摘要
本研究在大田裂区试验下比较了3个氮肥水平[N1：105kg·hm^-2（节氮）、N2：135kg·hm^-2（节氮）、N3：165kg·hm^-2（常氮）】和3个抛秧密度[M1：27万穴·hm^-2（常苗）、M2：31．5万穴·hm^-2（增苗）、M3：36万穴·hm也（增苗）]对‘湘早籼45号’抛秧群体生物学特性和产量的影响。结果表明：增苗节氮处理（N2M3）为产量最高的组合。株高、生育期受氮肥影响较大，密度影响不显著，N1比N3和N2的生育期分别延长7．0d和3．4d；氮肥、密度的增加对分蘖表现为相反的趋势，总体表现为茎蘖数随施氮量增加而增加，随密度增加而减少。通过对氮肥、密度与产量间进行二次多项式回归分析可知，产量最大值点Y=8．60t·hm^-2，对应施氮量为蜀=127．5kg·hm^-2，密度为X2=48．0万穴·hm^-2，其比常氮（165kg·hm^-2）节省氮肥22．7％。表明早稻抛秧可以通过增苗来弥补节氮所带来的产量损失，早稻施氮量和抛秧密度搭配时应该以“增苗节氮”为原则。最佳施氮量在127．5～135kg·hm^-2，最佳抛秧密度在36～48万穴·hm^-2。综上所述，双季抛秧的季节性矛盾能通过早稻“增苗节氮”来解决，有利于减少环境污染，延缓农业生态系统水体富营养化。
The biological characteristics of population of nitrogen levels [NI： 105 kg（N）·hm^-2 （low nitrogen dose）; rice ＇Xiangzhaoxian 45＇ of throwing transplanting under three N2：135 kg（N）·hm^-2 （low nitrogen dose）; N3：165 kg（N）·hm^-2 （regular nitrogen dose）] combined with 3 seedling densities [MI： 0.27 million hills per hectare （regular seedling rate）; M2： 0.315 million hills per hectare （high seedling rate）; M3：0.36 million hills per hectare （high seedling rate）] in a split-plot trial field were compared. The results showed that treatment of high seedling rate with low nitrogen rate （N2M3） were the best combination for high yield. Plant height and growth period increased with increasing nitrogen dose, but not significantly changed with increasing seedling density. The growth period under N3 was 7.0 days and 3.4 days longer than that under N2 and N1, respectively. Tiller number increased with increasing nitrogen rate and dropped with increasing seedling density. Regression analysis showed quadratic polynomial relationship among nitrogen application rate （X1）, seedling density （X2） and yield （11）. The maximum yield occurred at Y = 8.60 t·hm^-2, corresponding with X1 = 127.5 kg（N）·hm^-2 of nitrogen rate and X2 = 0.48 million hills per hectare of rice seedling density, it＇s yield was similar to N2M3, and it was 22.7% reduction in nitrogen rate in comparison with regular nitrogen （N3）. Thus the best nitrogen application rate for early rice was 127.5-135 kg（N）·hm^-2 and the best seed- ling density was 3.60 × 10^5- 4.80 ×10^5 hills·hm^-2. The study showed that increasing seedling rate and decreasing nitrogen rate could lay the basis of early rice cultivation for maximum yield in the study area. In summary, the time contradiction between double season rice of throwing transplanting could be solved by increasing seedlings rate and decreasing nitrogen rate in early rice fields. This benefited low environmental pollution and alleviated eutr
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2014年第7期774-781,共8页
Chinese Journal of Eco-Agriculture
基金
"十二五"国家科技支撑计划重大项目(2013BAD07B11)
湖南省科技重大专项(2011fj1002)资助
关键词
早稻
抛秧
生物学特性
增苗
节氮
Early rice
Throwing transplanting
Biological characteristics
Seedling increase
Nitrogen reduction
