不同株型小花生品种氮素养分吸收利用特性

Nitrogen uptake and utilization of small-seed peanut cultivars with different plant architecture

南方小花生植株高大的地方良种与矮化改良的品种并存。为探明其需氮规律,实现差异化施肥的高产管理,以湖南主栽的高秆地方良种安化小籽、矮秆现代品种湘黑小果为材料,设置4个基施复合肥用量0、450、600、750 kg/hm^(2),分别代表土壤背景(CK)、低肥(F30)、中肥(F40)、高肥(F50)水平,于4个生育时期测定并分析植株各器官氮含量、积累与分配状况。结果表明:氮含量以高秆品种果>叶>根>茎为序;矮秆品种则以叶>果>根>茎为序。叶、根氮含量表现为高秆<矮秆,而茎、果反之。增施肥料对氮含量的影响程度总体趋势为茎>叶>根>果,利于营养器官的氮素同化吸收。氮积累量两品种各器官以叶>果>茎>根为序。除苗期外,其余时期的全株、叶、茎氮积累量表现为高秆>矮秆;根在苗期、结荚期为高秆<矮秆,其余时期相反;果则为高秆<矮秆。施肥利于营养器官前期的氮素积累。氮素分配率两品种均以叶最高,荚果和茎其次,根最少。地上部为高秆>矮秆,而地下部反之,说明矮秆植株吸收的氮素更利于转运到荚果。氮素利用效率均为矮秆>高秆,氮素生产效率、氮肥偏生产力两品种均以F40、F30最高,过度施肥降低氮素利用效率。综上,矮秆品种氮素积累量对增肥的响应度较低,总积累量虽然较少而在荚果中分配较多,并具有更高的氮素利用效率;品种株型特点应作为南方典型贫瘠酸性红壤区小籽花生生产上确定施肥量的主要依据。

In the production of small-seed peanut cultivars in South China,landraces with high plants and bred cultivars with dwarf plants were both planted.Thus a differential fertilization strategy had to be figured out according to their nitrogen requirements.In this study,the main landrace with high plants Anhua Xiaozi and improved dwarf cultivar Xianghei Xiaoguo were used as materials.Four compound fertilization rates were set including 0,450,600,and 750 kg/hm^(2),representing soil background(CK),low(F30),medium(F40),and high(F50)fertilizer levels.Nitrogen content,accumulation,and distribution were recorded at 4 growth stages.Results showed that,in high landrace Anhua Xiaozi,N content were in the order of pod>leaf>root>stem,while those of dwarf cultivar Xianghei Xiaoguo were in leaf>pod>root>stem.N content in leaves and roots of Anhua Xiaozi was less than dwarf cultivar Xianghei Xiaoguo.The opposite trend was found in stems and pods.The influence degree of increasing fertilizer on N content was in the order of stem>leaf>root>pod,which was beneficial to N assimilation and absorption in vegetative organs.N accumulation in different organs of the 2 materials was leaf>pod>stem>root.Except the seedling stage,N accumulations of the whole plant,leaf and stem in other stages were larger in Anhua Xiaozi stem.N accumulations were both higher in Anhua Xiaozi pods and roots,but only in roots during seedling and podding stages.Fertilization was beneficial to N accumulation in early stages.N distribution rate of both varieties was the highest in leaves,and then in pods and stems.N distribution rate in higher variety were larger in aboveground parts,while the underground parts was the opposite.It indicated that N absorbed by dwarf variety was more conducive to transport to pods.N production efficiency was higher in dwarf Xianghei Xiaoguo.N production efficiency and N partial factor productivity of F40 and F30 treatments were both high,indicated that excessive fertilization decreased N use efficiency.In conclusion,lower response of N accumulation to fertilizer increase was found in dwarf cultivar Xianghei Xiaoguo,with less total accumulation but more distribution in pods.Therefore,in barren and acidic red soil regions in South China,peanut plant architecture should be considered during fertilizer determination.