Boron (B) is very soluble and mobile in soil, and for this reason, it can be easily leached when applied as boric acid (H₃BO₃), particularly in sandy soils. High application rates of B may be toxic to plants. Alginate beads containing layered double hydroxides intercalated with borate (LDH-B-ALG) can potentially minimize the B leaching in soils and reduce the toxicity to plants. The aims of this work were to evaluate the leaching of B in sandy soils from different B sources such as H₃BO₃, Ulexite, and alginate beads containing H₃BO₃ (BA-ALG), and LDH-B-ALG, and investigate the bioavailability of B from these sources in consecutive cultivations of plants. The LDH-B-ALG was synthesized, characterized, and evaluated through the B leaching test in sandy soil. For the leaching column study, the B sources were homogenized with the soil, and incubated before leaching. Sunflower and cotton were cultivated for two seasons in a greenhouse experiment without leaching. Additionally, a greenhouse experiment with leaching was carried out, in which sunflower and cotton were sequentially cultivated after B leaching. In the leaching tests, throughout the incubation time, the percentage of B leached from LDH-B-ALG was significantly lower compared to other B commercial sources. In a greenhouse experiment with leaching, the residual concentration of B in the soil after first cultivation was 1.57, 0.73, 0.66, and 0.61 mg dm⁻³ of B for LDH-B-ALG, Ulexite, H₃BO₃, and BA-ALG treatments, respectively. The residual B in the soil was significantly higher for LDH-B-ALG compared to the other B sources after first cultivation, and, resulted in a higher B uptake in shoots and total (shoots and roots) for the cotton (second cultivation) and for the sum of sunflower and cotton (total cultivation). These results suggest that LDH-B-ALG can improve the B accumulation in topsoil, the fertilizer efficiency, and also B uptake by plants.

中文翻译：

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包含层状双氢氧化物和硼酸盐的藻酸盐珠粒：在砂质土壤中的潜在缓释硼肥

硼（B）在土壤中非常易溶和活动，因此，硼酸作为硼酸（H ₃ BO ₃）施用时，特别是在沙质土壤中，很容易浸出。高剂量的硼可能对植物有毒。含有层状双氢氧化物和硼酸盐（LDH-B-ALG）的藻酸盐珠粒可潜在地减少土壤中的B淋溶，并降低对植物的毒性。这项工作的目的是评估来自不同B来源（例如H ₃ BO ₃，Ulexite和含有H ₃ BO _3的藻酸盐珠）的沙质土壤中B的浸出（BA-ALG）和LDH-B-ALG，并研究了这些来源中B在连续种植植物中的生物利用度。通过B淋溶试验，在沙质土壤中对LDH-B-ALG进行了合成，表征和评估。对于浸出柱研究，将B源与土壤均质化，并在浸出之前进行孵育。向日葵和棉花在温室实验中培养了两个季节，没有浸出。另外，进行了具有浸出的温室实验，其中在B浸出之后依次种植向日葵和棉花。在浸出试验中，在整个孵育时间内，从LDH-B-ALG浸出的B的百分比明显低于其他B商业来源。在温室淋洗实验中，初次种植后土壤中B的残留浓度为1。B的^-3分别用于LDH-B-ALG，Ulexite，H ₃ BO ₃和BA-ALG处理。第一次种植后，LDH-B-ALG的土壤中残留的B明显高于其他B来源，导致棉花（第二次种植）和棉花的芽和总（茎和根）中的B吸收更高。用于向日葵和棉花的总和（总种植）。这些结果表明LDH-B-ALG可以改善表土中的B积累，肥料效率以及植物对B的吸收。