耕作方式对黑钙土主要肥力特征及玉米产量的影响

为揭示不同耕作方式对黑钙土主要肥力特征及玉米产量的影响,田间试验设置了旋耕(RT)、深松(ST)、免耕(NT)、深翻(DP)和深翻秸秆还田(DPS)等5种耕作方式,分析了玉米不同生长时期0～60 cm土层土壤容重、水稳性团聚体等物理指标,氮、钾、有机质等化学指标及玉米产量。结果表明,与RT处理相比,NT和ST处理土壤容重平均增加4.7%和3.8%,DP和DPS处理分别降低3.4%和2.6%;NT处理的田间持水量比RT降低2.7%,ST与RT相近,而DP和DPS处理分别比RT增加8.6%和7.0%,二者都显著高于RT(P0.05);土壤大团粒结构(0.25 mm)含量表现为苗期DP处理最高,抽雄期DPS最高、DP次之,整体来看,平均含量以DPS最高;除抽雄期NT含量较高外,DPS和DP是有机质含量整体较高的处理,说明翻耕的过程有利于土壤有机质含量的提升;从土壤全氮的比较来看,不同处理下差别不大,但碱解氮含量以RT最高,其他处理降低了6.8%～12.9%;与RT处理相比,ST和DPS处理玉米产量降低了7.4%和3.3%,NT、DP分别增加2.3%和7.8%。综合来看,虽然NT处理有一定的提升土壤结构和有机质的潜力,但改变效果不大,DP和DPS处理具有较好的土壤肥力特征,其中DP是兼具土壤肥力和增产效果的耕作方式。

Effects of tillage methods on major fertility characteristics of chernozem soil and maize yield

Proper tillage mode is a necessary measure to maintain the sustainable development of agriculture.In order to reveal the effects of different tillage methods on the main fertility characteristics of Chernozem soil and maize yield,five tillage methods were set up in this study including rotary tillage (RT), subsoiling tillage (ST), no\|tillage (NT), deep ploughing (DP), and deep ploughing straw returning (DPS).Physical properties such as soil bulk density, water content, water\|stable aggregates, and chemical properties such as nitrogen, potassium, and organic matter in 0~60 cm soil layer at different growth stages of maize and maize yield were analyzed.The results showed that soil bulk density increased by 4.7% and 3.8% for NT and ST treatments, and decreased by 3.4% and 2.6% for DP and DPS treatments, respectively, compared with RT treatments.The field water holding capacity of NT treatment was 2.7% lower than that of RT while ST and RT were similar, while DP and DPS treatments were 8.6% and 7.0% higher than RT, respectively (P<0.05). The content of soil aggregate structure (>0.25 mm) was the highest for the DP treatment at the seedling stage, followed by DPS and DP at the tassel stage. The content of soil aggregate for the DPS treatment was the highest.In addition to the higher NT content in the tasseling stage, DPS and DP were still the treatment with higher organic matter content as a whole, indicating that the process of ploughing was conducive to the improvement of soil organic matter content.According to the comparison of soil total nitrogen, there is little difference under different treatments, but the content of alkali\|hydrolyzed nitrogen was the highest in RT, and decreased by 6.8%~12.9% for other treatments.Compared with RT treatment, ST and DPS yields decreased by 7.4% and 3.3%, NT and DP increased by 2.3% and 7.8%, respectively.In conclusion, although NT had the potential to improve soil structure and organic matter, the effect of NT was not significant. DP and DPS had good fertility characteristics under the experimental conditions, and DP is a farming method with both soil fertility and yield increasing effect.