Abstract:

In order to improve the utilization rate of recycled water for potted flowers in Hongta District and explore effective ways of integrated fertilization, 42 irrigation water samples and 85 backflow water samples were collected regularly from 3 potted flower planting enterprises. Seven nutrient indicators, such us pH value, EC value, and available nitrogen, were tested to analyze the correlation between backflow water EC value and nutrient content. The results showed that: (1) the EC value of irrigation water for potted flowers ranged from 82.10 to 2170.00 µs/cm, with an average of 544.40 µs/cm and a coefficient of variation of 119.42%. (2)The EC value of the backflow of potted flowers ranged from 85.00 to 2960.00 µs/cm, with an average of 1115.99 µs/cm and a 95% confidence zone of 980.65 to 1251.33 µs/cm. (3)Compared with irrigation water, the EC value of return water increased by 571.58 µs/cm, the available nitrogen increased by 362.43 mg/L, the available phosphorus increased by 102.81 mg/L, the available potassium increased by 50.93 mg/L, the available sulfur increased by 27.73 mg/L, and the exchangeable magnesium increased by 15.59 mg/L. This indicates that there is a large amount of residual available nitrogen, available phosphorus, available potassium, available sulfur, and exchangeable magnesium in the return water, and there is a great potential for utilization. (4)The EC value of the return water was positively correlated with the content of five nutrients, including available nitrogen, available phosphorus, available potassium, exchangeable magnesium, and available sulfur, all of which were above a significant level. Therefore, in the production of potted flowers in Hongta district, the content of available nitrogen, available phosphorus, available potassium, available sulfur, and exchangeable magnesium in the recycled water can be quickly determined by measuring the EC value when using the recycled water, and timely guidance can be provided for the fertilization of potted flowers.

Key words: potted flowers, backflow water, EC value, integrated water and fertilizer management, nutrient content, relativity