种肥播施方式对红壤旱地油菜产量及肥料利用率的影响

Effects of sowing and fertilizing methods on yield and fertilizer use efficiency in red-soil dryland rapeseed(Brassica napus L.)

为明确红壤旱地油菜适宜的种肥播施方式,本研究通过2017—2018年和2018—2019年2年的田间试验,系统分析传统种肥土表撒播(T1)、种子条播而肥料土表撒施(T2)、种肥等行异位同步播施(T3)和种肥宽窄行异位同步播施(T4)4种不同种肥播施方式对油菜产量、密度动态、干物质变化、养分吸收和肥料利用率的影响。结果表明,种肥播施方式对红壤旱地油菜产量形成和肥料利用率均产生了显著影响,且在低肥力条件下影响更为显著。相比T1和T2,T3、T4显著促进了油菜高产的形成和肥料利用率的提高,但T3与T4二者之间差异不显著。种肥异位同步播施明显提高了各时期油菜干物质量,尤其是显著增加了初花期至成熟期的干物质积累量,促进了花后根部与地上部干物质同步增长;同时促进了对N、P、K的吸收,保证较高的植株密度并协同产生充足的角果数,最终提高油菜产量和肥料利用率。因此,种肥异位同步播施可显著提高红壤旱地油菜生产力,建议结合机械化种植因地制宜地推广应用。

In order to explicit proper sowing and fertilizing methods of rapeseed production in red-soil dryland,a two-year field experiment covering two rapeseed seasons(2017–2018 and 2018–2019)was conducted with four treatments of sowing and fertilizing methods to analyze the impact on yield formation and fertilizer use efficiency of rapeseed,including conventional sowing and fertilizing method(T1),sowing in row with surface broadcast fertilizing(T2),synchronous sowing in uniform row with side deep fertilizing(T3)and synchronous sowing in wide-narrow row with side deep fertilizing(T4).The results were as follows:The yield and fertilizer use efficiency of rapeseed in red-soil dryland were significantly affected by sowing and fertilizing methods.Besides,these differences were more significant in poor soil condition and drought season(2017–2018)than those in nutrient-rich soil condition and rainy season(2018–2019).Compared with T1 and T2,T3 and T4 promoted the yield formation and increased its fertilizer use efficiency significantly,whereas there was no significant difference between T3 and T4.Specifically,the technique of synchronous drilling sowing with side deep fertilizing could improve dry matter production during the whole growth period of rapeseed,especially from anthesis to maturity,with a corresponding rise of dry matter accumulation of both underground and aboveground after anthesis.Meanwhile,compared with the conventional cultivation,the technique of synchronous drilling sowing with side deep fertilizing increased the uptake of nutrients(N,P and K),effective plant density and maintained sufficient pod number,and thus improved the yield and fertilizer use efficiency of rapeseed.This study indicated that the technique of synchronous drilling sowing with side deep fertilizing had the potential of improving rapeseed productivity in red-soil dryland of southern China.Therefore,it should be suggested to promote the application according to local condition.