Record ID No. |
153 |
Author(s) |
Covacevich F., Echeverria H.E., Aguirrezabal L.A.N. , 2007 |
Affiliation |
Unidad Integrada INTA Balcarce, Facultad de Ciencias Agrarias UNMP, CC 276, RA-7620 Buenos Aires, DF, Argentina |
Title |
Soil available phosphorus status determines indigenous mycorrhizal colonization of field and glasshouse-grown spring wheat from Argentina |
Source. Vol.(no):Page |
Applied Soil Ecology. 35(1): 1-9p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Soil plant relations |
Sub-subjects |
Fungal evaluation |
Host |
Triticum aestivum |
Organism |
AMF |
Country |
Argentina, South America |
Abstracts |
Wheat production (Triticum aestivum L.) has increased across the world during last century with the intensification of agriculture. Phosphorus (P) fertilization is a common practice to improve wheat growth in Argentina. We investigate whether indigenous arbuscular mycorrhizal colonization (AMC) of hard red spring wheat is controlled by shoot P content (SPc) or by available soil P in an agricultural soil from the southeastern Argentine Pampas. In the field, AMC was monitored four times during two growing seasons of a conventional wheat crop. Treatments were: without P supply, annual supply of 11 and 22 kg P ha(-1) during the last 5 years, and 164 kg P ha(-1) applied once 5 years before the experiment. In the glasshouse, AMC was assessed three times in wheat growing in pots filled with the soil from unfertilized plots; treatments were: P (0 and 20 mg P pot(-1)), and nitrogen (N) fertilization (0 and 150 mg N pot(-1)). A range of soil P between 6 and 60 mg P kg(-1) was obtained and the AMC ranged from 1% to 67% of root length colonized under both field and glasshouse conditions. P supplied annually increased growth and SPc but decreased AMC. N fertilization did not affect growth or AMC. Variations in SPc did not account for AMC. Variability in AMC was best accounted for local current soil available P content (r(2) = 0.59). A linear-plateau relationship between soil P and indigenous AMC was established in wheat plants growing under contrasting environmental and experimental (field and glasshouse) conditions. Indigenous AMC was depressed by available soil P in the range 0-27 mg P kg(-1) (a decrease of 2.8% mg P-1 kg(-1)). Above 27 mg P kg soil(-1), AMC was stabilized at about 10%. Grain yield increased with fertilization and the highest relative shoot dry matter in field was obtained at 15.5 mg P kg soil(-1). The soil P range that ensures high wheat production without deterring indigenous AMC is discussed. |