【摘要】 通过1990年的密度和施氮肥的单因子试验和1991年的密度与施氮肥的双因子试验,应用二次回归正交设计方法,在辽宁省北部铁岭县、辽宁南部海城市和辽宁西南部的锦县3个不同试验地点,研究了密度和施氮肥量对掖单13号和铁单8号产量的影响,得出了密度与施氮量对产量影响的效应方程;再用边际利润分析的方法,得出最高产量时的措施配合和最大纯收益的措施配合。更多还原

【Abstract】 The planting densities and nitrogen fertilization for maize(Zea mays L.) were studied in 1991. This experiment was engaged in three different ecological conditions, including soil, climate and so on. Regression equations were established by electronic computer according to the ex- perimental results. The analysis of economical benefit with these regres- sion equation showed that higher net income can be obtained when op- timum planting density and proper nitrogen quantity are applied.更多还原