Plant facilitation shifts along with soil moisture and phosphorus gradients via rhizosphere interaction in the maize-grass pea intercropping system

Ecological Indicators

Rui Zhou¹  Yi-Bo Wang²  Aziz Khan³  Hong-Yan Tao⁴  Shuang-Guo Zhu⁴  You-Cai Xiong⁴  Jing Wang⁴  Hao Zhu⁴  Bao-Zhong Wang⁴  Yu-Miao Yang⁴  Asfa Batool⁴  Sai-Yong Zhu⁴  Wei Wang⁴  Zheng-Guo Cheng⁴ 

[1] Gansu Key Laboratory of Resource Utilization of Agricultural Solid Wastes, Tianshui Normal University, Tianshui 741000, China;Gansu Key Laboratory of Resource Utilization of Agricultural Solid Wastes, Tianshui Normal University, Tianshui 741000, China;School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China;State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China;

关键词: Competition;    Biodiversity;    Productivity;    Environmental gradients;    Phosphatase;   

DOI  :  

来源: DOAJ

【 摘 要 】

Plant-plant facilitation is widely studied to increase productivity and resource utilization in cereal-legume intercropping system. However, physiological and ecological mechanisms driving interspecific interaction shift along the environmental gradients is largely unknown. To clarify this issue, we first tested plant-plant facilitation along with four phosphorus (P) gradients in maize-grass pea intercropping system. Results illustrated a progressive transition of seed yield-based facilitation from mutually facilitated (+/+) to maize facilitated but grass pea as facilitator (+/-) along with low to high P gradients. Secondly, above trend was evidently enhanced when combining with drought stress gradients, in which severe drought amplified facilitative effects, whereas the magnitude of facilitation was relatively weak under well-watered condition. Interestingly, biomass-based facilitation transition did not synchronize with seed-based one, in which occurred in a broader threshold range of water and P gradients. Specifically, total yield, biomass, N and P uptake increased by 0.5%, 4.1%, 1.8% and 2.9% under the sufficient P and water availability, whereas these indicators increased by 25.3%, 18.5%, 20.5% and 21.4% in P and water deficient soils. And the total net effect was positive under all the environmental conditions. Rhizosphere interaction plays a crucial role in facilitation judgment, and the driving mechanism was associated with soil acidification and microbial community promotion under P-deficient condition. Under low soil moisture and available P, soil acidification and lower rhizosphere soil pH of intercropped maize were observed. Rhizosphere phosphatase secretion were significantly activated in P-deficient soils and accelerated the mineralization of soil organophosphorus, and the microbial biomass P was improved for stronger facilitation. Taken together, our findings confirmed the P and water driven facilitation shift along with stress gradients and highlighted the roles of rhizosphere interaction in affecting species diversity advantage. In conclusion, our work provided a relatively full picture for plant facilitation evaluation and more accurate management regarding intercropping productivity.

【 授权许可】

Unknown