DataSheet_1_Sustainable Cannabis Nutrition: Elevated root-zone phosphorus significantly increases leachate P and does not improve yield or quality.pdf

Phosphorus (P) is an essential but often over-applied nutrient in agricultural systems. Because of its detrimental environmental effects, P fertilization is well studied in crop production. Controlled environment agriculture allows for precise control of root-zone P and has the potential to improve sustainability over field agriculture. Medical Cannabis is uniquely cultivated for the unfertilized female inflorescence and mineral nutrition can affect the yield and chemical composition of these flowers. P typically accumulates in seeds, but its partitioning in unfertilized Cannabis flowers is not well studied. Here we report the effect of increasing P (25, 50, and 75 mg P per L) in continuous liquid fertilizer on flower yield, cannabinoid concentration, leachate P, nutrient partitioning, and phosphorus use efficiency (PUE) of a high-CBD Cannabis variety. There was no significant effect of P concentration on flower yield or cannabinoid concentration, but there were significant differences in leachate P, nutrient partitioning, and PUE. Leachate P increased 12-fold in response to the 3-fold increase in P input. The P concentration in the unfertilized flowers increased to more than 1%, but this did not increase yield or quality. The fraction of P in the flowers increased from 25 to 65% and PUE increased from 31 to 80% as the as the P input decreased from 75 to 25 mg per L. Avoiding excessive P fertilization can decrease the environmental impact of Cannabis cultivation.

磷（P）是农业系统中一种不可或缺但常被过度施用的营养元素。鉴于其对环境产生的负面影响，磷肥在作物生产中的应用已得到了广泛研究。可控环境农业允许精确控制根区磷含量，并有望提升相较于传统田间农业的可持续性。医用大麻的独特种植是为了未经施肥的雌性花蕾，而矿质营养素的影响可及这些花朵的产量和化学成分。磷通常积累在种子中，但其在未经施肥的大麻花蕾中的分配情况尚未得到充分研究。本研究报告了在连续液体肥料中增加磷含量（每升含25、50和75毫克的磷）对高CBD大麻品种花朵产量、大麻素浓度、淋溶磷、营养分配以及磷利用效率（PUE）的影响。磷浓度的增加并未对花朵产量或大麻素浓度产生显著影响，但在淋溶磷、营养分配和PUE方面存在显著差异。淋溶磷含量在磷输入量增加三倍的情况下，增加了十二倍。未经施肥的花蕾中的磷含量增加到超过1%，但这并未增加产量或品质。随着磷输入量从每升75毫克降至25毫克，花蕾中的磷比例从25%增加到65%，而PUE从31%增加到80%。避免过度施用磷肥可以降低大麻种植对环境的影响。