不同沼液灌溉量下橡胶幼苗生长及土壤肥力特征

为明确不同沼液灌溉量下橡胶幼苗的生长状况及土壤肥力特征,以便科学指导施肥,本研究以橡胶树实生苗为研究对象,采用土培试验方法,设置7个不同沼液用量处理,分别为0 mL（T0）、471 mL（T1）、942 mL（T2）、1413 mL（T3）、1884 mL（T4）、2355 mL（T5）、2826 mL（T6）,测定分析了不同沼液用量的橡胶幼苗长势及主要土壤肥力因子。结果表明：沼液灌溉有利于橡胶幼苗生长,不同处理间橡胶幼苗苗木质量指数大小顺序为：T4（1884 mL）>T3（1413 mL）、T5（2355 mL）>T2（942 mL）>T0（0 mL）、T1（471 mL）>T6（2826 mL）,沼液施用量为T4处理时苗木质量指数最佳,株高、地径指标偏优,预示植株定植成活率高;同时施用沼液有利于土壤养分含量的增加,并提高土壤脲酶、过氧化氢酶、酸性磷酸酶和多酚氧化酶活性;采用主成分分析法和隶属度函数法对试验组土壤质量综合指数进行计算,结果表明,试验组土壤质量综合指数表现为T3（0.933）>T5（0.906）>T4（0.855）>T2（0.826）>T6（0.794）>T1（0.742）。研究认为,施加沼液可明显改良土壤化学性质,但过度施加沼液会降低苗木质量指数,且沼液量为1413~1884 mL时为最适灌溉量。

Growth and Soil Fertility Characteristics of Rubber Seedlings in Different Biogas Slurry Irrigation

The growth of rubber seedlings and the main soil fertility factors were measured by the soil culture method with seven different biogas slurry treatments to clarify the growth status and soil fertility characteristics of rubber seedlings in different quantity of biogas slurry irrigation and to guide its fertilization scientifically. The total amount of biogas liquid irrigation was 0 mL (T0), 471 mL (T1), 942 mL (T2), 1413 mL (T3), 1884 mL (T4), 2355 mL (T5) and 2826 mL (T6) respectively. Biogas slurry irrigation was beneficial to the growth of rubber seedlings with the order of quality index (QI) of rubber seedlings in different treatments T4 (1884 mL)>T3 (1413 mL), T5 (2355 mL)>T2 (942 mL)>T0 (0 mL), T1 (471 mL)>T6 (2826 mL). The plant height and ground diameter of treatment T4 were better, and the survival rate of the seedlings was higher after planting. Biogas slurry irrigation was beneficial to the increase of soil nutrient content and the activities of urease, catalase, acid phosphatase and polyphenol oxidase. Using principal component analysis and membership function to calculate the comprehensive index of soil quality in the experimental group, the comprehensive index of soil quality in the experimental group was T3 (0.933)>T5 (0.906)>T4 (0.855)>T2 (0.826)>T6 (0.794)>T1 (0.742). The results showed that the chemical properties of soil could be improved by biogas slurry irrigation, but the quality index of seedlings might be decreased by over irrigation, and the optimal irrigation amount was when the biogas slurry was 1413-1884 mL.