Applied and Environmental Soil Science

Research Article

Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar): A Mesocosm Experiment

Table 1

Abundance (individuals kg of dry soil) of nematodes in treatments: Earthworm—No earthworms, No residues added—with rice residue—with soybean residues, and in treatments with buried residue—mulch residue. Significant differences are indicated in bold by * or different letters (Newman-Keuls test, P < .05). Results of analysis of effects of earthworms and residues were obtained by a 2-way anova (n = 50) including all the samples, whereas the effect of localisation was assessed by a 3-way anova () excluding samples with no residue inputs. Significant interactions of the 2-way anova (earthworm (E) × residues (R) and of the 3-way anova (E × R, Localisation (L) × E, L × R, E × R × L) are indicated in the table by * (P < .05).


	Earthworm	Residues
	c-p	Earthworm	No earthworm		No residue addition		With rice residue addition		With soybean residue		Interaction anova2	Buried residue	Mulched residue	Interaction anova3
											E × R			E × R	E × L	R × L	E × R × L

*Nematodes trophic groups*
Bacterial-feeders
Monhysteridae	1	20	25		4		33		21			28	26
Panagrolaimidae	1	2054	2587		1203	b	2123	ab	3075	a		*4127*	*1071*	*		*
Rhabditidae	1	944	652		60	b	1451	a	514	b		1370	595	*
Acrobeles	2	147	291		383	a	104	b	252	c		230	126
Acrobeloides	2	7001	2840	*	4162		3054		7166			6513	3707	*
Cervidellus	2	196	229		236	a	267	a	147	b		*330*	84	*			*
Drilocephalobus	2	592	613		598	ab	388	b	818	a		608	598
Plectidae	2	24	34		14		50		17			52	15	*
Prismatolaimidae	3	628	427	*	491		475		599			*672*	*402*	*		*	*
Rhabdolaimus	3	345	322		292		346		343		*	*484*	*205*	*	*	*
Alaimus	4	447	481		173	b	549	a	525	ab		697	377			*	*
Amphidelus	4	41	30		12	b	71	a	12	b		52	31	*

Total		12 439	8531		7628		8911		13 489			15 163	7237	*

Fungal-feeders
Aphelenchoididae	2	1108	297		135		1317		372			567	1121
Aphelenchus	2	1133	793	*	750	b	798	b	1235	a		991	1042			*
Ditylenehus	2	286	139		16	b	141	a	382	a		*473*	50	*			*
Diphterophoridae	3	44	27		33		41		31			29	43
Tylencholaimoidea	4	46	34		13		29		64			80	13	*

Total		2617	1289	*	946	b	2326	a	2084	a		2140	2270

Entomopathogenic		235	175		338		235		110			268	77	*
Plant-feeders		1000	722		983		912		749			602	1059			*
Root hair-feeders		547	553		564		617		476			845	247	*
Omnivores and predators		155	189		140		200		160			203	158			*	*
*Nematode density*		16 994	11 460	*	10 600		13 200		17 068			19 220	11 047	*