ÇëÇó£ºÓÐûÓмȶ®Ó¢ÓïÓÖ¶®Î÷°àÑÀÓïµÄ³æ×Ó£¬¿É²»¿ÉÒÔ°ï潫ÏÂÃæµÄÓ¢ÎÄÎÄ×Ö·Òë³ÉÎ÷°àÑÀÓÍò·Ö¸Ðл£¡
1 Spatial status of arbuscular mycorrhizal development, rhizospheric microbe populations and soil enzyme activities in citrus orchards under two types of no-tillage soil management
2 The spatial arbuscular mycorrhizal (AM) status [total AM colonization (RLT), ratio of root length with arbuscules (RLA) and vesicles (RLV), spore density and hyphal density], microbial populations and soil enzyme activities were investigated in the citrus (Satsuma Mandarin grafted on Poncirus trifoliata L. Raf) orchards. Two types of no-tillage soil management, namely natural grass and using herbicides, were employed in these orchards. The citrus root AM colonization (37.26%-70.09%) was heavy in experimental orchards. The highest RLA (43.83%) spore density (384.63 spores 100 g-1 soil), hyphal length density (4.09 m g-1 soil), rhizospheric microbial populations and enzymes activities were observed in the natural grass orchards, and the lowest ones except urease activity in the using herbicides orchards. The spore density, hyphal length density, catalase activity and phosphatase activity varied notably between the no-tillage/natural grass (NN) and no-tillage/using herbicides (NU) orchards at the soil layers above 40 cm. A correlation analysis showed that the relationships among the spore density, hyphal length density, organic matter, rhizospheric microbe populations and enzyme activities were significantly positively correlated. The data presented here demonstrated the RLA, spore density, hyphal length density, rhizospheric microbe populations and enzyme activities were significantly better in the natural grass orchards soils than in the herbicides used soils. So, no-tillage and planting grass is an effective way for citrus production and soil quality improvement in hills citrus orchards, Southern China.
3 colonization; spore density; hyphal length density; microbial activity; natural grass |