论文部分内容阅读
春玉米施氮具有玉米本茬效应和较大的后茬效应。玉米孕穗期施氮能实现较大的边际利润（施氮效益）。基苗肥＋穗肥的两次施氮法既有利于缓解玉米前期共生阶段生长弱势的矛盾，又能充分发挥玉米孕穗期施氮具有的高额利润报酬率，实现全年多熟高产高效。春玉米的施氮应根据施氮的后效应和穗肥高利润特点，在两茬施氮边际利润大于零的前提下，首先实现春玉米高产。其施氮量应视土壤肥力水平保持在３３３８７ｋｇ／ｈａ上下，基苗肥和穗肥比例５∶５左右，其中，穗肥用量控制在２２５ｋｇ／ｈａ以下，适施时间为叶龄余数５３７叶。
Spring maize nitrogen application has corn stubble effect and large stubble effect. The billet application of corn at booting stage can achieve greater profit margin (benefit of nitrogen application). The two nitrogen application methods of seedling fertilizer and panicle fertilizer not only help to alleviate the contradiction between the growth stages of the pre-corn stage of symbiosis, but also give full play to the high rate of return on the rate of nitrogen fertilization at the booting stage of maize and achieve high yield and high efficiency throughout the year. Spring maize nitrogen application should be based on the post-application of nitrogen and high-profit characteristics of spike fertilizer, two cropping of N margin under the premise of greater than zero, the first to achieve high yield spring maize. The amount of nitrogen application should be kept at 33387 kg / ha as the level of soil fertility, and the ratio of basal fertilizer to panicle fertilizer is about 5: 5, of which, the amount of panicle fertilizer is controlled below 225kg / ha, and the suitable application time is 5 37 leaves.