The water extract of compost termed "compost tea" retains all the beneficial soluble bioactive components, making it a potent source of plant stimulatory and defensive compounds. The exact nature and extent of these features are, however, modified by composting system, feedstock quality, tea preparation and resultant use and management, including application dynamics of the compost tea. Compost teas contain a significant quantity of total nutrients with the majority being primary macronutrients. Secondary and micronutrient concentrations are more variable, but contents are generally insufficient to satisfy crop requirements. Noting this, compost tea use in agriculture and horticulture supports crop nutrition directly and indirectly. Improvements in soil quality have been widely reported for a range of soils and compost teas. A key feature of compost teaamended soils is the increase in soil organic matter and microbial diversity and its associated benefits. Research on appropriates rates for field and container use show large variability associated with edapho-climatic factors and crop species. However, foliar application seems best suited to maximising the dual nutrition and phytopathogenic effects of compost tea. Regardless of the purpose of compost tea use, its positive effects on crop growth and soil fertility, whilst controlling pest and disease, make it a contemporary sustainable tool aligned to organic agriculture.

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Carbon to nitrogen (C/N) ratio influences substrate combinations and earthworm performance in vermicomposting systems. To elucidate these factor effects, a comparative evaluation of species, C/N ratio combined with feed rate, was conducted on three local earthworm species: Perionyx excavatus, Eudrilus eugeniae, and Dichogaster annae. Earthworms were stocked at similar densities and fed shredded paper (SP), cattle manure (CM), and lawn clippings (LC) combined to form C/N ratios of 28, 36, and 53. Earthworms were fed at rates of 1, 1.25, and 2 g feed (dry wt.)/g worm/day for a period of 8 weeks. Percent vermiconversion, earthworm adult and juvenile biomass, and vermicast quality were measured. Vermicast production was significantly affected by the combination of C/N ratio and feed rate and varied among species. All treatment combinations resulted in > 70% conversion, except E. eugenaie fed at the medium rate. Vermiconversion increased for P. excavatus and D. annae with increasing C/N ratio but decreased with increasing the feed rate. Vermicast EC, pH, and C/N ratio was strongly affected by species, relative to other experimental factors. D. annae showed the greatest change in biomass, which peaked at the highest feed rate and lowest C/N ratio. Average adult biomass decreased for P. excavatus with increasing feed rate, while differences were nonsignificant for E. eugenaie and D. annae. Significant increases in average juvenile biomass were only evident for D. annae in response to increasing feed rates. Feed rate had a greater influence on earthworm population dynamics and vermicast quality compared to initial feedstock C/N ratio.

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A cyclic order may be thought of informally as a way to seat people around a table, perhaps for a game of chance or for dinner. Given a set of agents such as {A, B, C}, we can formalize this by defining a cyclic order as a permutation or linear order on this finite set, under the equivalence relation whereAs with other collections of sets with some structure, we might want to aggregate preferences of a (possibly different) set of voters on the set of possible ways to choose a cyclic order.However, given the combinatorial explosion of the number of full rankings of cyclic orders, one may not wish to use the usual voting machinery. This raises the question of what sort of ballots may be appropriate; a single cyclic order, a set of them, or some other ballot type? Further, there is a natural action of the group of permutations on the set of agents. A reasonable requirement for a choice procedure would be to respect this symmetry (the equivalent of neutrality in normal voting theory).In this paper we will exploit the representation theory of the symmetric group to analyze several natural types of ballots for voting on cyclic orders, and points-based procedures using such ballots. We provide a full characterization of such procedures for two quite different ballot types for n = 4, along with the most important observations for n = 5.