Improving Phosphorus Use Research Articles

Corn Yield and Phosphorus Use Efficiency Response to Phosphorus Rates Associated With Plant Growth Promoting Bacteria

The use of plant growth promoting bacteria that can solubilize phosphorus (P) has shown potential to improve nutrient availability in grass crops such as corn (Zea mays L.) This study was developed to investigate if inoculation with Azospirillum brasilense, Bacillus subtilis or Pseudomonas fluorescens associated with P2O5 rates can improve phosphorus use efficiency (PUE) reflecting on greater corn development and yield. The field trial was set up in a Rhodic Hapludox under no-till system under Savannah conditions, in a completely randomized block design with four replicates. Treatments were tested in a full factorial design and included: i) five P2O5 rates (0 to 105 kg ha-1) and ii) four PGPB seed inoculation (Control – without inoculation, A. brasilense, B. subtilis or P. fluorescens). Inoculation was found to increase grain yield by 17.5% when B. subtilis was inoculated associated with 70 kg P2O5 ha-1 and by 34.7% when A. brasilense was inoculated with application of 105 kg P2O5 ha-1. In addition, inoculation with B. subtilis and A. brasilense were found to increase biomass and grain P uptake, number of grains per row, stem diameter, ear length and PUE. The results of this study showed positive improvements in P uptake as a result of B. subtilis and A. brasilense inoculation, with an increase of 86.9 and 40.6% on PUE, respectively; while the P. fluorescens inoculation were less evident. Further research should be conducted under biotic or/and abiotic conditions to better understand the role of PGPB, inoculated alone or in combination as the co-inoculated method.

Improving Phosphorus Use Efficiency and Optimizing Phosphorus Application Rates for Maize in the Northeast Plain of China for Sustainable Agriculture

Optimizing the phosphorus (P) application rate can increase grain yield while reducing both cost and environmental impact. However, optimal P rates vary substantially when different targets such as maximum yield or maximum economic benefit are considered. The present study used field experiment conducted at 36 experiments sites for maize to determine the impact of P application levels on grain yield, plant P uptake, and P agronomy efficiency (AEP), P-derived yield benefits and private profitability, and to evaluated the agronomically (AOPR), privately (POPR), and economically (EOPR) optimal P rate at a regional scale. Four treatments were compared: No P fertilizer (P0); P rate of 45–60 kg ha−1 (LP); P rate of 90–120 kg ha−1 (MP); P rate of 135–180 kg ha−1 (HP). P application more effectively increased grain yield, reaching a peak at MP treatment. The plant P uptake in HP treatment was 37.4% higher than that in P0. The relationship between P uptake by plants (y) and P application rate (x) can be described by the equation y = −0.0003x2 + 0.1266x + 31.1 (R2 = 0.309, p < 0.01). Furthermore, grain yield (y) and plant P uptake (x) across all treatments also showed a significant polynomial function (R2 = 0.787–0.846). The MP treatment led to highest improvements in P agronomic efficiency (AEP), P-derived yield benefits (BY) and private profitability (BP) compared with those in other treatments. In addition, the average agronomically (AOPR), privately (POPR), and economically optimal P rate (EOPR) in 36 experimental sites were suggested as 127.9 kg ha−1, 110.8 kg ha−1, and 114.4 kg ha−1, which ranged from 80.6 to 211.3 kg ha−1, 78.2 to 181.8 kg ha−1, and 82.6 to 151.6 kg ha−1, respectively. Economically optimal P application (EOPR) can be recommended, because EOPR significantly reduced P application compared with AOPR, and average economically optimal yield was slightly higher compared with the average yield in the MP treatment. This study was conducive in providing a more productive, use-effective, profitable, environment-friendly P fertilizer management strategy for supporting maximized production potential and environment sustainable development.

Variation in root system architecture and morphology of two wheat genotypes is a predictor of their tolerance to phosphorus deficiency

Variation in root system architecture (RSA) and morphology are important for improving phosphorus use efficiency (PUE) in wheat. This work aims to analyze the root system architecture and morphology of wheat genotypes to explain their variation in PUE. Two genotypes differing in PUE, RAC875 (P efficient) and Wyalkatchem (P inefficient) were grown in a sandy soil amended with adequate basal nutrients and two P rates (10 and 30 mg P kg−1). RSA traits were measured by freely available software, GiA roots and DIRT, and root hair features were measured using a microscope with an attached camera and LAS v3.6 software. Under low P supply, RAC875 produced greater shoot dry matter (DM) at 24, 27 and 48 days after sowing (DAS), and at maturity, RAC875 also had a higher grain yield at maturity. Enhanced P efficiency (biomass and seed yield at inadequate P supply relative to adequate P supply) was observed more so in RAC875 at all harvest times. P supply affected most RSA traits, with low P leading to reductions in convex hull area (CHA), root surface area, root volume, total root length and root tip number. RAC875 produced significantly greater CHA than Wyalkatchem at low P supply while Wyalkatchem had significantly larger CHA than RAC875 when P was non-limiting. RAC875 also had greater root hair density (RHD) than Wyalkatchem at low P level, but no difference was observed at adequate P. When grown under low P supply, a greater CHA and RHD in RAC875 were likely to contribute to improved P uptake, resulting in its higher shoot biomass and grain yield.

Root/Rhizosphere Management for ImprovingPhosphorus Use Efficiency and Crop Productivity

Rhizosphere processes affect soil P availability and efficient use of P by plants. This paper summarizes the principles of root/rhizosphere management, and highlights case studies on how to exploit root-soil-microbe interaction processes to improve crop productivity and P use efficiency.

Novel value-added phosphorus-potassium-activator fertilizers improve phosphorus use efficiency and crop yields

ABSTRACTIt is thus essential and critical to enhance phosphorus (P) fertilizer use efficiency of crops to improve agricultural and environmental sustainability. A pot experiment was conducted to examine the impact of different kinds of value-added P-potassium (K)-activator fertilizers (VPAFs) on soil nutrient bioavailability, growth and yield of wheat-maize crops. Compared with that of the control (NPK) treatment, the wheat yields of VPAF treatments increased from 6.59% to 18.61%, and the maize yields increased from −0.22% to 15.58%. In addition, the P fertilizer utilization rate of VPAF treatments increased by an average of 10.87% and 5.75% for wheat and maize, respectively. Therefore, VPAF application in agriculture can introduce multiple benefits including increasing crop yield, improving fertilizer utilization efficiency, enhancing nutrient bioavailability, and reducing pollution.

Quantifying the Urban Food-Energy-Water Nexus: The Case of the Detroit Metropolitan Area.

The efficient provision of food, energy, and water (FEW) resources to cities is challenging around the world. Because of the complex interdependence of urban FEW systems, changing components of one system may lead to ripple effects on other systems. However, the inputs, intersectoral flows, stocks, and outputs of these FEW resources from the perspective of an integrated urban FEW system have not been synthetically characterized. Therefore, a standardized and specific accounting method to describe this system is needed to sustainably manage these FEW resources. Using the Detroit Metropolitan Area (DMA) as a case, this study developed such an accounting method by using material and energy flow analysis to quantify this urban FEW nexus. Our results help identify key processes for improving FEW resource efficiencies of the DMA. These include (1) optimizing the dietary habits of households to improve phosphorus use efficiency, (2) improving effluent-disposal standards for nitrogen removal to reduce nitrogen emission levels, (3) promoting adequate fertilization, and (4) enhancing the maintenance of wastewater collection pipelines. With respect to water use, better efficiency of thermoelectric power plants can help reduce water withdrawals. The method used in this study lays the ground for future urban FEW analyses and modeling.

A novel glycerophosphodiester phosphodiesterase improves phosphate deficiency tolerance in rice

Soil phosphate (Pi) deficiency is major constraint for rice cultivation worldwide. Cellular membranes account for one third of cellular organic phosphorus (P) in the form of phospholipids. Therefore, remobilization of Pi from membrane phospholipids under Pi deficiency can be an important strategy to improve phosphorus use efficiency. Glycerophosphodiester phosphodiesterases (GDPDs) hydrolyse intermediate product of phospholipid catabolism, glycerophosphodiesters to glycerol-3-phosphate, a precursor for P and non P-lipid biosynthesis. Here, we show that OsGDPD2 is a Pi deficiency responsive gene, which is transcriptionally regulated by OsPHR2. In silico analysis of active site residues and enzymatic assays confirmed phosphodiesterase activity of OsGDPD2. All overexpression lines showed higher GDPD activity, Pi content, root growth, and biomass accumulation as compared with wild type. Conversely, silencing of OsGDPD2 led to decreased GDPD activity and Pi content. Notably, most of the P-containing metabolites and fatty acids were elevated in transgenic lines. Further, quantitative analysis of polar lipids revealed higher accumulation of several classes of phospholipids and galactolipids in overexpression lines indicating a potential role of OsGDPD2 in de novo glycerolipid biosynthesis. Thus, present study provides insights into novel physiological roles of OsGDPD2 in low Pi acclimation in rice.

Phosphorus Application Rates Affected Phosphorus Partitioning and Use Efficiency in Tomato Production

Core Ideas The partitioning of P uptake to fruit was maximized at 72 kg ha−1 in 2014. Increasing P rate linearly increased P concentrations in both soil and leachate. Efficiency of converting P fertilizer into yield decreased with increasing P rate. The rate 56 kg ha−1 was considered the sufficient P rate based on tomato yield. Understanding P accumulation and partitioning is essential for improving phosphorus use efficiency (PUE) and minimizing environmental impact. A 2‐yr study was conducted to determine P distribution and PUE in tomato (Solanum lycopersicum L.) production as influenced by P application rates in a calcareous soil. Phosphorus was applied at 0, 29, 49, 78, 98, and 118 kg ha−1 as pre‐plant dry fertilizers. At 95 d after transplanting, total phosphorus uptake (TPU) was not significantly affected by P rates in either year. In 2014, the highest proportion of TPU was accumulated in fruits and the maximum partitioning of TPU to fruits occurred at 72 kg ha−1. A higher or similar percentage of TPU was allocated to leaves comparing with fruits in 2015, which was probably due to the higher rainfall accumulation. Positive soil P budgets occurred with P rates ranging from 29 to 118 kg ha−1 in both years. Phosphorus concentrations in surface soil and subsurface leachate increased linearly with increasing P rate. Tomato marketable yield at the first and second combined harvest was not affected in 2014, whereas the yield increased linearly and attained a plateau at 56 kg ha−1 in 2015. There were no significant differences among treatments in the total season marketable yields in either year, thus, the partial factor productivity decreased with increasing P rate. Consequently, in the calcareous soils with 37 to 51 mg kg−1 of Mehlich‐3 extractable P, 56 kg ha−1 can be the sufficient P rate for tomato production.

Polymer coated novel controlled release rock phosphate formulations for improving phosphorus use efficiency by wheat in an Inceptisol

Non-renewable nature of rock phosphate (RP) reserves coupled with low use efficiency of applied phosphorus (P) fertilizers in the soil system results in irreversible loss of huge quantity of P to the environment. The technology of controlled release fertilizers which harmonizes crop demand and release of P from fertilizers are promising to prevent the loss as well as improve the P use efficiency. This article aimed to synthesize and assess some polymer coated novel controlled release rock phosphate formulations to synchronize P release with crop demand and increasing P recovery by wheat. Polymer coated novel products were synthesized by partially acidulating RP with sulphuric and phosphoric acids followed by coating with polyvinyl alcohol and liquid paraffin @ 2 and 3% levels of coating. These products were characterized through X-ray diffraction, fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phosphorus release pattern from novel coated fertilizers were monitored under controlled conditions in a laboratory incubation experiment at different moisture and temperature regimes. The products were also evaluated for their P supplying capacity to wheat in a greenhouse experiment. Results emanated from incubation study in a P-deficient Typic Haplustept revealed higher release of P at 20% moisture regime and 30 oC temperature. Phosphoric acid based coated products produced greater biomass yield than commercial diammonium phosphate and sulphuric acid formulated products. Product coated with polyvinyl alcohol @ 2% coating released P gradually that synchronized well with the plant P demand and resulted in greater biomass yield, P uptake and recovery by wheat than that of liquid paraffin and 3% level of coating. It can be concluded that novel technology of controlled release RP formulations using different coating agents could be exploited commercially as the alternative to water soluble P-fertilizers for enhancing P use efficiency.

Regulatory feedback response mechanisms to phosphate starvation in rice

Phosphorus is a growth-limiting nutrient for plants. The growing scarcity of phosphate stocks threatens global food security. Phosphate-uptake regulation is so complex and incompletely known that attempts to improve phosphorus use efficiency have had extremely limited success. This study improves our understanding of the molecular mechanisms underlying phosphate uptake by investigating the transcriptional dynamics of two regulators: the Ubiquitin ligase PHO2 and the long non-coding RNA IPS1. Temporal measurements of RNA levels have been integrated into mechanistic mathematical models using advanced statistical techniques. Models based solely on current knowledge could not adequately explain the temporal expression profiles. Further modeling and bioinformatics analysis have led to the prediction of three regulatory features: the PHO2 protein mediates the degradation of its own transcriptional activator to maintain constant PHO2 mRNA levels; the binding affinity of the transcriptional activator of PHO2 is impaired by a phosphate-sensitive transcriptional repressor/inhibitor; and the extremely high levels of IPS1 and its rapid disappearance upon Pi re-supply are best explained by Pi-sensitive RNA protection. This work offers both new opportunities for plant phosphate research that will be essential for informing the development of phosphate efficient crop varieties, and a foundation for the development of models integrating phosphate with other stress responses.

Improving phosphorus use efficiency: a complex trait with emerging opportunities.

Phosphorus (P) is one of the essential nutrients for plants, and is indispensable for plant growth and development. P deficiency severely limits crop yield, and regular fertilizer applications are required to obtain high yields and to prevent soil degradation. To access P from the soil, plants have evolved high- and low-affinity Pi transporters and the ability to induce root architectural changes to forage P. Also, adjustments of numerous cellular processes are triggered by the P starvation response, a tightly regulated process in plants. With the increasing demand for food as a result of a growing population, the demand for P fertilizer is steadily increasing. Given the high costs of fertilizers and in light of the fact that phosphate rock, the source of P fertilizer, is a finite natural resource, there is a need to enhance P fertilizer use efficiency in agricultural systems and to develop plants with enhanced Pi uptake and internal P-use efficiency (PUE). In this review we will provide an overview of continuing relevant research and highlight different approaches towards developing crops with enhanced PUE. In this context, we will summarize our current understanding of root responses to low phosphorus conditions and will emphasize the importance of combining PUE with tolerance of other stresses, such as aluminum toxicity. Of the many genes associated with Pi deficiency, this review will focus on those that hold promise or are already at an advanced stage of testing (OsPSTOL1, AVP1, PHO1 and OsPHT1;6). Finally, an update is provided on the progress made exploring alternative technologies, such as phosphite fertilizer.

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Brachiaria as a Cover Crop to Improve Phosphorus Use Efficiency in a No-till Oxisol

Oxidic soils are phosphorus drains in soil; hence, P availability is a limiting factor in tropical, weathered Oxidic soils. It has been shown that some brachiarias grown as cover crops may increase soil available P to subsequent crops. The objective of this study was to evaluate soil P cycling and availability, as well as the response of soybean to soluble and natural reactive phosphates as affected by ruzi grass (Urochloa ruziziensis, R. Germ. and C.M. Evrard, Crin) grown as a cover crop in a no-till system. Experimental treatments consisted of the presence or absence of ruzi grass in combination with a control (0.0 P) and soluble and reactive rock phosphate broadcast on the soil surface in the winter (80 kg ha-1 P2O5), plus three rates of P applied to soybean furrows (0, 30, and 60 kg ha-1 of P2O5) at planting, in the form of triple superphosphate. Soybean was cropped in two seasons: 2010/2011 and 2011/2012. Soil samples were taken before soybean planting (after desiccation of Brachiaria) at 0.00-0.05 and 0.05-0.10 m for soil available P. Total weight of dry matter and P accumulated in ruzi grass were determined, as well as soybean yields, P in soybean grains, and P use efficiency (PUE). The use of natural phosphate increased soil P availability. The highest yields were obtained with higher application rates of triple superphosphate in the planting furrow combined with broadcast rock phosphate. Broadcast application of Arad reactive phosphate increases and maintains soil available P, and this practice, associated with ruzi grass grown as a cover crop and the use of triple superphosphate applied to soybean furrows, results in higher use of P by soybeans.

Improving phosphorus use efficiency in agriculture: opportunities for breeding

AbstractPhosphorus (P) is often an important limiting factor for crop yields, but rock phosphate as fertilizer is a non-renewable resource and expected to become scarce in the future. High P input levels in agriculture have led to environmental problems. One of the ways to tackle these issues simultaneously is improving phosphorus use efficiency (PUE) of the crops through breeding. In this review, we describe plant architectural and physiological traits important for PUE. Subsequently, we discuss efficient methods of screening for PUE traits. We address targeted cultivation methods, including solid and hydroponic systems, as well as testing methods, such as image analysis systems, and biomass and photosynthesis measurements. Genetic variation for PUE traits has been assessed in many crops, and genetics of PUE has been studied by quantitative trait loci (QTL) analyses and genome-wide association study. A number of genes involved in the plant’s response to low P have been characterized. These genes include transcription factors, and genes involved in signal transduction, hormonal pathways, sugar signalling, P saving metabolic pathways, and in P scavenging, including transporters and metabolites and/or ATP-ases mobilizing P in the soil. In addition, the role of microorganisms promoting PUE of plants, particularly arbuscular mycorrhizal fungi is discussed. An overview is given of methods for selecting for optimal combinations of plant and fungal genotypes, and their genetics, incl. QTLs and genes involved. In conclusion, significant progress has been made in selecting for traits for PUE, developing systems for the difficult but highly relevant root phenotyping, and in identifying QTLs and genes involved.

Improving phosphorus use efficiency for snap bean production by optimizing application rate

Liu G.D., Morgan K., Hogue B., Li Y.C., Sui D. (2015): Improving phosphorus use efficiency for snap bean pro duction by optimizing application . Hort. Sci. (Prague), 42: 94–101.

Improving Phosphorus Use Efficiency in the Future

World demand for phosphorus (P) fertilizer and increasing environmental regulations concerning water quality will continue to motivate the search for ways to improve P use efficiency in potato production. While much effort has gone into understanding P availability and uptake from soil, relatively little is known about the possibility of increasing uptake efficiency through genetic improvement or improved root health. Potato exhibits considerable genetic variation in uptake efficiency of nutrients like nitrogen, and it is likely that genetic variation also exists in P use efficiency. Increased efficiency may be due to differences in tuber yield per unit of available P (utilization efficiency), or in rate of P absorption from the soil (uptake efficiency). Likewise, genetic improvements in resistance to root-decaying pathogens, such as Verticillium dahliae, and improved control practices are likely to help maintain a healthy root mass to aid in maintaining P uptake during periods of higher P demand during the growing season.

Effect of Phosphorus Fertilization to P Uptake and Dry Matter Accumulation in Soybean with Different P Efficiencies

Phosphorus (P) is an essential element for plant growth and yield. Improving phosphorus use efficiency of crops could potentially reduce the application of chemical fertilizer and alleviate environmental damage. Soybean (Glycine max (L.) Merr.) is sensitive to phosphorus (P) in the whole life history. Soybean cultivars with different P efficiencies were used to study P uptake and dry matter accumulation under different P levels. Under low P conditions, the P contents of leaf in high P efficiency cultivars were greater than those in low P efficiency cultivars at the branching stage. The P accumulation in stems of high P efficiency cultivars and in leaves of low P efficiency cultivars increased with increasing P concentration at the branching stage. At the late podding stage, the P accumulation of seeds in high and low P efficiency cultivars were 22.5 and 26.0%, respectively; and at the mature stage were 69.8 and 74.2%, respectively. In average, the P accumulation in whole plants and each organ was improved by 24.4% in high P efficiency cultivars compared to low P efficiency cultivars. The biomass between high and low P efficiency cultivars were the same under extended P condition, while a significant difference was observed at late pod filling stage. At the pod setting stage, the biomass of high P efficiency cultivars were significant greater (17.4%) than those of low P efficiency cultivars under high P condition. Meanwhile, under optimum growth conditions, there was little difference of biomass between the two types of cultivars, however, the P agronomic efficiency and P harvest index were significant higher in high P efficiency cultivars than those in low P efficiency cultivars.

Improving Phosphorus use Efficiency with Polymer Technology

Abstract The soil microenvironment surrounding a P fertilizer granule or within a fluid P fertilizer band is subject to a series of primary and secondary solution reactions which substantially impact P availability to plants. Influencing or slowing these reactions is a means of improving applied P use efficiency, improving yields and profitability with positive implications for environmental concerns. It is well recognized that even under the best conditions, only 5 to 25% of fertilizer P is taken up by the crop during the first growing season. Thus, the historical problem with the soil chemistry of P fertilizers has been the lack of availability due to soil fixation reactions. The patented Avail polymer technology positively affects P use efficiency by limiting soil solution reactions which fix P thus extending availability of applied fertilizer P and ultimately providing economical and profitable benefits for growers, manufacturers and distributors. The functionality of the polymer is predicated on the polymer's high effective charge density. Extensive studies with Avail have been conducted since 1999 with investigations in the United States, Canada, United Kingdom, Argentina, The Philippines and many other countries. A wide number of crop species and soil conditions have been involved in these investigations with both solid and fluid P sources. Results of many of these investigations are reported in this paper.

Modeling an Improvement in Phosphorus Utilization in Tropical Agriculture

Studies of Terra Preta soils have generated interest in recreating their fertility elsewhere. Much of the research has focused on soil amendment charcoal (“biochar”). Terra Preta also contains bone fragments, producing a high concentration of phosphorus. Some forecast worldwide declines in phosphorus supplies, and better agricultural system management is required to improve phosphorus use efficiency. A conceptual model is offered to consider the influence of charcoal on bioavailability of phosphorus. The model describes a system where improvements in the chemical and biological condition of the soil result in increased phosphorus availability and cycling. Mechanisms of phosphorus/charcoal interaction are considered, and an assessment is made of the potential impact on African subsistence agriculture from the incorporation of biogenic, allogenic phosphorus through biochar.

Improving Phosphorus Use through Co-inoculation of Vesicular Arbuscular Mycorrhizal Fungi and Phosphate-Solubilizing Bacteria in Maize in an Acidic Alfisol

Performance of three vesicular arbuscular mycorrhizal (VAM) fungi cultures and a phosphate-solubilizing bacteria (PSB) culture alone or in combination with or without 75% of the recommended P2O5 dose based on soil-test crop response model was examined in maize in a phosphorus (P)-deficient acidic Alfisol in a glasshouse pot experiment. Sole application of VAM besides co-inoculation with PSB (Pseudomonas striata) and inorganic P stimulated mycorrhizal root colonization. Sole application of PSB, VAMT (Glomus intraradices), and VAMI (Glomus mosseae) as well as co-inoculation of VAM with PSB significantly improved crop productivity besides grain protein content, thus indicating a synergistic interaction between VAM and PSB. Application of VAMT or VAMI + PSB + 75% P2O5 remained at par with sole application of 100% P2O5 dose with regard to productivity, nutrient uptake, and soil fertility status (particularly P), thus indicating economization of fertilizer P to the tune of about 25% without compromising crop productivity and soil fertility in an acidic Alfisol.