The Impacts of Applying Cobalt and Chitosan with Various Water Irrigation Schemes at Different Growth Stages of Corn on Macronutrient Uptake, Yield, and Water Use Efficiency

Abstract

While previous studies have demonstrated the positive effects of low cobalt (CB) levels and chitosan (CH) on yield and nutrient status, information about their individual and combined applications on plants under stress is still lacking. Therefore, we conducted a study to investigate CB and CH impacts on mitigating water stress during growth stages and their effects on corn macronutrient uptake and yield. Four irrigation schemes were employed, including (1) control (full irrigation), (2) 70% of irrigation water during the vegetative stage, (3) 70% of irrigation water during the flowering stage, and (4) 85% of irrigation water during both the vegetative and flowering stages. The plants were treated with (7.5 mg l−1) CB injected into the irrigation water and CH foliar application (500 mg l−1), while distilled water was used as the control. Plants that were exposed to water stress during the flowering stage and treated with CB, or those subjected to water stress during the vegetative stage and treated with CH, showed increased macronutrient uptake and growth, which had a positive effect on yield and water use efficiency. However, when CB and CH were applied in combination, their potential to enhance these features depended on the pattern of water stress adopted. Overall, the application of CB and CH was effective in mitigating water stress, and their combined application was particularly effective when 70% of irrigation water was applied during the flowering stage. This approach resulted in the highest yield, macronutrient uptake, water use efficiency, and tolerance index.

Impact of different sowing dates and irrigation levels on NPK absorption, yield and water use efficiency of maize

“…Additionally, this approach proves beneficial in mitigating the impacts of water stress and conserving significant amounts of irrigation water and increasing WUE in arid climatic conditions. These findings align with previous studies 14,59,67 , that have reported similar enhancements in yield characteristics.…”

“…One of these mechanisms is the activation of an effective root system, which involves the penetration of the root system within the soil profile, the modification of root architecture as well as the accumulation of root exudate production, which is consistent with previous studies [56][57][58] . However, with reduced water applications (Ir 70 ), the soil pH increased subsequently affecting negatively on the availability of P 59 . The plants employ increasing root exudates to decrease soil pH and allow root systems increase the absorption of P. Increased accumulation of P in grains improves the synthesis of carbohydrates.…”

Impacts of cobalt and zinc on improving peanuts nutrient uptake, yield and irrigation water use efficiency under different irrigation levels

“…Conversely, under (100 & 80%) GWR levels, many stomata were open due to adequate soil moisture, resulting in increased transpiration rates 67 , 68 . This caused an imbalance in nutrient uptake activities between the most active plant aerial parts and roots, consistent with previous studies 5 , 23 . The current study’s findings suggest that under similar growth conditions (100 & 80%) GWR, applying foliar applications of Znfol to peanut plants has desirable effects.…”

“…Dang et al 73 also highlighted that plant growth and metabolism vary based on the concentration and state of Co in the rhizosphere and soil. Hence, previous studies 5 , 23 demonstrated that Co benefits are correlated with the irrigation level used. Hence, supplying stressful peanut plants with sole applications of Co proved to be a harmful technique, resulting in adverse impacts on yield and IWUE.…”

“…Applying Co to legume crops increases root and microbiome exudates in the rhizosphere, leading to soil acidification 21 . However, like some micronutrients, plants respond positively to low concentrations of Co in the soil, which promotes plant growth, yield, decreases water loss, and affects the content of macronutrients and micronutrients 5 , Gad et al 22 , 23 , while higher concentrations induce phytotoxicity 24 . Despite several studies demonstrating the benefits of low Co on plant growth and nutrient uptake under normal conditions, there is a lack of research investigating its impacts on nutritional uptake status when peanuts are exposed to prolonged water stress conditions, which may result in an increase in Co molecules around the roots and ultimately affect plant development and yield.…”