ABSTRACT In greenhouse organic horticulture there is a great challenge in supplying the crop with adequate amounts of nutrients at the right stage of crop development. This has been identified as one of the main factors compromising yields in organic systems as compared with conventional hydroponic systems based on the use of synthetic fertilisers. In organic systems, the supply of nutrients is reliant on microbial degradation of organic complexes, a process that is dependent on factors such as temperature, soil water content and pH. Different organic fertilisers will also have different characteristics with respect to mineralisation of nutrients. In order to evaluate different strategies for organic fertilisation in long-term greenhouse crops such as high-wire tomato crops, an experiment with three different treatments was performed. The different strategies evaluated were one based on blood meal, kalimagnesia and the commercial product Baralith Enslow (composed of clay and ground lucerne), one with poultry manure and kalimagnesia, and one with solid biogas digestate and kalimagnesia. A five-month tomato crop was grown. Lysimeter samples were taken from the growing media biweekly for monitoring of plant available nutrients. The results suggested that nitrogen was likely to have been the limiting factor for plant growth, however, the biogas digestate delivered mineralised nitrogen throughout the experiment.

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有机肥番茄生产中养分有效性的动态变化

摘要 在温室有机园艺中，在作物发育的正确阶段为作物提供足够的养分是一个巨大的挑战。与基于使用合成肥料的传统水培系统相比，这已被确定为影响有机系统产量的主要因素之一。在有机系统中，养分的供应依赖于有机复合物的微生物降解，这一过程取决于温度、土壤含水量和 pH 值等因素。不同的有机肥料在养分矿化方面也将具有不同的特性。为了评估高线番茄作物等长期温室作物的不同有机施肥策略，进行了三种不同处理的试验。评估的不同策略是一种基于血粉、钾镁和商业产品 Baralith Enslow（由粘土和磨碎的苜蓿组成），一种使用家禽粪便和钾镁，另一种使用固体沼气消化物和钾镁。种植了五个月的番茄作物。每两周从生长培养基中取出蒸渗仪样品，以监测植物的有效养分。结果表明，氮可能是植物生长的限制因素，然而，沼气消化物在整个实验过程中都提供了矿化氮。种植了五个月的番茄作物。每两周从生长培养基中取出蒸渗仪样品，以监测植物的有效养分。结果表明，氮可能是植物生长的限制因素，然而，沼气消化物在整个实验过程中都提供了矿化氮。种植了五个月的番茄作物。每两周从生长培养基中取出蒸渗仪样品，以监测植物的有效养分。结果表明，氮可能是植物生长的限制因素，然而，沼气消化物在整个实验过程中都提供了矿化氮。