Effects of Water,Nitrogen and Salt Coupling on Growth and Photosynthesis of Arundo donax L.
To investigate the impact of water,nitrogen and salt interaction on the growth and photosynthesis of the energy plant Arundo donax,identify the optimal water and nitrogen conditions for the cultivation of Arundo donax in different types of salinized soil,a three-factor and four-level orthogonal experiment was designed,soil salinity levels were categorised as follows:(S0:non-salinized soil,S1:mildly salinized soil,S2:moderately salinized soil and S3:severely salinized soil),amount of pure nitrogen applied was categorised as follows:(N0:0,N1:60,N2:120 and N3:180 kg/hm2),and irrigation quota was categorised as follows:(W0:2 850,W1:4 275,W2:5 700 and W3:7 125 m3/hm2).The results showed that individual factors of water,nitrogen and salt had significant influence on the plant height,stem diameter,leaf width,single cluster fresh weight and dry weight of Arundo donax(P＜0.05).The coupling of water and salt,as well as water and nitrogen,were found to show significant effects on the plant height,stem diameter,leaf width,single cluster fresh weight and dry weight of Arundo donax(P＜0.05).Single factors of water and salt had significant effects on the net photosynthetic rate,transpiration rate and stomatal conductance of Arundo donax(P＜0.05).When the nitrogen application rate and irrigation amount were certain,compared with the control,the characteristics such as plant height,stem diameter,leaf length,leaf width,fresh and dry weight per cluster,net photosynthetic rate,transpiration rate,and stomatal conductance of Arundo donax on mildly salinized soil did not show significant differences(P＞0.05).The aforementioned characteristics exhibited notable disparities in moderately and severely salinised soils(P＜0.05).With the escalation of nitrogen application or irrigation quantities,the plant height,stem diameter,leaf length,leaf width,single cluster fresh and dry weight,net photosynthetic rate,transpiration rate and stomatal conductance of Arundo donax demonstrated a tendency to initially increase and subsequently decline.In soil with medium nitrogen and medium water treatment,the maximum values for the single cluster fresh weight and dry weight of Arundo donax were observed in treatments with non-saline soil,they were 148.45g and 45.90g,respectively.In soil with mild salinization and medium nitrogen,Arundo donax exhibited the potential to achieve high biomass accumulation and water and nitrogen use efficiency simultaneously.In soil with moderate salinity,medium nitrogen and medium water treatment,the maximum value for yield of Arundo donax was observed in a single cluster.This was accompanied by a relatively high water and nitrogen use efficiency.The growth and development of Arundo donax were clearly impeded in severely salinised soil,with water and nitrogen use efficiency also exhibiting a relatively low level.In conclusion,the regulation of water and nitrogen can facilitate the accumulation of biomass by Arundo donax on soil with elevated salt concentrations.
water nitrogen and salt couplinggrowthphotosynthesissalinized soilArundo donax
万方数据
维普
