牛粪好氧和蚯蚓堆肥腐熟料成型基质块制备及育苗试验

为优化蔬菜育苗成型基质的配方,提高成型基质蔬菜育苗效果,分别以牛粪好氧堆肥腐熟料和牛粪蚯蚓堆肥腐熟料为主料,草炭为辅料,吸水树脂为膨胀剂,木醋液为调节剂,黄瓜为指示植物,研究不同配方对成型基质块成型及育苗效果的影响,并对各目标指标进行综合评价,以确定较佳的成型育苗基质配方。试验结果表明:牛粪好氧堆肥腐熟料制成的成型基质块在膨胀性能、抗跌碎性及育苗期间破损情况优于牛粪蚯蚓堆肥腐熟料制成的成型基质块,但其p H值、EC值较高,使其存活率和茎粗株高等育苗特性与牛粪蚯蚓堆肥腐熟料相比较差。2种腐熟料基质配方可采取不同的调节方法改善其特性,蚯蚓堆肥腐熟料中添加适量秸秆类纤维状物质可以减小其成型基质块的跌碎率和破损率,牛粪好氧堆肥腐熟料中添加硫磺粉可以调节p H值。从基质块质量综合指数来看,既适合成型又有利于育苗效果的配方为:腐熟料和辅料的体积比为3:2~4:3;成型基质块中膨胀剂的含量以该试验中最小添加量27 m L左右最为合适,与总物料(腐熟料和辅料混合后的物料)的比值为5.5 m L/L;木醋液在2种腐熟料中的添加量不同,在牛粪好氧腐熟料中,木醋液添加量约为8.5 m L/L,而牛粪蚯蚓腐熟料中则为18 m L/L,此时两种腐熟料成型基质块的跌碎率均小于5%,破损率均小于20%和小于40%,幼苗存活率分别大于40%和大于70%,全株干质量全部大于100 mg。该研究结果可为蔬菜有机栽培成型基质的开发及其品质改善提供理论依据,具有重要意义。

Experiment on seedling of compressed substrates with cow dung aerobic composting and earthworm cow dung composting

Abstract: Compared with the traditional substrate for nursery, compressed substrates could provide a good environment for seedlings to grow. The seedling planted in compressed substrates could be transplanted well into the field as a whole, which could protect the root system of seedling and shorten recovering period, and would promote the development of agricultural mechanization in China. In addition, it could reduce the usage of plastic seedling trays and then reduce plastic pollution. This study was aimed to evaluate the feasibility of using the compost material mainly composed of cow dung and rice straw or the earthworm and cow dung compost as compressed substrates for the production of vegetable seedlings, and optimized the formula of compressed substrates for nursery. The aerobic compost and earthworm compost from cow dung were respectively mixed with peat, water absorption resin and wood vinegar as compressed substrates for the cucumber seedling production. The Four-factor three-level orthogonal experiment was carried out: the levels of the aerobic compost and earthworm compost were respectively 3, 4 and 5 L; the levels of peat were 1, 2 and 3 L; the levels of water absorption resin were 27, 54 and 81 mL; the levels of wood vinegar were 30, 60 and 90 mL; the cucumber was the indicator plant. The expansion properties, broken rate and damage rate of compressed substrates, and the survival rate, stem diameter and plant height of the seedlings were determined for comprehensive evaluation. It showed that the expansion properties, broken rate and damage rate in the seedling period for the compressed substrates obtained from cow dung aerobic compost were better than that for the compressed substrates composed of cow dung earthworm compost, and the expansion coefficient would be increasing with the levels of the aerobic compost increasing, but the opposite trend occurred in the broken rate and damage rate. However, the pH value and EC (electrical conductivity) value of the compressed substrates obtained from cow dung aerobic compost were higher, so the survival rate, stem diameter and plant height of the seedlings in the cow dung aerobic compost compressed substrates were worse, and the survival rate, stem diameter and plant height of the seedlings were increased when the usage of earthworm compost increased. The highest comprehensive evaluation index in the formulas of aerobic compost occurred under the T6 treatment (4 L aerobic compost, 3 L peat, 27 mL water absorption resin, and 60 mL wood vinegar), which was 84.89, and that in the formulas of earthworm compost occurred under the TS8 treatment (3 L earthworm compost, 2 L peat, 27 mL water absorption resin, and 90 mL wood vinegar), which was 86.09. In accordance with the comprehensive evaluation index of compressed substrates, a set of suitable formulas were determined: the 2 kinds of main raw materials were mixed with peat at a rough ratio of 57.14%-60.0% by volume; there were 27 mL expansive agent added in the 5-6 L total material, and 60 mL wood vinegar liquid in the 7 L total material in formulas of aerobic composts, but the latter ratio in the earthworm compost was 18 mL:1 L. With these ratios, the broken rates were both under 5%, the damage rate of cow dung compost formula was under 20% and that of earthworm compost was under 40%, the survival rates of those were beyond 40% and 70%, respectively, and the plant dry weights were both beyond 100 mg.