Efficacy of vegetable waste biogas slurry on yield, quality and nitrogen use efficiency of cauliflower

Abstract

Biogas slurry can be used as a nitrogen (N) fertilizer, and has been suggested to reduce chemical fertilizer input and improve vegetable quality. The present study aimed to evaluate the effects of vegetable waste biogas slurry topdressing on the yield, quality and nitrogen (N) use efficiency of cauliflower. A field experiment consisting of five treatments during topdressing (CK: no N input, CON: farmer’s conventional N fertilizer input, HBS: substitution of half the amount of N fertilizer with vegetable waste biogas slurry, BS: substitution of the total amount of N fertilizer with vegetable waste biogas slurry, and DBS: substitution of double the amount of N fertilizer with vegetable waste biogas slurry) was conducted. When compared with that of the CON treatment, the HBS, BS, and DBS treatments increased the yield of cauliflower by 4.7%, 13.7%, and 15.3%, respectively. Furthermore, the BS and DBS treatments improved cauliflower quality compared with that of the CON treatment. The HBS and BS treatments increased the N use efficiency and the DBS treatment reduced the N use efficiency compared with that of the CON treatment. Considering the increased fruit quality and N use efficiency, the substitution of fertilizer N with equal amount of vegetable waste biogas slurry during topdressing in the production of cauliflower is recommended in northern China.

Effects of fermented biogas slurry returning of tail vegetables on soil enzyme activity and fertility

“…Chai et al [33] showed that the substitution of chemical fertilizer with biogas slurry by 50% could signi cantly increase the content of soil organic matter and available potassium, but have no signi cant effect on total nitrogen, alkali hydrolyzable nitrogen and available phosphorus, and the substitution of chemical fertilizer with biogas slurry by 100% increased sucrase activity and urease activity, but decreased phosphatase. ZHao et al [13] showed that the application fermented biogas slurry of taille vegetables could signi cantly maintain the production yield of cauli ower and improve the quality of cauli ower, but the excessive application could greatly reduce the utilization rate of nitrogen.…”

“…Tail vegetables are waste products generated during the production and processing of vegetables, and are usually accumulated as household waste. Vegetable wastes have high moisture content and if they are piled indiscriminately, they can easily rot, breed mosquitoes and ies, spread germs [11,12] and even lead to clogging of water channels [13]. In addition, the liquid leaking from the accumulation of vegetable wastes can ow into the river, causing water pollution problems.…”

“…The results showed that the contents of total nitrogen, total phosphorus, and total potassium and C/N were 1.96%~5.39%, 0.35%~1.82%, 0.80%~5.42%, and 6.70~20. 35, respectively in tail vegetables, which had high fertilizer utilization value [14],and unreasonable disposal would not only pollute the environment, but also cause waste of resources [13].The remaining liquid (biogas slurry) generated from the anaerobic fermentation of tail vegetables can be returned to the eld as fertilizer [15,16], which not only enables the recycling of tail vegetable resources, but also reduces environmental risks and planting costs. This approach is in line with China's development requirements to promote green and circular agriculture.…”