不同种植模式对黑龙江黑土理化性状的影响

Effects of Different Planting Pattern on Soil Physical and Chemical Properties of Heilongjiang Black Soil

为明确种植模式对黑龙江黑土理化性状的影响,筛选适合该地的种植模式,于2019—2021年在黑龙江省克山县进行试验,设置玉米-大豆-小麦轮作(T1)、玉米-大豆-马铃薯轮作(T2)、玉米-大豆-高粱轮作(T3)、玉米连作(CK1)、大豆连作(CK2)5个处理,分析种植模式对土壤理化性状的影响。结果表明,不同种植模式对土壤团聚体影响不同,10~20 cm土层轮作处理0.5~2 mm粒级土壤机械稳定性团聚体占比高于连作处理,且以T2处理最高;20~30 cm土层0.5~2 mm粒级水稳性团聚体以T1、T2、T3处理较高;不同粒级团聚体稳定指数表明,T2处理水稳性团聚体含量较高,结构破坏率较低,稳定性较好。不同种植模式对黑土土壤养分的影响也不同,CK1、CK2土壤碱解氮、有效磷、速效钾、有机质含量较T1、T2、T3处理低,且土壤发生酸化。T1、T2、T3处理中,以T2处理提高土壤养分含量及调节土壤酸度整体效果较好。综上,T2(玉米-大豆-马铃薯轮作)处理可以提高土壤机械稳定性团聚体和水稳性团聚体,并且粒径<0.25 mm的小团聚体占比低,结构破坏率低,同时可以提高土壤碱解氮、有机质含量,减弱土壤酸化,建议在当地推广该种植模式。

In order to clarify the soil physical and chemical properties of different planting patterns in Heilongjiang black soil area,and screen out the suitable planting patterns for this area,the effects of five different planting patterns,corn‐soybean‐wheat rotation(T1),corn‐soybean‐potato rotation(T2),corn‐soybean‐sorghum rotation(T3),maize continuous cropping(CK1),soybean continuous cropping(CK2),on soil physical and chemical properties were studied from 2019 to 2021.The results showed that different planting pattern had different effects on soil aggregates.The proportion of 0.5—2 mm mechanically stable aggregates in rotation treatment of 10—20 cm soil layer was higher than that in continuous cropping treatment,and T2 treatment was the highest.The 0.5—2 mm grain size of water‐stable aggregates in the 20—30 cm soil layer was higher when treated with T1,T2 and T3.The stability index of aggregates of different grain sizes showed that the content of water‐stable aggregates of T2 treatment was higher,the structural failure rate was lower,and the stability was better.The effects of different planting methods on soil nutrients of black soil were also different.The contents of alkali‐hydrolyzed nitrogen,available phosphorus,available potassium and organic matter in CK1 and CK2 soils were lower than those in T1,T2 and T3 treatments,and soil acidification occurred.Among T1,T2 and T3 treatments,T2 treatment had a better overall effect on increasing soil nutrient content and adjusting soil acidity.In conclusion,T2(corn‐soybean‐potato rotation)treatment could improve the mechanical stability and water stability of soil aggregates,with a lower proportion of small aggregates with particle size<0.25 mm and lower structural failure rate,increase the content of soil alkyl‐hydrolyzed nitrogen and organic matter,and reduce soil acidification.It is recommended to popularize this planting mode locally.