Subjects: Biology >> Zoology submitted time 2024-03-22 Cooperative journals: 《古脊椎动物学报》
Abstract： The affinity of ‘Dongfangaspis qujingensis’, initially assigned to Dongfangaspis but later to Laxaspis, has long been controversial. However, the taxonomical revision raises a new problem of junior homonym since the type species of Laxaspis is L. qujingensis. Here, we describe some new materials of ‘Dongfangaspis qujingensis’ and Damaspis vartus from the Xishancun Formation (early Lochkovian, Early Devonian) in Qujing, Yunnan Province. ‘Dongfangaspis qujingensis’ strikingly resembles Damaspis vartus in the slightly longer headshield, bifurcated ends of the lateral transverse canals, unconnected V-shaped posterior supraorbital canals, and at least seven pairs of lateral transverse canals issuing from the lateral dorsal canal. These similarities indicate that ‘D. qujingensis’ is more suggestive of Damaspis than Dongfangaspis and Laxaspis. Therefore, we propose to remove ‘Dongfangaspis qujingensis’ from Laxaspis to Damaspis. The new specimens of Damaspis vartus reveal five long lateral transverse canals on the right side, corroborating that the asymmetric sensory canal system in the holotype is the intraspecific variation.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：为明确川中丘陵地区紫土小麦-玉米两熟种植模式下机播玉米生产适宜的秸秆还田方式与耕作方式, 改善土壤的瘠薄、黏性过大等问题, 提高耕层土壤的播种条件、播种质量, 达到作物高产的目的, 设置秸秆还田旋耕(RTS)、秸秆还田免耕(NTS)、秸秆不还田旋耕(RT)、秸秆不还田免耕(NT)4 个处理, 研究麦秸还田与旋耕对川中丘区紫色黏土物理性状及机播夏玉米播种质量的影响。结果表明: 与秸秆不还田相比, 麦秸还田显著增加了拔节期0~10 cm 土层土壤毛管孔隙度和免耕处理0~10 cm 全生育时期土壤含水量, 显著降低出苗率、播种均匀度和幼苗整齐度等指标。与免耕相比, 旋耕处理降低了0~10 cm 土壤容重、含水量, 增加了毛管孔隙度, 出苗率提高9.9%, 幼苗株高、茎粗、叶面积和干重显著提高。麦秸还田条件下, 旋耕处理较免耕处理0~10cm 土壤容重降低2.0%~12.1%, 出苗率、播种均匀度、每穴苗数、幼苗整齐度显著提高, 其中出苗率增加17.9%。玉米出苗率与0~10 cm 土壤含水量呈显著正相关, 播种均匀度与幼苗整齐度均与0~10 cm 土壤容重呈显著负相关。可见, 麦秸还田下旋耕处理改善了土壤结构, 增加了土壤含水量, 更有利于川中丘陵地区小麦-夏玉米种植模式机播玉米质量和幼苗素质的提高。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：为明确川中丘陵地区紫土小麦-玉米两熟种植模式下机播玉米生产适宜的秸秆还田方式与耕作方式, 改善土壤的瘠薄、黏性过大等问题, 提高耕层土壤的播种条件、播种质量, 达到作物高产的目的, 设置秸秆还田旋耕(RTS)、秸秆还田免耕(NTS)、秸秆不还田旋耕(RT)、秸秆不还田免耕(NT)4 个处理, 研究麦秸还田与旋耕对川中丘区紫色黏土物理性状及机播夏玉米播种质量的影响。结果表明: 与秸秆不还田相比, 麦秸还田显著增加了拔节期0~10 cm 土层土壤毛管孔隙度和免耕处理0~10 cm 全生育时期土壤含水量, 显著降低出苗率、播种均匀度和幼苗整齐度等指标。与免耕相比, 旋耕处理降低了0~10 cm 土壤容重、含水量, 增加了毛管孔隙度, 出苗率提高9.9%, 幼苗株高、茎粗、叶面积和干重显著提高。麦秸还田条件下, 旋耕处理较免耕处理0~10cm 土壤容重降低2.0%~12.1%, 出苗率、播种均匀度、每穴苗数、幼苗整齐度显著提高, 其中出苗率增加17.9%。玉米出苗率与0~10 cm 土壤含水量呈显著正相关, 播种均匀度与幼苗整齐度均与0~10 cm 土壤容重呈显著负相关。可见, 麦秸还田下旋耕处理改善了土壤结构, 增加了土壤含水量, 更有利于川中丘陵地区小麦-夏玉米种植模式机播玉米质量和幼苗素质的提高。
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