Application Case

Soil Health Enviromental

Effects of foliar spraying of potassium Fulvate(Fulvicmax) on rice yield and quality

September 16, 2022

By setting different spraying concentrations, the effects of potassium fulvate on rice yield, quality and nutrient accumulation were explored. The results showed that spraying potassium fulvic acid once at the jointing stage and breaking stage of rice could significantly improve rice yield, quality and accumulation of nitrogen and potassium nutrients. Among them, with 200 mg/L as the optimum spraying concentration, the yield increased by 24.54%, the nitrogen accumulation increased by 28.46%, the potassium accumulation increased by 47.55%, and the whole milled rice rate increased by 8.37%.

Potassium fulvate has small molecular weight, high physiological activity, and has the function of plant growth regulator, and has become a research hotspot in recent years [1, 2]. Foliar fertilizer has the advantages of direct absorption, low cost, quick effect, high utilization rate and convenient operation [3], and has been widely used in practical production. Therefore, the application of potassium humate to foliar spraying has become a new direction for fertilizer research and development [4-6]. Relevant studies have shown that foliar spraying of potassium fulvate at a concentration of 133 mg/L can significantly increase the 1000-kernel weight and yield of summer maize [7]. Spraying 67 mg/L potassium fulvate once in the flag picking period and grain filling period of winter wheat can increase the yield by 21.6% to 39.9%[8]. Foliar spraying of 500 mg/L potassium fulvate can increase soybean yield by 25.3%[9]. The application of potassium fulvate in rice is mainly focused on seed dressing and basal application [10], and there are few reports on the effect of spraying potassium fulvate on rice quality. Therefore, this study investigated its effects on rice yield, nutrient accumulation and quality by spraying different concentrations of potassium fulvate, in order to provide a theoretical basis for rice foliar fertilization.

Effects of foliar spraying of potassium Fulvate(Fulvicmax) on rice yield and quality

1.1 Test time

June 22-November 12, 2019

1.2 Tested fertilizers

Potassium Fulvate FULVICMAX (mineral source, solid powder, fulvic acid≥50%, K2O≥12%), urea (46% N), compound fertilizer (26-10-12), compound fertilizer (28-0-10) , all supplied by Zhengzhou Shengda Khumic Biotechnology Co., Ltd.

1.3 Test crops

Rice, the variety is "Lianjing 16".

1.4 Test method

The experiment set up 5 treatments, sprayed with clear water control (CK), 50 mg/L potassium fulvate (T1), 100 mg/L potassium fulvic acid (T2), 200 mg/L potassium fulvate ( T3), 300 mg/L potassium fulvic acid (T4), and the spray rate of each treatment was 450 L/hm2.

Each treatment was sprayed with the corresponding concentration of potassium fulvic acid once at the jointing stage and the breaking stage of the rice, and each treatment was 220 m2, repeated three times. In each treatment, compound fertilizer (26-10-12) 600 kg/hm2 was applied as base fertilizer on June 22, urea 225 kg/hm2 was applied as tiller fertilizer on July 10, and compound fertilizer was applied on August 10. Fertilizer (28-0-10) 225 kg/hm2 was used as booting fertilizer, and other cultivation and management measures were the same.

1.5 Index determination and detection methods

Yield measurement: Before harvesting, 5 wells of rice with uniform growth were randomly selected for each treatment, including the determination of grain number per panicle, effective panicle number, seed setting rate, and 1000-grain weight; the yield was measured at the time of harvest. Determination of grain nutrient accumulation: the rice grains were fixed at 105 °C for 2 h, dried at 70 °C to constant weight, the dry samples were ground by a pulverizer, digested with H2SO4-H2O2, and the total nitrogen of the plant was determined by the semi-micro Kelvin method. Molybdenum-antimony resistance colorimetric method was used to determine total phosphorus in plants, and flame photometry was used to determine total potassium in plants [11]. Quality determination: The determination of rice quality indicators such as the rate of whole milled rice, chalkiness degree, chalky rice rate, and amylose refers to "High Quality Rice" (GB/T 17891-2017).

1.6 Data processing

Excel 2016 software was used for data processing and charting, SPSS 23.0 software was used for data statistics and analysis of variance, and Duncan's test was used for one-way analysis of variance and multiple comparisons.

2 Results and Analysis

2.1 Effects of spraying different concentrations of potassium fulvate on rice yield

According to Table 1, it can be seen that spraying 200 mg/L potassium fulvic acid significantly increased the number of grains per ear, and the difference among other treatments was not significant; the difference in effective panicle number among the treatments was not significant; The seed setting rate was improved, but there was no significant difference among the treatments of spraying potassium fulvic acid; Other treatments (except 200 mg/L potassium fulvic acid); spraying potassium fulvic acid can significantly increase the yield of rice, when the spraying concentration is 200 mg/L and 300 mg/L, the rice yield is significantly higher than other treatments.

2.2 Effects of spraying different concentrations of potassium fulvate on nutrient accumulation in rice grains

Spraying potassium fulvate had a greater effect on nitrogen and potassium accumulation in rice, but less on phosphorus accumulation (Fig. 1). After spraying, the nitrogen accumulation increased by 15.85% to 28.46% compared with the control, among which the T3 treatment was the highest at 80.72 kg/hm2, which had no significant difference with the T4 treatment, and both treatments were significantly higher than the other treatments ( P < 0.05). The potassium accumulation of each treatment also showed the same trend, the potassium accumulation of T3 treatment was the highest, which was 62.34 kg/hm2, which was significantly higher than that of other treatments (P < 0.05), and the potassium accumulation of control treatment was the lowest, which was significantly lower than other treatments. Each treatment (P < 0.05). There was no significant difference in phosphorus accumulation among the treatments (P < 0.05)

2.3 Effects of spraying different concentrations of potassium humate on rice quality

The whole rice rate is an important indicator of the quality of rice milling. The higher the whole rice rate, the higher the processing quality. The degree of chalkiness and the rate of chalky rice are indicators of appearance quality. The higher the value, the worse the appearance quality. The chalky rice will also reduce the processing quality of the rice. Amylose is the quality of cooking and eating. Rice varieties with low amylose content have softer taste, crystal and shiny rice grains, and relatively high eating quality. The amylose content of high-quality japonica rice is 13% to 20%. According to Table 2, it can be seen that spraying potassium fulvate can significantly improve the rate of milled rice, but there is no significant difference between treatments with different concentrations of potassium fulvate. The chalkiness was significantly reduced when potassium humate was sprayed at a concentration of 300 mg/L, but there was no significant difference among the other treatments. Spraying 200 and 300 mg/L potassium fulvate could significantly reduce the chalky rice rate, and the difference was not significant among other treatments. After spraying potassium humate, the amylose content decreased, but the difference was not significant when spraying the concentration below 100 mg/L and the control, and the amylose content was significantly lower when spraying the concentration of 200 mg/L and 300 mg/L Control treatment.

Conclusion: Foliar spraying of a certain concentration of potassium fulvate at the jointing and breaking stages can effectively increase the number of grains per ear, seed setting rate, 1000-grain weight and yield of rice. Spraying potassium fulvated also promoted the accumulation of nitrogen and potassium nutrients in rice grains, and also improved rice quality by increasing the rate of milled rice, reducing chalkiness, chalky rice rate, and amylose content. On the whole, T3 treatment had the highest gain for various indicators under the experimental conditions, that is, the best treatment was to spray 200 mg/L potassium fulvic acid once in the jointing stage and the breaking stage.


TAG:  potassium Fulvate  Fulvicmax fulvic acid on rice