• ISSN 1008-505X
  • CN 11-3996/S
GU He-he, CUI Xin, LI Jing, ZHOU Yang-guo, LU Zhi-feng, ZHANG Yang-yang, CONG Ri-huan, LI Xiao-kun, REN Tao, LU Jian-wei. Effects of potassium application rate on the yield and quality of oilseed rape (Brassica napus L.)[J]. Journal of Plant Nutrition and Fertilizers, 2023, 29(6): 1091-1102. DOI: 10.11674/zwyf.2022553
Citation: GU He-he, CUI Xin, LI Jing, ZHOU Yang-guo, LU Zhi-feng, ZHANG Yang-yang, CONG Ri-huan, LI Xiao-kun, REN Tao, LU Jian-wei. Effects of potassium application rate on the yield and quality of oilseed rape (Brassica napus L.)[J]. Journal of Plant Nutrition and Fertilizers, 2023, 29(6): 1091-1102. DOI: 10.11674/zwyf.2022553

Effects of potassium application rate on the yield and quality of oilseed rape (Brassica napus L.)

  • Objectives The available potassium (K) content in most farmland soils in south China is low, and K deficiency is a major limiting factor for oilseed rape production in some areas. Here, we investigate the effect of different K fertilizer application rates on oilseed rape yield and seed quality to provide theoretical support for the rational application of K fertilizer in winter oilseed rape production for high yield and quality.
    Methods A field trial was conducted for two consecutive years from 2019—2021 in Wuxue City, Hubei Province, with five K2O application levels of 0 (K0), 60 (K60), 120 (K120), 180 (K180), and 240 K2O kg/hm2 (K240) . Since the 15 day at full flowering stage, silique samples were collected every six days in K0 and K120 plots for determination of N and K contents. At maturing stage, the yield, yield components, oil content, protein content, fatty acid composition, glucosinolate content, seed N and K contents were analyzed.
    Results 1) Compared with K0, K application (P<0.05) increased rapeseed yield by 62.9%−103.7% and 31.0%−9.2% in 2020 and 2021, respectively. The rapeseed yield did not stop increasing until K2O application rate beyond 120 kg/hm2. K application increased yield through enhancing the number of siliques per plant and the seed number per silique. 2) K application improved rapeseed nutritional and feeding quality. Compared with K0, K180 increased rapeseed oil content in 2019−2020 and K120 in 2020−2021 (P<0.05) by 4.8% and 6.9%, K180 and K240 in 2019−2020 and K240 in 2020−2021 decreased the protein content by 9.1%, 14.2%, and 12.1%, respectively. With the increase in K2O rate, the oleic acid in rapeseed showed an increasing trend, while the glucosinolate content decreased. K application (P<0.05) increased rapeseed oil and protein yield. There was no further increase in rapeseed oil yield at K2O 180 kg/hm2 and above. There was no significant difference (P>0.05) in protein yield among the K application treatments. K application (P<0.05) reduced seed N content, with 13.1%−21.9% and 15.9%−22.0% reduction in 2019−2020 and 2020−2021, respectively, compared to K0. Seed K content (P<0.05) increased with increasing of K2O rate, recording 8.1%−37.8% and 6.3%−27.1% in 2019−2020 and 2020−2021. During silique development, seed N content in K0 treatment was higher than in K120, while seed K content was lower than in K120. K fertilizer application also increased the photosynthetic capacity of silique, and the net photosynthetic rate (Pn) of silique in K120 was 35.5% higher than K0.
    Conclusions K fertilizer application increases rapeseed oil yield through enhancing the silique number per plant and the seed number per silique. K application reduces rapeseed N but significantly increasing K content and photosynthetic capacity of silique, thereby promoting oil and protein synthesis, improving the composition of fatty acids, and reducing glucosinolate content. K2O rate between 131−160 kg/hm2 improves rapeseed’s nutrition and feeding quality while recording higher oil and protein yields.
  • loading

Catalog

    Turn off MathJax
    Article Contents

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return