摘要
Effets of conventional and optimized water and nitrogenmanagements on spinach (Spinacia oleracea L.) growth and soil mineralN (N_min) residues were compared in an open field experiment in whichwater balance method and N recommendation with the KNS-system wereincluded. It was shown that the conventional water treatment(seasonal irrigated amount: 175 mm) reduced spinach growth comparedto the water balance treatments (seasonal irrigated amount: 80 and 85mm) at he same N supply level due to N loss through leaching causedby excessive water supply.
Effects of conventional and optimized water and nitrogen managements on spinach (Spinacia olerocea L.)growth and soil mineral N (Nmi.) residues were compared in an open field experiment in which water balancemethod and N recommendation with the KNS-system were included. It was shown that the conventionalwater treatment (seasonal irrigated amount: 175 mm) reduced spinach growth compared to the water balancetreatments (seasonal irrigated amount: 80 and 85 mm) at the same N supply level due to N loss throughleaching caused by excessive water supply. Although 309 kg N ha-1 was applied in the conventional Ntreatment, compared to 82 and 66 kg N ha-l in the optimum N treatments, no significant difference in cropyield was investigated between the N treatments with the same irrigation practice. N uptake in spinach andsoil residual Nmin contents were also significantly affected by the irrigation practices. The conventional watersupply not only decreased water use efficiency, but also
基金
Natural Science Foundation of Beijing(No.6991004)
Joint Lab between theInstitute of Soil Science, CAS,
Hong Kong Baptist University (No. 99122202)
Federal Ministry of Education and Research, Germany.
