Beneficial organisms for nutrient uptake
Bindraban, Prem S.
Thomas W. Kuyper
Phosphorus (P) availability is a major global limiting factor in crop production. The global input of mineral P fertilizer in food production is significant, but its efficiency is low, with only approximately 20% of applied P being converted into consumed P in food. Moreover, excessive application of P can lead to its accumulation in soils. As P resources are finite, maximizing their efficient use and stimulating the uptake of newly applied P fertilizers is crucial. This study investigates the hypothesis that enhancing early plant growth can improve plant P uptake, regardless of soil P levels. Experiments demonstrate that the recovery of mineral P fertilizer by crops is generally low, often less than 30%. Much of the applied fertilizer becomes bound to the soil complex, rendering it unavailable for plant uptake. Soil chemical processes produce very low P concentrations in the soil solution, whereas root concentrations are significantly higher. P deficiency in soils produces low crop yields, particularly in developing countries. To address this, the P concentration in the soil solution must be increased, or plants should possess enhanced abilities to extract P from the soil complex. Increasing P availability in soils requires substantial P application over several years, exceeding the crop's yearly uptake. Soil "loading" with P can occur unintentionally in regions with nutrient surpluses, such as areas with concentrated livestock production. These fertile soils contain excessive amounts of P compared to the crop's annual uptake. Similarly, less fertile soils have lower total P content but also lower crop off-take. In both cases, soil P reserves are abundant and could sustain agricultural production for many years if made available to the crop. This study emphasizes the importance of enhancing early plant growth to improve P uptake efficiency and utilize indigenous soil resources effectively. By increasing our understanding of plant-soil interactions and developing strategies to optimize P availability and uptake, we can enhance agricultural productivity while minimizing the environmental impact of excessive P application.
Soil organisms, Synergism, Mycorrhizae, Fertilizers
Nina Koele, Thomas W. Kuyper and Prem S. Bindraban, 2014.Beneficial organisms for nutrient uptake. VFRC Report 2014/1, Virtual Fertilizer Research Center, Washington, D.C. 63 pp.; 4 figs.; 330 ref. nbsp;