Economic Evaluation of Organic and Inorganic Resources for Recapitalizing Soil Fertility in Smallholder Maize-based Cropping Systems of Central Kenya

Structural adjustments programs (SAPs) in the last two decades have eliminated all farm-support programs leading to low usage of fertilizers by Kenyan smallholders. One way of addressing this problem is use of organic nutrient resources. This paper examines their cost-effectiveness as capital investments in replenishment of Nitrogen (N), Phosphorus (P), Potassium (K) and soil organic matter (SOM) in smallholder, Maize-based cropping systems. On-farm trials were established in Maragwa and Kirinyaga Districts in 2003/04. Maize was planted in 3 replicates in randomised complete block design (RCBD) using different levels of organic and inorganic fertilizer resources. A blanket rate of 40kg P/ha was applied in all treatment except the control to increase organic N-utilization efficiency. The test crop was harvested, oven-dried and weighed. Net Present Values (NPV) were computed using Partial Budgeting Analysis Model. Increasing levels of inorganic N increased maize yields significantly (P<0.05). However, higher yields were necessary but not sufficient criteria to determine profitability of different treatments. Manure + 60 kg N/ha gave highest NPV (USD 564), Manure + 40kg N/ha gave second highest NPV (USD 511) in Maragwa District while Manure + 60kg N/ha gave highest NPV (USD 633) and Manure + 40kg N/ha second highest NPV (USD 618) in Kirinyaga District. These results suggested that higher N-levels were not necessarily the most economical. Use of organic resources with modest amounts of mineral fertilizers seemed more profitable and held the key to enhancement of nutrient budgets, food security and rural livelihoods.Natural resource capital, Net present values (NPV), Nutrient budgets, Smallholder farmers, Soil organic matter (SOM), Structural adjustment programs (SAPs), Crop Production/Industries, Land Economics/Use,

Observation of exponential spectra and Lorentzian pulses in the TJ-K stellarator

An experimental investigation of the low-frequency density fluctuations in the plasma edge region of the TJ-K stellarator [N. Krause et al., Rev. Sci. Inst. 73, 3474 (2002)] finds that the ensemble- averaged frequency spectra exhibit a near exponential frequency dependence whose origin can be traced to individual pulses having a Lorentzian temporal shape. Similar features have been previously observed [D. C. Pace et al., Phys. Plasmas 15, 122304 (2008)] in a linear magnetized device under conditions in which cross-field pressure gradients are present. The reported observation of such features within the turbulent environment of a toroidal confinement device provides support for the conjecture that the underlying processes are a general feature of pressure gradients. Also presented is the magnetic field strength dependence of the pulse widths and the waiting time distribution between pulses

Validation of GBS plasma turbulence simulation of the TJ-K stellarator

We present a validation of a three-dimensional, two-fluid simulation of plasma turbulence in the TJ-K stellarator, a low temperature plasma experiment ideally suited for turbulence measurements. The simulation is carried out by the GBS code, recently adapted to simulate 3D magnetic fields. The comparison shows that GBS retrieves the main turbulence properties observed in the device, namely the fact that transport is dominated by fluctuations with low poloidal mode number. The poloidal dependence of the radial $\text{E}\times\text{B}$ turbulent flux is compared on a poloidal plane with elliptical flux surfaces, where a very good agreement between experiment and simulation is observed, and on another with triangular flux surfaces, which shows a poorer comparison. The fluctuation levels in both cases are underestimated in the simulations. The equilibrium density profile is well retrieved by the simulation, while the electron temperature and the electrostatic potential profiles, which are very sensitive to the strength and localization of the sources, do not agree well with the experimental measurements

Indicators of soil quality: a South-South development of a methdological guide for linking local and technical knowledge

The increasing attention paid to local soil knowledge results from a greater recognition that farmer knowledge can offer many insights into the sustainable management of tropical soils and that the integration of local and technical knowledge systems helps extension workers and scientists work more closely with farmers. A participatory approach and a methodological guide were developed to identify and classify local indicators of soil quality and relate them to technical soil parameters, and thus develop a common language between farmers, extension workers and scientists. This methodological guide was initially developed and used in Latin America and the Caribbean-LAC (Honduras, Nicaragua, Colombia, Peru, Venezuela, Dominican Republic), and was later improved during adaptation and use in eastern African (Uganda, Tanzania, Kenya, Ethiopia) through a South–South exchange of expertise and experiences. The aim of the methodological guide is to constitute an initial step in the empowerment of local communities to develop a local soil quality monitoring and decision-making system for better management of soil resources. This approach uses consensus building to develop practical solutions to soil management constraints identified, as well as to monitor the impact of management strategies implemented to address these constraints. The particular focus on local and technical indicators of agroecosystem change is useful for providing farmers with early warnings about unobservable changes in soil properties before they lead to more serious and visible forms of soil degradation. The methodological approach presented here constitutes one tool to incorporate local demands and perceptions of soil management constraints as an essential input to relevant research for development activities. The participatory process followed was effective in facilitating farmer consensus; for example, about which soil related constraints were most important and what potential soil management options could be used. Development of local capacities for consensus building constitute a critical step prior to collective action by farming communities resulting in the adoption of integrated soil fertility management strategies at the farm and landscape scale

Neo-Suprahepatic cava: A case report of a modified technique for domino liver transplantation

Domino liver transplantation, introduced in 1997, originally consisted of a graft from a patient with familial amyloidotic polyneuropathy used as a donor for a compatible recipient, thus increasing the pool of hepatic grafts for liver transplantation. The aim of this report was to present a modification on the technique for outflow reconstruction in domino liver transplantation first proposed by Liu et al and Cescon et al. In this description we proposed a new technique that differs from the one mentioned above by performing a neo-suprahepatic cava, constructed using only an iliac vein graft, facilitating the anastomosis as if it was a regular cadaveric liver transplant.Fil: Padín, J. M.. Fundación Favaloro; ArgentinaFil: Pfaffen, G.. Fundación Favaloro; ArgentinaFil: Pérez Fernández, I.. Fundación Favaloro; ArgentinaFil: Sandi, M.. Fundación Favaloro; ArgentinaFil: Ramisch, D.. Fundación Favaloro; ArgentinaFil: Barros Schelotto, P.. Fundación Favaloro; ArgentinaFil: Gondolesi, Gabriel Eduardo. Fundación Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Prospects for integrated soil fertility management using organic and inorganic inputs: evidence from smallholder African agricultural systems

This paper reviews current organic nutrient management practices and their integration with mineral fertilizers in Sub-Saharan Africa with a view to understanding the potential impacts on a range of input markets. A number of different organic nutrient management practices have been found to be technically and financially beneficial, but they differ considerably as to their effectiveness and resource requirements. A review of African smallholder experiences with integrated soil fertility management practices finds growing use, both indigenously and through participation in agricultural projects. Patterns of use vary considerably across heterogeneous agroecological conditions, communities and households, but are stimulated by profitable commercially oriented agricultural opportunities. The potential for integrated soil fertility management to expand markets for organic inputs, labor, credit, and fertilizer is explored. We found that there are few direct analyses of these links and indirect evidence at this point in time is inconclusiv

New insights into lake responses to rapid climate change : the Younger Dryas in Lake Goscia(z) over dot, central Poland

The sediment profile from Lake Goscia(z) over dot in central Poland comprises a continuous, seasonally resolved and exceptionally well-preserved archive of the Younger Dryas (YD) climate variation. This provides a unique opportunity for detailed investigation of lake system responses during periods of rapid climate cooling (YD onset) and warming (YD termination). The new varve record of Lake Goscia(z) over dot presented here spans 1662 years from the late Allerod (AL) to the early Preboreal (PB). Microscopic varve counting provides an independent chronology with a YD duration of 1149+14/-22 years, which confirms previous results of 1140 +/- 40 years. We link stable oxygen isotopes and chironomid-based air temperature reconstructions with the response of various geochemical and varve microfacies proxies especially focusing on the onset and termination of the YD. Cooling at the YD onset lasted similar to 180 years, which is about a century longer than the terminal warming that was completed in similar to 70 years. During the AL/YD transition, environmental proxy data lagged the onset of cooling by similar to 90 years and revealed an increase of lake productivity and internal lake re-suspension as well as slightly higher detrital sediment input. In contrast, rapid warming and environmental changes during the YD/PB transition occurred simultaneously. However, initial changes such as declining diatom deposition and detrital input occurred already a few centuries before the rapid warming at the YD/PB transition. These environmental changes likely reflect a gradual increase in summer air temperatures already during the YD. Our data indicate complex and differing environmental responses to the major climate changes related to the YD, which involve different proxy sensitivities and threshold processes.Peer reviewe

Isoenergetic Feeding of Low Carbohydrate-High Fat Diets Does Not Increase Brown Adipose Tissue Thermogenic Capacity in Rats

Low-carbohydrate, high-fat (LC-HF) diets are popular for inducing weight loss in overweighed adults. Adaptive thermogenesis increased by specific effects of macronutrients on energy expenditure has been postulated to induce this weight loss. We studied brown adipose tissue (BAT) morphology and function following exposure to different LC-HF diets