Jizzakh Province in Uzbekistan is one of the largest irrigated areas in Central Asia without natural drainage. In combination with aridity, climate change and extensive irrigation practices, this has led to the widespread salinization of agricultural land. The aim of this study was to identify opportunities to improve the reclamation status of the irrigated area and how best to effectively use the water resources in Jizzakh Province based on investigations conducted between 1995 and 2016. A database of field measurements of groundwater levels, mineralization and soil salinity conducted by the provincial Hydro-Geological Reclamation Expeditions was used in the study. The total groundwater mineralization was determined using a portable electric conductometer (Progress 1T) and the chloride concentration was determined using the Mohr method. The soil salinity analyses were conducted by applying two different methods: (1) the extraction and assessment of the soluble salt content, and (2) using an SM-138 conductivity sensor applied to a 1:1 mixture of soil sample and water. The analyses of the monitoring results and the salt balance in the “irrigation water-soil-drainage water” system clearly demonstrated that the condition of the irrigated land in the province was not significantly improved. Under these conditions, the stability of crop yields is achieved mainly through the use of large volumes of fertilizer. However, excess amounts of mineral fertilizers can also cause the salinization of soils. The average groundwater salinization value in most of the irrigated land (75.3%) fluctuated between 1.1 and 5.0 g/L, while the values were less than 1.0 g/L in 13.1% of the land and in the range of 5.1–10.0 g/L in 10.5% of the land. During the period of 1995–2016 the salinization level of the irrigated land in Jizzakh Province increased slightly and the area could be divided into the following classes: no salinity (17.7% of the total area), low salinity (51.3%), moderate salinity (29.0%), and high salinity (2.0%). Detailed studies of the salt balance in irrigated land, the impact of climate change, increased fertilizer use, and repeated remediation leaching on the groundwater level and mineralization should be conducted in the future, due to the possibility of accelerated salinization, fertility decline, and reduced yields of agricultural crops.

中文翻译：

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乌兹别克斯坦吉扎克灌溉区在气候变化和盐渍化加剧下可持续利用水和土地资源的挑战

乌兹别克斯坦的吉扎克省是中亚最大的没有自然排水系统的灌溉区之一。再加上干旱、气候变化和广泛的灌溉做法，这导致了农业用地的广泛盐碱化。本研究的目的是根据 1995 年至 2016 年间进行的调查，确定改善灌溉区开垦状况的机会以及如何最好地有效利用吉扎克省的水资源。研究中使用了省级水文地质开垦探险队进行的土壤盐分。使用便携式电导仪 (Progress 1T) 确定地下水总矿化，并使用莫尔法确定氯化物浓度。通过应用两种不同的方法进行土壤盐度分析：(1) 可溶性盐含量的提取和评估，以及 (2) 使用 SM-138 电导率传感器应用于土壤样品和水的 1:1 混合物。监测结果和“灌溉水-土壤-排水”系统盐分平衡分析表明，全省灌溉土地状况没有明显改善。在这些条件下，主要通过使用大量肥料来实现作物产量的稳定。然而，过量的矿物肥料也会导致土壤盐碱化。大部分灌区（75.3%）地下水平均盐渍化值在1.1~5.0 g/L之间波动，13个地区低于1.0 g/L。1% 的土地，10.5% 的土地在 5.1–10.0 g/L 范围内。1995-2016年吉扎克省灌溉地盐渍化程度略有增加，可分为以下几类：无盐度（占总面积的17.7%）、低盐度（51.3%）、中盐度(29.0%) 和高盐度 (2.0%)。今后应详细研究灌溉地盐分平衡、气候变化的影响、化肥用量的增加以及地下水位和矿化的反复修复浸出，因为有可能加速盐渍化、肥力下降和减少农作物的产量。1995-2016年吉扎克省灌溉地盐渍化程度略有增加，可分为以下几类：无盐度（占总面积的17.7%）、低盐度（51.3%）、中盐度(29.0%) 和高盐度 (2.0%)。今后应详细研究灌溉地盐分平衡、气候变化的影响、化肥用量的增加以及地下水位和矿化的反复修复浸出，因为有可能加速盐渍化、肥力下降和减少农作物的产量。1995-2016年吉扎克省灌溉地盐渍化程度略有增加，可分为以下几类：无盐度（占总面积的17.7%）、低盐度（51.3%）、中盐度(29.0%) 和高盐度 (2.0%)。今后应详细研究灌溉地盐分平衡、气候变化的影响、化肥用量的增加以及地下水位和矿化的反复修复浸出，因为有可能加速盐渍化、肥力下降和减少农作物的产量。