Journal ArticleDOI
Leaf litter decomposition of Piper aduncum, Gliricidia sepium and Imperata cylindrica in the humid lowlands of Papua New Guinea
TLDR
Piper leaf litter is a significant and easily decomposable source of K which is an important nutrient for sweet potato and the decomposition and nutrient release patterns had significant effects on the soil.Abstract:
No information is available on the decomposition and nutrient release pattern of Piper aduncum and Imperata cylindrica despite their importance in shifting cultivation systems of Papua New Guinea and other tropical regions. We conducted a litter bag study (24 weeks) on a Typic Eutropepts in the humid lowlands to assess the rate of decomposition of Piper aduncum, Imperata cylindrica and Gliricidia sepium leaves under sweet potato (Ipomoea batatas). Decomposition rates of piper leaf litter were fastest followed closely by gliricidia, and both lost 50% of the leaf biomass within 10 weeks. Imperata leaf litter decomposed much slower and half-life values exceeded the period of observation. The decomposition patterns were best explained by the lignin plus polyphenol over N ratio which was lowest for piper (4.3) and highest for imperata (24.7). Gliricidia leaf litter released 79 kg N ha(-1), whereas 18 kg N ha(-1) was immobilised in the imperata litter. The mineralization of P was similar for the three species, but piper litter released large amounts of K. The decomposition and nutrient release patterns had significant effects on the soil. The soil contained significantly more water in the previous imperata plots at 13 weeks due to the relative slow decomposition of the leaves. Soil N levels were significantly reduced in the previous imperata plots due to immobilisation of N. Levels of exchangeable K were significantly increased in the previous piper plots due to the large addition of K. It can be concluded that piper leaf litter is a significant and easily decomposable source of K which is an important nutrient for sweet potato. Gliricidia leaf litter contained much N, whereas imperata leaf litter releases relatively little nutrients and keeps the soil more moist. Gliricidia fallow is more attractive than an imperata fallow for it improves the soil fertility and produces fuelwood as additional saleable products.read more
Citations
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Journal ArticleDOI
Effects of Exotic Plant Invasions on Soil Nutrient Cycling Processes
TL;DR: This work has reviewed studies that compare pool sizes and flux rates of the major nutrient cycles in invaded and noninvaded systems for invasions of 56 species and suggests that invasive plant species frequently increase biomass and net primary production, increase N availability, alter N fixation rates, and produce litter with higher decomposition rates than co-occurring natives.
Book ChapterDOI
Agriculture, Forestry and Fisheries
TL;DR: In this paper, the authors focus on the role of agriculture and fishing in the European level in the Common Agricultural Policy (CAP) and Common Fisheries Policy (CFP) and show that agriculture dominates in terms of direct contribution to GDP and numbers of people engaged in it, as well as accounting for the largest amount of public support expenditure.
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Cogongrass (Imperata cylindrica)—Biology, Ecology, and Management
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Journal ArticleDOI
Effects of shade-tree species and spacing on soil and leaf nutrient concentrations in cocoa plantations at 8 years after establishment
Shahla Hosseini Bai,Stephen J. Trueman,Tio Nevenimo,Godfrey Hannet,Peter Bapiwai,Mathew Poienou,Helen M. Wallace +6 more
TL;DR: It is indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T. cacao in all of the plantations, however, all three plantations required fertilisation and better nutrient management.
Journal ArticleDOI
Biomass and nutrient accumulation of Piper aduncum and Imperata cylindrica fallows in the humid lowlands of Papua New Guinea
TL;DR: Piper accumulated large amounts of biomass and nutrients, particular K, which is an important nutrient for root crops that dominate the cropping phase in the shifting cultivation systems of the humid lowlands.
References
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Journal Article
The decomposition of the leaf mulches of Leucaena leucocephala, Gliricidia sepium and Flemingia macrophylla under humid tropical conditions.
TL;DR: Based on the data decomposition-and nutrient release functions are developed for the three mulches that are useful in alley-cropping system analysis and models.
Journal ArticleDOI
Air-drying depresses rates of leaf litter decomposition
TL;DR: In an aspen forest in the Rocky Mountains of Alberta, Canada, the authors compared first-year decomposition of air-dried leaf litter (7-8% moisture) of trembling aspen (Populus tremuloides) and green alder (Alnus crispa) against decomposition (57-62%) of freshly fallen leaf litter that was still moist when placed in the litterbags Contrary to expectations, mass loss was substantially faster from fresh litter than from air-dry leaf litter, even in the first month in the field.
Journal ArticleDOI
N recovery from legume prunings and priming effects are governed by the residue quality
TL;DR: The scope for regulation of N release from tree prunings during these later stages of decomposition appears to be limited, although Treatments which led to a large N recovery initially, continued to provide greater N benefits in subsequent cycles although with increasing harvest time this trend decreased.
Journal Article
Sweet potato (Ipomoea batatas) production and research in Papua New Guinea.
Journal ArticleDOI
Quality of different mulch materials and their decomposition and N release under low moisture regimes
TL;DR: This study indicates that leaves with a fast rate of decomposition should be mixed with other species, leaves which decompose more slowly in order to increase the conservation of soil moisture and also improve the synchronization between N release from the mulch and its demand by crops.