Liu Chuncheng, Wang Juan, Huang Pengfei, Hu Chao, Gao Feng, Liu Yuan, Li Zhongyang, Cui Bingjian
Institute of Farmland Irrigation, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
Key Laboratory of High-Efficient and Safe Utilization of Agriculture Water Resources, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
Plants (Basel). 2023 Jun 12;12(12):2285. doi: 10.3390/plants12122285.
The scarcity of freshwater resources has increased the use of nonconventional water resources such as brackish water, reclaimed water, etc., especially in water-scarce areas. Whether an irrigation cycle using reclaimed water and brackish water (RBCI) poses a risk of secondary soil salinization to crop yields needs to be studied. Aiming to find an appropriate use for different nonconventional water resources, pot experiments were conducted to study the effects of RBCI on soil microenvironments, growth, physiological characteristics and antioxidation properties of crops. The results showed the following: (1) compared to FBCI, the soil moisture content was slightly higher, without a significant difference, while the soil EC, sodium and chloride ions contents increased significantly under the RBCI treatment. With an increase in the reclaimed water irrigation frequency (Tri), the contents of EC, Na and Cl in the soil decreased gradually, and the difference was significant; the soil moisture content also decreased gradually. (2) There were different effects of the RBCI regime on the soil's enzyme activities. With an increase in the Tri, the soil urease activity indicated a significant upward trend as a whole. (3) RBCI can alleviate the risk of soil salinization to some extent. The soil pH values were all below 8.5, and were without a risk of secondary soil alkalization. The ESP did not exceed 15 percent, and there was no possible risk of soil alkalization except that the ESP in soil irrigated by brackish water irrigation went beyond the limit of 15 percent. (4) Compared with FBCI, no obvious changes appeared to the aboveground and underground biomasses under the RBCI treatment. The RBCI treatment was conducive to increasing the aboveground biomass compared with pure brackish water irrigation. Therefore, short-term RBCI helps to reduce the risk of soil salinization without significantly affecting crop yield, and the irrigation cycle using reclaimed-reclaimed-brackish water at 3 g·L was recommended, according to the experimental results.
淡水资源的稀缺增加了对微咸水、再生水等非常规水资源的利用，尤其是在缺水地区。使用再生水和微咸水的灌溉周期（RBCI）是否会对作物产量造成次生土壤盐渍化风险尚需研究。为了找到不同非常规水资源的合适利用方式，进行了盆栽试验，以研究RBCI对土壤微环境、作物生长、生理特性和抗氧化性能的影响。结果表明：（1）与淡水-微咸水灌溉（FBCI）相比，RBCI处理下土壤含水量略高，但差异不显著，而土壤电导率（EC）、钠离子和氯离子含量显著增加。随着再生水灌溉频率（Tri）的增加，土壤中EC、Na和Cl含量逐渐降低，差异显著；土壤含水量也逐渐降低。（2）RBCI模式对土壤酶活性有不同影响。随着Tri的增加，土壤脲酶活性总体呈显著上升趋势。（3）RBCI在一定程度上可以缓解土壤盐渍化风险。土壤pH值均低于8.5，不存在次生土壤碱化风险。交换性钠百分比（ESP）不超过15%，除微咸水灌溉土壤的ESP超过15%的限值外，不存在土壤碱化风险。（4）与FBCI相比，RBCI处理下地上和地下生物量无明显变化。与纯微咸水灌溉相比，RBCI处理有利于增加地上生物量。因此，短期RBCI有助于降低土壤盐渍化风险，且对作物产量无显著影响，根据试验结果，建议采用3 g·L的再生水-再生水-微咸水灌溉周期。
