富磷有机肥对油菜生长和磷素吸收分配的影响

使用有机肥替代化肥是解决当前化肥用量过高、防控畜禽粪污污染和农田面源污染的重要结合点。以水稻—油菜轮作制中的油菜为研究对象,采用田间小区试验,系统研究了富磷有机肥替代化学磷肥的应用效果。试验设置5个处理:不施肥对照(CK)、化肥(T1)、富磷有机肥替代25%化肥(T2)、富磷有机肥替代40%化肥(T3)和富磷有机肥替代55%化肥(T4)。富磷有机肥全部作基肥一次性施入。试验结果表明,用富磷有机肥替代部分化学磷肥,以25%替代比例为最佳,油菜的生物产量和经济产量均为最高,分别达13 231.0kg/hm~2和2 801.2 kg/hm~2,比100%化肥处理高14.6%和11.5%。有机肥替代化肥对油菜增产的主要机理可能在于:降低菌核病发生率、显著提高不同阶段油菜叶片的SPAD值,提高单株有效角果数、角果粒数等产量构成要素。但是有机肥替代比例超过40%会显著降低油菜的生物产量和经济产量,也会降低磷素表观利用率,并增加土壤磷素累积风险。本研究结果对于合理确定化肥减量幅度及有机肥替代比例有重要参考价值。

Effects of phosphorus-rich organic fertilizer on the growth of rapeseed and its phosphorus absorption and distribution

The substitution of organic fertilizer for part of chemical fertilizer is an important measure to solve the problem of excessive use of chemical fertilizer and to control the pollutions of animal manure and farmland non-point source. The phosphorus-rich organic fertilizer was applied to replace part of chemical phosphorus fertilizer on rapeseed in a field plot experiment with rice-rape rotation system. The experiment was carried out with a completely random design method, including 5 treatments: no fertilizer (CK), chemical fertilizer (T1), phosphorus-rich organic fertilizer instead of 25% chemical fertilizer (T2), phosphorus-rich organic fertilizer instead of 40% chemical fertilizer (T3), and phosphorus-rich organic fertilizer instead of 55% chemical fertilizer (T4). Phosphorus-rich organic fertilizer was applied as basal fertilizer. Results showed that the best substitution ratio of phosphorus-rich organic fertilizer to chemical phosphorus fertilizer was 25%. The biomass and economic yields of rapeseed were the highest, and the amount reached to 13 231.0 kg/hm2 and 2 801.2 kg/hm2, respectively. And these yields were higher than that of chemical fertilizer treatment by 14.6% and 11.5%, respectively. The main mechanism of rapeseed yield increase by organic fertilizer substitution might be related to the significant reduction of disease incidence of Sclerotinia, the increase of the SPAD value of rapeseed leaves at different stages, and the enhancement of yield components such as effective number of pods per plant and number of grains per pod. However, organic fertilizer substitution over 40% significantly reduced the biomass and economic yields of rapeseed, and further reduced the phosphorus utilization efficiency and increased the risk of soil phosphorus accumulation. This research could provide important reference value for the rational determination of chemical fertilizer reduction range and the organic fertilizer substitution proportion.