Earthworm Diversity and Abundance in Various Cropping Systems under Conventional and Organic Farming

Earthworms form an integral part of the soil ecosystem, contributing to the development of soil structure, nutrient cycling, pedogenesis, water regulation and pollution remediation. The present study is an attempt to assess the earthworm abundance and diversity in the different cropping systems (basmati-wheat, basmati-chickpea, soybean-wheat, moong-wheat) under organic and conventional farming systems in the fields of Punjab Agricultural University, Ludhiana. The four earthworm species found during the study period are Metaphire posthuma, Lampito mauritti, Amynthas morrisi and Travoscolides chengannur which belong to two families - Megascolicidae and Octochateidae. Out of these Travoscolides chengannur was reported for the first time in Punjab. The results indicated that richer earthworm diversity is found in the organic farming systems as compared to the conventional farming systems. The annual overall abundance of earthworms in kharif season i.e. M. posthuma (61.75) was found in basmati rice-wheat, (62.75) in basmati rice-chickpea, (36.5) in soyabean-wheat, (43.5) in moong-wheat cropping systems in the organic farming. This abundance was higher as compared to the conventional farming as found (8.2) in basmati rice-wheat, (9.2) both in basmati rice-chickpea and soyabean-wheat, (8.2) in moong-wheat cropping systems (Rabi). The same trend was found for other species. The current study demonstrates that conventional farming management practices such as chemical fertilizers and pesticides negatively influence the earthworm population, which could explain the existence of fewer earthworm species in conventional fields.