Three kinds of derivative carboxymethyl cellulose (DCMC) materials, CMC-Na, CMC-K, and CMC-NH₄, were prepared from cotton straw fiber. Their chemical structure, film morphology, water retention, biodegradability, and growth promotion were investigated with infrared spectroscopy (IR), scanning electron microscope (SEM), and field experiments. The results showed that the infrared absorption peaks of the three materials were similar. It was observed that the DCMC materials could form films after being sprayed at the amount of 4.00 g/m² and 12.00 g/m², and the film thickness was showed in the order of CMC-K, CMC-NH₄, and CMC-Na. The largest water holding capacity increased significantly after DCMC was sprayed on the soil. The water retention of CMC-Na, CMC-K, and CMC-NH₄ increased by 47.74%, 72.85%, and 61.40% severally while sprayed with 12.00 g/m² compared to the control group (CK), and the water retention rate increased with 6.93, 9.75, and 8.67 times, respectively, on the seventh day. The total number of soil microorganisms increased with the DCMC materials being sprayed; the number in the upper layer increased by 92.31%, 123.08%, and 138.46%, respectively, compared with CK. When the three materials were used to the cornfield at the amount of 100.00 kg/hm², the corn yield increased by 33.11%, 70.93%, and 50.60%, respectively. The DCMC materials, as the sole carbon source, could be degraded by soil microorganisms. The nutrient elements such as NH₄⁺ in the materials could further promote the growth of microorganisms and crops. This study might provide a new way to apply straw-based DCMC in soil water retention, soil amendment, and high value-added transformation of straws in arid areas.

中文翻译：

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棉秸秆羧甲基纤维素衍生材料的成膜性能、保水性和促生长

以棉秸秆纤维为原料制备了CMC-Na、CMC-K和CMC-NH ₄ 3种羧甲基纤维素(DCMC)衍生物材料。通过红外光谱 (IR)、扫描电子显微镜 (SEM) 和现场实验研究了它们的化学结构、薄膜形态、保水性、生物降解性和生长促进作用。结果表明，三种材料的红外吸收峰相似。观察到DCMC材料在喷涂量为4.00 g/m ²和12.00 g/m ^{2 后可}成膜，膜厚依次为CMC-K、CMC-NH ₄, 和 CMC-Na。土壤喷施DCMC后，最大持水量显着增加。CMC-Na、CMC-K、CMC-NH ₄喷施12.00 g/m ²的保水率分别比对照组（CK）提高47.74%、72.85%和61.40% ，保水率分别提高第七天分别上涨 6.93、9.75 和 8.67 倍。土壤微生物总数随着DCMC材料的喷洒而增加；与CK相比，上层数量分别增加了92.31%、123.08%和138.46%。当三种材料以100.00 kg/hm ²的用量施用于玉米田时，玉米单产分别增长33.11%、70.93%和50.60%。作为唯一碳源的DCMC材料可以被土壤微生物降解。材料中的NH ₄ ⁺等营养元素可进一步促进微生物和作物的生长。本研究为秸秆基DCMC在干旱地区土壤保水、土壤改良和秸秆高附加值转化等方面的应用提供了一条新途径。