冬油菜施钾的增产效果和肥料利用率研究

Effect of potassium fertilizer on yield increase and potassium nutrient utilization for winter rapeseed

通过总结2004/2005～2006/2007年3个年度在长江流域冬油菜主产区10个省（市）的72个田间试验数据,以产量、增产率、偏生产力、农学效率、生理利用率及表观利用率等指标分析了长江流域施钾增产效果及钾肥利用率,以期为油菜进一步增产提供依据.分析结果表明,长江流域冬油菜施钾效果显著,与对照不施钾处理相比,施用钾肥油菜籽平均增产量为349 kg hm-2,平均增产率为19.8％,其中增产率小于5％的试验数占总数的20.8％,另外,油菜籽增产率随着土壤速效钾含量的升高而明显下降;施钾处理油菜地上部钾素积累量比不施钾处理显著增加38.1％;钾肥的平均偏生产力、农学效率、生理利用率和表观利用率分别为21.1、2.9、8.5 kg·kg-1和46.7％.综合结果表明,在施用氮、磷及硼肥基础上增施钾肥能够明显提高油菜地上部的生物量及钾素的累积,从而增加油菜籽产量,且根据基础地力及油菜对钾的需求规律而合理施肥极为重要.

Field experiments were carried out to study the effect of potassium application on winter rapeseed in the Yangtze River Valley and further to explore approaches of increasing rapeseed yield and improving potassium use efficiency. Data from 72 field experiments were collected across 10 main rapeseed production provinces in the period of 2004/2005 - 2006/ 2007 in this paper. The yield increasement by potassium application and yield increase rate, partial factor productivity, ag- ronomic efficiency, physiological efficiency and apparent recovery efficiency were calculated in order to provide basis for the increase. The results indicated that application of potassium fertilizer increased winter rapeseed yield significantly. Average seed yield increment would reach to 349 kg · hm-2 compared with no potassium treatment, with the yield increased rate of 19. 8%. However, there were 20. 8% of the experiments showed little yield increase （i. e. , yield increase rate lower than 5% ） with potassium fertilization. The study showed that yield increase rate declined with the increase of soil available potas- sium content. Apparently, soil potassium accumulation rose with potassium fertilization, with an increase of 38. 1% as compared with the treatment with no potassium fertilization. The results also showed that the mean values of PFP, AE, PE and RE by potassium fertilization were 21.1 kg · kg-1 , 2. 9 kg · kg-1 , 8.5 kg · kg-1 and 46. 7% , respectively. The re- sults suggest that applying potassium fertilizers would improve aboveground biomass of winter rapeseed and potassium accu- mulation, thus increase the seed yield significantly. Therefore, both soil fertility and the regular pattern of demand for po- tassium should be considered in the regional fertilization strategy.