不同耕作模式下秸秆还田对潮土肥力特征的影响

2016—2017年通过田间试验对比研究夏玉米季不同耕作模式下秸秆还田对潮土肥力特征的影响。试验设置:免耕(NT)、免耕(NT)+秸秆还田(S)、翻耕(T)和翻耕(T)+秸秆还田(S)4个处理。结果表明,免耕、翻耕模式下,秸秆还田均显著增加了土壤碱解氮(+6.10 mg·kg~(-1)、+10.66 mg·kg~(-1))、有效磷(+2.76 mg·kg~(-1)、+6.53 mg·kg~(-1))、速效钾(+38.94 mg·kg~(-1)、+47.7 mg·kg~(-1))、有机质(+1.85 g·kg~(-1)、+0.80 g·kg~(-1))含量,及土壤孔隙度(+2.81%、+1.77%),降低了土壤容重(-5%、-3%),促进水稳定性大团聚体(0.25 mm)的形成。免耕、翻耕模式下的秸秆还田均有利于土壤肥力的提高,尤其在免耕模式下土壤容重、孔隙度、团聚体和有机质含量状况得到明显改善。翻耕对大团聚体有破碎作用,不利于有机质累积。

Effects of straw residue on the fertilities of fluvo-aquic soil in different farming modes

To study the effect of straw returning on soil fertility in summer maize, a field experiment was conducted from 2016 to 2017. Experimental settings: no-tillage (NT), tillage (T), no-tillage (NT) + straw incorporation (S) and tillage (T) + straw returning (S), four treatments in total. The results showed that, under both modes, straw incorporation not only significantly increased the amount of available nitrogen (+6.10 mg·kg^-1, +10.66 mg·kg^-1), available phosphorus (+2.76 mg·kg^-1, +6.53 mg·kg^-1), available potassium (+38.94 mg·kg^-1, +47.7 mg·kg^-1), porosity (+2.81%, +1.77%) and organic matter (+1.85 g·kg^-1, +0.80 g·kg^-1) in the soil, but also effectively reduced the soil bulk density (-5%, -3%), Meanwhile, the formation of water-stable aggregates was promoted as well. Straw incorporation enhanced soil fertility under both modes, especially for the mode of no-tillage, soil bulk density, porosity, water-stable aggregates and organic matter contents were obviously improved in this mode, whereas tillage would crush the aggregates, which is unfavorable to the accumulation of organic matters.