河北平原麦玉两熟轮耕模式对土壤特性及作物产量的影响

于2016-2017年冬小麦-夏玉米一年两熟生长季,设小麦季深松+玉米季免耕（S-N）、小麦季旋耕+玉米季深松（R-S）和小麦季深松+玉米季深松（S-S）处理,以常规耕作方式小麦季旋耕+玉米季免耕（R-N）为对照,在河北平原中部南和县对不同轮耕模式下土壤理化性状、微生物特性、水热状况、产量及水分利用效率进行研究。结果表明,对比小麦播种前,R-S和S-S处理土壤非毛管孔隙度均有显著上升,0~15和15~30cm土层分别平均提高15.2%和18.0%;R-N处理0~15和15~30cm土层非毛管孔隙度比小麦播前分别下降11.3%和7.3%。单季或两季深松可显著提高农田土壤碱性磷酸酶、多酚氧化酶、过氧化氢酶和脲酶活性,其中R-S和S-S处理提高最明显。单季深松或两季深松均可显著提高微生物生物量碳和活跃微生物量,0~30cm土层分别平均提高6.3%和20.6%。两季深松土壤呼吸平均提高12.4%,且呼吸速率变幅增大。深松可增大土壤周年温度变幅,提高水分利用效率,两季深松可显著提高周年作物产量达8.62%。深松可改善土壤物理性状,提高作物产量,提高土壤关键酶活性和呼吸速率,扩大土壤温度日变幅,优化土壤微生物环境。

Effects of Wheat-Maize Double Crops Rotational Tillage on Soil Characteristics and Crop Yield in Hebei Plain

In the double cropping growing season of winter wheat-summer maize from 2016 to 2017, four rotation tillage treatments were established. Setting wheat season subsoiling+maize season no-tillage (S-N), wheat season rotary tillage+maize season subsoiling (R-S), wheat season subsoiling+maize season subsoiling (S-S), and conventional tillage mode wheat season rotary tillage+maize season no-tillage (R-N) as the control. Soil physiology, microorganism characteristics, water and heat conditions, soil water use efficiency and grain yield of grain fields under different rotation modes were studied in Nanhe, central Hebei Plain. The results showed that: compared with before the sowing of wheat, the non-capillary porosity of R-S and S-S treatments increased significantly, and the avarage soil thickness of 0-15 and 15-30cm increased by 15.2% and 18.0%, respectively. R-N treatment 0-15 and 15-30cm soil layer non-capillary porosity ratio decreased by 11.3% and 7.3% before wheat sowing. Soil alkaline phosphatase (ALP), polyphenol oxidase (PPO), catalase (CAT) and urease (UU) activities were significantly increased by single-season or double-season subsoiling, especially by R-S and S-S treatments. Single season subsoiling or two season subsoiling could significantly increase the number of SMBC and active microorganisms, with an average increase of 6.3% and 20.6% in 0-30cm soil layer, respectively. The annual average soil respiration was increased by 12.4% and the variation of soil respiration rate was increased by two-season subsoiling rotation. Under different rotation tillage measures, the annual average soil temperature had little effect, but deep-loosening could increase the annual temperature variation of wheat fields. The water use efficiency (WUE) could also be promoted by single-season subsoiling or two-season subsoiling rotation. The annual crop yield could also be significantly increased by two-season subsoiling, with an average increase of 8.62%. The main conclusions are as follows: subsoiling can significantly improve soil physical properties, increase soil key enzyme activity and respiration rate, expand daily variation of soil temperature, and optimize soil microbial environment. Soil subsoiling can also significantly increase maize yield, of which two-season subsoiling treatment has the greatest yield increase.