Guangdong nongye kexue (Aug 2023)
Effects of Potassium Application Rate on the Yield, Quality and Potassium Utilization Efficiency of 'Chuanyan 200'
Abstract
【Objective】The aim was to explore the effects of potassium application rate on the growth and development, yield and quality of tobacco leaves and potassium utilization efficiency of new flue-cured tobacco variety 'chuanyan 200', so as to provide theoretical support for rational application of potassium fertilizer.【Method】Taking 'chuanyan 200' as the test object, a field experiment was carried out with six potassium application rates of 0, 240, 285, 315, 345 and 390 kg/hm2 (named K0, K240, K285, K315, K345 and K390, respectively). The characteristics of agronomic traits, yield, output value, internal chemical composition and potassium utilization efficiency of tobacco plants under different potassium application rates were analyzed.【Result】The application of potassium fertilizer could promote the growth and development of tobacco plants in the early stage (before the rosette stage), especially the growth of plant height, effective leaf number and pitch, but had little effect on the growth in the middle stage (from the rosette stage to the topping stage). Compared with K0 (CK), the yield, output value and average price of flue-cured tobacco increased by 19.02%-22.60%, 24.65%-47.28% and 3.26%-20.33% respectively after potassium application. K315 treatment showed the best performance in all indexes, and the proportion of superior tobacco in K315 treatment was the largest, which was 5.5 percentage points higher than that of K0 (CK). Compared with K0 (CK), potassium application could significantly increase the nicotine content in tobacco leaves by 37.29%-66.10%, and the application amount of potassium fertilizer in 315-345 kg/hm2 was more conducive to the coordination of chemical components in tobacco leaves. Compared with K0 (CK), the appropriate application of potassium fertilizer could increase the biomass of each organ and the whole plant of tobacco plant. The biomass accumulation of stem was the highest in K315 treatment, which was 1 585.77 kg/hm2. There was no significant difference in biomass accumulation of root, leaf and whole plant among different potassium treatments.The distribution characteristics of potassium in different organs of flue-cured tobacco were leaf>stem>root, and potassium was mainly distributed in leaves. The distribution ratio of potassium in leaves treated with K315 was as high as 50.89%. Compared with K0 (CK), potassium application significantly increased the accumulation of potassium in tobacco leaves by 54.27%-109.31%. The accumulation of potassium in stem, leaf and whole plant of K315 treatment was the largest, which was 25.73, 35.06 and 68.90 kg/hm2, respectively. The apparent use efficiency, recovery rate and economic utilization efficiency of potassium fertilizer increased first and then decreased with the increase of potassium application rate, and K315 treatment showed the best performance. The apparent use efficiency, recovery rate and economic utilization efficiency of potassium fertilizer were 14.06%, 13.15% and 7.01%, respectively. However, the agronomic efficiency, partial factor productivity and physiological efficiency of potassium fertilizer decreased with the increase of potassium application rate, and the surplus amount of soil potassium also increased significantly with the increase of potassium application rate.【Conclusion】Reasonable application of potassium fertilizer can increase the yield and output value of tobacco leaves, increase the proportion of high-quality tobacco leaves, coordinate the chemical composition of tobacco leaves, promote nutrient absorption, and improve the utilization efficiency of potassium fertilizer. Considering the quality, economic traits and potassium fertilizer utilization efficiency of tobacco leaves, the reasonable recommended amount of potassium fertilizer for 'chuanyan 200' in Guangyuan tobacco area is 315 kg/hm2.
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