不同耕作方式对东北旱地土壤养分和生物学性质的影响

Effects of Different Tillage Methods on Soil Nutrients and Biological Properties of Dry Land in Northeast China

为提高黑土区土壤质量和作物产量,并促进区域农业可持续发展,进行了4年田间定位试验,设置了深松、免耕以及传统耕作3种耕作方式,研究了不同耕作方式对土壤速效养分、土壤微生物数量以及土壤酶活性的影响。结果表明,与传统耕作相比,深松能够显著提高上层土壤(0~20 cm)碱解氮、有效磷以及速效钾含量(分别提高23.6%、49.6%和63.3%),同时,显著提高了下层土壤(20~40 cm)有效磷含量(86.2%);深松处理上层土壤pH显著提高,下层土壤各处理间pH变化较小;深松和免耕能够显著增加上层土壤细菌和真菌的数量,深松显著增加放线菌数量;下层土壤各处理间微生物数量差别较小,表现为深松>免耕>传统耕作;深松处理上层土壤蔗糖酶和过氧化氢酶活性最高,免耕增加了土壤脲酶和磷酸酶活性;除过氧化氢酶外,其他3种酶活性均为上层土壤高于下层。深松和免耕处理能增加土壤速效养分含量、微生物数量及酶活性,有助于改善土壤化学和生物学性状,进而提高土壤质量,其中,深松方式效果最为显著,对于培肥土壤和维护土壤生物的生存环境等方面具有重要作用。

In order to improve soil quality and crop yield in the black soil region and promote the sustainable development of regional agriculture.A field experiment for four consecutive years under three tillage treatments,including subsoiling tillage(ST),no tillage(NT)and conventional tillage(CT)were set up to investigate the effects of tillage methods on soil available nutrients,soil microbial quantity and enzyme activities.Results showed that,compared with CT,ST could significantly increase the contents of alkaline nitrogen,available phosphorus and available potassium in the upper soil layer(0-20 cm)(by 23.6%,49.6%,and 63.3%,respectively),also for content of available phosphorus in the lower soil layer(20-40 cm)(86.2%).The pH of ST in the upper soil layer significantly increased,while the pH changed less among different treatments of in the lower soil layer;ST and NT treatments could significantly increase the number of bacteria and fungi in the upper soil layer,while ST significantly increased the number of actinomycetes;the differences of microbial quantities among in the lower soil layer were relatively small,decreased in the order:ST>NT>CT.There were highest activities of sucrase and catalase in the upper soil layer under ST,while NT increased soil urease and phosphatase activities.Except for catalase,the activities of other enzymes were higher in the upper soil than in the lower soil.ST and NT could increase the content of soil available nutrients,the number of microorganisms and enzyme activities,which helps to improve soil chemical and biological properties,thereby improving soil quality.Among them,subsoiling tillage played an important role in fertilizing soil and maintaining the living environment of soil organisms.