Santos César, Malta Marcelo Ribeiro, Gonçalves Mariana Gabriele Marcolino, Borém Flávio Meira, Pozza Adélia Aziz Alexandre, Martinez Herminia Emilia Prieto, de Souza Taylor Lima, Chagas Wantuir Filipe Teixeira, de Melo Maria Elisa Araújo, Oliveira Damiany Pádua, Lima Alan Dhan Costa, de Abreu Lívia Botelho, Reis Thiago Henrique Pereira, de Souza Thaís Regina, Builes Victor Ramirez, Guelfi Douglas
Department of Soil Science, Federal University of Lavras, Lavras 37203-202, Brazil.
Agricultural Research Company of Minas Gerais (EPAMIG), Belo Horizonte 31170-495, Brazil.
Plants (Basel). 2023 Feb 15;12(4):885. doi: 10.3390/plants12040885.
The present study had the objective to evaluate the effect of blends of KCl and KSO fertilizers and their influence on the yield and the nutritional state of coffee plants, as well as on the chemical composition and quality of the coffee beverage. The experimental design was in randomized blocks with four repetitions and six treatments (T1: 100% KCl; T2: 75% KCl + 25% KSO; T3: 50% KCl + 50% KSO; T4: 25% KCl + 75% KSO; T5: 100% KSO; and a control, without application of K). The following analyses were performed: K and Cl content in the leaves and the soil, stocks of Cl in soil, yield, removal of K and Cl with the beans, cup quality of the beverage, polyphenol oxidase activity (PPO), electric conductivity (EC), potassium leaching (KL), the content of phenolic compounds, the content of total sugars (TS), and total titratable acidity (TTA). The stocks of Cl in the soil decreased as the proportion of KCl in the fertilizer was reduced. The fertilization with KCl reduces the cup quality and the activity of the polyphenol oxidase, probably due to the ion Cl. The increase in the application of Cl directly relates to the increase in potassium leaching, electric conductivity, and titratable acidity. Indirectly, these variables indicate damages to the cells by the use of Cl in the fertilizer. The activity of the polyphenol oxidase enzyme and the cup quality indicate that the ion Cl- reduces the quality of the coffee beverage. K content in the leaves was not influenced by the application of blends of K fertilizer while Cl content increased linearly with KCl applied. The application of KCl and KSO blends influenced coffee yield and the optimum proportion was 25% of KCl and 75% of KSO. The highest score in the cup quality test was observed with 100% KSO.
本研究旨在评估氯化钾（KCl）和硫酸钾（KSO）肥料混合物的效果及其对咖啡植株产量、营养状况以及咖啡饮品化学成分和品质的影响。实验设计采用随机区组，重复四次，设有六个处理（T1：100% KCl；T2：75% KCl + 25% KSO；T3：50% KCl + 50% KSO；T4：25% KCl + 75% KSO；T5：100% KSO；以及一个对照，不施钾）。进行了以下分析：叶片和土壤中的钾（K）和氯（Cl）含量、土壤中的氯存量、产量、咖啡豆带走的钾和氯、饮品的杯测品质、多酚氧化酶活性（PPO）、电导率（EC）、钾淋失（KL）、酚类化合物含量、总糖含量（TS）以及总可滴定酸度（TTA）。随着肥料中KCl比例的降低，土壤中的氯存量减少。施用KCl会降低杯测品质和多酚氧化酶活性，这可能是由于氯离子的缘故。氯施用量的增加直接导致钾淋失、电导率和可滴定酸度的增加。间接而言，这些变量表明肥料中使用氯对细胞造成了损害。多酚氧化酶活性和杯测品质表明氯离子会降低咖啡饮品的品质。叶片中的钾含量不受钾肥混合物施用的影响，而氯含量随KCl施用量呈线性增加。KCl和KSO混合物的施用影响咖啡产量，最佳比例为25% KCl和75% KSO。100% KSO的杯测品质测试得分最高。
