Phosphorus solubilisation with varying drying and rewetting stresses under four contrasting soils from different regions of China

Phosphorus solubilisation with varying drying and rewetting stresses under four contrasting soils from different regions of China  

Nyamdavaa Mongol1, Jianbo Shen2, Philip M. Haygarth1  

  

1Lancaster Environment  Centre, Lancaster University, Lancaster, LA1 4YW, United Kingdom.  

2Department of Plant Nutrition, China Agriculture University, Key Laboratory of Plant-Soil Interactions, Beijing 100193, PR China  

  

Abstract 

We tested the hypothesis that agricultural soils with a recent history of drying and rewetting (DRW) can trigger phosphorus (P) solubilisation in the rhizosphere, with a subsequent growth response of maize (Zea mays). Specifically, it aimed at investigating a possible delayed effect of DRW stresses on the soils by studying the relationship between P solubilisation in the rhizosphere, plant P acquisition and performance, and root growth under different types of agricultural soils with the previous history of a series of DRW events. The soils were collected from four different agricultural regions of China, Shandong, Chongqing, Heilongjiang and Beijing (sieved <2 mm), and then treated with four varying cycles of DRW events prior to the experiment to raise levels of soil biotic and abiotic activities. A controlled pot experiment was conducted in order to establish the Olsen’s P concentration in the soil, maize shoot P concentrations, root morphology and other rhizosphere parameters, for a duration of 43 days after planting. The results show a positive relationship between plant biomass, plant P concentration and Olsen`s P. The effect was most clearly demonstrated by the level of plant growth and their biological performance in the rhizosphere, as the plants responded better in the soil with a DRW background than to a soil that did not have a history of DRW in the past. Notably, the most positive results were obtained from the Haplic Phaeozems soil of Heilongjiang, leading to an acceptance of the hypothesis. However, the soluble P concentration and plant growth response varied depending on P application rates and soil types.