Effects of Nitrogen Application Rate on Photosynthetic Characteristics and Yield of Different Varieties of Sorghum
In order to explore the regulation effect of nitrogen fertilizer on yield and photosynthetic characteris-tics,clarify the interaction between varieties and nitrogen fertilizer,reveal its physiological mechanism,reasonably match nitrogen fertilizer application amount,and improve crop yield.In this study,sorghum varieties of'Longzal0','Jiza124'and'Jinza22'were used as test materials,combined with different nitrogen application rates,the net photosynthetic rate(Pn)and stomatal conductance(Gs)of sorghum of different varieties and different peri-ods,intercellular CO2 concentration(Ci),transpiration rate(Tr)and harvest yield were measured to explore the op-timum nitrogen application rate for different varieties.The results showed that Pn,Gs and Tr were significantly posi-tively correlated with each treatment,but negatively correlated or not significantly correlated with Ci.'Longza10'and'Jiza124'had the highest yields when the nitrogen fertilizer was 205 kg/hm2,which were 7 112.196 and 11573.163 kg/hm2 respectively,which increased by 10％and 30％respectively compared with the control;'Jinza22'had the highest yield of 11 081.436 kg/hm2 when topdressing nitrogen fertilizer 205 kg/hm2 at the jointing stage,an increase of 25％.The overall yield under the same treatment was'Jiza124'＞'Jinza22'＞'Longza10'.The effects of nitrogen application rate and variety on sorghum yield were proved,which provided theoretical support for variety layout,resource potential mining and formulation of efficient green cultivation measures.
Net photosynthetic rateStomatal conductanceIntercellular CO2 concentrationTranspiration rateYield
NETL
NSTL
万方数据
