An Assessment of Climate Induced Increase in Soil Water Availability for Soil Bacterial Communities Exposed to Long-Term Differential Phosphorus Fertilization

Abstract

The fate of future food productivity depends primarily upon the health of soil used for cultivation. For Atlantic Europe, increased precipitation is predicted during both winter and summer months. Interactions between climate change and the fertilization of land used for agriculture are therefore vital to understand. This is particularly relevant for inorganic phosphorus (P) fertilization, which already suffers from resource and sustainability issues. The soil microbiota are a key indicator of soil health and their functioning is critical to plant productivity, playing an important role in nutrient acquisition, particularly when plant available nutrients are limited. A multifactorial, mesocosm study was established to assess the effects of increased soil water availability and inorganic P fertilization, on spring wheat biomass, soil enzymatic activity (dehydrogenase and acid phosphomonoesterase) and soil bacterial community assemblages. Our results highlight the significance of the spring wheat rhizosphere in shaping soil bacterial community assemblages and specific taxa under a moderate soil water content (60%), which was diminished under a higher level of soil water availability (80%). In addition, an interaction between soil water availability and plant presence overrode a long-term bacterial sensitivity to inorganic P fertilization. Together this may have implications for developing sustainable P mobilization through the use of the soil microbiota in future. Spring wheat biomass grown under the higher soil water regime (80%) was reduced compared to the constant water regime (60%) and a reduction in yield could be exacerbated in the future when grown in cultivated soil that have been fertilized with inorganic P. The potential feedback mechanisms for this need now need exploration to understand how future management of crop productivity may be impacted.

Global Mapping of Potential and Climatic Plant‐Available Soil Water

“…Sandy soils require more frequent irrigation than silty soils with larger PASW storage capacity. For natural systems, the concept of PASW has been used in ecological studies (Liu et al., 2009; Randall et al., 2020) to investigate how soil modulates climatic inputs or forcing affecting vegetation. In other words, PASW is not used for “design” or crop selection, but for interpretation of natural vegetation response to climatic conditions or changes in rainfall patterns.…”

Effects of long‐term phosphorus fertilizer inputs and seasonal conditions on organic soil phosphorus cycling under grazed pasture

“…Under controlled environments, P fertilization has been found to have a more prominent effect on acid and alkaline phosphatase enzyme activities than soil moisture or temperature (Randall et al, 2020;Sun et al, 2018). However, field studies conducted in intensively managed agroecosystems and grasslands showed that seasonal changes in soil moisture and temperature had a more significant impact on alkaline phosphatase enzyme activity compared with P fertilization (Shi et al, 2013(Shi et al, , 2020.…”

“…Perrott et al (1992) found that microbial biomass P increased with increasing soil moisture in a low P grassland soil, whereas He et al (1997) described no clear relationship between microbial biomass P and air temperature in both unfertilized and P fertilized pasture systems in the United Kingdom. On the other hand, Randall et al (2020) pointed out a significant response of acid phosphatase activity to historical soil P status but not of water availability in soils taken from a long‐term P fertilization experiment under pastures. A more refined understanding of P immobilization and mineralization processes as affected by soil moisture, temperature, and P availability is needed to better predict organic P cycling, especially under future scenarios of climate change.…”