Effect of organic manure and the endogeic earthworm Pontoscolex corethrurus (Oligochaeta: Glossoscolecidae) on soil fertility and bean production

Abstract

A biofertilisation assay was conducted in Maripasoula (French Guiana), testing the effects of three different organic amendments (manioc peels, sawdust and wood charcoal) and the inoculation of the endogeic earthworm Pontoscolex corethrurus on pod production of Vigna unguiculata sesquipedalis and on soil chemical 2 properties (pH, C, N, total and exchangeable P and K). Pod production was highest with manioc peels as available P increased in the soil. Wood charcoal also had a beneficial effect on pod production as it decreased acidity and increased the C:N ratio in the soil. In sawdust-amended soil, pod production did not differ from that in unamended soil. Inoculation of earthworms at a density of 80 sub-adults m-2 did not significantly affect either pod production or soil nutrient content directly, although it increased the positive effect of manioc peels on pod production. Soil nutrient content, pod production and earthworm density at the end of the experiment were negatively correlated with soil moisture and positively with each other. Despite the strong effect of moisture, this assay demonstrated an interaction between the earthworm P. corethrurus and the legume V. unguiculata sesquipedalis mediated by soil nutrient content and organic matter inputs. We conclude that manioc peels improved soil P availability and were an interesting amendment for legume crops. We discuss also the effect of earthworm inoculation.

Bio-Char Soil Management on Highly Weathered Soils in the Humid Tropics

“…Additions of bio-char to soil have shown definite increases in the availability of major cations and phosphorus as well as in total nitrogen concentrations (Glaser et al, 2002;Lehmann et al, 2003a). Both CEC and pH are also frequently increased through such applications, by up to 40% of initial CEC and by one pH unit, respectively (Tryon, 1948;Mikan and Abrams, 1995;Topoliantz et al, 2002). Higher nutrient availability for plants is the result of both the direct nutrient additions by the bio-char and greater nutrient retention (Lehmann et al, 2003a), but it can also be an effect of changes in soil microbial dynamics, discussed in the following section.…”

Harmful or useful? A case study of the exotic peregrine earthworm morphospecies Pontoscolex corethrurus

“…Some restoration strategies of degraded soils have included the introduction of the morphospecies. For instance, it was used for the biofertilisation of tropical agricultural lands Topoliantz et al, 2002), the remediation of polluted sites (Duarte et al, 2012;Ganihar, 2003;Liang et al, 2011), and the improvement of phytoextraction treatments (Jusselme et al, 2012). Additionally, its use has been proposed in vermicomposting (Chaudhuri and Bhattacharjee, 2011;Molina-Murguia et al, 2009;Nath and Chaudhuri, 2012;Sabrina et al, 2013) and as a source of protein in animal feed for poultry and pork, and in fisheries .…”

Stability and stabilisation of biochar and green manure in soil with different organic carbon contents

“…Biochar is highly recalcitrant to decomposition (Schmidt and Noack 2000), typically has a high ratio of carbon (C) to nitrogen (N), and has the ability to increase soil cation exchange capacity (CEC) (Tryon 1948;Mikan and Abrams 1995;Topoliantz et al 2002;Lehmann et al 2006;Liang et al 2006). Due to its long half-life (Baldock and Smernik 2002), biochar could be one of the best approaches to sequester C in soils, contributing to a net carbon dioxide withdrawal from the atmosphere (Lehmann 2007;Laird et al 2009).…”