Improving Phosphorus Use Research Articles

Numerical Variables Analysis and Improving Phosphorus Use Efficiency in Groundnut with Microbial Cultures in Coastal Zone of Puducherry

Background: The precise application of phosphorus fertilizer is pivotal in determining Groundnut (Arachis hypogaea L.) productivity. The high demand of phosphorus for energy transfer molecules involved in nitrogen fixation makes it essential for leguminous crop. A field experiment was conducted at Perunthalaivar Kamaraj Krishi Vigyan Kendra, Puducherry during 2021 to 2023 to explore the performance of groundnut by employing an optimal combination of microbial culture alongside varying levels of phosphorus. Methods: The experiment was laid out in randomized block design with 10 treatments and replicated thrice. The treatments consisted of different doses of phosphorus (@ 20, 40 and 60 kg/ha) with and without seed treatment with DGRC culture. Result: The experiment results of the three years study revealed that a variable response of groundnut to P fertilizer rates and rhizobium inoculant on sandy loam soil in puducherry. P fertilizer rates combined with DGRC inoculant had a significant influence on growth, root nodule, nodule dry weight, pod and kernel yield. From this study, it may concluded that combined application of P fertilizer @ 60 kg/ha and seed treatment of DGRC culture inoculants @ 20 g/kg seed have the potential to increase the productivity and profitability of groundnut. Correlation and Regression analysis also indicated that the yield attributes had a positive impact on groundnut yield.

Legacy soil phosphorus bioavailability in tropical and temperate soils: Implications for sustainable crop production

Improving phosphorus (P) use efficiency is key to improving the productivity and sustainability of cropping systems and slowing the exploitation rate of mineral P resources required for fertilizer production. At present, large amounts of added P in fertilizers and manure each year are retained in the soil and are not used by the crop. This ‘legacy P’ progressively accumulates in soil and represents an untapped P resource in tropical soils while in temperate soils it contributes to eutrophication. In the context of legacy P, the aim of this study was to quantify changes in soil P pools of contrasting bioavailability (determined using conventional chemical extraction procedures) during 12 successive brachiaria (Urochloa ruziziensis) cropping cycles in which no additional P was added. The study was undertaken in the greenhouse with 10 tropical (Brazil) and 6 temperate (UK) agricultural topsoils. Above-ground dry matter yield (DM) and P offtake was measured at each harvest alongside operationally-defined measures of the labile, moderately-labile and non-labile P pools at the start and end of the experiment. Over twelve repeated cultivation cycles, brachiaria demonstrated an ability to efficiently mine legacy P from all measurable soil pools across both sets of soils. This included the depletion of up to 87 % of non-labile soil P in some soils from the UK and up to 66 % from soils in Brazil after one year. While the amounts of initial labile P showed the closest positive relationship with plant P export, contrary to expectation the non-labile P pool also clearly contributed to plant nutrition across all the soils. As a cover crop, brachiaria clearly possesses traits which enable both the solubilization and efficient capture of soil P that can be harnessed to actively recycle historically non recalcitrant soil P fractions. Incorporating brachiaria into crop rotations or intercropping systems therefore shows promise as a strategy to enhance the longer-term sustainability of soil P management.

Phosphorus solubilizing Bacillus sp. strain MN-54 increased the yield and economic returns of pearl millet due to improved phosphorus use efficiency

Phosphorus (P) deficiency is a frequent problem in calcareous soils of Pakistan because of P-fixation, which poses significant threats to pearl millet productivity. The use of P-solubilizing bacteria (PSB) is regarded as a promising approach for improving P-availability in soil-plant systems. However, it needs optimization of P application into the soil. Therefore, this 2-year field study was conducted to optimize P doses in combination with PSB (Bacillus sp. MN54) inoculation to improve phosphorus use efficiency (PUE), yield, economic returns, and grain quality of pearl millet. Five P doses, i.e. 0 (native soil P only - control), 30, 60, 90, and 120 kg P2O5 ha−1 combined with and without PSB inoculated seeds were used in the study. The application of 90 kg P2O5 ha−1 + seed inoculation with PSB improved the grain yield by 36.8% and 36.0% during 1st and 2nd year, respectively. The same treatment significantly improved the PUE, grain protein, zinc (Zn), and total grain P contents compared to the control treatment. Furthermore, the highest economic returns (1053.3 and 1050.5 $ ha−1) and benefit:cost ratio were observed under 90 kg P2O5 ha−1 + seed inoculation with PSB during both years. In conclusion, application of 90 kg P2O5 ha−1 combined with PSB seed inoculation is a pragmatic option to improve P uptake, grain yield, PUE, grain quality and economic returns of pearl millet grown on calcareous soils.

OsPHR2-mediated recruitment of Pseudomonadaceae enhances rice phosphorus uptake

Plants can shape their root microbiome to promote growth and nutrient uptake. PHOSPHATE STARVATION RESPONSE 2 (OsPHR2) is a central regulator of phosphate signaling in rice, but whether OsPHR2 can shape the root microbiome to promote phosphorus uptake is unclear. Here, we investigate the role of OsPHR2 in recruiting microbiota for phosphorus uptake using high-throughput sequencing and metabolite analysis. OsPHR2-overexpressing (OsPHR2 OE) rice showed 69.8% greater shoot P uptake in natural soil compared with sterilized soil under high-phosphorus (HP) conditions, but there was only a 54.8% increase in the wild-type (WT). The abundance of the family Pseudomonadaceae was significantly enriched in OsPHR2 OE roots relative to those of WT rice. Compared with the WT, OsPHR2 OE rice had a relatively higher abundance of succinic acid and methylmalonic acid, which could stimulate the growth of Pseudomonas sp. (P6). After inoculation with P6, phosphorus uptake in WT and OsPHR2 OE rice was higher than that in uninoculated rice under low-phosphorus (LP) conditions. Taken together, our results suggest that OsPHR2 can increase phosphorus use in rice through root exudate-mediated recruitment of Pseudomonas. This finding reveals a cooperative contribution of the OsPHR2-modulated root microbiome, which is important for improving phosphorus use in agriculture.

Characterization of yellow‐green leaf1 mutant for improved phosphorus use efficiency and rapid offspring screening in Tartary buckwheat

AbstractLeaf color mutations provide valuable genetic resources for elucidating the molecular regulatory mechanisms of plant growth and serve as efficient tools for screening offspring in crossbreeding. In this study, a Tartary buckwheat (Fagopyrum tataricum) mutant with yellow‐green leaves (yl1) was isolated from 60Co‐γ‐radiation mutation bank. Compared to wild type (WT), yl1 showed similar biomass and yield, despite a lower chlorophyll content and net photosynthetic rate. However, yl1 displayed significantly higher total phosphorus content after 14 days of medium and low phosphorus treatment. By using yl1 as the maternal parent, hybrid offspring could be visually distinguished at the cotyledon stage. Genetic analysis revealed that the yl1 phenotype was attributed to a single recessive mutation. Combined metabolome and transcriptome analysis identified 205 differential expressed metabolites (DEMs) and 123 differential expressed genes enriched in 30 pathways or metabolisms between yl1 and WT. Remarkably, the upregulation of SPX3, 5PTase2, PHO1, PAP3, PAP2, PAP7, and IPAP16, which are involved in enhancing phosphorus absorption, assimilation, transport, and remobilization, along with PLDζ1, GDPD1, MGD2, and NPC4L, which contribute to improving lipid metabolism, collectively resulted in high accumulation of 41 phosphorus‐containing DEMs (including 37 lipids) in yl1. This study emphasizes the potential of yl1 for effective screening of offspring and uncovers the interplay between photosynthesis and lipid metabolism, providing valuable insights to improve phosphorus use efficiency in Tartary buckwheat.

Polymeric-Coated Monoammonium Phosphate with Different Release Profiles for Improving Phosphorus Use Efficiency in Forage Production

Polymeric-Coated Monoammonium Phosphate with Different Release Profiles for Improving Phosphorus Use Efficiency in Forage Production

Placement and acidification of biowastes: Potential strategies for improving phosphorus use efficiency

This study aimed to improve the phosphorus (P) use efficiency of various biowastes. To achieve this, we proposed the combination of placement and the acidification of biowastes for the development of P-efficient biobased fertilizers. Seven biowastes were used as P-fertilizers, including two meat and bone meals (MBM), two solid fractions of biogas digestate (BGF), and three sewage sludges (SS). Two acidification approaches were evaluated: pre-treatment with sulfuric acid (73.5 g sulfuric acid per kg fresh weight) and co-application with ammonium sulfate (15 mg N per kg soil). The treated materials were placed close to winter wheat (Triticum aestivum cv. Benchmark) seeds in a 42-day pot experiment in a growth chamber. The P use efficiency was compared to the corresponding untreated material homogeneously mixed or similarly placed in the soil. A 33P indirect labeling method was used to differentiate P uptake from soil and fertilizer. The negative control showed a shoot dry matter of 0.42 g ( ± 0.05) and a total P uptake of 0.62 ( ± 0.06) mg per plant. The placement of acidified sewage sludge did not show significant differences in shoot dry matter and P uptake compared to the negative control. On the other hand, the placement of acidified MBM significantly increased plant growth (MBM I: 2.93 ± 0.46; MBM II: 1.78 ± 0.09 g) and P uptake (MBM I: 7.38 ± 1.10; MBM II: 6.21 ± 0.53 mg) compared to the untreated MBM placed and the negative control. Similarly, the placement of acidified BGF showed promising results, with a 3-fold increase in P uptake from the fertilizer compared to untreated BGF mixed with the soil (7.74 ± 1.47 vs. 2.71 ± 0.26 mg). Therefore, our results demonstrate that the placement of acidified MBM and BGF can increase the P use efficiency of these biowastes and may provide a basis for formulating P-efficient biobased fertilizers using these materials.

Improving phosphorus use efficiency in groundnut with microbial cultures

Field experiments were carried out during 2018 to 2021 at Oilseeds Research Station, Tindivanam, to study the improved phosphorus use efficiency in groundnut with microbial culture. The results revealed that higher mean pod yield (2581 kg/ha) was recorded in the treatment that involved application of 40 kg/ha of P + DGRC culture which was on par with the treatment T4, that involved application of 60 kg/ha of Phosphorus. Control recorded the lowest yield.

Advances for Improving Phosphorus Use Efficiency in Agriculture

An impending crisis is the continuous availability of phosphate fertilizers, which underlie global food production. The rock phosphate deposits on which the world depends are not only finite but many are polluted and many are located in geopolitically unstable locations, implying that significant changes will be required to maintain food supply for an increasing global population. There is no single solution, but a combination of phosphorus management measures is required not just to extend the life of the remaining non-renewable rock phosphate sources, but also to result in a more efficient, sustainable phosphorus cycle. Improving the effectiveness of fertilizer applications to agricultural land, as well as a better understanding of phosphorus cycling in soil-plant systems and the interplay between soil physics, chemistry and biology in conjunction with plant characteristics are among the solutions. The finite nature of rock phosphate supply and the development of other sources of phosphorus fertilizers is unavoidable. There are clear prospects and it is now critical to prioritize a concerted effort to increase phosphorus usage efficiency.

Enhancing productivity, quality, and economics of rose scented geranium (Pelargonium graveolens L.) through a novel integrated approach to phosphorus application

Phosphorus limitation is a major factor that adversely affects rose scented geranium (Pelargonium graveolens L.) herbage followed by essential oil yield which is extracted from the green herbage of this high-value aromatic plant. To ensure sustainable yield, the need to improve phosphorus use efficiency in geranium cultivation is inevitable. Current study was undertaken to develop a cost-effective integrated phosphorus management package for the grower’s community to maximize yield, quality, and economics of geranium by combining optimizing phosphorous dose with paddy straw mulch and inoculation with vesicular arbuscular mycorrhiza (VAM). Field experiments were conducted for two consecutive years (2020–21 and 2021–22) at the research farm of CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India. Twelve treatment combinations were executed in a split plot design. Treatment comprised of two levels of paddy straw mulch (7.5 t ha−1 and no mulch), two levels of vesicular-arbuscular mycorrhizae (VAM) inoculation (6.5 kg ha−1and no VAM), and three levels of phosphorous doses (100 kg P2O5 ha−1, 150 P2O5 kg ha−1, and no Phosphorus). Mean data of two years revealed that rose scented geranium is a highly responsive crop towards all the variables applied. Growth parameters, yield attributes, herbage and oil yield, and essential oil quality were significantly improved. Nutrient uptake which is a prime concern of this study was also enhanced due to improvement in soil enzymatic activity, soil microbial biomass carbon, and soil nutrient status due to the combined effect of paddy straw mulching, VAM application, and optimum P doses. Maximum fresh herb yield (657.41 kg ha−1) was recorded in M1V1P1 while the highest volatile oil content, and oil yield (0.131% and 69.11 kg ha−1 respectively) were found in M1V1P2. At both the crop stages, maximum nutrient uptake (N = 1.44% and 1.85%, P = 0.30% and 0.35%, and K= 2.03% and 2.45% respectively) were also recorded with M1V1P2. The same treatment combination (M1V1P2) was recorded with maximum gross return (10403.3 US$ ha−1), total net profit (7795.5 US$ ha−1), and B:C ratio (2.99). Thus, this study recommends that geranium should be grown with appropriate phosphorus dose i.e. 150 kg P2O5 ha−1 along with VAM application (6.5 kg ha−1) and paddy straw mulching @ 7.5 t ha−1 for higher, cost-effective, and better quality oil production.

Talaromyces purpurogenus Isolated from Rhizosphere Soil of Maize Has Efficient Organic Phosphate-Mineralizing and Plant Growth-Promoting Abilities

The scarcity of phosphorus (P) makes improving phosphorus use efficiency a critical issue in crop production. Plant rhizosphere microorganisms play a vital role in increasing phosphorus bioavailability and promoting the level of plant-absorbable P in agroecosystems. In this study, Talaromyces purpurogenus SW-10 strain with efficient organic phosphate-mineralizing ability was isolated from maize rhizosphere soil. SW-10 showed efficient phytate utilization with corresponding soluble P levels of 525.43 mg/L and produced phytase in the liquid medium. The response surface methodology (RSM) analysis showed that glucose as the carbon source and (NH4)2SO4 as the nitrogen source at 28 °C and pH 7.0 promoted higher mineralization of insoluble organic phosphate. When cocultivated with different genotypes of maize seedlings, SW-10 significantly increased the shoot’s dry weight by 37.93%, root’s dry weight by 31.25%, and the plant height by 13.03% for low-P sensitive inbred line 31778, while no significant change was observed in the low-P tolerance inbred line CCM454. In addition, SW-10 strain significantly increased total P-concentration in the shoots (22.4%~32.9%) and roots (3.10%~9.77%) for both inbred lines. In conclusion, the isolated T. purpurogenus SW-10 strain possesses an efficient organic phosphate-mineralizing ability and maize plant growth-promoting effect, especially for the low-P sensitive genotype that could be exploited for enhancing P availability in agriculture.

Breeding and genomics approaches for improving phosphorus-use efficiency in grain legumes

Phosphorus (P) is an essential plant macronutrient, but P sources for plant growth are non-renewable, causing great concern for future sustainable agriculture and global food security. Thus, enhancing plant P-use efficiency (PUE) by improving P-acquisition and P-utilization efficiencies is urgently needed in various crops, including grain legumes, for intensive cropping systems. This review discusses how to harness the genetic variability in PUE traits across grain legume gene pools to improve PUE using various conventional breeding approaches and emerging breeding tools. The genetic architecture of PUE traits is complex, being quantitatively inherited and highly influenced by the environment. Thus, we discuss how the biparental QTL mapping approach has been used to dissect the genetic architecture of PUE traits. Unprecedented advances in legume genomics resources, especially high-throughput single nucleotide polymorphisms, have facilitated uncovering genomic regions related to PUE across the whole genome using a genome-wide association mapping approach. Likewise, the availability of complete genome sequence information, pangenome sequences, and the whole-genome resequencing approach have provided novel insights into structural variation, including presence/absence and copy number variations, underpinning PUE. Simultaneously, progress in functional genomics, including transcriptomics and computational biology, has facilitated the discovery of various underlying transcription factors and the corresponding downstream P signal perception genes and candidate gene(s) controlling PUE and conferring low-P tolerance in various legumes with putative function. We also discuss updated metabolomics and proteomics approaches that have improved our understanding of various gene networks, P-starvation signaling pathways, and P acquisition and utilization of molecular mechanisms important for PUE. Finally, we summarize how novel breeding schemes, including genomic selection, speed breeding, and emerging CRISPR/Cas9-based genome editing tools, will assist in designing P-use-efficient cultivars and adapting grain legumes to low-P environments. Thus, enhancing PUE by integrating various ‘omics’ approaches could improve P-acquisition and P-utilization efficiencies in various modern grain legume cultivars grown in intensive cropping systems to restrict P-fertilizer overuse and preserve the declining non-renewable global rock phosphate reservoir for securing an economical and sustainable future agriculture. • Phosphorus (P) is one of the most essential nutrients required for plant growth and development. • P fertilizers being non-renewable, judicious utilization of P fertilizer is urgently needed for sustaining legume yield for ensuring global food security. • Plants have evolved several molecular, physiological and biochemical mechanisms to sense, acquire and utilize soil P and adapt under P impoverished environments. • ‘Omics’ approach could greatly assist in unraveling the underlying genomic regions with their function contributing to improving phosphorus use efficiency in legume crops.

Innovative Phosphate Fertilizer Technologies to Improve Phosphorus Use Efficiency in Agriculture

The main discoveries and advances in the development of industrial processes for the most commercially used phosphate fertilizers in the world (single superphosphate, triple superphosphate, monoammonium phosphate, and diammonium phosphate) occurred from 1830 to 1970, followed by improvements and investments to expand worldwide production capacity. A main opportunity now is aggregating new technologies to conventional phosphate fertilizers so they may become even more efficient in supplying P to plants, which involves research related to the technologies for reduction in soil P losses. Thus, some innovations and technologies have begun to be developed and marketed and continue in continual refinement and adoption in agriculture worldwide to reduce conversion of soluble P applied through conventional phosphate fertilizers into unavailable forms in the soil. This is the case of enhanced efficiency fertilizers, which includes groups of phosphate fertilizers with fixation inhibitors and the chemically modified, controlled-release, blends, multifunctional, and synergistic phosphate fertilizers. The technologies presented in detail in this paper were developed to improve the agronomic efficiency of phosphate fertilization in comparison with conventional fertilizers, with costs varying according to raw materials, production technologies, and distance from the consumer market. This synthesis expands knowledge regarding technologies in use, stimulating the development and application of technologies that increase nutrient efficiency, based on results obtained through suitable methods and equipment along with laboratory, greenhouse, and field results. Increased fertilization efficiency should always be linked with greater economic profitability and the lowest environmental impact, following the principles of sustainability and circular economy. The great challenge for innovation is transforming the knowledge generated regarding fertilizers present in patents and scientific publications into technologies appropriate for the fertilizer market and for adoption in agriculture.

Interfaces between biodegradable organic matrices coating and MAP fertilizer for improve use efficiency

Improving phosphorus (P) use efficiency is a challenge to promote a circular economy and greening the phosphorus cycle towards planetary sustainability. The disruptive innovation for phosphate fertilizers may help to reduce some unwelcome reactions that occur to P in soils. Monoammonium phosphate (MAP) coating with biodegradable organic polymers and the addition of magnesium (Mg) - a nutrient with a synergistic effect on the uptake of P, zinc (Zn), and boron (B) - emerge as a smart strategy to applying these micronutrients uniformly in soils. The objectives of this study were: to characterize the coated-MAP with biodegradable organic polymers, quantify the diffusion and availability of P in the soil, and evaluate the corn crop nutrition and yield during two crop seasons. The treatments were: MAP, MAP coated with biodegradable organic polymer (BOP), MAP + BOP + 1.3% of Zn + 0.33% of B, and MAP + BOP + 1.76% of Mg. The laboratory tests showed that the diffusion of MAP-based fertilizers was: MOMg (7.86 mm) = MO (8.82 mm) = MAP (8.84 mm) = MOM (8.51 mm) after 432 h. Coatings did not cause delays in the P-release in water at 25 °C since more than 95% of P was released within 24 h. In the field trials, the application of Mg, Zn, and B in the MAP coating did not increase nutrient leaf concentration. In the summer crop season, grain yield increased up to the P-rates of 85 kg of P2O5 ha−1, reaching the value of 6731 kg ha−1. Physical and chemical characteristics of MAP-fertilizers tend to improve with the coatings. The addition of biodegradable organic polymers, Mg, B, and Zn, as MAP-coatings did not enhance P diffusion, release, and availability in the soil and the crop nutrition. Coated-MAP improved corn yield only in the 2nd crop season.

Root Traits Related with Drought and Phosphorus Tolerance in Common Bean (Phaseolus vulgaris L.)

Roots are key organs for water and nutrient acquisition and transport. Therefore, root phenes that are associated with adaptation to low phosphorus (P) environments could enhance top-soil exploration, while deeper allocation is important for acquiring water and mobile nutrients. The understanding of interactions among root phenes can help in the development of common bean (Phaseolus vulgaris L.) genotypes adapted to drought and low fertility through genetic improvement. Two experiments (pot and field) were conducted at the Agricultural Research Institute of Mozambique to assess the contribution of root phenes to common bean shoot biomass and grain yield under combined stress (drought and low P). The pot study assessed eight genotypes, with four treatments combining water regimes (drought and non-stress) and phosphorus levels (200 and 25) mg P kg−1 soil. In the field study, 24 common bean genotypes were also grown in high and low phosphorus (40 kg P ha−1 and without P application) under irrigation and limited water. The grain yield from fields under drought and P stress were correlated with the pot data on root traits. The response of root phenes to drought and phosphorus stress appeared to be related to the deep and shallow root systems, respectively. Deep rooted genotypes produced more total root biomass and high taproot lateral branching density, which resulted in high total root length under drought and low P stress, while shallow rooted genotypes had low total root biomass and less taproot lateral branching. Increased shoot biomass and grain yield under drought and low P was associated with higher mean values of taproot lateral branching density and total taproot length. Genotypes SER 125, BFS 81, FBN12111-66 and MER 22 11-28 showed a greater score of tap root branching density in the pot study with the highest grain yield in the field under low P and drought stress. Therefore, these can be recommended for use in low phosphorus and drought stress environment or serve as parents for improving phosphorus use efficiency and drought tolerance in common bean.

A Review on Microbial Intervention for Improving Phosphorus Use Efficiency in Pigeon Pea-Wheat Cropping System

A Review on Microbial Intervention for Improving Phosphorus Use Efficiency in Pigeon Pea-Wheat Cropping System

Response of Wheat to Foliar and Soil P Fertilization on Grain Yield and Phosphorus use Efficiency in Southeastern Algeria

Background: P deficiency is very common in alkaline - calcareous soil. Therefore, application of foliar-absorbed fertilizers may be an effective strategy to overcome the low bioavailability of phosphorus in soil, by improving phosphorus use efficiency and reduced nutrients loses.Methods: A field experiment was carried out in 2006-07 growing season at El-Menia (southeastern Algeria) to evaluated the effect of two foliar P (agriphos and leader-start) and three soil P (TSP P 46, Fosfactyl NP 3:22 and NPKs 8:36:13,5+15) on yield and P use efficiency of durum wheat crop Triticum durum Desf. var. Carioca and on available P and total P in soil.Result: Data showed that significant effect of soil P fertilizer on grain yield components (ears m-², grains ear-1 and the 1000 grains weight), grain P use efficiency and available P in soil. The best values were recorded by NPKs fertilizer, but no differences were observed for these parameters among foliar fertilizer sources.

Assessment of phosphorus fixing capacity in different soil orders of India

An experiment was conducted to assess the phosphorus fixation capacity in five soils orders with contrasting characteristics at different concentration of added phosphorus. The surface soil (0-15cm) samples were collected from five soil orders namely Alfisols, Inceptisols, Vertisols, Aridisols and Entisols of different locations of India. The collected soil samples were analyzed for physico-chemical properties and phosphorus fixing capacity. The initial soils samples were acidic (5.77) to alkaline (8.53) in reaction, high organic carbon content and low to medium available phosphorus with presence of 663 ppm to 1669 ppm active iron. The maximum phosphorus fixation (%) was observed in Alfisols (88.68) followed by Inceptisols (68.73), Entisols (68.33), Vertisols (66.84) and Aridisols (58.24). About 58-89% of added phosphorus was fixed in the soils and the maximum fixation was in the Alfisols while the least fixation was observed in Aridisols. Alfisols soil showing higher phosphorus fixing capacity might be due to presence of sesquioxide (active iron and aluminum oxides) that complex with phosphate ions. Phosphorus fixation capacity was negative and significant correlated (r = − 0.76*) with soil pH and positively correlated with active iron (r = 0.84*). Multiple regression analysis revealed that 85 percent of phosphorus fixing capacity of soil depends on soil pH, organic carbon, clay and active iron. Under such condition, it must be overcome by application of phosphorus on the basis of cropping sequence instead of individual crop needs to be taken into consideration and use of otherphosphorus sources such as Phosphorus bio-fertilizers, organic manures, and low grade rock phosphates for improving phosphorus use efficiency.

Main Root Adaptations in Pepper Germplasm (Capsicum spp.) to Phosphorus Low-Input Conditions

Agriculture will face many challenges regarding food security and sustainability. Improving phosphorus use efficiency is of paramount importance to face the needs of a growing population while decreasing the toll on the environment. Pepper (Capsicum spp.) is widely cultivated around the world; hence, any breakthrough in this field would have a major impact in agricultural systems. Herein, the response to phosphorus low-input conditions is reported for 25 pepper accessions regarding phosphorus use efficiency, biomass and root traits. Results suggest a differential response from different plant organs to phosphorus starvation. Roots presented the lowest phosphorus levels, possibly due to mobilizations towards above-ground organs. Accessions showed a wide range of variability regarding efficiency parameters, offering the possibility of selecting materials for different inputs. Accessions bol_144 and fra_DLL showed an interesting phosphorus efficiency ratio under low-input conditions, whereas mex_scm and sp_piq showed high phosphorus uptake efficiency and mex_pas and sp_bola the highest values for phosphorus use efficiency. Phosphorus low-input conditions favored root instead of aerial growth, enabling increases of root total length, proportion of root length dedicated to fine roots and root specific length while decreasing roots’ average diameter. Positive correlation was found between fine roots and phosphorus efficiency parameters, reinforcing the importance of this adaptation to biomass yield under low-input conditions. This work provides relevant first insights into pepper’s response to phosphorus low-input conditions.

Synthesis of Poly(vinyl alcohol) and Liquid Paraffin-Based Controlled Release Nitrogen-Phosphorus Formulations for Improving Phosphorus Use Efficiency in Wheat

Polymer coating of water soluble fertilizers to curb excess solubilization of nutrients is well-acknowledged fact. Lack of information on phosphorus (P) release from controlled release nitrogen-phosphorus (NP) formulation and its impact on nutrient use indices has driven us to conduct this experiment. We developed NP formulations by reacting liquid ammonia and orthophosphoric acid in laboratory. Resulting NP formulations were characterized by solubility fractions, microscopy, spectroscopy, and X-ray diffraction. After coating with poly(vinyl alcohol) (PVA) and liquid paraffin (LP) at 2 and 3 w/w% concentration, P release kinetics and temperature sensitivity (Q10) of the formulations were compared with diammonium phosphate (DAP) at 20 and 30 °C temperature in a P-deficient soil for 120 h of incubation. Finally, nutrient use efficiency and relative efficiency indices were determined from a greenhouse experiment in potted soil to assess the effect of polymer-coated formulations and of DAP at two application rates in comparison with a non-P amended control. Laboratory synthesized NP formulations were alkaline in reaction, definite cubical to hexagonal crystalline structure with smooth surface generating peaks related to P and N in fingerprinting region of Fourier transform infrared spectroscopy. Polymer coating of NP formulations delayed the P release compared with DAP, while LP-coated formulations showing slower P release than PVA-based coatings. Despite LP-coated formulations showed greater temperature sensitivity (Q10), the PVA-based formulation significantly increased yield and biomass accumulation of wheat, with concomitant increase in crop P uptake and P use efficiency. Both LP and PVA-coated formulations showed a significant residual P accumulation in post-harvest soils. The findings underline the potential of polymer coating technology for enhancing P use efficiencies, thereby reducing environmental P footprints.