西瓜果实膨大期追施氮钾肥对土壤及果实品质的影响

摘要

以京欣1号西瓜(南瓜砧木嫁接苗)为试验材料,采用二因素四水平随机区组设计,以尿素(N≥46％)和硫酸钾(K2O ≥50％)为肥源,研究在果实膨大期追施不同配比氮钾肥对土壤理化性状、土壤微生物及西瓜果实品质的影响.结果表明,在本试验条件下增施氮肥,土壤速效养分和有机质含量均有所降低,土壤理化性状变差,土壤中的微生物数量降低,果实品质显著下降;西瓜果实膨大期需要大量的钾元素,当减氮增钾(追施硫酸钾≤450 kg/hm2)时,土壤中的速效养分和有机质含量提高,理化性状逐渐变好,土壤中的微生物数量和多样性得到明显改善,真菌与放线菌的比例有所降低,土壤向“细菌型”转变.果实品质也得到一定改善.%Selecting Jingxin No.1 watermelon (pumpkin seedlings for grafting) as material,using two factors and four levels random design method,the effects of topdressing different ratios of nitrogen and potassium fertilizer on physicochemical properties and microorganisms of soil,and fruit quality of watermelon were studied during fruit enlargement period with domestic urea (N≥46％) and domestic potassium sulfate (K2O ≥50％) as fertilizer source.The results showed that increasing nitrogen fertilizer,the available nutrients and organic matter content in the soil decreased,the physiochemical properties of soil became worse,the microbial population showed a significant reduction,and the fruit quality significantly declined.The fruit enlargement period of watermelon needs a lot of potassium fertilizer.When applying potassium fertilizer which less than 450 kg/hm2,the available nutrients and organic matter content in the soil increased,the physicochemical properties of soil got better,the quantity and diversity of microorganisms in soil became richer,the proportions of fungi and actinomycetes declined,and the soil transformed into bacterial form.Meanwhile,the fruit quality was improved to a certain extent.