4N Katerji, J W van Horrn, A Hamdy, M Mastrorilli. Salt tolerance classification of crops according to soil salinity and to water stress day index[J]. Agricultural Water Management, 2000,43 : 99 - 109,.
5Arthur Wallace, A M Abou-Zamzam. Low levels, but excess of five different trace elements singly and combination, on interactions in bush beans grown in solution culture[J]. Soil Science, 1989,147(6) :439 - 441.