Nitrification in soils incubated with pig slurry

Cooper, J. E.

doi:10.1016/0038-0717(75)90009-7

Cited by 32 publications

(10 citation statements)

References 7 publications

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“…This seems to indicate that up to V12 stage, the plots fertilized with a combination of organic and inorganic N performed better in terms of plant vigour than those only fertilized with inorganic N. The reason for this may be a progressive mineralization of organic N, which would have facilitated N availability during all development stages [39,40]. The experimental plots in which these treatments were applied also produced the highest grain yields, although not exclusively, as the N200, N250, N0Ps250, N100Ps150, N300 and N400 were also classified in homogeneous group "a", the one with the highest yields.…”

Section: Multiple-rank Analysis Of Spectral Indices Crop Height and mentioning

confidence: 97%

Analysis of Vegetation Indices to Determine Nitrogen Application and Yield Prediction in Maize (Zea mays L.) from a Standard UAV Service

et al. 2016

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Abstract:The growing use of commercial unmanned aerial vehicles (UAV) and the need to adjust N fertilization rates in maize (Zea mays L.) currently constitute a key research issue. In this study, different multispectral vegetation indices (green-band and red-band based indices), SPAD and crop height (derived from a multispectral compact camera mounted on a UAV) were analysed to predict grain yield and determine whether an additional sidedress application of N fertilizer was required just before flowering. Seven different inorganic N rates (0, 100, 150, 200, 250, 300, 400 kg·N·ha −1 ), two different pig slurry manure rates (Ps) (150 or 250 kg·N·ha −1 ) and four different inorganic-organic N combinations (N100Ps150, N100Ps250, N200Ps150, N200Ps250) were applied to maize experimental plots. The spectral index that best explained final grain yield for the N treatments was the Wide Dynamic Range Vegetation Index (WDRVI). It identified a key threshold above/below 250-300 kg·N·ha −1 . WDRVI, NDVI and crop height showed no significant response to extra N application at the economic optimum rate of fertilization (239.8 kg·N·ha −1 ), for which a grain yield of 16.12 Mg·ha −1 was obtained. This demonstrates their potential as yield predictors at V12 stage. Finally, a ranking of different vegetation indices and crop height is proposed to overcome the uncertainty associated with basing decisions on a single index.

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Section: Multiple-rank Analysis Of Spectral Indices Crop Height and mentioning

confidence: 97%

Analysis of Vegetation Indices to Determine Nitrogen Application and Yield Prediction in Maize (Zea mays L.) from a Standard UAV Service

et al. 2016

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“…Other workers have shown that addition of urea and urea-related compounds (including animal slurries) are particularly stimulatory to nitrification in coniferous forest soils (e.g. Cooper, 1975;Heilman, 1974;Martikainen, 1984Martikainen, , 1985Overrein, 1971;Popovic, 1977). That Williams (1972) found urea-stimulation of nitrification, even in the presence of high concentrations of lime, strongly suggests, however, that stimulation is not simply a pH phenomenon.…”

Section: Factors Controlling Nitrification In Coniferous Forest Soilsmentioning

confidence: 99%

Nitrification in coniferous forest soils

Killham

1990

Plant Soil

163

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Net nitrification rates tend to be low or negligible in the forest floor of many coniferous forests of North-East Scotland. The most likely process controls are substrate availability, pH, allelopathy, water potential, nutrient status and temperature. These are discussed in relation to field and laboratory studies of net and potential rates of nitrification.Fungi make up by far the largest part of the nitrifier community in the coniferous forest floor. Very little is known about the distribution and activity of autotrophs in these systems, although it is certain that in vitro evidence suggesting autotrophs cannot nitrify at pH levels characteristic of coniferous forest soils is unrealistic.Because of the metabolic diversity of nitrifying fungi, a variety of organic and inorganic nitrification pathways may exist in coniferous forests. The possible involvement of free radicles in fungal nitrification in coniferous forest soils is also suggested.A complete understanding of nitrification in coniferous forest soils can only result from field characterisation of N flux such as through the use of 15N. This must be combined with ecophysiological characterisation of the organisms involved in order that the complexity of nitrification in coniferous forest soils can be resolved.

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“…There are three principal characteristics of the nitrification process in these soils. First, autotrophic nitrifiers cannot be isolated from such soils in significant numbers (Lemee, 1967;Overrein, 1971;Herlichy, 1973;Ayanaba and Omayuili, 1975;Ishaque and Cornfield, 1974;Cooper, 1975;Verstraete and Voets, 1976). As mentioned earlier, this point on its own is equivocal because of enumeration problems.…”

Section: Phmentioning

confidence: 99%