土壤圈(意译名)
土壤圈(意譯名)
토양권(의역명)
PEDOSPHERE AN INTERNATIONAL JOURNAL
2002年
2期
171-178
,共8页
Nmin residue%spinach%water and nitrogen recommendation
Nmin residue%spinach%water and nitrogen recommendation
Nmin residue%spinach%water and nitrogen recommendation
Effects of conventional and optimized water and nitrogen managements on spinach (Spinacia oleracea L.)growth and soil mineral N (Nmin) residues were compared in an open field experiment in which water balance method and N recommendation with the KNS-system were included. It was shown that the conventional water treatment (seasonal irrigated amount: 175 mm) reduced spinach growth compared to the water balance treatments (seasonal irrigated amount: 80 and 85 mm) at the same N supply level due to N loss through leaching caused by excessive water supply. Although 309 kg N ha-1 was applied in the conventional N treatment, compared to 82 and 66 kg N ha-1 in the optimum N treatments, no significant difference in crop yield was investigated between the N treatments with the same irrigation practice. N uptake in spinach and soil residual Nmin contents were also significantly affected by the irrigation practices. The conventional water supply not only decreased water use efficiency, but also resulted in excessive NO-3-N being leached below the root zone. In order to meet the same target value of N requirement for the next crop, cauliflower, based on the KNS-system, at least extra 50 kg N ha-1 was needed in the conventional water treatments in comparison to the water balance treatment.
