Rice husk and charred husk amendments increase porewater and plant Si but water management determines grain As and Cd concentration
Rice husk and charred husk amendments increase porewater and plant Si but water management determines grain As and Cd concentration
复制标题
DOI：
10.1007/s11104-022-05350-3
复制
发表时间：
2022-03
期刊：
影响因子：
4.9
通讯作者：
Franklin Linam;Matt A. Limmer;R. Tappero;A. Seyfferth
中科院分区：
文献类型：
--
作者：
Franklin Linam;Matt A. Limmer;R. Tappero;A. Seyfferth
水稻是世界范围内的主要农作物，也是硅超富集植物，硅含量达到其质量的5-10%;如果植物残留物管理不当，这可能导致脱硅和缺硅。水稻也是唯一受到砷（As）和镉（Cd）污染，这取决于土壤条件。我们的目标是量化稻壳（富含Si的碾磨副产品）修正案和不同的水管理策略对水稻吸收Si，As和Cd.MethodsWe的影响采用4壳修正案处理：控制（无壳），壳（未经处理的外壳），生物炭（壳热解在450 °C），和CharSil（壳燃烧在> 1000 °C）。每一个这些修正案进行了研究，根据nonflooded，交替湿润和干燥（AWD），并淹没在一个盆栽研究的水管理。孔隙水化学和成熟的植物元素组成measured.ResultsHusk和生物炭治疗，沿着与洪水，增加孔隙水和植物硅。营养组织As随孔隙水Si的增加而减少，但籽粒As和植株Cd主要受水分管理的控制。在所研究的土壤中，As和Cd在225-275 mV的氧化还原电位（Eh）范围内呈负相关，并同时最小化。根铁菌斑中的水合铁减少了As从孔隙水到籽粒的转运，但改良剂不能增加菌斑中水合铁的含量。在低硅和砷土壤上，4年的最低限度的预处理强烈地增加了水稻的硅含量，但可能不足以降低籽粒砷。
PurposeRice is a staple crop worldwide and a silicon (Si) hyperaccumulator with Si levels reaching 5–10% of its mass; this can result in desilication and Si-deficiency if plant residues are not managed correctly. Rice is also uniquely subject to arsenic (As) and cadmium (Cd) contamination depending on soil conditions. Our goal is to quantify the effects of rice husk (a Si-rich milling byproduct) amendments and different water management strategies on rice uptake of Si, As, and Cd.MethodsWe employed 4 husk amendment treatments: Control (no husk), Husk (untreated husk), Biochar (husk pyrolyzed at 450 °C), and CharSil (husk combusted at > 1000 °C). Each of these amendments was studied under nonflooded, alternate wetting and drying (AWD), and flooded water management in a pot study. Porewater chemistry and mature plant elemental composition were measured.ResultsHusk and Biochar treatments, along with flooding, increased porewater and plant Si. Vegetative tissue As decreased with increasing porewater Si, but grain As and plant Cd were primarily controlled by water management. Grain As and Cd were inversely correlated and are simultaneously minimized in a redox potential (Eh) range of 225–275 mV in the studied soil. Ferrihydrite in root iron plaque decreased As translocation from porewater to grain, but amendments were not able to increase plaque ferrihydrite content.ConclusionWe conclude moderate husk amendment rates (i.e., 4 years’ worth) with minimal pretreatment strongly increases rice Si content but may not be sufficient to decrease grain As in low Si and As soil.