National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment , Shandong Agricultural University , Tai'an , Shandong 271018 , China.
State Key Laboratory of Nutrition Resources Integrated Utilization , Shandong Kingenta Ecological Engineering Company, Ltd. , Linyi , Shandong 276700 , China.
J Agric Food Chem. 2018 Jun 13;66(23):5762-5769. doi: 10.1021/acs.jafc.8b00872. Epub 2018 May 31.
To reduce the preparation cost of superabsorbent and improve the N release rate at the same time, a novel low-cost superabsorbent (SA) with the function of N slow release was prepared by chemical synthesis with neutralized acrylic acid (AA), urea, potassium persulfate (KPS), and N, N'-methylenebis(acrylamide) (MBA). The order of influence factors on the water absorbency property was determined by an orthogonal L(3) experiment. On the basis of the optimization results of the orthogonal experiment, the effects of a single factor on the water absorption were investigated, and the highest water absorbency (909 g/g) was achieved for the conditions of 1.0 mol urea/mol AA ratio, 100% of AA neutralized, K, 1.5% KPS to AA mass fraction, 0.02% MBA to AA mass fraction, 45 °C reaction temperature, and 4.0 h reaction time. The optimal sample was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Swelling behaviors of the superabsorbent were investigated in distilled water and various soil and salt solutions. The water-release kinetics of SA in different negative pressures and soils were systematically investigated. Additionally, the maize seed germination in various types of soil with different amounts of SA was proposed, and the N could release 3.71% after being incubated in distilled water for 40 days. After 192 h, the relative water content of SA-treated sandy loam, loam, and paddy soil were 42, 56, and 45%, respectively. All of the results in this work showed that SA had good water retention and slow N-release properties, which are expected to have potential applications in sustainable modern agriculture.
为降低高吸水性树脂的制备成本并提高氮素释放率，采用中和度为 100%的丙烯酸（AA）、尿素、过硫酸钾（KPS）和 N，N'-亚甲基双丙烯酰胺（MBA）为原料，通过化学合成制备具有氮素缓释功能的低成本新型高吸水性树脂（SA）。通过正交 L(3)实验确定了影响吸水性能的因素顺序。在正交实验优化结果的基础上，考察了单因素对吸水性能的影响，得到的最佳条件为：尿素与 AA 的物质的量比为 1.0、AA 的中和度为 100%、KPS 与 AA 的质量分数比为 1.5%、MBA 与 AA 的质量分数比为 0.02%、反应温度为 45℃、反应时间为 4.0 h，此时的最高吸水率为 909 g/g。采用扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对最优样品进行了表征。研究了高吸水性树脂在去离子水和不同土壤及盐溶液中的溶胀行为。系统研究了 SA 在不同负压和土壤中的水分释放动力学。此外，提出了在不同施用量的 SA 存在下，玉米种子在不同类型土壤中的萌发情况，SA 在去离子水中培养 40 天后，氮素释放了 3.71%。192 h 后，SA 处理的砂壤土、壤土和稻田的相对含水量分别为 42%、56%和 45%。本工作中的所有结果表明，SA 具有良好的保水和缓释氮素性能，有望在可持续现代农业中具有潜在应用。
