Production and characterisation of biochar from different farm wastes

Three different carbon-rich materials called biochars were produced from three different agricultural wastes using slow pyrolysis technique. The abundance of these wastes (maize cobs, maize stovers and cocoa pod husks) in most farms in Nigeria informed their choice. In this study, the biochars produced were characterized to determine their inherent nutrient potentials as soil amendments for high crop productivity. The percentage mass of biochars obtained were: maize cobs 27.6%, maize stovers 26.0% and cocoa pod husks 22.3% at 332°C, 361°C and 500°C temperature respectively. The highest carbon content (511.1 g kg-1) and total nitrogen (12.1 g kg-1) were obtained from maize stovers biochar, while cocoa pod husks gave the least values. Highest pH (11.98), moisture content (14.0%) and phosphorus (1150.0 mg kg-1) were however obtained in the biochar from cocoa pod husks. We concluded that cocoa pod husks, maize cobs and maize stovers are feedstocks for making biochars of different physical forms and properties and these biochars are potential sources of valuable soil amendments in a humid tropical soil environment.Keywords: Biochar, charcoal-fired reactor, cocoa pod husks, maize cobs, maize stovers, slow pyrolysis

The Effect Of Ricinus Communis Variety Minor On Reproductive Organs Of The Wistar Rat And Haematological Indicies In Women Volunteers

OBJECTIVES: To determine the effect of the extract on reproductive organs of the wistar rat and its reproductive cyclicity and also to determine the safety of the extract in women volunteers who have been on it for between 1 10 years with respect to their haematological indicies. MATERIALS AND METHOD: The seed extract of Ricinus Communis variety minor given in a dose of 1.2kg/kg body weight to female wistar rats subcutaneously. The oestrous cycle were studied and the ovaries and uteri were obtained , fixed in Boiun`s fluid and prepared for Haematoxylin and Eosin(H&E) stining for histology. Similarly, the ante cubital venous blood of women already on the seed as a means of family planning were obtained and their haematological indices determined. RESULTS.: Thee estrous cycle of the rats were distorted. Furthermore, this seed extract induced changes in the ovarian and uterine histology, which may be due partly to alteration in the estrogen/ progesterone balance, as well as direct effect on these reproductive organs. Hematological indices were not affected in women volunteers who have been on the plant seed of as 3 seeds as a single dose as a means of family planning. CONCLUSION: The seed extract distorted the oestrous cyclce of the female wistar rat. It did not adversely affect the haematologic indicies which may suggest its safety from some known haematological complications of family planning pills such as thrombo embolism etc. KEY WORDS: Ricinus communis, Reproductive organs, women volunteers. Highland Medical Research Journal Vol.1(3) 2003: 31-3

Effects of the inoculation of cyanobacteria on the microstructure and the structural stability of a tropical soil.

International audienceCyanobacteria are widespread photosynthetic microorganisms among which some are able to fix atmospheric nitrogen. We investigated the impact of indigenous cyanobacteria strains (Nostoc) inoculation on physical characteristics of poorly aggregated soils from Guquka (Eastern Cape, South Africa). The soil aggregates (3–5 mm) were arranged into a layer of 10–20 mm thick, and sprayed with cyanobacteria solution. Subsequently the inoculated and un-inoculated samples were incubated (30C, 80% humidity, continuous illumination at 100 lmol m–2 s–1). Their micromorphological characteristics and aggregate stability were investigated, after 1, 2, 3, 4 and 6 weeks of incubation, by using high resolution Cryo-SEM and aggregate breakdown tests.Micromorphological investigations revealed that the surface of uninoculated samples remained uncovered, while the inoculated samples were partially covered by cyanobacteria material after one week of incubation. Adense superficial network of cyanobacterial filaments and extracellular polymer secretions (EPS) covered their surface after 4 and 6 weeks of incubation. Organo-mineral aggregates comprising cyanobacterial filaments and EPS were observed after 6 weeks of incubation. The results of aggregate breakdown tests showed no significant difference between un-inoculated samples after 1, 2, 3, 4 or 6 weeks, while they revealed improvement of aggregate stability for inoculated samples. The improvement of aggregate stability appeared in a short while following inoculation and increased gradually with time and cyanobacteria growth. The increase in aggregate stability is likely related to the changes induced in micromorphological characteristics by cyanobacterial filaments and EPS. It reflects the effect of coating, enmeshment, binding and gluing of aggregates and isolated mineral particles by cyanobacteria material