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通过7年的定位试验(2007~2013年),研究不同施氮水平对辽北地区玉米产量稳定性、可持续性及其增产潜力的影响。试验氮肥用量从低到高共设N0(不施氮)、N_1(138 kg hm~(-2))、N_2(241.5 kg hm~(-2))、N_3(345 kg hm~(-2))4个水平。结果表明,施氮可以显著增加玉米产量,在一定范围内产量和产量稳定性随施氮量的增加而增加,其中N2处理的产量(平均产量9598.1kg hm~(-2))和增产率(70.7%)最高,年际间变异系数最小,相应的稳定性最高;N_3处理虽然施氮量比N_2处理增加43%,然而产量和产量的稳定性并没有显著提高。根据7年的平均产量研究结果得出肥料-产量效应函数,曲线符合报酬递减率,可知玉米增产潜力为1279.3 kg hm~(-2),由此说明辽北地区的玉米单产还有很大的增产空间。
Through seven years’ positioning experiment (2007 ~ 2013), the effects of different N application rates on the yield stability, sustainability and yield potential of maize in northern Liaoning were studied. The results showed that N 0 (no nitrogen application), N 1 (138 kg hm -2), N 2 (241.5 kg hm -2), N 3 (345 kg hm -2) ) 4 levels. The results showed that nitrogen application could significantly increase the yield of maize, and the yield and yield stability increased with the increase of nitrogen application rate in a certain range. The yield of N2 treatment (average yield 9598.1kg hm -2) and yield ( 70.7%), the lowest coefficient of variation in the inter-annual period, and the highest corresponding stability. The N_3 treatment did not significantly increase the yield and yield stability when the N application rate was increased by 43% compared with the N_2 treatment. According to the results of 7-year average yield, the fertilizer-yield effect function is obtained, and the curve accords with the rate of return decline. It can be seen that the yield potential of corn is 1279.3 kg hm -2, indicating that there is still a large Increase production space.