Journal of
Horticulture and Forestry

  • Abbreviation: J. Hortic. For.
  • Language: English
  • ISSN: 2006-9782
  • DOI: 10.5897/JHF
  • Start Year: 2009
  • Published Articles: 302

Full Length Research Paper

Effect of polyethylene mulching on the spatial variability of soil physical properties and growth parameters of taro (Colocasia esculantum)

Nsalambi V. Nkongolo1*, Mitate Yamada2 and Izumi Nakagawa
1Department of Agriculture and Environmental Science, College of Agricultural and Natural Sciences, Lincoln University, Jefferson City, MO 65102-0029, U.S.A. 2Crop Production and Postharvest Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba Science City, Japan 305-8686. 3Vegetable Cultivation Technology System Laboratory, Department of Farmland Utilization, National Agriculture Research Center, Tsukuba, Ibaraki 305-8666, Japan.
Email: [email protected]

  •  Accepted: 26 November 2010
  •  Published: 30 November 2011


The objective of this study was to investigate the spatial variability of soil physical properties and growth of taro (Colocasia esculantum) in an unfertilized 42 m ridge covered with black plastic mulch. The study was conducted at the National Agriculture Research Centre Tsukuba (Japan). The experimental field was made of 3 adjacent ridges of 42 m long and 0.90 m width each. Uniform taro corms were planted in the middle of each ridge at 0.30 m spacing. At the end of growing season, soil samples were taken for measurements of air content (¦a), bulk density (rb), gravimetric (qg) and volumetric water contents (qv), total pore space (TPS), pore tortuosity (t), gas diffusion coefficient (DSDO) and water-filled pore space (WFPS). Taro plants were harvested, separated into leaves (LFW), petioles (PFW), corms (CFW), roots (RFW) and tubers (TFW). All autocorrelation functions (r(h)) for soil properties and taro growth dropped sharply after one lag. Except forqg, (r(h) for qa, rb, Ds/Do and WFPS dropped below zero at about 16 lags, which revealed that these soil properties could be sampled at 4.8 m for independent observations. For taro growth parameters, only PFW, TFW and RFW could be sampled together at 14 lags or 4.2 m for uncorrelated observations. Except for RFW, all taro growth parameters significantly correlated among themselves and with qg, ¦a, rb, Ds/Do, WFPS and t with correlation coefficients ranging from 0.16 to 0.99. Plastic mulch improved soil properties which in turn improved the relationship between these properties and taro growth parameters. 


Key words: Soil physical properties, taro growth parameters, plastic mulch, volcanic ash soil.