覆盖作物翻压对华北平原春玉米产量和土壤养分的影响

Effects of the incorporation of winter cover crop on succeeding spring maize yield and soil nutrient in the north China plain

冬季覆盖作物-春玉米种植模式是减缓华北平原冬小麦减少导致的耕地裸露及其环境影响的新型农业生产方式,但其翻压后对华北平原下一季春玉米生长季作物产量和土壤养分及微生物学性质的影响研究鲜见。本研究以华北平原冬闲田-玉米(WFM)为对照,设置毛叶苕子-玉米(VrM)、二月兰-玉米(OvM)以及冬油菜-玉米(BcM)3个覆盖作物处理,通过盆栽试验研究了冬季种植覆盖作物翻压对玉米生长季土壤理化性质、微生物量和玉米生长特性的影响。结果表明:(1)翻压覆盖作物显著提高了玉米产量以及作物养分吸收量。与WFM处理相比,OvM处理秸秆产量和籽粒产量提高幅度最大,分别为33.3%和35.5%(P<0.05);BcM处理地上部氮、磷、钾和地下部磷素吸收量显著提高(P<0.05),分别为30.7%、74.7%、57.6%和171.4%。(2)翻压覆盖作物能显著提高0~10和10~20 cm土层有机质、碱解氮、有效磷、速效钾、全氮和全钾含量(P<0.05)。此外,翻压覆盖作物能显著降低玉米幼苗期土壤NH4^+-N和NO3^--N含量(P<0.05),范围为0.50~3.52和21.40~33.13mg·kg^-1。(3)在玉米的不同生育期,覆盖作物翻压处理的SMBC、SMBN和SMBP均显著高于冬闲处理(P<0.05)。综合翻压覆盖作物对华北平原玉米产量及土壤理化性质和微生物量含量的影响,华北平原冬油菜-玉米和二月兰-玉米轮作模式效果较好。

The winter cover crop-spring maize rotation system is a new agricultural mode in decreasing the area of bare farmland and its environmental impact due to the decrease of winter wheat in the north China Plain.However,the effects of incorporation of cover crops on crop yield,soil nutrients and microbial properties in the succeeding spring maize growing season in the north China Plain are rarely studied.The four treatments,maize-bare farmland(WFM),maize-hairy vetch(VrM),maize-February Orchid(OvM)and maize-winter rape(BcM)were designed to investigate the effects of incorporation of winter cover crops on the soil physicochemical and microbiological properties and maize growth in the north China Plain.The results showed that incorporation of winter cover crops increased maize yield and nutrients uptake by plant. Compared with the WFM,the straw and grain yield were the highest in OvM,increased by 33.3% and 35.5% significantly(P<0.05),and the uptake of nitrogen,phosphorus and potassium by upper parts and phosphorus by underground parts of plant were significantly increased in BcM(P<0.05),by 30.7%,74.7%,57.6% and 171.4%,respectively.The soil organic matter,alkaline nitrogen,available phosphorus,available potassium,total nitrogen and total potassium content in 0~10 cm and 10 ~ 20 cm soil layers were increased significantly under the cover crop treatments(P<0.05).Additionally,soil NH4^+-N and NO3^--N contents in young maize period were significantly reduced by 0.50 ~ 3.52 mg·kg^-1 and 21.40 ~ 33.13 mg·kg^-1,respectively.The incorporation of cover crops also increased the SMBC,SMBN and SMBP contents significantly compared with treatment without cover crop at different growth stages of maize(P<0.05).The maizewinter rapeseed rotation and maize-February orchid rotation were appropriate models in the north China Plain,taking consideration of maize yield and soil physicochemical properties and microbial content.