6Tanner, C. B, Weis, G. G. and Curwen, D. Russet Burbank rooting in sandy soils with pans following deep plowing. American Potato Journal, 1982, 59:107 - 112.
7Ghosh, P K, Dayal D, Bandyopadhyay, et al. Evaluation of straw and polythene mulch for enhancing productivity of irrigated summer ground - nut[J]. Field Crop Res, 2006, 99:76 - 86.
8Wang F X, Feng S Y, Hou X Y, et al. Potato growth with and without plastic mulch in two typical regions of North- em China[J]. Field. Crop Res, 2009,110 : 123 - 129.
9Haraguchi T, Marui A, Yuge K, et al. Effect of plastic - film mulching on leaching of nitrate nitrogen in an upland field converted from paddy[J]. Paddy and Water Environ- ment,2004,2:67 - 72.
10Gao Y J, Li Y, Zhang J C, et al. Effects of mulch, N fer-tilizer, and plant density on wheat yield, wheat nitrogen uptake, and residual soil nitrate in a dryland area of China [J]. Nutrient Cycling in Agroecosystem, 2009,85 : 109 - 121.
