State Key Laboratory of Eco-Hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China.
School of Water Resource and Hydropower, Xi'an University of Technology, Xi'an , 710048, China.
BMC Plant Biol. 2023 Apr 3;23(1):174. doi: 10.1186/s12870-023-04199-7.
Spring irrigation with freshwater is widely used to reduce soil salinity and increase the soil water content in arid areas. However, this approach requires a huge amount of freshwater, which is problematic given limited freshwater resources. Utilizing brackish water for spring irrigation in combination with magnetized water technology may be a promising alternative strategy.
The objective of this study was to evaluate the effects of four spring irrigation methods (freshwater spring irrigation (FS), magnetized freshwater spring irrigation (MFS), brackish water spring irrigation (BS), and magnetized brackish water spring irrigation (MBS)) on soil water and salt distribution, emergence, growth, and photosynthetic characteristics of cotton seedlings. The results showed that for both freshwater and brackish water, magnetized water irrigation can increase the soil water content for improved desalination effect of irrigation water. Additionally, spring irrigation with magnetized water promoted cotton emergence and seedling growth. Compared with FS treatment, cotton finial emergence rate, emergence index, vigor index, plant height, stem diameter, and leaf area index of MFS treatment increased by 6.25, 7.19, 12.98, 15.60, 8.91, and 20.57%, respectively. Compared with BS treatment, cotton finial emergence rate, emergence index, vigor index, plant height, stem diameter, and leaf area index of MBS treatment increased by 27.78, 39.83, 74.79, 26.40, 14.01, and 57.22%, respectively. Interestingly, we found that spring irrigation with magnetized water can increase the chlorophyll content and net photosynthetic rate of cotton seedlings. The rectangular hyperbolic model (RHM), non-rectangular hyperbolic model (NRHM), exponential model (EM), and modified rectangular hyperbolic model (MRHM) were used to fit and compare the cotton light response curve, and MRHM was determined to be the optimal model to fit the data. This model was used to calculate the photosynthetic parameters of cotton. Compared with FS treatment, the net photosynthetic rate (P), dark respiration rate (R), light compensation point (I), light saturation point (I), and the range of available light intensity (ΔI) of MFS were increased by 5.18, 3.41, 3.18, 2.29 and 2.19%, respectively. Compared with BS treatment, the P, R, I, I and ΔI of MBS were increased by 26.44, 29.48, 30.05, 5.13, and 2.27%, respectively.
The results show that spring irrigation with magnetized brackish water may be a feasible method to reduce soil salt and increase soil water content when freshwater resources are insufficient.
在干旱地区，春季淡水灌溉被广泛用于降低土壤盐分并增加土壤含水量。然而，这种方法需要大量的淡水，而淡水资源有限，这是一个问题。利用咸水进行春季灌溉，并结合磁化水技术，可能是一种很有前途的替代策略。
本研究的目的是评估四种春季灌溉方式（淡水春季灌溉（FS）、磁化淡水春季灌溉（MFS）、咸水春季灌溉（BS）和磁化咸水春季灌溉（MBS））对棉花幼苗土壤水分和盐分分布、出苗、生长和光合作用特性的影响。结果表明，对于淡水和咸水，磁化水灌溉均可增加土壤含水量，从而提高灌溉水的脱盐效果。此外，磁化水春季灌溉促进了棉花出苗和幼苗生长。与 FS 处理相比，MFS 处理的棉花最终出苗率、出苗指数、活力指数、株高、茎粗和叶面积指数分别提高了 6.25%、7.19%、12.98%、15.60%、8.91%和 20.57%。与 BS 处理相比，MBS 处理的棉花最终出苗率、出苗指数、活力指数、株高、茎粗和叶面积指数分别提高了 27.78%、39.83%、74.79%、26.40%、14.01%和 57.22%。有趣的是，我们发现磁化水春季灌溉可以增加棉花幼苗的叶绿素含量和净光合速率。使用矩形双曲线模型（RHM）、非矩形双曲线模型（NRHM）、指数模型（EM）和修正矩形双曲线模型（MRHM）对棉花的光响应曲线进行拟合和比较，确定 MRHM 是拟合数据的最佳模型。该模型用于计算棉花的光合参数。与 FS 处理相比，MFS 的净光合速率（P）、暗呼吸速率（R）、光补偿点（I）、光饱和点（I）和有效光强范围（ΔI）分别提高了 5.18%、3.41%、3.18%、2.29%和 2.19%。与 BS 处理相比，MBS 的 P、R、I、I 和 ΔI 分别提高了 26.44%、29.48%、30.05%、5.13%和 2.27%。
结果表明，在淡水资源不足的情况下，利用磁化咸水进行春季灌溉可能是一种降低土壤盐分和增加土壤含水量的可行方法。
