Improving P-efficiency in Crops Through the Management of Highly Effective Beneficial Soil Microorganisms
Better use efficiency of both indigenous soil phosphorus (P) and applied P fertilizer by cropping systems will extend the life of current mined world phosphorus deposits and reduce the need to develop lower grade phosphate rock deposits.
IPNI-2014-CAN-SK43
01 Apr 2014
Project Description
Potential benefits to the agriculture industry derived from the project
Better use efficiency of both indigenous soil phosphorus (P) and applied P fertilizer by cropping systems will extend the life of current mined world phosphorus deposits and reduce the need to develop lower grade phosphate rock deposits. This will help make agricultural cropping systems more sustainable in the longer term.
Supporting the development of highly sustainable 2nd generation crop production systems based on soil ecology principles are of interest to both organic and conventional production sectors. Supporting the development of tomorrow`s agriculture will improve the environmental quality and the future of humanity.
Background information
Our research results indicate that the diversity of arbuscular mycorrhizal (AM) fungi in the Canadian Prairies has been negatively impacted by past crop production practices such as the use of fallowing and the prevalence of only small grain cereals in rotation. Consequently, the functionality provided by the original diversity of AM fungi to crop P nutrition has been reduced. Including a pulse crop such as lentils in rotation, along with inoculation of this crop with highly effective AM fungal isolates may be a good strategy to increase the functionality of the AM symbiosis of crop plants and increase the sustainability and profitability of agriculture. We now have tools to assess the abundance of various AM fungi in soils, and we are completing the evaluation of the functionality of 49 Prairie native AM fungal isolates to be used as crop inoculates to improve P use from soils. We also have isolates of native plant-growth- promoting-rhizobacteria (PGPR) that are closely associated with both pulse crop roots and AM hyphae. These 140 isolates are highly effective P-solubilizing microorganisms and could be used in the AM inoculants for the Prairie. Results indicate that crop plants and AM fungi do ‘manipulate’ soil microbial diversity; we can produce a technology that reliably improves the P-efficiency of a cropping system using the ability of plants to collaborate with microbial associates. We want to do this within Round II of the Organic Science Cluster, which multiplies industry dollars, because both organic and conventional growers are interested in making more efficient use of P in crop soils. A previous survey conducted by us in the Prairies shows that wheat is P-limited in 57% of the organic fields in best years, an effect that is even greater in dry years. These inoculants could also be used to improve the use of P fertilizers and effectively reduce P fertilizer rates.
Objectives for 2014-2017
We propose to raise the efficiency of P use by crops through (1) the development of inoculants combining highly effective AM fungal strains and companion plant-growth-promoting-rhizobacteria and P-solubilising microorganisms, and (2) the identification of agronomic practices improving rhizosphere community function. Through hypothesis testing, information will be generated under a set of three specific research objectives. A fourth objective relates to technology transfer.
We would like to:
A. Develop improved commercial AM inoculants with Premier Tech Biotechnologies using AM fungi adapted to Prairie soils combined with highly effective and adapted P-solubilizing and PGPR bacteria, using a 6-step approach:
- Select in the greenhouse the best combination of highly effective microorganisms for use on lentil.
- Develop inoculants based on different combinations of AM fungi and bacteria identified above.
- Evaluate the performance of the best inoculants, for their effects on the efficiency of various P sources (soil P only, Soil test recommendation rates [100% and 75%] of ammonium phosphate fertilizer, rock phosphate, and manure) in lentil, grown in the field at Swift Current and Lethbridge.
- Develop specific molecular probes to trace the highly effective AM fungal isolates, identified above.
- Evaluate the residual effects of highly effective inoculants applied on lentil, on the P- efficiency of subsequent crops of wheat.
- Using a metagenomic approach and the Illumina technology, to document the impact of fertilizers and inoculants on soil microbial function.
C. Prepare a guide of best practices for the management of the AM symbiosis in crop production for the Americas in English, Spanish, and French.