The influence of inoculation, starter nitrogen and some micronutrients on groundnut grown on a granitic soil in the Sudan-savana zone of Ghana

No abstract

Direct and residual effects of phosphate fertilizer on maize (Zea mays L.) grown on an Ultisol in Kumasi, Ghana

Long-term field experiments were conducted for 13 cropping seasons on a Typic Paleustult in Ghana to study response of maize (Zea mays L.) to P fertilization, evaluate the relative efficiency of broadcast versus band applications, estimate residual effects of applied P and determine the critical P level for maize. The results showed no significant direct effect of P fertilization on maize yield for the first four crops. Thereafter, grain yields consistently and significantly increased due to the residual effects of applied P and the effects increased as the broadcast rates increased but decreased when banded P rates increased. The overall residual effect of the banded P was significantly superior to the broadcast application. The critical P level for maize on this soil was estimated to be 12-16 ppm Bray 1 P. There was a significant direct effect of applied P on grain yield for the tenth through the thirteenth crops when the available P level in the soil was below the critical level

Disease-Toxicant Interactions in Manganese Exposed Huntington Disease Mice: Early Changes in Striatal Neuron Morphology and Dopamine Metabolism

YAC128 Huntington's disease (HD) transgenic mice accumulate less manganese (Mn) in the striatum relative to wild-type (WT) littermates. We hypothesized that Mn and mutant Huntingtin (HTT) would exhibit gene-environment interactions at the level of neurochemistry and neuronal morphology. Twelve-week-old WT and YAC128 mice were exposed to MnCl2-4H2O (50 mg/kg) on days 0, 3 and 6. Striatal medium spiny neuron (MSN) morphology, as well as levels of dopamine (DA) and its metabolites (which are known to be sensitive to Mn-exposure), were analyzed at 13 weeks (7 days from initial exposure) and 16 weeks (28 days from initial exposure). No genotype-dependent differences in MSN morphology were apparent at 13 weeks. But at 16 weeks, a genotype effect was observed in YAC128 mice, manifested by an absence of the wild-type age-dependent increase in dendritic length and branching complexity. In addition, genotype-exposure interaction effects were observed for dendritic complexity measures as a function of distance from the soma, where only YAC128 mice were sensitive to Mn exposure. Furthermore, striatal DA levels were unaltered at 13 weeks by genotype or Mn exposure, but at 16 weeks, both Mn exposure and the HD genotype were associated with quantitatively similar reductions in DA and its metabolites. Interestingly, Mn exposure of YAC128 mice did not further decrease DA or its metabolites versus YAC128 vehicle exposed or Mn exposed WT mice. Taken together, these results demonstrate Mn-HD disease-toxicant interactions at the onset of striatal dendritic neuropathology in YAC128 mice. Our results identify the earliest pathological change in striatum of YAC128 mice as being between 13 to 16 weeks. Finally, we show that mutant HTT suppresses some Mn-dependent changes, such as decreased DA levels, while it exacerbates others, such as dendritic pathology

Phosphorus requirement of onion (Allium cepa L.) in the Sudan savanna zone of Nigeria

No Abstract

Comparative effectiveness of nitrogen applied as straight and in compound fertilizers on maize on a coastal savanna ultisol

No Abstract

N2O Emissions and Inorganic N Release Following Incorporation of Crop Residue and/ or Inorganic N Fertiliser into Soil

Nitrous oxide emissions are usually increased following incorporation of crop residues or inorganic N fertiliser into soil, but the effect of combining these inputs at different proportions on N dynamics and NO emissions has 2 yet to be adequately examined. The interactive effect of combining crop residues barley (Hordereum vulgare) and clover (Trifolium pretense) and inorganic N fertiliser (NH4NO3) on N2O emission and mineral N dynamics under controlled laboratory conditions is reported. Emissions of NO were significantly higher from soils amended with 2 the low C:N ratio clover residues compared to the high C:N ratio barley residue treatments and was further increased, following combined application of crop residues and inorganic N fertiliser. Furthermore, the magnitude of emission was influenced by the proportions at which the residue-N and the fertiliser-N were combined with the 75:25 fertiliser:clover treatment emitting the highest (P < 0.05) amount of 65 mgN2O-N m-2 30 d-1. Incorporation of sole clover residues resulted in net N mineralization and addition of sole barley residues led to a net N immobilization. However, combined application of either residue with inorganic N fertiliser resulted in netNmineralisation. The results from the study demonstrated that whilst there is the potential for N2O emission to be controlled through varying ratios of residue:fertiliser input, the magnitude and direction of interactions between these N sources vary between different species as a result of their different qualities. This relationship should be verified under field conditions