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ARS Home » Northeast Area » Orono, Maine » New England Plant, Soil and Water Research Laboratory » Research » Publications at this Location » Publication #253845

Title: Soil test and microbial biomass phosphorus levels impacted by potato cropping system and water management

Author
item He, Zhongqi
item Honeycutt, Charles
item Olanya, Ocen
item Larkin, Robert
item Halloran, John

Submitted to: International Symposium on Phosphorus Dynamics in the Soil Plant Continuum
Publication Type: Abstract Only
Publication Acceptance Date: 7/13/2010
Publication Date: 9/20/2010
Citation: He, Z., Honeycutt, C.W., Olanya, O.M., Larkin, R.P., Halloran, J.M. 2010. Soil test and microbial biomass phosphorus levels impacted by potato cropping system and water management. International Symposium on Phosphorus Dynamics in the Soil Plant Continuum. September 19-23, 2010. CD-ROM.

Interpretive Summary:

Technical Abstract: Potato crops generally require high amounts of phosphorus (P) fertilizer to reach economically acceptable yields. However, high inputs of P not only increase production cost, but also may increase the environmental risk of P runoff. We evaluated soil test P and microbial biomass P in soils from five different potato cropping systems with and without irrigation. Olsen and ammonia oxalate extractable P were not significantly influenced by crop rotation. The modified Morgan P level differed between soils from different cropping systems. Correlation analysis revealed that modified Morgan P in soil sampled in the Spring was negatively correlated with potato yield from the previous Fall. Microbial biomass-P was measured by both microwave irradiation and chloroform fumigation. P concentrations measured after microwave treatment were always lower than their control counterparts, indicating inapplicability of this method for soil microbial biomass P measurement. Upon using chloroform fumigation, we observed more microbial biomass P under rainfed management (18.9 – 32.7 mg/kg) than under irrigated management (12.3 – 21.2 mg/kg). Both soil test P and microbial biomass P data indicated that crop rotation can impact soil P status. However, more data from longer term field studies are needed to confirm and more fully quantify this impact.