scholarly journals Changes of nematode community under monoculture wheat and wheat/jujube intercropping system in Xinjiang, Northwest China

2015 ◽  
Vol 52 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Y. B. Liu ◽  
L. L. Zhang ◽  
Q. Z. Liu
Keyword(s):  
Rhizosphere Soil ◽  
Northwest China ◽  
Arid Area ◽  
Structural Index ◽  
Soil Food Web ◽  
Dominance Index ◽  
Wheat Rhizosphere ◽  
Ziziphus Jujuba ◽  
Nematode Abundance ◽  
Soil Status

Summary Nematode communities in the soils of wheat (Triticum aestivum Linn.) rhizosphere grown alone and grown in jujube (Ziziphus jujuba Mill.) orchard were investigated for three years in Hetian arid area, Xingjiang Uygur Autonomous Region, northwest of China. The results showed that eu-dominant families were Rhabditidae, Cephalobidae and Aphelenchidae among 15 families and 19 genera. Nematode abundance in wheat rhizosphere soil was smaller in wheat/jujube intercropping system, mainly because of lower numbers of bacterial feeders and fungal feeders. Besides, the nematode numbers of cp-1 and cp-2 (cp, colonizer-persister) guilds were significantly lower in wheat/jujube intercropping system than that in monoculture wheat system, due to the markedly lower numbers of Rhabditidae and Cephalobidae, although those of cp-3 and cp-4 guilds had no significant differences between monoculture and intercropping systems. Shannon-Weaver index (H’), genus dominance index (Ig) and structural index (SI), represented soil food web diversity and structure, had no differences between monoculture and intercropping systems. Significantly lower values of Wasilewska index (WI) and PPI/MI in monoculture wheat than in intercropping system. It was concluded that the soil status in monoculture wheat system exhibited better soil ecosystem in compared with wheat/ jujube intercropping system.

STUDIES ON THE RELATIONSHIPS BETWEEN NEMATODES AND OTHER SOIL MICROORGANISMS: IV. INCIDENCE OF NEMATODE-TRAPPING FUNGI IN THE VICINITY OF PLANT ROOTS

1965 ◽  
Vol 11 (3) ◽  
pp. 491-495 ◽  
Author(s):  
E. A. Peterson ◽  
H. Katznelson
Keyword(s):  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Red Clover ◽  
Root Surface ◽  
Plant Roots ◽  
Favorable Effect ◽  
Bacterial Isolates ◽  
Rhizosphere Effect ◽  
Root Extracts ◽  
Wheat Rhizosphere

A study was made of the occurrence of nematode-trapping fungi in the rhizosphere and on the root surface of different plants. Arthrobotrys oligospora was the predominant predaceous fungus isolated. It was almost completely absent from plant roots but occurred in varying frequency in rhizosphere soil and in root-free soil. The incidence of this fungus was consistently greater in the soybean rhizosphere and lower in the wheat rhizosphere than in corresponding soil devoid of roots, whereas for other plants, red clover, flax, etc., there was no obvious rhizosphere effect. Spore germination tests and growth of A. oligospora in root extracts of soybeans and wheat failed to account for the differences observed. However, bacterial isolates from the wheat rhizosphere were, on the whole, more antagonistic to this fungus than those from the soybean rhizosphere, whereas isolates from the latter appeared to exert a favorable effect.

Human-Water Relationship Evaluation Based on Cloud Model for Arid Area in Northwest China

2014 ◽  
Vol 1065-1069 ◽  
pp. 2942-2947
Author(s):  
Mei Wang ◽  
De Shan Tang ◽  
Wei Shan Hu ◽  
Yi Fan Bai
Keyword(s):  
Evaluation Method ◽  
Cloud Model ◽  
Water System ◽  
Northwest China ◽  
Arid Area ◽  
Three Dimensions ◽  
Evaluation Index ◽  
Entropy Weight ◽  
Evaluation Indexes ◽  
Entropy Weight Method

Human-water relationship evaluation method based on cloud model is put forward to cope with the vagueness in evaluation language. With the intensive study of the specialty in human-water relationship in Northwest China arid area, three dimensions related to human-water relationship, natural water cycle’s health degree (NWHD), Social water cycle’s rationality degree (SWRD) and human-to-water fitness degree (HWFD) are selected to describe the harmony degree between water system and human system. The limit of evaluation index subordinate to each dimension corresponding to every harmony level is determined, and thus we can generate a comprehensive cloud model with evaluation index harmony level. When numeric values substitute for basic evaluation indexes, combined with the weights calculated from entropy weight method and AHP method, we get the certainty distributions of dimension indexes and integration objects among each harmony level. Case shows that human-water relationship evaluation method based on cloud model can effectively solve the vagueness and uncertainty in evaluation language. The evaluation results reflect the harmony degree in Northwest China arid area precisely.

scholarly journals Two Severe Local Storms as Observed in the Arid Area of Northwest China

1995 ◽  
Vol 73 (6) ◽  
pp. 1269-1284 ◽  
Author(s):  
Yasushi Mitsuta ◽  
Taiichi Hayashi ◽  
Tetsuya Takemi ◽  
Yinqiao Hu ◽  
Jiemin Wang ◽  
...  
Keyword(s):  
Northwest China ◽  
Arid Area
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