福建滩涂缢蛏养殖区域施肥现状调查

Investigation on fertilization status of Sinonovacula constricta cultivation in tidal flats of Fujian Province

为了解福建滩涂缢蛏养殖区域的施肥现状,实现无公害、健康、高效的缢蛏规模化养殖,采用问卷调查、实地调查方式,对福建省三沙湾、湄洲湾、厦门湾3个典型缢蛏养殖区域的缢蛏养殖施肥情况(主要包括肥料品种、施肥方式、肥料用量等)进行了调查分析。调查结果显示:(1)三沙湾、湄洲湾、厦门湾3个区域内缢蛏养殖投入肥料种类繁多,且大多是在养殖区域四周的河沟内投放肥料进行肥水培藻,投入的常规单质肥料明显高于复合肥、有机肥和水溶性肥料等;(2)三沙湾、湄洲湾、厦门湾3个区域内缢蛏养殖过量施用氮、磷的现象较为严重,其中施氮量大于2000 kg/hm^(2)的养殖户达76.47%,施磷量大于400 kg/hm^(2)的养殖户达70.58%,氮、磷、钾素投入量自北向南整体呈逐渐减少的趋势;(3)从施肥结构上分析,三沙湾、湄洲湾、厦门湾3个区域施用氮、磷的比例平均为4.7∶1,其中以三沙湾区域最低(4.25∶1),厦门湾区域最高(5.1∶1),氮、磷比例失衡;(4)三沙湾、湄洲湾、厦门湾各区域的缢蛏养殖经济效益相差较大,净收益为-6.2万~20.5万元/hm^(2)。调查结果表明,在调查区域内,目前还没有统一的缢蛏养殖化肥施用标准,养殖户仅凭经验难以充分掌握正确的施肥方式、用量等,从而容易造成环境污染、经济效益薄弱等问题。建议研发氮、磷含量高的新型水溶性功能肥料,鼓励养殖户采取更加科学的肥水方式,提高施肥技术,避免不合理、无规则的肥料施用。

To realize pollution-free,healthy,and efficient large-scale breeding of Sinonovacula constricta,the fertilization situation(mainly including fertilizer variety,fertilization method,fertilizer dosage,etc.)of S.constricta cultivation was investigated and analyzed in three typical culture areas(Sansha Bay,Meizhou Bay and Xiamen Bay)in Fujian Province,with the method of questionnaire survey and field investigation.The results showed that:(1)A wide variety of fertilizers were applied in S.constricta cultivation in three survey areas,which mainly relied on river ditches around the farming areas to fertilize water and cultivate algae.The amount of conventional elemental fertilizer used was significantly higher than that of compound fertilizer,organic fertilizer,or water-soluble fertilizer.(2)Over-application of nitrogen and phosphorus fertilizers was prevalent in survey areas,among which,76.47%of farmers applied more than 2000 kg/hm^(2) of nitrogen fertilizers,and 70.58%of farmers applied more than 400 kg/hm^(2) of phosphorus fertilizers.The inputs of nitrogen,phosphorus,and potassium gradually decreased from north to south.(3)From the analysis of fertilization structure,the average ratio of nitrogen and phosphorus fertilizers in survey areas was 4.7∶1,with the lowest ratio in Sansha Bay area(4.25∶1),and the highest in Xiamen Bay area(5.1∶1),indicating an imbalance between nitrogen and phosphorus fertilizers.(4)The economic benefits of S.constricta farming in survey areas varied significantly,with net incomes ranging from-62000 to 205000 CNY/hm^(2).The results of the survey showed that there was no unified standard for the application of chemical fertilizer for S.constricta cultivation in the survey area,and it was difficult to fully grasp the correct fertilization method and dosage based on farmers’own experience,potentially leading to environmental pollution and reduced economic returns.It is recommended to develop new water-soluble functional fertilizers with high nitrogen and phosphorus content,encourage farmers to adopt more scientific manuring irrigation methods,and improve fertilization techniques to avoid unregulated and improper fertilizer application.