Determination of diagnostic standards on saturated soil extracts for cut roses grown in greenhouses

This work comprises the theoretical determination and validation of diagnostic standards for the analysis of saturated soil extracts for cut rose flower crops (Rosa spp.) growing in the Bogota Plateau, Colombia. The data included 684 plant tissue analyses and 684 corresponding analyses of saturated soil extracts, all collected between January 2009 and June 2013. The tissue and soil samples were selected from 13 rose farms, and from cultivars grafted on the 'Natal Briar' rootstock. These concurrent samples of soil and plant tissues represented 251 production units (locations) of approximately 10,000 m2 distributed across the study area. The standards were conceived as a tool to improve the nutritional balance in the leaf tissue of rose plants and thereby define the norms for expressing optimum productive potential relative to nutritional conditions in the soil. To this end, previously determined diagnostic standard for rose leaf tissues were employed to obtain rates of foliar nutritional balance at each analyzed location and as criteria for determining the diagnostic norms for saturated soil extracts. Implementing this methodology to foliar analysis, showed a higher significant correlation for diagnostic indices. A similar behavior was observed in saturated soil extracts analysis, becoming a powerful tool for integrated nutritional diagnosis. Leaf analyses determine the most limiting nutrients for high yield and analyses of saturated soil extracts facilitate the possibility of correcting the fertigation formulations applied to soils or substrates. Recommendations are proposed to improve the balance in soil-plant system with which the possibility of yield increase becomes more probable. The main recommendations to increase and improve rose crop flower yields would be: continuously check pH values of SSE, reduce the amounts of P, Fe, Zn and Cu in fertigation solutions and carefully analyze the situation of Mn in the soil-plant system.本研究完成了针对哥伦比亚波哥大高原种植的切花玫瑰作物（Rosa spp.）饱和土壤浸提液（saturated soil extracts）分析用诊断标准的理论确定与验证工作。本数据集包含684份植物组织分析样本与对应684份饱和土壤浸提液分析样本，所有样本采集于2009年1月至2013年6月期间。上述组织与土壤样本取自13家玫瑰种植农场，均为嫁接于‘纳塔尔荆棘’（Natal Briar）砧木的栽培品种。这些成对的土壤与植物组织样本覆盖研究区域内251个面积约10000平方米的生产单元（地块）。该诊断标准旨在作为优化玫瑰植株叶片组织营养平衡的工具，进而明确基于土壤营养条件的最优生产潜力表达规范。为此，本研究采用已确立的玫瑰叶片组织诊断标准，计算各分析地块的叶片营养平衡率，并以此作为确定饱和土壤浸提液诊断标准的依据。将该方法应用于叶片分析后，诊断指数呈现出更高的显著相关性；饱和土壤浸提液分析也呈现出类似的良好表现，使其成为集成营养诊断的有力工具。叶片分析可明确高产的首要限制养分，而饱和土壤浸提液分析则有助于修正施加于土壤或栽培基质的水肥一体化施肥配方。本研究提出了优化土壤-植物系统营养平衡的建议，以提升作物产量的实现概率。提升并改善玫瑰切花产量的核心建议包括：持续监测饱和土壤浸提液（SSE）的pH值，降低水肥溶液中磷（P）、铁（Fe）、锌（Zn）与铜（Cu）的施用量，并审慎分析土壤-植物系统中锰（Mn）的赋存状况。