Changes of Basic Nutrient Elements, Si, Fe2+ Content in Film-Bottomed Rice Soil in Horqin Sandy Land

Abstract

为达到修复荒漠化土壤的目的，自2014年起，在科尔沁奈曼旗沙地应用双膜覆盖技术种植水稻。对该稻田中的土壤进行研究，对比未经修复的沙地和修复后稻田土壤中氮、磷、钾、有机质、有效硅和亚铁的含量及变化。结果表明，双膜覆盖水稻技术的应用，使土壤中氮、磷、钾、有机质含量明显增加，与2014年未修复沙地土壤相比，应用双膜覆盖技术稻田土壤在2018年和2019年总氮含量分别增加了84%、116%，总磷含量分别增加了87%、97%，总钾含量分别增加93%、104%，有机质含量分别增加了187%、203%。经过5年的双膜覆盖水稻种植，稻田土壤中有效硅含量较2014年增长了15%，达到60.4 mg/kg，但增长速率较慢，且远低于缺硅临界值100 mg/kg，属于缺硅土壤；同时，稻田土壤中亚铁含量较2014年增长了68%，达到69 mg/kg。土壤中亚铁含量会在9月份达到峰值，约为151.8 mg/kg，低于亚铁毒害临界值300 mg/kg。但双膜覆盖水稻种植过程中不透气，亚铁逐年积累，增长较快，需要定时监测。研究表明在荒漠化土壤使用双膜覆盖技术种植水稻可以使土壤中基本营养元素得到有效的增加，使荒漠化土壤逐步修复。对于土壤中缺乏有效硅和亚铁浓度增长较快的问题，可以通过施加发酵稻壳来解决。 In order to restore desertified soil, the double-film mulching technology was applied to rice cultivation. Paddy soils planted with this technology from 2014 were selected as research objects. It was found that with the increase in the number of years of application of this technology, the contents of nitrogen, phosphorus, potassium, and organic matter in paddy soils increased. Compared with unrepaired sandy soils in 2014, paddy soils with double-membrane mulch technology increased total nitrogen content by 84% and 116%, total phosphorus content by 87%, 97%, and total potassium in 2018 and 2019, respectively. The contents increased by 93% and 104%, and the organic matter contents increased by 187% and 203%, respectively. After five years of double-mode rice planting, the effective silicon content in the soil reached 60.4 mg/kg, an increase of 15% compared to 2014, but the growth rate was slower and far below the critical silicon deficiency threshold of 100 mg/kg, which is a silicon deficiency soil. Meanwhile, the ferrous content reached 69 mg/kg, an increase of 68% over 2014. The ferrous content in the soil will reach a peak in September, about 151.8 mg/kg, which is lower than the threshold of 300 mg/kg for ferrous poisoning. However, during the planting process of double-film covered rice, air tightness, ferrous accumulation accumulates year by year, and the growth is fast, which requires regular monitoring. The results show that the application of double-film mulching technology can repair desertified soil, gradually bring the nutrients in the soil to the level of normal soil, restore the desertified soil, and provide the necessary nutrients for the next generation of film-covered rice. For the lack of effective silicon and ferrous iron in the soil, the problem of rapid growth can be solved by applying fermented rice husks.