Wheat growth in a saline sandy loam soil as affected by N form and application rate

作者：Elgharably Ahmed^*; Marschner Petra; Rengasamy Pichu

来源：Plant and Soil, 2010, 328(1-2): 303-312.

DOI：10.1007/s11104-009-0110-2

• Ammonium nitrate
• Ammonium sulphate
• Potassium nitrate
• Salinity
• Wheat

Plant growth in saline soils may be increased by fertilisation, but little is known about the effect of different forms of N on wheat growth in soils with different salinity levels. The aim of this study was to investigate the response of wheat (Triticum aestivum L., cv Krichauff) to (NH(4))(2)SO(4) or KNO(3) or NH(4)NO(3) at 0 (N0), 50 (N50), 100 (N100) and 200 (N200) mg N kg(-1) soil in a saline sandy loam. Salinity was induced using Na(+) and Ca(2+) salts to achieve three EC(e) levels, 2.8, 6.6 and 11.8 dS m(-1) denoted S1, S2 and S3, respectively, while maintaining a low SAR (> 1). Dry weights of shoot and root were reduced by salinity in all N treatments. Addition of N significantly increased shoot and root dry weights with significant differences between N forms. Under non-saline conditions (S1), addition of NO(3) -aEuro parts per thousand N at rates higher than N50 had a negative effect, while N100 as NH(4) -aEuro parts per thousand N or NH(4)NO(3) -aEuro parts per thousand N increased shoot and root dry weights. At N100, shoot concentrations of N and K were higher and P, Ca, Fe, Mn, Cu and Zn were lower with NO(3) -aEuro parts per thousand N than with NH(4) -aEuro parts per thousand N nutrition. The concentration of all nutrients however fell in ranges did not appear to be directly associated with poor plant growth with NO(3) -aEuro parts per thousand N. At all N additions, calculations indicated that soil salinity was highest with N addition as NO(3) -aEuro parts per thousand N and decreased in the following order: NO(3)-N > NH(4)-N > NH(4)NO(3)-N. Addition of greater than N50 as NO(3) -aEuro parts per thousand N, compared to NH(4) -aEuro parts per thousand N or NH(4) -aEuro parts per thousand NO(3,) increased soil salinity and reduced micronutrient uptake both of which likely limited plant growth. It can be concluded that in saline soils addition of 100 mg N kg(-1) as NH(4) -aEuro parts per thousand N or NH(4)NO(3) -aEuro parts per thousand N is beneficial for wheat growth, whereas NO(3) -aEuro parts per thousand N can cause growth depression.

• 出版日期2010-3