轮作油葵对马铃薯生长发育及抗性生理指标的影响

为了探究轮作油葵对连作马铃薯生长发育及抗性生理的影响,选取马铃薯连作4年、连作4年后轮作油葵1年、连作6年、连作6年后轮作油葵1年的同一块试验田,以该试验田前两年分别种植藜麦、玉米的地块为对照,测定土壤理化性质、土壤酶活性及土壤微生物数量变化,测评土壤环境。再在该试验田种植马铃薯,对其幼苗光合作用、抗氧化酶活性以及马铃薯生长发育指标进行测定。结果表明,随连作年限增加,马铃薯根际土壤pH总体升高,偏碱性,有机质和有效磷含量逐渐减少,碱解氮含量上升;土壤酶活性与连作年限呈负相关;随连作年限增加,土壤中细菌数量、放线菌数量和细菌与真菌比(B/F)呈下降趋势,真菌数量呈增加趋势;土壤环境的恶化导致马铃薯植株生长量减少,叶绿素相对含量降低,叶片光合速率下降,超氧化物酶(SOD)活性下降,O_2~-.产生速率加快,丙二醛(MDA含量上升。轮作油葵明显降低了土壤pH,提高了土壤有机质、有效磷和碱解氮含量,增加了土壤酶活性、细菌数量和B/F值,降低了真菌数量,改善了根际土壤微环境,对植株生长发育起到促进作用;增加了马铃薯叶片相对叶绿素含量、光合速率,SOD活性增强,而O_2~-.水平和MDA含量下降,可见轮作油葵减轻了马铃薯叶片膜脂过氧化作用和自由基伤害,促进了马铃薯生长发育,且整体效果以连作4年后轮作油葵较好。

Effects of Oil-sunflower Rotation on Growth and Resistance Physiology Indexes of Potato

Different farmlands including only cropping quinoa(CK), 4 years continuous cropping potato, 1 year oil- sunflower rotation after 4 years continuous cropping potato, 6 years continuous cropping potato, 1 year oil-sunflower rotation after 6 years continuous cropping potato were selected, and which soil properties, soil enzyme activities, soil microorganism quantities and the growth and development indicators of potatoes were measured and compared to explore the effects of oil-sunflower rotation on the growth and resistance physiology of potato under different continuous cropping potato. The results showed that with the increase of continuous cropping year, soil pH of potato rhizosphere increased and tended to alkalinity in general, the contents of organic matter and available phosphorus decreased, alkali-hydrolyzable nitrogen content increased. Soil enzyme activities were negatively correlated with continuous cropping year and were lowest in the 6 years continuous cropping. With the increase of continuous cropping year, the quantities of soil bacteria and actinomycetes and the ratio of bacteria and fungi (B/F) decreased, but fungi quantity increased. The deterioration of potato rhizosphere soil environment resulted in the reduction in potato growth, chlorophyll content, leaf photosynthesis, SOD activity and the increase in production rate of O2–. and MDA content. In general, compared with non-rotation, oil-sunflower rotation significantly reduced soil pH, increased contents of organic matter, available phosphorus and alkali-hydrolyzable, improved soil enzyme activities, the quantity of bacteria and B/F, reduced the quantity of fungi, improved soil microenvironment, promoted potato growth, increased relative chlorophyll content, photosynthesis and SOD activity, decreased production rate of O2–. and MDA content, reduced membrane lipid peroxidation and free radical damage, enhanced antioxidant capacity. Generally, oil-sunflower rotation in 4 years continuous cropping was better, which well alleviated potato continuous cropping obstacles.