The effect of Diammonium Phosphate Fertilization on Salinity Tolerance of Maize (Zea mays L.)

Abstract

A greenhouse experiment was carried out to examine the effect of phosphorus fertilization on the tolerance of maize (<em>Zea mays </em>L.) to different soil salinity levels in 2011 at Mohaghegh Ardabili University in Ardabil- Iran. Five levels of phosphorus (0, 20, 40, 80 and 160 kg Pha^-1asdiammonium phosphate) and 10 salt levels (0.75, 1.20, 2.29, 3.30, 4.25, 5.11, 6.19, 8.80, 10.88 and 14.00 dSm^-1) were investigated as a factorial combination with a randomized complete blocks design with three replications. The results showed that stem diameter, leaf number and area, leaves chlorophyll index and shoot and root dry weights at 60 days after germination were significantly increased with phosphorus applications but were decreased with increasing soil salinity levels. Shoot and root phosphorous concentrations were increased with increasing soil salinity and phosphorus level. The maize plants treated with 80 kg P ha^-1 produced higher shoot and root dry matter over other levels. Maximum stem diameter, leaf number and area, leaves chlorophyll index were obtained by using 160 kg P ha^-1. The interactive effects salinity and phosphorous on chlorophyll index and dry weight of shoot and root was significant, whereas other growth indices were not markedly changed. Application of phosphorus fertilizer mitigated the negative influences of salinity, causing the corn growth be increased.