Influence of 10 years of conservation tillage on some biological properties of a fine sandy loam in the potato phase of two crop rotations in Atlantic Canada

• Published in: Canadian journal of soil science Vol. 89; no. 4; pp. 391 - 402
• Main Authors: Carter, M.R, Peters, R.D, Noronha, C, Kimpinski, J
• Format: Journal Article
• Language: English
• Published: 01.08.2009
• Subjects: Acari; biological activity in soil; carbon; Collembola; conservation tillage; crop rotation; Fusarium; Helminthosporium solani; long term experiments; Nematoda; nitrogen; plant pathogenic fungi; Rhizoctonia solani; sandy loam soils; soil arthropods; soil biological properties; soil fertility; soil fungi; soil nematodes; soil structure; soil-borne diseases; Solanum tuberosum; Streptomyces scabiei; Thanatephorus cucumeris; Prince Edward Island; ANW, Canada, Prince Edward Island
• ISSN: 0008-4271; 1918-1841
• DOI: 10.4141/cjss08054

Conservation practices in potato (Solanum tuberosum L.) cropping systems can reduce excess tillage, provide crop residue cover, and maintain crop productivity; however, little is known about their long-term influence on soil biota and biological properties. Conservation tillage was evaluated in two potato rotations: a 2-yr barley-potato rotation and 3-yr clover-based (barley-red clover-potato) rotation initiated in 1994 on a fine sandy loam (Orthic Podzol) in Prince Edward Island, eastern Canada. Soil samples were obtained in 2003 from the 0- to 10-cm soil depth of the potato phase of both rotations to evaluate the influence of conservation, compared with conventional tillage, on changes in soil fertility, soil structural properties, soil C and N fractions, soil-borne pathogens, nematode communities, and micro-arthropod (Collembola and Acari) communities. The 3-yr conservation tillage practice improved soil structural stability, increased soil extractable P and K, increased soil organic C and total N and their particulate fractions, compared with the other treatments. Comparisons with earlier studies indicated that soil organic C had reached an equilibrium level at the 0- to 10-cm soil depth. Reduction of potato disease caused by Rhizoctonia solani was evident in the 3-yr rotation, compared with the 2-yr rotation, but was not influenced by tillage practice. Plant parasitic nematodes were not greatly influenced by rotation and tillage treatments; however, densities of the beneficial bacterial-feeding nematodes were increased under the 3-yr conservation tillage treatment. The abundance of micro-arthropods was increased by conservation tillage, while their diversity was mainly influenced by the rotation cycle rather than tillage practice. Overall, the 3-yr conservation tillage treatment provided a more beneficial soil biological condition than the other treatments, especially when compared with the 2-yr conventional tillage practice. Key words: Conservation systems, potato rotation, fine sandy loam, soil fertility, soil organic C and N fractions, soil structure, soil-borne pathogens, nematode, Collembola; Acari