Impact of elevated CO₂ on soil phosphorus dynamics of lentil (Lens culinaris L. medik) genotypes

The rising level of carbon-di-oxide (CO₂) has an enormous impact on crop growth and physiology especially in the case of legumes. In general elevated CO₂ (e[CO₂]) has a positive impact on legumes but, to maximize the benefit crops must be supplemented with adequate levels of essential nutrients especially phosphorus (P). Therefore, a controlled experiment under OTC has been taken to understand the impact of short-term e[CO₂] on soil P-dynamics and changes in labile and non-labile soil P-pools under two contrasting genotypes of lentil namely, IPL-316 and IPL-406. Results showed soluble-P (sol-P) and di-calcium P (Ca2-P) both increased significantly under e[CO₂] in the case of both the genotypes and results are more prominent in IPL-316. The ratio of labile: non-labile P increased under e[CO₂] by 28% and 18% for IPL-316 and IPL-406 respectively over ambient. Organic carbon and available nitrogen (N) and P also increased significantly under e[CO₂]. Short term exposure of e[CO₂] failed to show any noticeable change in bulk soil P-dynamics. Hence, short term e[CO₂] exposure can cause marked change in labile P-pools and the results are more prominent in IPL-316.