Abstract

At present, excessive fertilization in vegetable production not only leads to the decline of vegetable quality and yield, but also causes environmental pollution. In this study, a liquid urea-formaldehyde slow release fertilizer (LUFF) was synthesized by using formaldehyde, urea and diammonium hydrogen phosphate. The effects of LUFF on yield, quality, root growth, antioxidant enzyme activity and nutrient absorption of spinach were studied in a pot experiment. Five treatments with four replicates each were established as follows: (1) Control, no fertilizer; (2) CWSF1, conventional water-soluble fertilizer; (3) CWSF2, conventional water-soluble fertilizer reduced by 25%; (4) LUFF1, liquid urea-formaldehyde slow release fertilizer; (5) LUFF2, liquid urea-formaldehyde slow release fertilizer reduced by 25%. Normal N-P₂O₅-K₂O application rate of 2.83-2.73-3.94 g/pot and 25% reduction N-P₂O₅-K₂O of rate (2.12-2.05-2.96 g/pot) were set up. The fertilizer was applied five times-split for CWSF while the equivalent rates of LUFF used as twice-split fertigation. The results showed that the yield of LUFF treatments was significantly increased by 31.81%-77.31% compared with CWSF. Root indexes, such as root length, root projection area and root surface area, were significantly improved by LUFF treatments compared with CWSF. The vitamin C (Vc) concentration and superoxide dismutase (SOD) activity of spinach in LUFF were significantly increased by 7.34%-30.07% and 23.83%-42.52% compared with CWSF. It can be observed from the above results, the LUFF could increase the yield of spinach, improve the quality of spinach, while reducing the frequency of fertigation. Therefore, LUFF may have high application value in agriculture.

摘要

目前，蔬菜生产中过度施肥不仅导致蔬菜品质和产量下降，而且造成环境污染。在这项研究中，利用甲醛、尿素和磷酸氢二铵合成了一种液体尿素甲醛缓释肥料（LUFF）。通过盆栽试验研究了LUFF对菠菜产量、品质、根系生长、抗氧化酶活性和养分吸收的影响。设5个处理，每个处理4个重复：(1)对照，不施肥；(2) CWSF1，常规水溶肥；(3) CWSF2，常规水溶肥减量25%；(4)LUFF1，液体脲醛缓释肥；(5)LUFF2，液体脲醛缓释肥减少25%。普通NP ₂O ₅ -K ₂ O 施用率为 2.83-2.73-3.94 克/锅，减少 25% NP ₂ O ₅ -K ₂设定速率(2.12-2.05-2.96g/罐)。CWSF 施肥 5 次，而等量 LUFF 用作两次施肥。结果表明，与CWSF相比，LUFF处理的产量显着提高了31.81%-77.31%。与CWSF相比，LUFF处理显着提高了根系指标，如根长、根投影面积和根表面积。LUFF中菠菜维生素C(Vc)浓度和超氧化物歧化酶(SOD)活性较CWSF显着提高7.34%-30.07%和23.83%-42.52%。从以上结果可以看出，LUFF可以提高菠菜产量，提高菠菜品质，同时减少施肥次数。因此，LUFF在农业上可能具有较高的应用价值。