Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use ...Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.展开更多
Knowledge of evapotranspiration(ET)and energy partitioning is useful for optimizing water management,especially in areas where water is scarce.A study was undertaken in a furrow-irrigated vineyard(2015)and a drip-irri...Knowledge of evapotranspiration(ET)and energy partitioning is useful for optimizing water management,especially in areas where water is scarce.A study was undertaken in a furrow-irrigated vineyard(2015)and a drip-irrigated vineyard(2017)in an arid region of northwest China to compare vineyard ET and energy partitioning and their responses to soil water content(SWC)and leaf area index(LAI).ET and soil evaporation(E)and transpiration(T)were determined using eddy covariance,microlysimeters,and sap flow.Seasonal average E/ET,T/ET,crop coefficient(Kc),evaporation coefficient(Ke),and basal crop coefficient(Kcb)were 0.50,0.50,0.67,0.35,and 0.29,respectively,in the furrow-irrigated vineyard and 0.42,0.58,0.57,0.29,and 0.43 in the dripirrigated vineyard.The seasonal average partitioning of net radiation(Rn)into the latent heat flux(LE),sensible heat flux(H)and soil heat flux(G)(LE/Rn,H/Rn,and G/Rn),evaporative fraction(EF)and Bowen ratio(β)were 0.57,0.26,0.17,0.69 and 0.63,respectively,in the furrowirrigated vineyard and 0.46,0.36,0.17,0.57 and 0.97 in the drip-irrigated vineyard.The LE/Rn,H/Rn,EF,andβwere linearly correlated with LAI.The E,Kc,Ke,E/ET,LE/Rn,LEs/Rn(ratio of LE by soil E to Rn),H/Rn,EF andβwere closely correlated with topsoil SWC(10 cm depth).Responses of ET and energy partitioning to the LAI and SWC differed under the two irrigation methods.Drip irrigation reduced seasonal average E/ET and increased average T/ET.From the perspective of energy partitioning,seasonal average H/Rn increased whereas LE/Rn,especially LEs/Rn,decreased.Compared with furrow irrigation,drip irrigation decreased the proportion of unproductive water consumption thereby contributing to enhanced water use efficiency and accumulation of dry matter.展开更多
基金supported by the National Natural Science Fundation of China (51621061, 91425302) the 111 Program of Introducing Talents of Discipline to Universities (B14002)
文摘Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.
基金This work was funded by the National Natural Science Foundation of China(91425302,51621061)by the 111 Program of Introducing Talents of Discipline to Universities(B14002).
文摘Knowledge of evapotranspiration(ET)and energy partitioning is useful for optimizing water management,especially in areas where water is scarce.A study was undertaken in a furrow-irrigated vineyard(2015)and a drip-irrigated vineyard(2017)in an arid region of northwest China to compare vineyard ET and energy partitioning and their responses to soil water content(SWC)and leaf area index(LAI).ET and soil evaporation(E)and transpiration(T)were determined using eddy covariance,microlysimeters,and sap flow.Seasonal average E/ET,T/ET,crop coefficient(Kc),evaporation coefficient(Ke),and basal crop coefficient(Kcb)were 0.50,0.50,0.67,0.35,and 0.29,respectively,in the furrow-irrigated vineyard and 0.42,0.58,0.57,0.29,and 0.43 in the dripirrigated vineyard.The seasonal average partitioning of net radiation(Rn)into the latent heat flux(LE),sensible heat flux(H)and soil heat flux(G)(LE/Rn,H/Rn,and G/Rn),evaporative fraction(EF)and Bowen ratio(β)were 0.57,0.26,0.17,0.69 and 0.63,respectively,in the furrowirrigated vineyard and 0.46,0.36,0.17,0.57 and 0.97 in the drip-irrigated vineyard.The LE/Rn,H/Rn,EF,andβwere linearly correlated with LAI.The E,Kc,Ke,E/ET,LE/Rn,LEs/Rn(ratio of LE by soil E to Rn),H/Rn,EF andβwere closely correlated with topsoil SWC(10 cm depth).Responses of ET and energy partitioning to the LAI and SWC differed under the two irrigation methods.Drip irrigation reduced seasonal average E/ET and increased average T/ET.From the perspective of energy partitioning,seasonal average H/Rn increased whereas LE/Rn,especially LEs/Rn,decreased.Compared with furrow irrigation,drip irrigation decreased the proportion of unproductive water consumption thereby contributing to enhanced water use efficiency and accumulation of dry matter.
