亚磷酸盐作缓释磷肥对黄瓜体内养分吸收和光合特性的影响

本文以黄瓜为材料，采用营养液培养方法，研究了不同亚磷酸盐浓度对黄瓜植株各部位氮、 磷养分含量， 干重及根冠比， 植株氮、 磷总量以及叶片光合特性的影响。结果表明，黄瓜果实、 叶片和根部氮含量随亚磷酸盐浓度的增加而增加，茎部氮含量没有显著差异; 果实和茎部磷含量随亚磷酸盐浓度的增加呈增加趋势，根部磷含量呈降低趋势，叶片磷含量没有显著差异; 亚磷酸盐浓度增加到一定浓度时，各部位干重显著降低，根冠比没有显著差异; 植株氮、 磷总量随亚磷酸盐浓度的增加有下降的趋势; 黄瓜叶片净光合速率（Pn）随亚磷酸盐浓度的增加呈下降趋势。本研究结果显示，随着亚磷酸盐浓度的增加，植株表现出缺磷效应，对植株养分元素的吸收及光合作用产生了不利影响。该文讨论了亚磷酸盐作为缓释磷肥的可行性。

Effects of phosphite as a slow release phosphate fertilizer on nutrient absorption and photosynthetic characteristics of cucumber

Using nutrient solution cultivation technique, the effects of different concentrations of phosphite on nitrogen and phosphorus contents in root, shoot, leaf and fruit of cucumber, dry weight and root/shoot, nitrogen and phosphorus contents per plant and photosynthetic characteristics were investigated. The results show that as the phosphite concentration in solution increased, the N contents in the fruit, leaf and root are decreased, while the N contents in shoot is not in statistically difference. The P contents in fruit and shoot are increased, while the contents in root are decreased, and the contents remain no differences in leaf. When the phosphite concentration is increased to some extent, the dry weights of all parts are decreased significantly, while the root/shoot ratios remain no differences. The N and P contents per plant are decreased and the net photosynthetic rates (Pn) are declined as the phosphite concentration in solution increased. These results suggest that as the phosphite concentration increased, cucumber is more likely to show a syndrome of phosphorus deficiency which reduces nutrient absorption and photosynthesis. The feasibility of phosphate being used as a slow release phosphate fertilizer is discussed.