含氮磷聚合物复合材料植物培养基的制备

Preparation of Plant Medium Containing Nitrogen and Phosphorus Polymer Composites

【目的】研制具有可控孔洞的肥料、基体一体化的双交联网络水凝胶无土栽培基质。【方法】以聚乙烯醇(PVA)、海藻酸钠(SA)溶液为原料,利用造孔剂碳酸钙(CaCO_(3))与造孔助剂柠檬酸(C_(6)H_(8)O_(7))化学造孔,采用化学造孔辅助低温造孔法,制备Ca^(2+)-PVA/SA可控孔洞双交联网络水凝胶培养基,通过加入羟甲基脲(MU)、磷酸二氢钙[Ca(H_(2)PO_(4))_(2)]为植物生长提供营养,制备Ca^(2+)-PVA/SA-MU具有可控孔洞的肥料、基体一体化的双交联网络水凝胶无土栽培基质。采用FTIR、TG对制备基质的结构进行表征,通过SEM观察基质的表面形貌,研究原料配比、SA与Ca^(2+)配比对基质力学性能与孔洞密度及大小的影响。通过油菜培养试验,研究不同配比基质对幼苗鲜质量、干质量及出苗率的影响。【结果】结构表征表明,Ca^(2+)-PVA/SA-MU水凝胶具有大孔与微孔交叉结构;FTIR、TG测试表明,MU组分确实复合到Ca^(2+)-SA/PVA双交联网络水凝胶中,且MU与PVA有氢键作用;力学性能表明,PVA∶SA=20∶1的植物培养基质压缩性能最好,加入MU略微影响水凝胶的力学性能;培养实验表明,当SA∶CaCO_(3)=40∶1的Ca^(2+)-SA/PVA-MU双交联网络水凝胶的发芽率在第3天最高,5 d后达到100%。加入MU的Ca^(2+)-SA/PVA-MU双交联网络水凝胶的发芽增长率整体优于常规SA/PVA水凝胶培养基质。【结论】PVA和SA是一种安全、绿色的材料,适合作为植物生长的无土培养基质。

【Objective】A soilless culture substrate with double cross-linking network hydrogel containing fertilizer with controllable pores and substrate integration was developed.【Method】With polyvinyl alcohol(PVA)and sodium alginate(SA)solution as raw materials,the Ca^(2+)-PVA/SA double cross-linking network hydrogel medium with controllable pores was prepared by chemical pore-making method with pore-making agent calcium carbonate(CaCO_(3))and pore-making agent citric acid(C_(6)H_(8)O_(7)).By adding hydroxymethylurea(MU),calcium dihydrogen phosphate[Ca(H_(2)PO_(4))_(2)]provided nutrients for plant growth,and a soilless culture substrate of Ca^(2+)-PVA/SA-MU with controllable holes was prepared.The structure of the prepared substrate was characterized by FTIR and TG,and the surface morphology of the substrate was observed by SEM.The effects of ratio of raw materials as well as ratio of SA and Ca^(2+)on the mechanical properties of the substrate and the density and size of the pores were studied.The effects of different ratios of substrate on fresh weight,dry weight and seedling emergence rate of rapeseed were studied by culture experiment.【Result】The structure characterization result showed that Ca^(2+)-PVA/SA-MU hydrogel had macropore and micropore cross structure.FTIR and TG tests showed that MU was indeed compounded into Ca^(2+)-SA/PVA double cross-linked hydrogel,and MU had hydrogen bonding with PVA.The mechanical properties showed that PVA∶SA=20∶1 substrate had the best compression performance,and the addition of MU slightly affected the mechanical properties of hydrogel.Culture experiments showed that the germination rate of Ca^(2+)-SA/PVA-MU double crosslinking network hydrogel reached the highest at the 3rd day when SA∶CaCO_(3)=40∶1,and reached 100%after 5 days.The germination rate of Ca^(2+)-SA/PVA-MU double crosslinking network hydrogel added with MU was better than that of conventional SA/PVA hydrogel.【Conclusion】PVA and SA are safe and green materials,which are suitable to be selected as soilless culture substrates for plant growth.