保水剂-尿素凝胶对核桃苗根际土壤微生态环境影响

为探讨保水剂与尿素的之间的最佳结合利用方式，以核桃苗为试材，通过盆栽试验研究了不施肥和保水剂(CK)、单施尿素(U)、单施保水剂(S)、保水剂-尿素混施(SUM)与保水剂-尿素凝胶(SUG)5 个处理对核桃苗的生长及其根际土壤微生态环境的影响。结果显示：较U处理而言，SUG处理的核桃苗根系分泌物中有机酸总量、氨基酸总量与总糖含量显著增加；根际土壤蔗糖酶、多酚氧化酶、脲酶与过氧化氢酶活性得到了明显的提高；同时，SUG处理亦显著提高了根际土壤微生物数量与微生物量碳、氮含量。此外，SUG处理还明显促进了核桃苗地径与株高的生长，并显著高于其他处理。与SUG处理相比，S和SUM处理对核桃苗根际土壤微生态环境的影响效果较小。综上，保水剂-尿素凝胶方式能改善核桃苗根际土壤微生态环境，增强抵御干旱胁迫能力，对其生长达到一定的促进作用。

Gel Made by Super Absorbent Polymers and Urea: Effect on Micro-ecological Environment in the Rhizosphere Soil of Juglans regia

The paper aims to explore the best combination of SAP (Super Absorbent Polymers) and urea. We studied the effects of 5 treatments including CK (neither fertilizer nor SAP was applied), U (urea was applied alone), S (SAP was applied alone), SUM (SAP was mixed with urea) and SUG (gel was made of SAP and urea) on the growth of Juglans regia and the micro- ecological environment in the rhizosphere soil by a pot experiment. The results indicated that: compared with U treatment, the SUG treatment obviously increased total organic acids, total amino acids and total sugar in the root exudates; the activity of sucrose enzyme, polyphenol oxidase, urease enzyme and catalase enzyme in the rhizosphere soil was improved obviously; at the same time, the microbial populations, microbial biomass carbon and microbial biomass nitrogen were significantly higher in the SUG treatment than that in the other treatments; additionally, the SUG treatment obviously promoted the growth of ground diameter and plant height ofJuglans regia , and the ground diameter and plant height of SUG were higher than that in other treatments. However, S and SUM treatments had less effect on the micro-ecological environment in the rhizosphere soil than that in SUG treatment. In conclusion, the gel is beneficial to improve the micro-ecological environment in the rhizosphere soil, enhance the ability of drought resistance and promote the growth ofJuglans regia .