of N (25%), P (37.5%), K (33%), Mg (36.4%), Mn (22.7%) and Zn (48.3%) than cultivar Samoa 1. Even though maximum levels of total plant uptake of nutrients by
the two cultivars did not differ between the cultivars, cultivar Samoa 1 plants absorbed 17% less N,26% less P and 20% less K than those of cultivar Samoa 2 with the uptake uniformly distributed over the entire life cycle of the crop. Although cultivar Samoa 2 resulted in higher total plant (19.6%) and corm dry matter (10.4%) productions, cultivar Samoa 1 had a higher nutrient use efficiency, (kg of edible dry matter produced per kg of nutrient taken up), for N, P, K, Mg, Mn and Cu over cultivar Samoa 2. However, for Ca, Fe and Zn. Cultivar Samoa 2 had a higher nutrient use efficiency over cultivar Samoa 1. Based on nutrient use efficiency of the cultivars, Samoa 1 is recommended for marginal to rich soils while Samoa 2 for good to rich soils
A Critical Review of Value Chain for Irish Potato in Zimbabwe with Specific Regards to the Economic Policy: A Review
Potato production and consumption are booming worldwide, greater quantity of it is being processed into food and snacks. It is the most important horticultural crop which is a good substitute for maize to supplement carbohydrates. It was declared a national strategic food security crop on 18 May 2012 by the government of Zimbabwe. This paper critically review the value chain of Irish potato in Zimbabwe with a focus on its any government policy and support with regards to promoting the crop and key stakeholders involved in the value chain. The Irish potato value chain in Zimbabwe has great potential to improve and if well supported, it can contribute to the GDP of the country. This can be done if the government improve on its policy implementation through capacity development of its research and extension workers and more resources have to be availed to this area has showed great potential in terms of marketing and production. The key drivers at production level who will help in ensuring that necessary interventions are carried out to improve long term performance of the Irish potato value chain operate in an enabling environment. This is done by offering incentives to the potato farmers and all the value chain players. The economy of a country is driven by having well thought out policies and interventions that can even subsidies inputs and other raw material required along the value chain
The Eucalyptus Dilemma: The Pursuit for Socio-economic Benefit versus Environmental Impacts of Eucalyptus in Ethiopia
Eucalyptus is one of the most planted types of trees in the world, has been grown in Africa and elsewhere for over a century. The Ethiopia population is growing rapidly. The natural forest coverage and native forest tree species are decreasing in an alarming rate. There are many dilemmas among users, growers, environmentalists, researchers and policy makers on the ecological, socio-economic benefit and environmental impacts Eucalyptus. Ethiopia Farmers commonly plant eucalypts tree on their farmlands. Currently, growing eucalypt trees is becoming a great concern due to its socio-economic benefit and environmental impacts.In Ethiopia, where there are huge gaps between demand and supply of wood as a result of increasing deforestation, the use of fast growing plantation species such as eucalypts is unavoidable as they are preferred to other species, because of their peculiar features; these include they require minimum care, fast growth and good quality of wood and fibres, easy reproduction through seeds, coppice after harvested, grow in wide ecological zones and poor environments; resistant to environmental diseases and stress and generates substantial income to rural and urban households.On the other hand, Some of Eucalyptus impacts on the environment are: adverse effects of their leaf litter on soil humus, removal of too much water from farmlands, stream banks, catchments areas and underground water, heavy consumption of soil nutrients (deplete soil nutrients), failure to provide food supplies or adequate habitat for wildlife, inability to prevent soil erosion and inhibition of growth of other plants. Numerous study reports appeared that the benefits of Eucalyptus trees are far more than its negative impacts.Consequently, instead of complain whether to avoid plantation of Eucalyptus trees; emphasis should be given by the environmentalists, researchers and policy makers to support users and growers of Eucalyptus in selecting the appropriate place of plantation and species selection for the adequate uses and management on Eucalyptus planting, so that the environmental impacts are minimized and the socio- economic benefits of Eucalyptus were optimized. Therefore, this review paper briefly summarizes the socio-economic benefit and environmental Impacts of Eucalyptus trees. Keywords: Eucalyptus Dilemma; Socio-economic benefit; Environmental Impacts; Ecological effect
Demand-side decarbonization and electrification: EMF 35 JMIP study
Japan’s long-term strategy submitted to the United Nations Framework Convention on Climate Change emphasizes the importance of improving the electrification rates to reducing GHG emissions. Using the five models participating in Energy Modeling Forum 35 Japan Model Intercomparison project (JMIP), we focused on the demand-side decarbonization and analyzed the final energy composition required to achieve 80% reductions in GHGs by 2050 in Japan. The model results show that the electricity share in final energy use (electrification rate) needs to reach 37–66% in 2050 (26% in 2010) to achieve the emissions reduction of 80%. The electrification rate increases mainly due to switching from fossil fuel end-use technologies (i.e. oil water heater, oil stove and combustion-engine vehicles) to electricity end-use technologies (i.e. heat pump water heater and electric vehicles). The electricity consumption in 2050 other than AIM/Hub ranged between 840 and 1260 TWh (AIM/Hub: 1950TWh), which is comparable to the level seen in the last 10 years (950–1035 TWh). The pace at which electrification rate must be increased is a challenge. The model results suggest to increase the electrification pace to 0.46–1.58%/yr from 2030 to 2050. Neither the past electrification pace (0.30%/year from 1990 to 2010) nor the outlook of the Ministry of Economy, Trade and Industry (0.15%/year from 2010 to 2030) is enough to reach the suggested electrification rates in 2050. Therefore, more concrete measures to accelerate dissemination of electricity end-use technologies across all sectors need to be established
Sustainable Landscape Management. An Analysis with a Scientific and Social Perspective. Review
Context: The negative effects of climate change and the food production systems, based on an ever-growing, intensive, and unsustainable manner, are threatening the stability of landscapes, and therefore, their components, including humans. The implementation of land sustainable management offers a set of social and ecological benefits. However, it is mostly applied to very small spaces, as an agroecosystem.
Aim: To analyze the need for land sustainable management practice scaling of landscapes as a geographic space category, using a scientific approach.
Method: Documentary review was used along with the integration of land sustainable management approaches, and the need for landscape scaling, including other sustainability approaches, such as agroecology.
Results: The study found a theoretical gap in terms of land sustainable management practice scaling of landscapes as a geographic space category. The need for scaling is mainly explained by the fact that the extent of social and ecological problems goes beyond smaller spaces, such as a farm or an agroecosystem.
Conclusions: Landscape is an intrinsic part of cultural identity and heritage with high natural and anthropic values that must be highly regarded. The scaling of land sustainable management practices into the landscape is a necessity. The natural, economic, and social problems associated with land use must be addressed beyond the boundaries of a single agroecosystem
Determinants of Willingness to Pay (WTP) for organic fertiliser: a case of smallholder potato farmers in KwaZulu-Natal, South Africa
The South African smallholder sector is characterised by relatively low productivity due to persistent deterioration in soil fertility owing to declining organic matter and other essential soil nutrients. Consequently, adoption of sustainable agricultural inputs like organic fertiliser is essential. Although there is sufficient advocacy in the adoption of organic fertiliser, the economic linkage between farmers' socioeconomic factors and willingness to pay (WTP) remains under-explored. This study investigated the determinants of WTP a price premium for organic fertiliser among smallholder potato farmers using primary data collected from 189 smallholder farmers in three municipal areas in KwaZulu-Natal, South Africa, through a multi-stage sampling technique. The data was analysed using the ordered logit model and revealed that marital status, access to extension services, and knowledge of organic fertiliser usage, land ownership, livestock size and distance to the source of organic fertiliser influenced the farmers’ WTP for organic fertiliser. The study found that about 83.6% of the sampled smallholder farmers were willing to pay for organic fertiliser, while about 16.4% of them indicated that they were not willing to pay for organic fertiliser. This result justifies the prospect of commercialisation of organic fertiliser to facilitate the availability of organic fertiliser to those that are willing to pay for it. This study recommends improved access to extension services to enhance technical information dissemination and knowledge of organic fertiliser usage among smallholder farmers. Development of policies that strive to institute security of land tenure among smallholder farmers, which will encourage smallholder farmers WTP is also essential
Global Warming
This book is intended to introduce the reader to examples of the range of practical problems posed by "Global Warming". It includes 11 chapters split into 5 sections. Section 1 outlines the recent changes in the Indian Monsoon, the importance of greenhouse gases to life, and the relative importance of changes in solar radiation in causing the changes. Section 2 discusses the changes to natural hazards such as floods, retreating glaciers and potential sea level changes. Section 3 examines planning cities and transportation systems in the light of the changes, while section 4 looks at alternative energy sources. Section 5 estimates the changes to the carbon pool in the alpine meadows of the Qinghai-Tibet Plateau. The 11 authors come from 9 different countries, so the examples are taken from a truly international set of problems
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