Soil microbial biomass phosphorus as an indicator of phosphorus availability in a Gleyic Andosol

Abstract

The relationship between plant phosphorus (P) uptake and soil microbial biomass phosphorus (biomass P) or available phosphorus (Truog P) was estimated in a Gleyic Andosol in Sapporo, Hokkaido, in a 4-year field trial (2004)(2005)(2006)(2007). Every year, the soil was treated in duplicate (each plot 36 m 2 ) or triplicate (each plot 24 m 2 ) with chemical fertilizer, cow manure compost or sewage sludge compost, and then kidney beans (Phaseolus vulgaris) were planted. Pooled data of the shoot content of P at harvest over the 4 years was significantly correlated with biomass P determined 1 month after the application of fertilizer (P < 0.01). A multivariate analysis revealed that the grain yield was significantly positively correlated with the shoot content of P (P < 0.01) and significantly negatively correlated with the shoot content of calcium (P < 0.05), but not correlated with the shoot content of either nitrogen or potassium. These results suggest that P is the most limiting element to affect the productivity of kidney bean plants in this trial and that biomass P is an important P source that explains the differences in P availability among soil amendments. Biomass P is a better indicator of P availability for kidney beans grown in Gleyic Andosols compared with Truog P, which is widely used in Japan.

Compost and phosphorus amendments for stimulating microorganisms and growth of ryegrass in a Ferralsol and a Luvisol

“…The three fertilizer treatments differed in their effects on microbial biomass and plant biomass, although nutrients were supplied at virtually the same rate, suggesting that the form of application has a significant effect. It is well known that an easily soluble mineral P fertilizer such as TSP is strongly adsorbed immediately after application to soils with high contents of Fe and Al oxides (Ayaga et al, 2006;Takeda et al, 2009;Sugito et al, 2010). The application of compost considerably lowered this immediate fixation of TSP in the Ferralsol.…”

“…Incorporation of P into microbial biomass and its associated pool of metabolites is another mechanism that significantly improves P availability to plants (Khan and Joergensen, 2009;Sugito et al, 2010). The combined application of organic materials and inorganic P fertilizer stimulates the synthesis of soil microbial biomass and labile microbial metabolites rich in P (Khan and Joergensen, 2009), which act as a labile pool of P in soil protected against fixation (Ayaga et al, 2006;Gichangi et al, 2009;Sugito et al, 2010). During the turnover of the soil microbial biomass, this P may be slowly released and taken up more efficiently by the crops (Kouno et al, 2001).…”

Innovative methods in soil phosphorus research: A review

“…Although the microbial biomass contains usually only 0.4 to 2.5% of P t in cropped soils and up to 7.5% in grassland soils ( Oberson and Joner , 2005 ), soil microbial biomass P (P mic ) stores an essential labile P source for the vegetation ( Richardson and Simpson , 2011 ). It can be a good indicator of P availability for plants ( Sugito et al, 2010 ) and is composed of nucleic acids (75%), acid-soluble P-esters (20%), and phospholipids (5%) ( Webley and Jones , 1971 ). Based on a meta-analysis, Cleveland and Liptzin ( 2007 ) derived a global soil microbial C:N:P ratio of about 60:7:1.…”

Hidden miners – the roles of cover crops and soil microorganisms in phosphorus cycling through agroecosystems

“…Cover crops increase the abundance and diversity of microfauna (Blanchart et al 2006) which restricts long-term microbial immobilization during the decomposition of plant litter. Given the close relationship between Phaseolus vulgaris yield and P mic , microbial biomass P was proposed as an indicator of soil P availability on P-sorbing Andosols in Japan, instead of the widely used Truog-P (Sugito et al 2010).…”