Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BayCEER), University Bayreuth, Universitätsstraße 30, 95447, Bayreuth, Germany.
Leibniz Centre for Agricultural Landscape Research (ZALF), 15374, Müncheberg, Germany.
Sci Rep. 2020 Feb 12;10(1):2424. doi: 10.1038/s41598-020-59437-x.
More frequent and longer drought periods are predicted threatening agricultural yield. The capacity of soils to hold water is a highly important factor controlling drought stress intensity for plants. Biogenic amorphous silica (bASi) pools in soils are in the range of 0-6% and are suggested to help plants to resist drought. In agricultural soils, bASi pools declined to values of ~1% or lower) due to yearly crop harvest, decreasing water holding capacity of the soils. Here, we assessed the contribution of bASi to water holding capacity (WHC) of soil. Consequently, ASi was mixed at different rates (0, 1, 5 or 15%) with different soils. Afterwards, the retention curve of the soils was determined via Hyprop method. Here we show that bASi increases the soil water holding capacity substantially, by forming silica gels with a water content at saturation higher than 700%. An increase of bASi by 1% or 5% (weight) increased the water content at any water potential and plant available water increased by up to > 40% or > 60%, respectively. Our results suggest that soil management should be modified to increase bASi content, enhancing available water in soils and potentially decreasing drought stress for plants in terrestrial ecosystems.
预计更频繁和更长时间的干旱期将威胁农业产量。土壤保持水分的能力是控制植物干旱胁迫强度的一个非常重要的因素。土壤中的生物成因无定形硅（bASi）储量在 0-6%之间，被认为有助于植物抵抗干旱。在农业土壤中，由于每年的作物收获，bASi 储量下降到~1%或更低，从而降低了土壤的持水能力。在这里，我们评估了 bASi 对土壤持水能力（WHC）的贡献。因此，将 ASi 以不同的比例（0、1、5 或 15%）与不同的土壤混合。之后，通过 Hyprop 方法确定土壤的保留曲线。在这里，我们表明 bASi 通过形成水含量高于 700%的硅凝胶，显著增加了土壤的持水能力。bASi 增加 1%或 5%（重量）会增加任何水势下的水含量，植物可用水增加高达>40%或>60%。我们的结果表明，应该修改土壤管理以增加 bASi 含量，从而增加土壤中的可用水，并有可能减少陆地生态系统中植物的干旱胁迫。
