Assess Effect of Different Level of Biochar and Humic Acid on Crop Production and Nutrition Content of Maize Affected Water Stress Condition

BACKGROUND: Water deficit stress is one of the most important agricultural problems in arid and semi-arid regions. Biochar has a great ability to absorb and store nutrients and chemical fertilizers, even keeping elements such as phosphorus and nitrogen and preventing their leaching, increases the growth of plants.OBJECTIVES: The purpose of this research was to study the effect of Biochar and Humic acid amounts on the absorption of elements and the seed yield of corn hybrid (SC.704) under water deficit stress in Ahvaz region.METHODS: Current study was conducted in the form of a split split plot experiment based on randomized complete block design with three replications during the cropping years 2016-2018 and 2018-2019 in Ahvaz. The main plot includes water deficit stress with three levels of irrigation (irrigation after draining 30, 40 and 50% of the field capacity, respectively, optimal irrigation, mild stress and severe stress). Also the sub-plot includes biochar with 2 levels (no use of biochar and the application of 4 t.ha-1) and sub-subplot included humic acid with 4 levels (no application of humic acid, application of 2, 4 and 6 liters of humic acid per hectare).RESULT: The results of analysis of variance showed that the effect of water stress, biochar and humic acid on all measured traits was significant. Also interaction effect of treatments was significant (instead effect of water stress × biochar on seed yield, iron and zinc seed content and water stress × humic acid on seed yield) Under severe stress conditions, seed yield decreased (36%). Humic acid had a positive and significant effect on all studied traits. The maximum seed yield (8995.18 kg.ha-1) was related to the irrigation treatment after draining 40% of the field capacity and applying 4 t.ha-1 of biochar.CONCLUSION: In general, in conditions of moderate moisture stress, the use of 4 liters of humic acid per hectare increased the seed yield by 42% compared to the treatment of severe stress and no use of humic acid.