PDF(Pubmed)
Abstract：
Maize and alfalfa (Medicago sativa L.) have been used extensively in the animal husbandry to compensate for the lack of livestock and fodder yields in the chilly northeast of China. Little is known, however, about the impact on soil characteristics of consecutive plantings in various crops and alfalfa. In this research, the soil characteristics, bacterial community diversity, and structure of the meadow, maize, and alfalfa continuous cropping fields (i.e., 6, 10, 14, 20, and 30 years) were measured. The results showed that maize cropping and continuous cropping of alfalfa increased the soil bacterial alpha diversity compared with meadow cropping, and alpha diversity of alfalfa increased with the continuous planting years. Soil pH, total phosphorus (TP), available P, total potassium (TK), and nitrate nitrogen (NO3 -) content were soil variables significantly impacting the structure of soil bacterial communities in different plant types and different alfalfa continuous cropping systems. In addition, the relative abundance of some beneficial microbial species, such as Arthrobacter and Gaiellales, in the cropping maize and continuous cropping of alfalfa was much higher than that in the meadow field. Moreover, the networks differ among different plant types, and also differ among different continuous cropping years of alfalfa, and topologies of the networks suggested that continuous planting of alfalfa promotes cooperation between bacteria, which facilitates the long growth of alfalfa and is beneficial to the soil.
摘要：
玉米和苜蓿（MedicagosativaL.）已被广泛用于畜牧业，以弥补中国东北寒冷地区牲畜和饲料产量的不足。鲜为人知，然而,关于各种作物和苜蓿连续种植对土壤特性的影响。在这项研究中,土壤特性，细菌群落多样性，和草地的结构，玉米,和苜蓿连作田(即，6、10、14、20和30年)进行了测量。结果表明,与草甸种植相比,玉米种植和连作紫花苜蓿增加了土壤细菌α的多样性,苜蓿的α多样性随着种植年限的增加而增加。土壤pH值,总磷（TP），可用P,总钾（TK），和硝态氮（NO3-）含量是土壤变量，显着影响不同植物类型和不同紫花苜蓿连作系统的土壤细菌群落结构。此外,一些有益微生物物种的相对丰度，如节杆菌和盖勒莱斯，种植玉米和连作紫花苜蓿的产量远高于草甸田。此外，不同植物类型的网络不同，苜蓿不同连作年限也不同，和网络拓扑表明，连续种植苜蓿促进细菌之间的合作，这有利于苜蓿的长期生长，对土壤有益。
