Can we reduce phosphorus runoff from agricultural fields by stimulating soil biota?

J Environ Qual. 2020 Jul;49(4):933-944. doi: 10.1002/jeq2.20104.


When fertilizer phosphorus (P) is applied to soils, the P can run off fields and cause harmful algal blooms. Due to its chemistry, much of the added P that does not run off can bind to soil particles and become inaccessible to plants. In natural systems, microbial and faunal decomposers can increase soil P accessibility to plants. We tested the hypothesis that this may also be true in agricultural systems, which could increase P application efficiency and reduce runoff potential. We stimulated soil fauna with sodium (Na+ ) and microbes with carbon (C) by adding corn (Zea mays L.) stover and Na+ solution to plots in conventionally managed corn fields in northwestern Ohio. Stover addition increased microbial biomass by 65 ± 12% and respiration by 400-700%. Application of stover with Na+ increased soil detritivore fauna abundance by 51 ± 20% and likely did not affect the other invertebrate guilds. However, soil biological activity was low compared with natural systems in all treatments and was not correlated with instantaneous measures of P accessibility, though cumulative P accessibility over the course of the growing season was correlated with microbial phosphatase activity (slope = 1.01, p < .01) and respiration (slope = 0.42, p = .02). Therefore, in agricultural systems, treatments to stimulate decomposers already in those systems may be ineffective at increasing soil P accessibility in the short term, but in the long term, higher microbial activities can be associated with higher soil P accessibility.

MeSH terms

  • Biota
  • Fertilizers
  • Ohio
  • Phosphorus / analysis*
  • Soil*


  • Fertilizers
  • Soil
  • Phosphorus