Sustainable Practices for Diminishing Nitrate Leaching

Abstract

Investigating the factors affecting water and salt movement in the soil and utilizing new amendments, such as mineral nanoparticles and biochar, can significantly contribute to proper land management and reduce nitrate (NO₃^–) leaching, thus preventing groundwater pollution. This study aimed to investigate the effects of mineral nanoparticles and biochar derived from wheat residues on NO₃^– leaching from the soil and soil particle stability. The treatments used in this study included three treatments: nanozeolite, nanoclosite, and biochar, each at two levels (10 and 50 g/kg of soil, 1% and 5% w/w) and a control treatment. The duration of the experiment and the amount of fertilizer added to the soil columns matched the corn cultivation period. Nitrate fertilizer containing 46% pure nitrogen was used to introduce NO₃^– into the soil columns. The irrigation of the soil columns was performed by weighing the lost water from the control soil column. Compared with those in the control sample, the amount of NO₃^– leached from the soil columns in the 10-g biochar, 10-g nanozeolite, and 10-g nanoclosite treatments significantly decreased. Additionally, the amount of NO₃^– leached from the soil columns in the 50 g biochar, 50 g nanozeolite, and 50 g nanoclosite treatments significantly decreased compared to that in the control sample. Throughout all weeks of the experiment, the 50 g biochar treatment had the lowest NO₃^– leaching compared to the 50 g nanozeolite and 50 g nanoclosite treatments. Additionally, increasing the use of nanozeolite and nanoclosite enhances the stability of soil particles and decreases NO₃^– leaching from the soil columns, resulting in reduced groundwater contamination with NO₃^–.