间作对植株生长及养分吸收和根际环境的影响

通过盆栽实验研究了线辣椒和玉米间作对其植株生长、矿质养分吸收、根际环境以及铁载体分泌的影响,以探索间作促进铁、磷等养分吸收利用的可能生理机制.结果表明:(1)与单作相比,间作线辣椒地上部干重降低23.0%,根系干重增加44.2%,玉米地上部和根系的干重分别增加8.7%和22.9%;间作线辣椒根冠比和根系活力分别显著提高86.4%和29.8%;间作线辣椒、玉米叶绿素含量分别显著提高12.6%和7.8%.(2)与单作相比,间作线辣椒的铁、锌、锰含量分别增加1.50倍、1.39倍和1.34%,而间作玉米则无显著变化;间作线辣椒和玉米的钙含量都显著低于相应单作,氮含量没有显著变化,但磷、钾含量显著增加.(3)间作线辣椒和玉米的根际土、非根际土的酸性磷酸酶活性及根系酸性磷酸酶活性都显著高于相应单作,而其根际土和非根际土的pH值无显著变化;间作玉米根系的铁载体分泌比单作减少32.8%,间作线辣椒根系的铁还原酶活性是单作的1.10倍.研究发现,线辣椒/玉米间作能通过影响根际生物学特征和化学过程提高植株的铁、锌、磷和钾养分水平,缓解养分胁迫,是一种很有推广价值的种植模式.

Effects of Intercropping on Growth,Nutrient Uptake and Rhizosphere Environment in Plants

A greenhouse potted experiment was conducted to investigate the interspecific rhizosphere effects on iron(Fe),phosphorus(P),nitrogen(N),potassium(K),calcium(C),zinc(Z),and manganese(Mn)in capsicum(Capsicum annuum var.longunt) plants by intercropping them with maize(Zea mays L.).In addition,we studied plants growth character,the release of phytosiderophores and the ferric reductase activity of roots,pH and acid phosphatases activity in the rhizosphere and bulk soil,the secretion of acid phosphatases in roots,and the available N,P,K contents of rhizosphere soil.The results showed that shoot dry weight of capsicum plants intercropped with maize were decreased by 23.0%,root dry weight were increased by 44.2%;the dry weight of maize shoot and root were increased by 8.7%,22.9% respectively,as compared to monoculture plants.Growing capsicum plants in a mixture with maize,there were 86.4% and 29.8% increase in the ratio of root to shoot and root activities of capsicum respectively;In the case of maize,the ratio of root to shoot and root activities were not significantly affected by intercropping with capsicum.The chlorophyll contents of both capsicum and maize were also increased significantly by intercropping.The concentrations of Fe,Zn and Mn in intercropped capsicum increased by 1.50 fold,1.39 fold and 1.34%,respectively.While the concentrations of Fe,Zn and Mn in maize plants were not significantly affected by intercropping with capsicum.As far as the Ca concentrations of capsicum and maize plants were concerned,monoculture culture exceeded intercropping.Intercropping also improved significantly the K and P concentrations of capsicum and maize,while N concentrations of capsicum and maize were little affected by intercropping.In the intercropping of capsicum/maize,the acid phosphatase activities of the rhizosphere and bulk soil and root secreted acid phosphatase were significantly higher than that of monoculture capsicum and maize.In accordance,the P concentrations of capsicum and maize plants were much higher when they were intercropped with capsicum or maize,respectively.The rhizosphere and bulk soil pH values were not clearly affected by different cropping systems.As compared to their monoculture treatments,the secretion of phytosiderophore from maize roots decreased by 32.8%,but there was no significant difference between two treatments;the ferric reducing capacity of capsicum roots increased by 1.10 fold by the intercropping.The results indicate capsicum/maize intercropping pattern is a promising management practice,contributes to better nutrition of plants with Fe,Zn,P and K,most probably by affecting biological properties and chemical process in the rhizosphere.