Management of soil phosphorus and plant adaptation mechanisms to phosphorus stress for sustainable crop production: a review

Abstract

Phosphorus is one of the seventeen essential nutrients required for plant growth. Despite its importance, it is limiting crop yield on more than 40% of the world's arable land. Moreover, global P reserves are being depleted at a higher rate and according to some estimates there will be no soil P reserve by the year 2050.This is a potential threat to sustainable crop production. Most of the P applied in the form of fertilizers may be adsorbed by the soil, and is not available for plants lacking specific adaptations. Available soil P and hence crop yield can, however, be increased through applying P containing fertilizers to feed the ever increasing world population. The P contained in crop residues if left in the field can be recycled by incorporating the residues into the soil whereas part of P in crop residues fed to livestock can be returned back to the soil in the form of manure and as bone meal. Additionally, plants have evolved a diverse array of strategies to obtain adequate P for their growth under P limiting conditions (a term called as P-efficiency mechanisms). Plant P-efficiency mechanisms include both improved uptake efficiency (the ability of a plant to take up more P under P limiting condition) and improved utilization efficiency (the ability of a plant to produce higher dry matter yield per unit P taken up). Uptake efficiency mechanisms include modification of root architecture, development of large root system, longer root hairs and thinner roots, exudation of low molecular weight organic acids, protons and enzymes such as phosphatases and phytases, association with mycorrhiza, production of cluster roots and expression of high affinity P transporters all of which contribute to increased P uptake efficiency of the plant. Other mechanisms include the use of alternative P-independent enzymes and glycolytic pathways, efficient cytoplasmic P homeostasis and higher ability to remobilize P from other plant parts all of which are part of enhanced P utilization efficiency. Traits related to the above morphological, physiological, biochemical and molecular adaptation mechanisms under P stress can be utilized in improving cultivated crops for P efficiency through breeding programs.

Efeito de doses de fósforo na produtividade e armazenamento pós-colheita de dois cultivares de cebola

“…Como consequência, nas adubações, é o fósforo o nutriente que entra em maiores proporções (Coutinho et al, 1993). Estima-se que a produtividade das culturas é limitada pela deficiência de fósforo em 30 a 40% das terras agricultáveis do mundo (Vance et al, 2003;Balemi & Negisho, 2012).…”

Differential vineyard fertilizer management based on nutrient,s spatio-temporal variability

“…Therefore, a certain inconsistency exists among studies related to the use of spectroradiometers for this purpose and further research is necessary Differential vineyard fertilizer management to solve some still-unclear aspects between spectral responses and plant nutrient concentration, namely, the low concentration of some nutrients in the leaves (e.g. mean P 2 O 5 <0.5%) and the real influence of canopy structure on spectral measurements (Balemi and Negisho, 2012). Additional works should evaluate and validate the active optical sensors in confirmed situations of plant deficiency.…”

“…The complexity of soil phosphorus dynamics has been demonstrated by several studies. As a result of adsorption, precipitation and conversion to organic forms, only 10-30% of the applied mineral phosphate fertilizer can be recovered by the crop grown during the year of application (Balemi and Negisho, 2012). Despite the low potential for implementing site-specific management of phosphorus fertilizer, there is potential for implementing site-specific management of potassium fertilizer ( =16.3 ± 11.3%; more than 90% of the total area is stable or moderately stable and 45% below the reference value) and pH correction ( =2.6 ± 1.9%; 100% stable and…”

“…An integrated understanding of the complex defence mechanisms of grapevine to edaphic stresses could lead to actions targeted at enhancing natural nutrient cycling, reequilibrating the nutritional status of plants and reducing dependence on mineral fertilizers in vineyard systems (Stevanato et al, 2014). These adaptations in root morphology and root physiology are a major grapevine characteristic resulting from its deep root structure, which allows it to absorb water and nutrients from great depths (Shen et al, 2011;Balemi and Negisho, 2012), particularly important in the case of phosphorus because of the relative immobility of this nutrient in the soil (Balemi and Negisho, 2012). Smart et al, (2006) observed that vine nutrition is favoured in the upper horizons with the lower layers contributing to the overall water supply.…”

Grain yield and phosphorus use efficiency of wheat and pea in a high yielding environment

“…Soil phosphorus (P) deficiency is a major constraint to increased crop yields in many areas of the world (Vance et al, 2003). Relative to nitrogen and potassium, the recovery of P fertilizers by crop plants is usually very low due to soils' high capacity to fix P to soil constituents of little bioavailability (Manske et al, 2001;Lynch, 2007;Balemi and Negisho, 2012). Therefore, it is not surprising that since the green revolution, high amounts of P fertilizers have been applied to soils in order to meet the P demand of agricultural systems (Tilman et al, 2001).…”