Date palm production contributes significantly to socio-economic development and food security in the dryland areas of Southern Tunisia. Soil degradation and nutrient depletion have dramatically increased in recent years. This is leading to a decline in date palm yields in these oases-based production systems. Locally derived bentonite clay has been identified as a new soil amendment to improve date morphological characteristics and date production. In this study, a 3-year field experimental study was carried out on 3-year-old Deglet Nour date palms growing in sandy soil of a Tunisian oasis (Fatnassa, Southern Tunisia). The study’s aim was to compare the effect of two amendment types: (i) sand (S) mixed with farm manure (M) and bentonite clay (B) (=BSM) and (ii) sand mixed with farm manure (SM) on the soil characteristics and morphological features of date palm. The results indicated that soil macro- and micronutrient contents were enhanced under BSM. Soil water retention in BSM also increased to 290 ± 0.3 mm m⁻¹ compared to 70 ± 0.2 and 50 ± 0.5 mm m⁻¹ for an untreated (no amendment) and SM treatment, respectively. The amelioration of morphological characteristics was observed for the canopy diameter reaching 226 ± 0.6 cm in BSM treatment compared to 172 ± 0.6 cm in untreated palm trees. The height of the palms increased by 69 ± 0.8 cm from 29 ± 0.1cm in the control treatment, and leaf number increased from 40 leaves palm⁻¹ in BS to 60 leaves palm⁻¹ in BSM treatment. The leaf mineral content was significantly been improved in the third year, and the leaf NPK contents were 220 ± 0.6 mg kg⁻¹, 17 ± 0.1 mg kg⁻¹, and 200 ± 0.04 mg kg⁻¹, respectively, in BSM treatments. The effect of the farm manure and bentonite clay was noticeable for the yield production, and the SM and BSM treatments offered yields of 70 ± 0.9 kg palm⁻¹ and 80 ± 0.5 kg palm⁻¹, respectively. It could partly ameliorate the alternate year bearing phenomenon of the Deglet Nour date variety. We conclude that the joint application of farm manure and bentonite clay does represent a viable option to further improve the production and resilience of date palms in dryland areas.

枣椰子的生产为突尼斯南部干旱地区的社会经济发展和粮食安全做出了重要贡献。近年来，土壤退化和养分消耗急剧增加。这导致这些基于绿洲的生产系统中的椰枣产量下降。本地来源的膨润土被确定为一种新的土壤改良剂，可以改善枣的形态特征和枣的生产。在这项研究中，对3岁的Deglet Nour进行了3年的野外实验研究在突尼斯绿洲（突尼斯南部的法塔纳萨）的沙质土壤中生长的枣椰树。该研究的目的是比较两种修正类型的影响：（i）沙子（S）与农场肥料（M）和膨润土（B）（= BSM）混合，以及（ii）沙子与农场肥料（SM）混合。枣椰子的土壤特征和形态特征 结果表明，BSM能提高土壤中微量元素和微量元素的含量。在BSM土壤持水也增加至290±0.3毫米米^-1相比70±0.2和50±0.5毫米米^-1分别针对未治疗（未修正）和SM治疗。BSM处理的树冠直径达到226±0.6 cm，而未经处理的棕榈树则达到172±0.6 cm，形态特征得到了改善。棕榈的高度从对照处理中的29±0.1cm增加了69±0.8 cm，并且叶数从BS中的40个叶棕榈^-1增加到BSM处理中的60个叶棕榈^-1。第三年叶片矿物质含量显着提高，叶片NPK含量为220±0.6 mg kg ^-1，17 ±0.1 mg kg ^-1和200±0.04 mg kg ^-1分别在BSM处理中。农场肥料和膨润土的影响对于产量的生产是显着的，并且SM和BSM处理分别提供70±0.9 kg棕榈^-1和80±0.5 kg棕榈^-1的产量。它可以部分缓解Deglet Nour日期品种的隔年交替现象。我们得出的结论是，农场肥料和膨润土的联合施用确实是进一步提高旱地地区枣椰子产量和韧性的可行选择。