Effectiveness of Reduced Tillage on the Cast Production of Pheretima (Amynthas) carnosa and Yields of Chinese Cabbage on Volcanic-ash Soil

Abstract

Soil aggregation by earthworms is important for sustainable agriculture because soil aggregates are highly permeable and retain water. Casts are a soil aggregate and indicator of earthworm activity. The effects of reduced tillage using a rotary tiller on earthworm cast productivity and yield of Chinese cabbage were investigated in volcanic-ash soil. Five tillage practices were investigated; conventional tillage (CT), no tillage (NT), and three reduced tillage practices: shallow tillage, row tillage, and shallow row tillage respectively. Cast production of Pheretima (Amynthas) carnosa, the species which dominated the study site, and yields of Chinese cabbages were measured during three crop seasons. Crop yield under the NT treatment was lower than that under the CT treatment (p<0.05) in fall 2004, while in spring 2005 Chinese cabbage under NT treatment did not head out. Yields under reduced tillage treatments tended to decrease in spring 2005, but were similar to those under CT treatment in the other two cropping seasons. Under CT treatment, the surface cast production was almost zero. Cast production under reduced tillage exceeded that under CT treatment, but was lower than that under NT treatment. Accordingly, reduced tillage can combine the ability to preserve aggregate formation by earthworms while also preventing any decline in Chinese cabbage production yield in the cropping system studied.

Earthworms in Brazilian no‐tillage agriculture: Current status and future challenges

“…Earthworm bioturbation, particularly cast production, has rarely been measured under NT (e.g., Bescansa, Virto, Fernández‐Ugalde, Imaz, & Enrique, 2010; Bottinelli, Hallaire, Menasseri‐Aubry, Le Guillou, & Cluzeau, 2019; Kaneda, Nakajima, Urashima, & Murakami, 2014), and although surface casting rates may achieve up to 3 Mg of soil ha −1 yr −1 in temperate NT fields in Japan (Miura et al, 2008) and 68–112 g m −2 d −1 (2.5–4.1 Mg ha −1 yr −1 ) in Nigerian NT fields (Lal & Akinremi, 1983), similar measurements have not been performed in Brazilian NT systems (despite visual observations of the phenomenon; Figures 2b,c). Surface casts represent a variable proportion of earthworm casting, depending on the species present and soil conditions, particularly moisture, temperature, food supply and bulk density (Barley, 1952; Joschko, Diestel, & Larink, 1989; Scullion & Ramshaw, 1988; Whalen, Sampedro, & Waheed, 2004).…”

Synecological farming: Theoretical foundation on biodiversity responses of plant communities

“…Conventional tillage essentially destroys the soil faunal abundance and microbial activity, which degrades the productivity (Yagioka et al 2014). In some cases, even reduced tillage could bring devastating impact on soil aggregate formation, depending on the texture (Kaneda et al 2014). It is also the structural source of soil erosion and ground water pollution.…”