南海诸岛利用淡化海砂作为无土栽培基质的可行性研究

Feasibility Study on Desalted Sea Sand Used as Soilless Culture Substrates in the South China Sea Islands

泥炭、岩棉作为无土栽培基质需要频繁更换,不适合运输成本较高的南海诸岛,海砂可就地取材,是南海诸岛首选无土栽培基质。我国尚没有利用海砂作为无土栽培基质的研究,为明确其可行性,以3∶1椰糠蛭石混合基质(CK)为对照,以淡化海砂(T)为处理,进行生菜栽培对比试验,分析形态指标、产量、营养品质和食品安全指标。结果显示:砂栽培生菜商品产量和总干重分别比对照高14.93%和49.73%;砂栽培生菜可溶性糖含量(2.47%)比对照(0.37%)高,硝态氮含量(1.77 mg/g)比对照(12.67 mg/g)低,差异极显著(P<0.01),砂栽培生菜蛋白质含量和Vc含量与对照差异不显著;砂栽培生菜Ca、Fe、Mg、Zn含量与对照差异不显著,砂栽培生菜与对照As、Cd含量都符合国家标准。研究表明淡化海砂栽培生菜产量正常,营养品质好,食品安全,在南海诸岛利用淡化海砂作为无土栽培基质进行蔬菜生产是可行的。

Peat and rock wool needed frequent replacement,so it were not suitable as substrates in soilless culture for the South China sea islands because of the higher transportation costs. Sea sand,as local materials,was easy to draw and could be used as better substrates in soilless culture. There was no studies on using desalted sea sand as culture substrates in China. In order to clarify its feasibility,this experiment took 3 ∶1 coconut chaff and vermiculite mixedsubstrates as the CK and treated desalted sea sand（ T） to cultivate lettuce,and analyzed the morphological index,yield,nutritional quality and food safety indexes of lettuce. The result showed that：（1） The yield of lettuce commercial products and total dry weight cultured in T were 14.93% and 49.73% higher than the CK,respectively.（2） The soluble sugar content of lettuce cultured in T was 2.47% higher than the CK（ 0.37%）,while the nitrate nitrogen content was 1.77 mg/g lower than the CK（ 12.67 mg/g）. The differences were extremely significant（ P〈0.01）. The differences in soluble protein and vitamin C contents of lettuce cultured in T were not significant with that of the CK.（3） There were no obvious differences in Ca,Fe,Mg,Zn contents between lettuce cultivated in T and the CK. The As and Cd contents of lettuce cultivated in T and the CK were all accord with the national standard.These results indicated that yield of lettuce cultivated in desalted sea sand was normal. Its nutritional quality was good and food safety was OK. It was feasible to use desalted sea sand as substrates in soilless cultivation.