Effect of Using Lead-Contaminated Water by Surface Irrigation and Subirrigation on Silage Maize Yield and Uptake

The aim of this study was to investigate the possibility of using lead contaminated water in surface irrigation and subirrigation and its effect on silage maize yield. In this regard, lysimeter experiments were conducted in the College of Agriculture and Natural Resources, University of Tehran in 2017 in the form of a completely randomized factorial project with six treatments in three replications and a total of 18 experimental plots. Treatments included: Surface irrigation with lead-contaminated water (SP), Surface irrigation with fresh water as control treatment (SC), Subirrigation with lead-contaminated water and water table depth of 50 cm (50P), Subirrigation with fresh water and water table depth of 50 cm (50C), Subirrigation with lead-contaminated water and water table depth of 75 cm (75P), and finally, Subirrigation with fresh water and water table depth of 75 cm (75C). The results showed that the effect of irrigation management on plant height, plant dry weight and maize silage yield at 1% probability level, wet plant weight and maize wet weight at 5% level was significant and it had no effect on maize dry weight. Also, pollution had no effect on growth and yield and components of maize yield. The results also showed there was a 2.25 mg of lead per one kg of maize dry matter in the SP treatment, which this amount is in the group of low pollution according to the World Health Organization (WHO), No lead was observed in the plant samples of the 50P and 75P treatments. On the other hand, the highest maize yield was recorded in the 75P treatment with 49.65 t/ha and then in the 50P treatment with 47.04 t/ha. Crop yield increased by 36% and 29% in the 75P and 50P treatments compared to the control treatment, respectively. It is noteworthy that the amount of lead metal stabilized and rised in the subirrigation treatment was out of reach of the plant and there was no problem in terms of pollution and maize yeild.