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With the rapid development of the animal farming industry in China, the large amount of manure has caused a systematic environmental problem, while the demand for high-quality feed continues to increase. The application of dairy cattle slurry to alfalfa fields is a simple and inexpensive solution to the problems above. A repacked soil column study was conducted to investigate the effect of slurry nitrogen (N) on alfalfa biomass, as well as its photosynthetic characteristics. Dairy cattle slurry N or mineral fertilizer N was applied in two dressings at the first cut, with a target amount of 90 kg ha−1. A non-fertilization control (CK), a single mineral fertilizer N (MIN), and a slurry substitution for mineral N fertilizers (with equivalent N rate: FPS, 50% N from dairy cattle slurry; SLU, 100% N from dairy cattle slurry) were used. The results show that the slurry N increased the alfalfa biomass by 16.40–36.36% and the SPAD value by 30.27–61.34% with FPS and SLU treatments, respectively. Compared to the CK treatment, the FPS and SLU treatments meaningfully increased the net photosynthetic rate by 19.97–60.04% and 3.03–89.48%, the stomatal conductance by 10.53–57.14% and 15.38–88.89%, the intercellular CO2 concentration by 5.78–24.92% and 7.21–32.53%, and the transpiration rate by 13.16–103.50% and 16.44–111.19%. More specifically, compared with the CK treatment, the N absorption of the SLU treatment increased by 6.78–12.30%, and the use efficiency increased by 30.98–46.60% in the SLU treatment. Similarly, phosphorus (P) absorption of the SLU treatment increased by 36.73–52.57%, and the use efficiency increased by 30.98–46.60%. Overall, the dairy cattle slurry N was utilized efficiently as mineral N for alfalfa biomass, improved the photosynthetic characteristics of alfalfa leaves, and increased the N and P use efficiency. Our results clarify the optimal amount of dairy cattle slurry to be applied and provide a scientific basis for the use of dairy cattle slurry in agricultural systems. [ABSTRACT FROM AUTHOR]

AbstractRice cultivation in South Florida, especially within crop rotation systems, presents a promising avenue for mitigating phosphorus (P) levels in drainage water by optimizing nutrient absorption across varying flooding conditions. This study aimed to assess the impacts of different flooding depths on rice growth and nutrient efficiency while exploring the interrelationships among these factors. Conducted over a two-year period, the field study involved planting a single rice variety (Diamond: 95 kg ha−1, long-grain, short-season) at four distinct flooding depths (5, 10, 15, and 20 cm) without fertilizer application. Results revealed minimal effects of flooding depths on root and shoot length or dry matter accumulation. Additionally, concentrations of total P and potassium (K) in both shoot and root tissues remained consistent across the different flooding depths. Despite the absence of P and K fertilizer inputs, no significant changes were observed in P use efficiency (PUE), K use efficiency (KUE), or water use efficiency (WUE). Cultivating rice under optimal flood depths of 5 cm within the Everglades Agricultural Area (EAA) demonstrated potential for conserving water and essential nutrients such as P and K. These findings highlight the feasibility of rice cultivation in fertile soils as a means to decrease nutrient (P and K) concentrations in drainage water, thereby promoting sustainable agricultural practices in the region. [ABSTRACT FROM AUTHOR]

Highlights: Biochar and phosphate fertilizers combined to alleviate soda saline-alkali barriers. Addition of biochar decreased the rice Na+ concentration and Na+/K+ ratio in a soda saline-alkali paddy. Biochar enhances the efficiency of phosphate fertilizer utilization under soda saline-alkali stress. Soda saline-alkali significantly hinders rice growth, phosphorus utilization efficiency, and yield formation. The application of biochar can alleviate the adverse effects of saline-alkali stress on crops. However, there is limited research on the interaction between biochar and phosphorus fertilizer concerning ionic accumulation, phosphorus utilization efficiency, and rice yield in soda saline-alkali soils. A two-year field experiment was conducted to study the combined effects of biochar and phosphate fertilizer on ionic accumulation, physiological status, phosphorus utilization efficiency, and rice yield in soda saline-alkali soil. Four treatments were established for the study: NK (225 kg N, 75 kg K ha−1 year−1), NPK (225 kg N, 70 kg P, 75 kg K ha−1 year−1), NK + B [225 kg N, 75 kg K ha−1 year−1, 1.5% biochar (w/w)], and NPK + B [225 kg N, 70 kg P, 75 kg K ha−1 year−1, 1.5% biochar (w/w)]. The findings indicated that the combined application of biochar and phosphorus fertilizer (NPK + B) significantly reduced the Na+ concentration, Na+/K+ ratio, malondialdehyde (MDA), superoxide anion (O2−), and hydrogen peroxide (H2O2) levels in rice plants. Furthermore, it resulted in a significant increase in K+ concentration and elevated the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), proline (Pro), soluble protein (SP), soluble sugar (SS), and acid phosphatase (ACP). The NPK + B treatment exhibited a significant difference compared to the other treatments (p < 0.05). Compared with NK, phosphorus accumulation and phosphorus utilization efficiency under NPK + B were significantly increased (p < 0.05). The average of biomass yield, grain yield, and harvest index of NPK + B, NK + B, and NPK significantly surpassed those of NK by 6.28–12.25%, 19.80–42.13%, and 11.59–24.64%, respectively. Moreover, a significant difference was observed between NPK + B and the other treatments (p < 0.05). Principal component analysis of the two-year mean data revealed a strong positive correlation of 89.5% for PC1 and a minor negative correlation of 4.4% for PC2. Our research findings demonstrate that the combination of biochar and phosphorus fertilizer effectively enhances salt and alkali tolerance in rice plants, resulting in increased yield through improved ionic balance and physiological status. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is the key to several structural molecules and catalyzes numerous biochemical reactions in plant body besides its involvement in energy transfer. Any deficit in P availability is likely to result in reduced RNA and protein content, inhibiting crop growth and development. Thus, availability of soil P is extremely crucial for plant growth especially in acid soils of India, where most of the fraction is bound to solid phase rendering their availability. The present communication deals with the isolation of elite phosphate-solubilizing bacterial (PSB) strains from the acid soils to work out their ability to improve the fertilizer P use efficiency in the acidic environment. Initially twenty-six bacteria were isolated from the acid soils of Northeastern India. Among them, ten bacteria were selected based on formation of halo zone in the Pikovskaya agar plate. In addition, these bacteria were able to solubilize insoluble zinc (Zn) and potassium (K). The isolates were subject to in vitro optimization for P solubilization under different insoluble P source utilization and at different pH and salinity conditions. Strains AN3, AN11, and AN21 exhibited significant solubilization of insoluble P, Zn, and K, and were identified as Streptomyces sp., Enterobacter sp., and Paraburkholderia caribensis. These three bacteria solubilized 206.53 to 254.08 µg mL−1 P, 79.7 to 177.55 µg mL−1 Zn, and 0.96 to 1.56 µg mL−1 K from insoluble minerals. Their performance was further evaluated in pot culture experiment using green gram as test crop. These three bacteria were found to improve P uptake and dry matter accumulation in green gram plant substantially. Seed bio-priming with the PSB strains enhanced the efficiency of added P fertilizer, resulting in a 1.40 to 1.52 times higher effectiveness compared to the control. On the whole, AN11 may be ranked as best inoculant for the acidic soils of Northeastern India. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Water and nutrients are two main determinants of wheat yield, which are vital for maintaining high crop yields. In the present study, the effects of water and phosphate fertilization on wheat yield, photosynthetic parameters, water productivity and phosphate use efficiency were investigated. Five dryland wheat cultivars from the 1940s to the 2010s that are widely cultivated in Shaanxi Province, China, were used. Experiments were conducted from 2019 to 2022 using two irrigation levels (normal rainfall and no precipitation after the reviving stage) and two phosphorus application levels (0 and 100 kg ha−1).Compared with old cultivars (‘Mazha’), the grain yield of modern cultivars (‘Changhan 58’) was 89.24% higher and was closely correlated with chlorophyll index, leaf area index, photosynthetic rate and tillers. With the replacement of cultivars, the phosphorus content, water potential and phosphatase activity of wheat leaves increased. Considering water–phosphorus interactions, the water use efficiency and phosphorus use efficiency of wheat showed a significant positive correlation.Our findings indicate that modern wheat cultivars are more responsive to phosphorus. Further analysis revealed that modern varieties have evolved two phosphorus absorption strategies in response to phosphorus deficiency – namely, the formation of a phosphorus supply source, which may result in larger numbers of green organs; and an increase in phosphorus sinks, which tended to activation and transport of plant phosphorus. Our results may thus contribute to water conservation, increased yields and the development of strategies for efficient phosphorus fertilization. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

AbstractPhosphorus (P) is the second most important essential macronutrient after nitrogen for plant growth and development. Even though P is plentiful in soil, it is largely inaccessible to plants as it is strongly bound with metal ions and form insoluble metal-P complexes. Therefore, different agrochemicals are used to improve the P availability in soils and mitigate the plant need for sustainable growth and productivity of crops. However, those agrochemicals deteriorate ecosystem integrity and adversely affect the soil health. Consequently, there is a need for a more economical and ecologically beneficial P bio-fortification method by phosphate-solubilizing microorganisms (PSMs). The characterization of phosphorus pools and the assessment of different microbial communities can help to improve our understanding of plant–microbe interaction and P availability. The objective of this study is to discuss the PSMs that facilitate P nutrition mechanisms, including the molecular aspects of P solubilization in soil, and to characterize their features that promote plant growth and development. We mainly focused on how PSMs constitute a fundamental resource for the release of P nutrient where described the several pathways of solubilization and mineralization. The use of PSMs is a viable resource for the future sustainable agriculture, mainly due to its application can helps to reduce the fertilizer dose of P and ultimately reduce the exploitation of fertilizer P and its resources. [ABSTRACT FROM AUTHOR]

Abstract Background Phosphorus is a macronutrient necessary for plant growth and development and its availability and efficient use affect crop yields. Leaves are the largest tissue that uses phosphorus in plants, and membrane phospholipids are the main source of cellular phosphorus usage. Results Here we identify a key process for plant cellular phosphorus recycling mediated by membrane phospholipid hydrolysis during leaf senescence. Our results indicate that over 90% of lipid phosphorus, accounting for more than one-third of total cellular phosphorus, is recycled from senescent leaves before falling off the plants. Nonspecific phospholipase C4 (NPC4) and phospholipase Dζ2 (PLDζ2) are highly induced during leaf senescence, and knockouts of PLDζ2 and NPC4 decrease the loss of membrane phospholipids and delay leaf senescence. Conversely, overexpression of PLDζ2 and NPC4 accelerates the loss of phospholipids and leaf senescence, promoting phosphorus remobilization from senescent leaves to young tissues and plant growth. We also show that this phosphorus recycling process in senescent leaves mediated by membrane phospholipid hydrolysis is conserved in plants. Conclusions These results indicate that PLDζ2- and NPC4-mediated membrane phospholipid hydrolysis promotes phosphorus remobilization from senescent leaves to growing tissues and that the phospholipid hydrolysis-mediated phosphorus recycling improves phosphorus use efficiency in plants.

Crop production in Afghanistan suffers from limited phosphorus (P) availability, which severely hinders national agriculture sustainability. This study hypothesized that deep fertilizer placement could significantly enhance the uptake of immobile P and, thus, tissue P accumulation and crop yield. A two-year pot experiment growing two maize (Zea mays) hybrid cultivars (Xida-789 and Xida-211) was, therefore, conducted to test these hypotheses under three contrasting fertilizer placement methods (broadcast, side band, and deep band). In doing so, P concentrations in both maize tissues and soils were compared at 45, 60, and 115 days after sowing (DAS) under nine combinations of nitrogen (N) and P fertilizer rates (kg ha−1: N112P45, N112P60, N112P75, N150P45, N150P60, N150P75, N187P45, N187P60, N187P75). Results have shown that deep band placement significantly increased P uptake efficiency, leading to greater P concentration and accumulation in maize tissues compared to the other two fertilization methods. This improved P uptake was attributed to several factors associated with deep placement, including reduced P fixation, enhanced root access to P, and moisture availability for P uptake. Additionally, deep band placement combined with higher N application rates (N187 and N150) further enhanced plant P uptake by promoting P availability and utilization mechanisms. Deep band placement also resulted in significantly higher total soil P, Olsen-P, and P use efficiency than broadcast and side band methods, indicating a more efficient P fertilization strategy for maize that can improve growth and yield. This study also found positive correlations between P concentration in plant organs and soil Olsen-P, highlighting the importance of adequate soil P levels for optimal plant growth. Overall, our results have shown that deep band fertilizer placement emerged as a superior strategy for enhancing P uptake efficiency, utilization, and maize productivity compared to broadcast and side band placement. The outcome generated from the deep band fertilization by this greenhouse study can be recommended for field practices to optimize P fertilizer use and improve maize production while minimizing potential environmental P losses associated with broadcast fertilization. [ABSTRACT FROM AUTHOR]

This study investigated the physiological responses of four distinct Faba bean (Vicia faba L.) genotypes, Seville (SEV), Aguadulce (AGUA), Tunisian (TUN), and F7, when subjected to phosphorus deficiency, with a particular focus on their responses in terms of growth, chlorophyll pigments, photosynthetic activity, and nutrient efficiency. The results revealed that growing Faba bean in a phosphorus-deficient environment induced a reduction in the plant growth, net photosynthesis, SPAD index, and tissue phosphorus content. Genotypic variations were observed, with TUN demonstrating relative tolerance as compared to the other genotypes, by exhibiting a higher capacity for phosphorus uptake under deficiency conditions, lesser phosphorus deficiency stress index (PDSI), higher phosphorus tolerance index (PDTI), and better phosphorus use efficiency (PUE). The latter are two physiological traits that discriminate the studied genotypes. They can be used for further screening programs. Our research contributes to a broader understanding of how Faba bean plants react to phosphorus deficiency, shedding light on the genetic variations. [ABSTRACT FROM AUTHOR]

Phosphite, a reduced form of phosphate, has been proposed to be a better source of phosphorus due to its high mobility in soil and can be used as an alternative fertilizer with herbicide for growing crops engineered with bacterial phosphite dehydrogenase protein from Pseudomonas stutzeri. This enzyme uses NAD as a cofactor and its overexpression could deplete the cellular NAD pool, creating pressure on other cellular biochemical reactions. To take advantage of both NAD and NADP, we mutated the native phosphite dehydrogenase gene for relaxed cofactor specificity and overexpressed it in rice plants. The engineered rice plants were found to metabolize phosphite efficiently. However, use of phosphite as a herbicide was not met by mutated phosphite dehydrogenase overexpressing plants as compared to the rice plants overexpressing wild type phosphite dehydrogenase. Therefore, we conclude that mutant phosphite dehydrogenase has potential industrial application for NADPH regeneration and its use for engineering crops for dual fertilization and weed control system is limited. [ABSTRACT FROM AUTHOR]

In recent years, numerous studies have been conducted on predicting the depletion of phosphorus (P), thus researchers are increasingly inclined to explore different P sources that can be more readily absorbed by plants. The effectiveness of nanohydroxyapatite (nHAP) as an alternative P source was compared with diammonium phosphate (DAP). A barley-barley-maize-maize was sequentially grown, after which the residual effects of the P sources on the dry weight, P concentration, uptake, and P use efficiency (PUE) were determined for the first barley, and the subsequent barley-maize-maize plant. DAP was more effective than nHAP for investigated parameters. However, the impact of DAP decreased rapidly over time, particularly in the 3rd and 4th plantings. Incubation studies have shown a significant decrease in P following conventional P. DAP in the first month of the study resulted in 152 mg kg−1 of available P in the soil, but by the 13th month, the concentration had decreased to 23.7 mg kg−1. Similarly, in the samples taken after harvesting the plants, the plant-available P was 70 mg kg−1 after the first barley, and subsequently determined as 43.3, 38.7, and 24.7 mg kg−1 after the other plants, respectively. In the case of nHAP treatment, these values were determined as 5.62, 5.28, 8.60, and 4.65 mg kg−1, respectively. In conclusion, nHAP can continuously provide P to the soil an alternative P. Therefore, it can be stated that the application of nanofertilizers hold promise as an effective approach for enhancing nutrient efficiency and mitigating environmental impacts on modern agricultural practices. [ABSTRACT FROM AUTHOR]

Abstract Understanding the efficacy of alternative phosphorus (P) sources in tropical soils is crucial for sustainable farming, addressing resource constraints, mitigating environmental impact, improving crop productivity, and optimizing soil-specific solutions. While the topic holds great importance, current literature falls short in providing thorough, region-specific studies on the effectiveness of alternative P sources in Brazilian tropical soils for maize cultivation. Our aim was to assess the agronomic efficiency of alternative P sources concerning maize crop (Zea mays L.) attributes, including height, shoot dry weight, stem diameter, and nutrient accumulation, across five Brazilian tropical soils. In greenhouse conditions, we carried out a randomized complete block design, investigating two factors (soil type and P sources), evaluating five tropical soils with varying clay contents and three alternative sources of P, as well as a commercial source and a control group. We evaluated maize crop attributes such as height, dry weight biomass, and nutrient accumulation, P availability and agronomic efficiency. Our results showed that, although triple superphosphate (TSP) exhibited greater values than alternative P sources (precipitated phosphorus 1, precipitated phosphorus 2 and reactive phosphate) for maize crop attributes (e.g., height, stem diameter, shoot dry weight and phosphorus, nitrogen, sulfur, calcium and magnesium accumulation). For instance, PP1 source increased nutrient accumulation for phosphorus (P), nitrogen (N), and sulfur (S) by 37.05% and 75.98% (P), 34.39% and 72.07% (N), and 41.94% and 72.69% (S) in comparison to PP2 and RP, respectively. Additionally, PP1 substantially increased P availability in soils with high clay contents 15 days after planting (DAP), showing increases of 61.90%, 99.04%, and 38.09% greater than PP2, RP, and TSP. For Ca and Mg accumulation, the highest values were found in the COxisol2 soil when PP2 was applied, Ca = 44.31% and 69.48%; and Mg = 46.23 and 75.79%, greater than PP1 and RP, respectively. Finally, the highest values for relative agronomic efficiency were observed in COxisol2 when PP1 was applied. The precipitated phosphate sources (PP1 and PP2) exhibited a similar behavior to that of the commercial source (TSP), suggesting their potential use to reduce reliance on TSP fertilization, especially in soils with low clay contents. This study emphasized strategies for soil P management, aimed at assisting farmers in enhancing maize crop productivity while simultaneously addressing the effectiveness of alternative P sources of reduced costs.

Understanding the efficacy of alternative phosphorus (P) sources in tropical soils is crucial for sustainable farming, addressing resource constraints, mitigating environmental impact, improving crop productivity, and optimizing soil-specific solutions. While the topic holds great importance, current literature falls short in providing thorough, region-specific studies on the effectiveness of alternative P sources in Brazilian tropical soils for maize cultivation. Our aim was to assess the agronomic efficiency of alternative P sources concerning maize crop (Zea mays L.) attributes, including height, shoot dry weight, stem diameter, and nutrient accumulation, across five Brazilian tropical soils. In greenhouse conditions, we carried out a randomized complete block design, investigating two factors (soil type and P sources), evaluating five tropical soils with varying clay contents and three alternative sources of P, as well as a commercial source and a control group. We evaluated maize crop attributes such as height, dry weight biomass, and nutrient accumulation, P availability and agronomic efficiency. Our results showed that, although triple superphosphate (TSP) exhibited greater values than alternative P sources (precipitated phosphorus 1, precipitated phosphorus 2 and reactive phosphate) for maize crop attributes (e.g., height, stem diameter, shoot dry weight and phosphorus, nitrogen, sulfur, calcium and magnesium accumulation). For instance, PP1 source increased nutrient accumulation for phosphorus (P), nitrogen (N), and sulfur (S) by 37.05% and 75.98% (P), 34.39% and 72.07% (N), and 41.94% and 72.69% (S) in comparison to PP2 and RP, respectively. Additionally, PP1 substantially increased P availability in soils with high clay contents 15 days after planting (DAP), showing increases of 61.90%, 99.04%, and 38.09% greater than PP2, RP, and TSP. For Ca and Mg accumulation, the highest values were found in the COxisol2 soil when PP2 was applied, Ca = 44.31% and 69.48%; and Mg = 46.23 and 75.79%, greater than PP1 and RP, respectively. Finally, the highest values for relative agronomic efficiency were observed in COxisol2 when PP1 was applied. The precipitated phosphate sources (PP1 and PP2) exhibited a similar behavior to that of the commercial source (TSP), suggesting their potential use to reduce reliance on TSP fertilization, especially in soils with low clay contents. This study emphasized strategies for soil P management, aimed at assisting farmers in enhancing maize crop productivity while simultaneously addressing the effectiveness of alternative P sources of reduced costs. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity and phosphorus (P) deficiency are widely recognized as major constraints to agricultural productivity in acidic soils. Under this scenario, the development of ryegrass plants with enhanced P use efficiency and Al resistance is a promising approach by which to maintain pasture production. In this study, we assessed the contribution of growth traits, P efficiency, organic acid anion (OA) exudation, and the expression of Al-responsive genes in improving tolerance to concurrent low-P and Al stress in ryegrass (Lolium perenne L.). Ryegrass plants were hydroponically grown under optimal (0.1 mM) or low-P (0.01 mM) conditions for 21 days, and further supplied with Al (0 and 0.2 mM) for 3 h, 24 h and 7 days. Accordingly, higher Al accumulation in the roots and lower Al translocation to the shoots were found in ryegrass exposed to both stresses. Aluminum toxicity and P limitation did not change the OA exudation pattern exhibited by roots. However, an improvement in the root growth traits and P accumulation was found, suggesting an enhancement in Al tolerance and P efficiency under combined Al and low-P stress. Al-responsive genes were highly upregulated by Al stress and P limitation, and also closely related to P utilization efficiency. Overall, our results provide evidence of the specific strategies used by ryegrass to co-adapt to multiple stresses in acid soils. [ABSTRACT FROM AUTHOR]

Low phosphorus (P) stress in agricultural soils is a global problem in crop production. A greater understanding of the genotype-specific responses under low P stress is imperative for producing P-efficient genotypes. This study first evaluated Japanese core collections of maize (86 landraces) and soybean (94 landraces) to low P under hydroponic conditions. Ten cultivars of each species were further evaluated in a pot experiment with two P supply rates: low P (10 mg P kg−1) and high P (50 mg P kg−1). Root morphology, acid phosphatase (ACP) activity, and rhizosphere soil pH were characterized 30 days after planting. A sufficient genotypic variation was found in both species under both P conditions. A significant decrease in biomass, except in maize cultivar JMC 76 and soybean cultivar GmJMC033, and increased phosphorus use efficiency (PUE) under low P conditions were observed. The maize cultivars: JMC 76, JMC 57, JMC 58, and JMC 8 and soybean cultivars: GmJMC033, GmJMC040, and GmJMC085 showed distinctive root modifications characterized by the high root-to-shoot ratio (RRS), total root length (TRL) and specific root length (SRL) under low P stress indicating their low P tolerance. Maize had more significant ACP activity compared to soybean under low P stress. The maize cultivars, which showed low P tolerance, were highly dependent on root morphological traits rather than physiological traits (ACP activity, rhizosphere acidification, and PUE), whereas soybean cultivars were dependent on both traits. In conclusion, the plasticity of the root system is crucial in both maize and soybean to tolerate P deficiency. These genotype-specific adaptations could be combined with agronomic strategies to enhance the overall P-use efficiency in cropping systems. [ABSTRACT FROM AUTHOR]

Faced with the high cost of phosphate fertilisers in several African countries, including Algeria, and in order to better select varieties according to their fertiliser use efficiency, this study was proposed. The goal of the study was to determine how “variety” impacts durum wheat's capacity to utilize phosphorus effectively and to try to pinpoint the agromorphological factors that contribute to this efficiency so that they can be taken into consideration when choosing which varieties to sow in semi-arid environments. The experimental setup consisted of a split plot with two investigated factors and three repetitions, with the main plot receiving the phosphate treatment while the sub plot receives the variety. The trial set up consisted of 11 durum wheat varieties, which were cultivated over two years successively. The PUE of the fertiliser, provided in 46% triple superphosphate (TSP) granules, and agro-morphological parameters like aerial biomass, plant height, grain yield and yield components were determined. The findings demonstrated that triple superphosphate, a type of phosphorus fertilizer, increases grain yield by between 40 and 60% for all varieties examined as compared to the phosphorusfree control at the average dose employed in this field trial, or 20 kg P2O5.ha-1. This increase in yield is due to an increase: from 20 to 22% in the number of ears per m², 41.5% in the number of grains per ear, and 9% in the average weight of the grain. The PUE is strongly correlated to the yield components (Number of ears per square meterNEM, Number of grains per ear- NGE, thousand grain weight- TGW and Yield) but also to the height at heading (r=0.86) and dry matter (r=0.85). Phosphorus use efficiency is also strongly correlated to flag leaf length and width as well as leaf area. Also, that genotypes with higher weight of thousand grains (WTG) showed better use of available phosphorus. The principal component analysis (PCA) confirms that the efficiency of phosphorus use by the varieties tested explains a large portion of the variation noted in these varieties. This genetic variation in PUE was associated with plant height and phosphorus content of the sown grains. These results could be of a significant impact in improving rainfed durum wheat productivity in semi-arid areas and preserving the environment as well. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is essential for maximizing crop yield, yet many areas dedicated to rice cultivation suffer from a scarcity of plant-accessible inorganic phosphate (Pi) due to its fixation in the soil. Conversely, regions with ample P fertilization often resort to excessive application to compensate for deficiencies, resulting in adverse environmental impacts. While significant strides have been made in understanding the molecular mechanisms governing P uptake capacity (PUP/PAE) and P use efficiency (PUE) in rice, their practical implementation in breeding is impeded by the absence of robust, high throughput phenomics techniques, leading to inconsistencies in gene/quantitative trait loci (QTL) effects. This review underscores the necessity for a comprehensive understanding of Pi transporters, internal Pi remobilization, and root morphology modifications under Pi deficiency, correlating these traits with specific phenotypic markers. Developing precise, cost-effective, high-throughput phenotyping techniques is imperative for creating rice ideotypes with enhanced PAE/PUE. Additionally, we explore the potential of meta-QTL analysis in prioritizing genomic loci related to PUE, utilizing a “meta-genome” encompassing diverse rice reference genomes. We also delve into the potential in the development of phosphite (Phi)-tolerant rice, aiming to reduce dependence on P fertilizers and create herbicide-resistant rice through Phi-based fertilization. Finally, we discuss the utilization of arbuscular mycorrhizal fungi (AMF) to enhance P uptake in rice.

Phosphorus (P) is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop yield. Excessive P fertilizer application is widespread in agricultural production, which not only wastes phosphate resources but also causes P accumulation and groundwater pollution. Here, we hypothesized that the apparent P balance of a crop system could be used as an indicator for identifying the critical P input in order to obtain a high yield with high phosphorus use efficiency (PUE). A 12-year field experiment with P fertilization rates of 0, 45, 90, 135, 180, and 225 kg P2O5 ha−1 was conducted to determine the crop yield, PUE, and soil Olsen-P value response to P balance, and to optimize the P input. Annual yield stagnation occurred when the P fertilizer application exceeded a certain level, and high yield and PUE levels were achieved with annual P fertilizer application rates of 90–135 kg P2O5 ha−1. A critical P balance range of 2.15–4.45 kg P ha−1 was recommended to achieve optimum yield with minimal environmental risk. The critical P input range estimated from the P balance was 95.7–101 kg P2O5 ha−1, which improved relative yield (>90%) and PUE (90.0–94.9%). In addition, the P input–output balance helps in assessing future changes in Olsen-P values, which increased by 4.07 mg kg−1 of P for every 100 kg of P surplus. Overall, the P balance can be used as a critical indicator for P management in agriculture, providing a robust reference for limiting P excess and developing a more productive, efficient and environmentally friendly P fertilizer management strategy.

Soda saline-alkali significantly hinders rice growth, phosphorus utilization efficiency, and yield formation. The application of biochar can alleviate the adverse effects of saline-alkali stress on crops. However, there is limited research on the interaction between biochar and phosphorus fertilizer concerning ionic accumulation, phosphorus utilization efficiency, and rice yield in soda saline-alkali soils. A two-year field experiment was conducted to study the combined effects of biochar and phosphate fertilizer on ionic accumulation, physiological status, phosphorus utilization efficiency, and rice yield in soda saline-alkali soil. Four treatments were established for the study: NK (225 kg N, 75 kg K ha−1 year−1), NPK (225 kg N, 70 kg P, 75 kg K ha−1 year−1), NK + B [225 kg N, 75 kg K ha−1 year−1, 1.5% biochar (w/w)], and NPK + B [225 kg N, 70 kg P, 75 kg K ha−1 year−1, 1.5% biochar (w/w)]. The findings indicated that the combined application of biochar and phosphorus fertilizer (NPK + B) significantly reduced the Na+ concentration, Na+/K+ ratio, malondialdehyde (MDA), superoxide anion (O2−), and hydrogen peroxide (H2O2) levels in rice plants. Furthermore, it resulted in a significant increase in K+ concentration and elevated the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), proline (Pro), soluble protein (SP), soluble sugar (SS), and acid phosphatase (ACP). The NPK + B treatment exhibited a significant difference compared to the other treatments (p < 0.05). Compared with NK, phosphorus accumulation and phosphorus utilization efficiency under NPK + B were significantly increased (p < 0.05). The average of biomass yield, grain yield, and harvest index of NPK + B, NK + B, and NPK significantly surpassed those of NK by 6.28–12.25%, 19.80–42.13%, and 11.59–24.64%, respectively. Moreover, a significant difference was observed between NPK + B and the other treatments (p < 0.05). Principal component analysis of the two-year mean data revealed a strong positive correlation of 89.5% for PC1 and a minor negative correlation of 4.4% for PC2. Our research findings demonstrate that the combination of biochar and phosphorus fertilizer effectively enhances salt and alkali tolerance in rice plants, resulting in increased yield through improved ionic balance and physiological status.

Phosphorus (P) deficiency and low P use efficiency (PUE) are limiting factors in rice (Oryza sativa L.) production. Understanding the agronomic and physiological traits of P-tolerant rice varieties is crucial for improving PUE. However, the agronomic and physiological traits of rice varieties differing in tolerance to low P have not been fully studied or comprehensively explored. Two varieties with strong tolerance to low P (STVs, low P tolerance index > 0.9) and two with weak tolerance to Low P (WTVs, low P tolerance index < 0.5) were grown hydroponically with normal P level (NP, 8.02 mg L−1) and low P level (LP, 0.401 mg L−1) in year 2020 and 2021. Results showed that, compared with NP, the LP significantly decreased grain yield, but enhanced P translocation efficiency (PTE), internal P use efficiency (IPE), and P harvest index (PHI) in all the varieties. The STVs showed better performance than the WTVs. Specifically, the STVs exhibited a 131.33% higher grain yield, 15.95% higher PTE, 41.6% higher IPE, and 8.84% higher PHI compared to the WTVs. The STVs also exhibited superior shoot traits, including increased productive tillers, leaf area index (LAI), leaf photosynthetic rate, shoot biomass, contents of indole-3-acetic acid (IAA) and zeatin (Z) and zeatin riboside (ZR) in leaves, non-structural carbohydrates (NSC) remobilization during grain filling, and content of NSC per spikelet, when compared to the WTVs under the LP treatment. Additionally, the STVs demonstrated better root traits, such as higher root biomass, root oxidative activity (ROA), root acid phosphatase (RAP) activity, and greater root IAA and Z + ZR contents. These shoot and root traits exhibited highly positive correlations with grain yield, PTE, and IPE. In conclusion, the STVs maintain higher grain yield and PUE under the LP treatment, due mainly to their improved root and shoot agronomic and physiological traits, which provide valuable references for selecting for P-efficient rice varieties. [ABSTRACT FROM AUTHOR]

In potato production systems, runoff and erosion are major loss routes of phosphorus (P), while P loss through vertical leaching has been considered insignificant due to the poor mobility of P in soil. However, reduced water and nutrient retention capacity in coarse-textured soil as well as shallow root system of potato may result in significant P leaching beyond potato rooting zone, leading to lower P-use efficiency in potato production and increased environmental risk. The objective of this study was to evaluate phosphorus leaching in coarse soil during potato production under varied phosphorus application rates, by collecting leachate from 60 cm deep soil. Results indicated that accumulative P leaching during the potato production ranged from 0.61 to 4.67 kg ha−1, P concentration in leachate solution could reach 3.41 mg L−1, and it increased significantly with increasing P application rate. This high level of P leaching is a concern both environmentally and agronomically, and points to the importance of developing P fertilizer management aimed at diminishing P leaching and improving P-use efficiency in potato production in coarse soil worldwide. [ABSTRACT FROM AUTHOR]

Background: The excessive use of inorganic P (Pi) in soils is alarming as it is causing numerous environmental problems and may lead to the depletion of rock phosphate reserves earlier than expected. Hence, to limit the over‐dependence on Pi, there is the need to investigate organic phosphorus (Po), which is the dominant P form of soil P pool, as an alternate P source for plant growth. Aim: The present study seeks to investigate organic P use efficiency of eight varieties of faba bean grown symbiotically. Methods: The plants were grown in pots (6 kg soil) under greenhouse condition with three P source, namely, phytic acid (organic P, Po), KH2PO4 (inorganic P, Pi), and no‐P. The P was applied at the rate of 1.79 g kg−1 soil. Results: The plants grown with Po and Pi produced similar amounts of root, shoot, and total dry matters. Despite producing statistically similar dry matters, P uptake by Pi‐fertilized plants was twofold higher than by Po‐fertilized plants. Meanwhile, Pi differed significantly from Po in terms of nodulation characteristics such as nodule dry biomass and individual nodule dry biomass. However, Po varied significantly from Pi in P utilization and acquisition efficiencies. Principal component analysis of Pi and Po revealed no significant variation and close association, confirming the nonsignificant differences between the two P treatments. Among the varieties tested, Tiffany tended to accumulate more dry matter, coupled with highest organic P utilization efficiency (0.48 g mg−1) as well as the highest organic P beneficiary factor (80%). Conclusion: These results provide a solid basis for further comparisons at physiological, biochemical, and molecular levels between Tiffany (Po‐efficient) and Fuego (Po‐inefficient) varieties, offering deep insights into and making it easier to understand the mechanisms that allow soil Po to be utilized under symbiotic conditions. [ABSTRACT FROM AUTHOR]

Phosphorus is a major nutrient vital for plant growth and development, with a substantial amount of cellular phosphorus being used for the biosynthesis of membrane phospholipids. Here, we report that NON‐SPECIFIC PHOSPHOLIPASE C4 (NPC4) in rapeseed (Brassica napus) releases phosphate from phospholipids to promote growth and seed yield, as plants with altered NPC4 levels showed significant changes in seed production under different phosphate conditions. Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated nuclease 9 (Cas9)‐mediated knockout of BnaNPC4 led to elevated accumulation of phospholipids and decreased growth, whereas overexpression (OE) of BnaNPC4 resulted in lower phospholipid contents and increased plant growth and seed production. We demonstrate that BnaNPC4 hydrolyzes phosphosphingolipids and phosphoglycerolipids in vitro, and plants with altered BnaNPC4 function displayed changes in their sphingolipid and glycerolipid contents in roots, with a greater change in glycerolipids than sphingolipids in leaves, particularly under phosphate deficiency conditions. In addition, BnaNPC4‐OE plants led to the upregulation of genes involved in lipid metabolism, phosphate release, and phosphate transport and an increase in free inorganic phosphate in leaves. These results indicate that BnaNPC4 hydrolyzes phosphosphingolipids and phosphoglycerolipids in rapeseed to enhance phosphate release from membrane phospholipids and promote growth and seed production. [ABSTRACT FROM AUTHOR]

The Mediterranean agricultural sector faces many challenges related to water and mineral resource use for crop production and food security for an exponentially growing population. Phosphorus drip fertigation has recently emerged as an efficient and sustainable technique to improve water and nutrient use efficiency under such challenging pedoclimatic conditions. The classical methods for administering standard P fertilizers to crops (broadcasting and banding) have shown their limitations in terms of P acquisition and use efficiency. More than 60 % of applied P through dry P fertilizers is rapidly transformed into recalcitrant P forms and subsequently lost by soil erosion increasing the effects of P eutrophication issues on the ecosystem's sustainability. The emergence of new advanced irrigation technologies like high-frequent drip irrigation must be accompanied by the development of new P formulations with high water solubility and greater P use efficiency. This review illustrates the state of the art for P fertilizers used in Mediterranean agriculture in the last decades. An overall description is provided for the P fertilizer formulas, their physicochemical properties, as well as their suitability for drip fertigation systems and the consequent effects of their application on photosynthesis, plant growth, and crop productivity. The key factors influencing P fertilizer transformations and use efficiency under drip fertigation systems are extensively discussed in this review with a focus on the differences between orthophosphate and polyphosphate formulations.

Abstract Introduction Low phosphorus (P) use efficiency (PUE) of fertiliser is a critical problem in sustainable crop production, especially in strongly weathered tropical soils with a high P‐fixation capacity. Both intercropping and rhizobium inoculation have shown to improve the P availability of rhizosphere soil, but the effect of a combined approach of using both intercropping and rhizobium inoculation is still unclear. In this study, we aimed to evaluate the effect of rhizobium inoculation on the soil–plant P dynamics and fertilised PUE under the intercropping system in strongly weathered tropical soil. Materials and Methods We conducted an 85‐day cultivation pot experiment with pigeon pea (PP) and maize using highly weathered tropical soil under eight treatments: monocropping (CS) or intercropping, with or without rhizobium (Bradyrhizobium elkanii USDA61) inoculation (−I, +I) and with or without P fertilisation (0P, 50P) (2 × 2 × 2 = 8 treatments). We evaluated the effects of intercropping and rhizobium inoculation on plant growth parameters, P dynamics of the rhizosphere and bulk soil using the Hedley P fractionation method, the amount of organic acid from plant roots as a plant P‐mobilising capacity, and fertilised PUE. Results Total plant P uptake per pot was significantly increased by intercropping but not by combining intercropping and rhizobium inoculation, resulting in better fertilised PUE only in intercropping. The available inorganic P (Pi) and less labile Pi of the soil were higher in the rhizosphere than those in the bulk by intercropping under 50P and were similar in PP + I under 50 P. The amount of organic acid per pot under 50P increased with each treatment, that is, intercropping and rhizobium inoculation, but not with their combination. Conclusion The intercropping system has a strong potential to improve PUE by stimulating the P‐mobilising capacity of intercropping plant roots, whereas rhizobium inoculation of the intercropping system did not improve PUE in this study.

Crop production in Afghanistan suffers from limited phosphorus (P) availability, which severely hinders national agriculture sustainability. This study hypothesized that deep fertilizer placement could significantly enhance the uptake of immobile P and, thus, tissue P accumulation and crop yield. A two-year pot experiment growing two maize (Zea mays) hybrid cultivars (Xida-789 and Xida-211) was, therefore, conducted to test these hypotheses under three contrasting fertilizer placement methods (broadcast, side band, and deep band). In doing so, P concentrations in both maize tissues and soils were compared at 45, 60, and 115 days after sowing (DAS) under nine combinations of nitrogen (N) and P fertilizer rates (kg ha−1: N112P45, N112P60, N112P75, N150P45, N150P60, N150P75, N187P45, N187P60, N187P75). Results have shown that deep band placement significantly increased P uptake efficiency, leading to greater P concentration and accumulation in maize tissues compared to the other two fertilization methods. This improved P uptake was attributed to several factors associated with deep placement, including reduced P fixation, enhanced root access to P, and moisture availability for P uptake. Additionally, deep band placement combined with higher N application rates (N187 and N150) further enhanced plant P uptake by promoting P availability and utilization mechanisms. Deep band placement also resulted in significantly higher total soil P, Olsen-P, and P use efficiency than broadcast and side band methods, indicating a more efficient P fertilization strategy for maize that can improve growth and yield. This study also found positive correlations between P concentration in plant organs and soil Olsen-P, highlighting the importance of adequate soil P levels for optimal plant growth. Overall, our results have shown that deep band fertilizer placement emerged as a superior strategy for enhancing P uptake efficiency, utilization, and maize productivity compared to broadcast and side band placement. The outcome generated from the deep band fertilization by this greenhouse study can be recommended for field practices to optimize P fertilizer use and improve maize production while minimizing potential environmental P losses associated with broadcast fertilization.

Replacing chemical fertilisers with recycled products will require new advice for phosphorus (P) use.. Emerging P fertilisers derived from dairy processing sludge (DPS) include products such as struvite and hydrochar. A field study monitored temporal changes in available, exchangeable, and Mehlich3 P pools in a P deficient grassland amended with DPS-derived hydrochar and struvite. Herbage P content and yields were compared with data from plots amended with a mineral P fertiliser. Regardless of fertiliser used, there was no statistical difference in dry matter yield. However, herbage P content varied depending on the fertiliser type. The optimal P content in herbage for cattle feed (0.3–0.4 %) was reached using struvite and mineral fertiliser. Application of struvites increased available, exchangeable, and Mehlich3 P, raising the available P levels to the agronomic optimal value for crop production (>5 mg l-1) within one month. In hydrochar amended plots, the optimal level of P was reached 4 months after fertilisation, at the end of the growing season. During the low growth or dormancy period, soil P levels decreased and remained low regardless of the treatment. In the struvite amended plots, available and exchangeable P pools recovered at the beginning of the second season. This effect was not observed in mineral fertiliser and hydrochar amended plots. A single application of struvite can replace mineral fertilisers supplying crops with P for more than one season. This needs to be reflected in the advice for growers to avoid excessive P application and legacy P deposition.

The present study aimed to assess the efficiency of monoammonium phosphate (MAP), with controlled-release technology, on cowpea, soybean, and corn in the Brazilian Eastern Amazon edaphoclimatic conditions. It were evaluated MAP conventional, FH Humics MAP that incorporates humic acid, and Potenza MAP that incorporates polymer, and two soils with different clay contents (23.1 and 37.6%), on the growth of cowpea, soybean, and corn, in a greenhouse. Simultaneously, it were evaluated four levels of P (0, 40, 80, and 120 kg ha-1 of P2O5), for the mentioned formulations on cowpea grain yield, in cerrado, and upland forest environments. Fertilization with MAP Humics and MAP Potenza promotes similar soybean, cowpea, and corn growth, and cowpea grain yield compared to conventional MAP, under greenhouse and field conditions, respectively. MAP formulations promote greater soybean, cowpea, and corn growth, and cowpea grain yield in the sandy loam and cerrado than in sandy clay soil and upland forest environment, respectively. Increasing levels of MAP formulations have no effect on cowpea grain yield in the cerrado but promote linear cowpea grain yield increase in the upland forest environment. [ABSTRACT FROM AUTHOR]

Reduced row spacing has shown to increase maize (Zea mays L.) nitrogen (N) use efficiency, but little is known about it effects on phosphorous (P) use efficiency (PUE). The objective of this study was to evaluate the PUE of maize under reduced row spacing and varying N regimes. No till maize was grown in Balcarce, Argentina, during two growing seasons using three rows spacing (35, 52, and 70 cm) and three N rates (0, 90, and 180 kg N ha−1). Shoot dry matter (DM), grain yield, and accumulated P content were determined. At V6 and R6 growth stages, the P use efficiency (PUE = g aboveground DM or grain yield per g P available) and it components P utilization efficiency (PUTE = g aboveground DM or grain yield per g P uptake), and P uptake efficiency (PUPE = g P uptake/g P available) were determined. N rate and narrower rows increased total DM, grain yield, and accumulated P content. Phosphorous concentration, PUTE, PUPE and PUE were not affected by row spacing or N rate. The present study showed that row spacing did not affect P use efficiency in no till maize when the soil P availability was adequate. [ABSTRACT FROM AUTHOR]

Phosphorus use efficiency (PUE) is a complex trait, governed by many minor quantitative trait loci (QTLs) with small effects. Advances in molecular marker technology have led to the identification of QTLs underlying PUE. However, their practical use in breeding programs remains challenging due to the unstable effects in different genetic backgrounds and environments, interaction with soil status, and linkage drag. Here, we compiled PUE QTL information from 16 independent studies. A total of 192 QTLs were subjected to meta-QTL (MQTL) analysis and were projected into a high-density SNP consensus map. A total of 60 MQTLs, with significantly reduced number of initial QTLs and confidence intervals (CI), were identified across the rice genome. Candidate gene (CG) mining was carried out for the 38 MQTLs supported by multiple QTLs from at least two independent studies. Genes related to amino and organic acid transport and auxin response were found to be abundant in the MQTLs linked to PUE. CGs were cross validated using a root transcriptome database (RiceXPro) and haplotype analysis. This led to the identification of the eight CGs (OsARF8, OsSPX-MFS3, OsRING141, OsMIOX, HsfC2b, OsFER2, OsWRKY64, and OsYUCCA11) modulating PUE. Potential donors for superior PUE CG haplotypes were identified through haplotype analysis. The distribution of superior haplotypes varied among subspecies being mostly found in indica but were largely scarce in japonica. Our study offers an insight on the complex genetic networks that modulate PUE in rice. The MQTLs, CGs, and superior CG haplotypes identified in our study are useful in the combination of beneficial alleles for PUE in rice. [ABSTRACT FROM AUTHOR]

Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plantavailable P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical 'catch and release' wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify 'phosphorus use efficiency' using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype. [ABSTRACT FROM AUTHOR]

Lettuce (Lactuca sativa L.) is the most common leafy vegetable produced hydroponically in the United States. Although hydroponic systems are advantageous due to lower pest and disease pressure, and reduced water and nutrient requirements, the increasing prices of fertilizers, including phosphorus (P), still influences the profitability of hydroponic production of lettuce. Characterizing lettuce germplasm capable of producing high yield using less P inputs may help reduce fertilizer use, production costs, and P loads in wastewater. In this study, 12 lettuce accessions were grown in four experiments in a nutrient film technique system. In the first two experiments, the treatments consisted of two P concentrations (3.1 and 31 mg·L−1). Lettuce cultivated with 3.1 mg·L−1 of P had variable shoot and root biomass, root–shoot ratio, P uptake efficiency, and P utilization efficiency, indicating the existence of genetic variation. Five accessions (‘Little Gem’, 60183, ‘Valmaine’, BG19-0539, and ‘Green Lightning’) were considered efficient to P because produced similar shoot biomass with the low and high P treatments. In the third and fourth experiments, the treatments consisted of two P sources (monosodium phosphate (NaH2PO4) and tricalcium phosphate [TCP; Ca3(PO4)2]. Initially, extra 5 mM of calcium (Ca) was added to the TCP solution to reduce the TCP solubility and, hence, P bioavailability to plants. All accessions produced similar shoot and root weight with both treatments, indicating that the TCP treatment did not cause low-P stress to the plants. After, the extra Ca concentration added to TCP was increased to 10 mM, resulting in low-P stress and a significant reduction in shoot weight of all accessions. Despite the severe P stress, ‘Little Gem’ and 60183 were among the accessions with the least shoot weight reduction in the TCP treatment. Variability was observed in root biomass root–shoot ratio among accessions under the TCP treatment, suggesting that lettuce accessions responded differently to P stress conditions. The genetic variation for P use efficiency (PUE) and PUE-related traits in lettuce grown hydroponically suggests the feasibility of breeding new lettuce cultivars from elite lettuce germplasm adapted to low P availability in hydroponics.

Abstract Key message Short-term nitrogen (N) deposition stimulates phosphorus (P) demand owing to the growth improvment of Phyllostachys edulis seedlings. Increased N loads led to the acquisition and utilization of sufficient P, while the limitation of P starvation could be alleviated by the higher activity of soil acid phosphatase and P use efficiency rather than P resorption from senescent organs. Context Plants in most terrestrial ecosystems are usually subjected to natural phosphorus (P) deficiency or surplus by overfertilization associated with increasing global nitrogen (N) deposition. As the widely distributed gramineous plant in Southern China, moso bamboo (Phyllostachys edulis (Carrière) J. Houz) grows fast and it also shows a relatively good growth performance under the variable N and P conditions. However, few studies focus on the special mechanism of P mobilization and utilization of moso bamboo, especially with the N loads. Aims The objective of this study was to figure out the mechanisms of P mobilization and utilization in P. edulis seedlings under varying levels of soil P and N deposition conditions in the subtropical region of China. Methods We grew P. edulis seedlings under 3 experimental N deposition rates (0 (N −), 30 (N +), and 60 (N + +) kg N ha−1·a−1) and 3 levels of soil P (2.99 mg·kg−1, soil available P content under natural conditions, denoted as P1; 20 mg·kg−1, P2; and 40 mg·kg−1, P3). We measured growth traits and analyzed the related P use indices. Results Dry weight and P accumulation of new leaves and stems increased with increasing N loads under the 3 P treatments, with the positive effects of N deposition being stronger in the P2 and P3 treatments. Compared with N − , N + , and N + + significantly increased P use efficiency (PUE) (+ 15.54% and + 12.47%, respectively) regardless of soil P conditions. The P resorption efficiency showed a decreasing tendency under variable P conditions with increasing N, whereas PUE was further increased. Acid phosphatase (APase) activity and soil available P content were significantly improved by N loads in P1. Conclusion Phyllostachys edulis seedlings showed high growth plasticity and P mobilization mechanisms under different soil P availability with N loads. In general, N addition stimulated P demand of P. edulis seedlings owing to the growth promotion in the short period of experiment. A special P use mechanism in P deficiency conditions was that the limitation of P starvation was alleviated by the higher soil APase activity and PUE instead of P resorption from senescent organs. The long-term effect of N deposition on P mobilization and utilization in P. edulis forests requires further monitoring.

Aluminum (Al) toxicity and phosphorus (P) deficiency are widely recognized as major constraints to agricultural productivity in acidic soils. Under this scenario, the development of ryegrass plants with enhanced P use efficiency and Al resistance is a promising approach by which to maintain pasture production. In this study, we assessed the contribution of growth traits, P efficiency, organic acid anion (OA) exudation, and the expression of Al-responsive genes in improving tolerance to concurrent low-P and Al stress in ryegrass (Lolium perenne L.). Ryegrass plants were hydroponically grown under optimal (0.1 mM) or low-P (0.01 mM) conditions for 21 days, and further supplied with Al (0 and 0.2 mM) for 3 h, 24 h and 7 days. Accordingly, higher Al accumulation in the roots and lower Al translocation to the shoots were found in ryegrass exposed to both stresses. Aluminum toxicity and P limitation did not change the OA exudation pattern exhibited by roots. However, an improvement in the root growth traits and P accumulation was found, suggesting an enhancement in Al tolerance and P efficiency under combined Al and low-P stress. Al-responsive genes were highly upregulated by Al stress and P limitation, and also closely related to P utilization efficiency. Overall, our results provide evidence of the specific strategies used by ryegrass to co-adapt to multiple stresses in acid soils.

Phosphorus (P) is a vital element required by all living organism (plants, animals and microbes etc.). Its application in agriculture, whether in conventional or conservation agriculture, requires careful attention due to its low use efficiency, which typically does not exceed 20%. With the increasing acceptance of conservation agriculture (CA), it is crucial to develop protocols for P management to ensure sustainable wheat production. Therefore, a field trial was conducted from 2016–2017 to 2017–2018 in the India's semiarid eco-region to study the role of P on wheat productivity, quality, and resource use efficiency under CA-based production system. We assessed the impact of tillage operations and P management practices on wheat productivity, quality, and resource use efficiency. Three tillage and residue management options such as CT-R (conventional tillage without residue); NT-R (no tillage without maize residue) and NT + R (no tillage with maize residue @ 2.5 Mg ha−1) were laid-out in main plot and five P management options subplots viz. P1 (nitrogen and potash according to recommended but not P); P2 (17.2 kg P ha−1); P3 (17.2 kg of P ha−1 + microbial fertilizer); P4 (17.2 kg P ha−1 + compost inoculant culture) and P5 (34.4 kg P ha−1) in split plot design with three replicates. The results indicates that the combination of no-tillage with residue retention (maize residue @ 2.5 Mg ha−1) (NT + R) and the application of 34.4 kg P ha−1 (P5) significantly improved grain yield by ~43.2% compared to the control treatment (conventional tillage with no residue, CT – R, and no phosphorus application). NT + R also resulted in significantly better amino acid (~22.7%) and net protein yield (~21.2%) compared to CT – R. Regarding the P management strategy, the highest amino acid (49.1%) and protein yield (12.5%) were observed under the P5 treatment compared to the no-phosphorus treatment. Conjoint use of NT – R, along with the application of 17.2 kg P ha−1 and PSB (Phosphorus Solubilizing Bacteria), resulted in a significant increase in energy use efficiency of ~58% over other treatments combination. Furthermore, the NT + R plot that received 17.2 kg P ha−1 + PSB demonstrated higher P agronomic efficiency (~43%) and recovery efficiency (~53%) over control. The study's findings underscore the significance of adopting efficient P management strategies in CA to ensure the sustainable production of wheat.

Degradation of agricultural productivity in sodic and saline soils is attributed to reducing phosphorus (P) supply capacity. The available P supply intensity and crop yields could be enhanced by artificial P fertilizer application. The effects of blending 70% controlled‐release phosphorus (CRP) and 30% triple superphosphate (TSP) on cotton physiological‐biochemical properties in sodic and saline soils were investigated by a pot incubation trial. A pot experiment was used two types of P fertilizers and three P levels (120, 96 and 72 kg P2O5 ha−1). The results showed that the SPAD value and photosynthetic rate of BBF (blending 70% CRP and 30% TSP) treatments were higher than that of TSP treatments. The root length, root surface area, and root volume of the BBF treatments increased by 10.04% and 5.31%, 3.67% and 6.80%, 3.05% and 13.77% compared to TSP treatments, respectively. In comparison with TSP1 (full‐dose of TSP) and TSP2 (to reduce 20% dose of TSP), the average lint yield of BBF1 (full‐dose of BBF) and BBF2 (to reduce 20% dose of BBF) were significantly increased by 8.35%, 7.39%, respectively. The phosphorus use efficiency of BBF2 treatment was increased by 16.59%–22.87% compared with TSP2 treatment, with the largest increase range. Furthermore, soil available P content of BBF treatments increased by 4.65%–76.77% compared with TSP treatments from the blooming to maturity stage. In a word, with P fertilization rate reduced by 20%, the combination of two P fertilizers (BBF2 treatment) can achieve high quality and high yield of cotton in sodic and saline soil. [ABSTRACT FROM AUTHOR]

The use of nanotechnology in agriculture has become an area of great interest for soil scientists. Therefore, it is important and necessary to investigate the effects of nanoparticles on plant growth and its nutritional interactions. The aim of this study was to investigate the effects of acid modified rice husk (MRH) and nano-Silicon (Si) derived from rice husk on the growth and phosphorus uptake and phosphorus use efficiency in Si accumulator wheat and non-accumulator lettuce plants. MRH and nano-Si were applied at 200 mg kg−1 and P was applied 100 mg kg−1 for wheat and 200 mg kg−1 for lettuce plants. The highest dry weight was obtained with the application of nano Si + P treatment; while both MRH and nano-Si had no significant effect over the applied 100 mg P kg−1. Phosphorus fertilization significantly reduced Si concentrations in both plants of wheat and lettuce. However, the decrease in Si concentration was partly compensated by nano-Si treatment. When P was applied together with nano-Si, its uptake and phosphorus use efficiency (PUE) significantly increased in wheat plants as compared to other treatments. Nano-Si derived from rice husk is a sustainable waste biomass and is an important alternative Si fertilizer source, which can be a valid strategy for the effective use of P fertilizers. The depletion of available Si in soil can be recovered by applying nano-Si as a fertilizer. The overall results obtained from the current research were promising. [ABSTRACT FROM AUTHOR]

Sustainability of maize production systems is threatened by poor economic returns and resource intensiveness. Therefore, an experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during 2016–17 to 2017–18 to assess the effect of tillage and microbial inoculantsintegrated phosphorus (P) management on productivity, quality, economic outcome and energy dynamics of maize. Three tillage practices viz., CT–R (conventional tillage with no residue), ZT–R (zero tillage with no residue) and ZT + R (zero tillage with wheat crop residue at 2.5 Mg/ha) were assigned in main plots and five P management practices viz., P1 (control–NK as per recommendation, but no P), P2 (17.2 kg P/ha), P3 (17.2 kg P/ha + PSB), P4 (17.2 kg P/ha + compost inoculants) and P5 (34.4 kg P/ha) were allocated in subplots in three times replicated split-plot design. The maximum grain yield (5.96 Mg/ha), protein content (9.13%), protein yield (546 kg/ha) and gross energy returns (209 × 103 MJ/ha) were recorded under ZT + R while higher benefit: cost ratio (B: C ratio – the amount of economic gain per unit investment) (1.53) and energy efficiency (12.5) was noticed under ZT–R. Among the P management practices, the application of 34.4 kg P/ha recorded the highest grain yield (6.45 Mg/ha), protein content (9.34%), protein yield (603 kg/ha), B: C ratio (1.65) and energy efficiency (10.1). The results suggested that the application of P at the rate of 34.4 kg/ha under ZT + R is an economically robust approach for the quality maize production in semi-arid region. [ABSTRACT FROM AUTHOR]

Phosphorus (P) availability is the major constrain in obtaining optimum crop yield in calcareous soils due to its precipitation as dicalcium and octacalcium phosphate by reacting with Ca+2 and Mg+2. Therefore, we explored the role of phosphate solubilizing bacteria (without and with PSB @ 2 kg ha-1) in optimizing maize yield and P availability from soluble and insoluble P sources applied @ of 100 kg P2O5 into calcareous soil. PSB inoculation significantly improved maize plant height (5.6%), 1,000 grain weight (11%), dry matter (7.5%), stover (10.8%) and grain yield (6.8%), plant P concentration (10.1%) and uptake (18.6%), extractable P (3.1%), agronomic (48%) and uptake (53%) P use efficiency over un-inoculated plots. Phosphorus application significantly improved maize yield, soil health and agronomic P use efficiency (4.84 times over control); however, its impact was more pronounced when applied as 50% P each from farmyard manure (FYM) and single super phosphate (SSP). On the basis of overall performance, the sources were ranked as 50% FYM + 50% SSP >50% rock phosphate (RP) + 50% SSP > 100% SSP > 75% FYM + 25% SSP > 75% RP +25% SSP > 100% FYM > 100 RP > control. Interactively, a significant and maximum increased over absolute control in most of the soil and plant tested characteristics were observed when 100 kg P2O5 ha-1 was supplemented 50% each as FYM and SSP along with PSB inoculation which was followed by 50% P each as FYM and SSP demonstrating that PSB were effective in enhancing RP solubilization under calcareous soil. Maximum value cost ratio of 3.1 was observed for 50% P each as FYM and SSP + PSB which was similar to 100% P as FYM + PSB and 75% FYM+ 25% SSP + PSB. Therefore, in calcareous soil P shall be amended 50% each as organic and mineral sources with PSB for its efficient utilization and obtaining optimum yield of maize. [ABSTRACT FROM AUTHOR]

The availability of phosphorus (P) and organic matter in Chromic Luvisols, predominant in the Caatinga biome, is generally low and makes it difficult to reintroduce native plants in forest recovery projects. The objective was to evaluate the production of dry mass, accumulation a and use efficiency of P by three tree species native from Caatinga biome with application of doses of P and organic matter. This experiment was carried out in a greenhouse in a completely randomized design in a 2 × 3 × 5 factorial scheme, consisting of with two doses of organic matter (0 and 50 g kg−1), three species of plants (Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S Moore, Amburana cearensis, Allemão AC Smith and Caesalpinia ferrea Mart. Ex Tul.) and five doses of P (0, 50, 100, 150 and 200 mg dm−3). At 120 days after transplanting, concentrations of P available in the soil and leaf soluble P fractions increased linearly with the P doses. The availability of P in the soil and, consequently, the accumulation of soluble and total P in the plant tissues were greater with organic matter application. The studied species use different P compartmentalization strategies depending on their dry mass production capacity. Phosphate and or organic matter application is necessary in the initial growth phase of the studied species, notably T. aurea and C. ferrea. The dry mass of T. aurea was greater than that of C. ferrea and A. cearensis. [ABSTRACT FROM AUTHOR]

Soil microorganisms directly participate in phosphorus (P) cycle, which in turn affects crop yield and quality. However, how biological and chemical parameters respond to mineral P fertilizer application rates in rhizosphere soil remains unclear. Here, a pot experiment was conducted to investigate the effects of different mineral P fertilizer application rates (0, 60, 120, and 300 kg P2O5 ha−1) on soil chemical properties and bacterial community in maize rhizosphere in a Mollisol. With increasing P fertilizer rates, soil organic carbon concentration decreased, while soil Olsen P and inorganic P and organic P (Po) fractions concentrations increased. High-throughput 16S rRNA gene sequencing showed that the relative abundances of some beneficial bacteria (Anaerolinea, Anaeromyxobacter, Kaistia and Rhodobacter) significantly increased with reduced P fertilizer rates, and meanwhile those of other beneficial bacteria (Mesorhizobium, Microvirga, Rhizobacter and Skermanella) significantly decreased under high P fertilizer rates. Redundancy analysis (RDA) showed that labile Po was the main driver of the differences in bacterial community structure. Bacterial community diversity and composition significantly and indirectly affected maize yield via octacalcium-bound P, occluded Fe/Al-bound P, labile Po, and moderately labile Po. The results suggested that reducing P fertilizer rates can promote beneficial bacterial growth and increase bacterial community diversity. [ABSTRACT FROM AUTHOR]

Lettuce (Lactuca sativa L.) is the most common leafy vegetable produced hydroponically in the United States. Although hydroponic systems are advantageous due to lower pest and disease pressure, and reduced water and nutrient requirements, the increasing prices of fertilizers, including phosphorus (P), still influences the profitability of hydroponic production of lettuce. Characterizing lettuce germplasm capable of producing high yield using less P inputs may help reduce fertilizer use, production costs, and P loads in wastewater. In this study, 12 lettuce accessions were grown in four experiments in a nutrient film technique system. In the first two experiments, the treatments consisted of two P concentrations (3.1 and 31 mg·L-1). Lettuce cultivated with 3.1 mg·L-1 of P had variable shoot and root biomass, root-shoot ratio, P uptake efficiency, and P utilization efficiency, indicating the existence of genetic variation. Five accessions ('Little Gem', 60183, 'Valmaine', BG19-0539, and 'Green Lightning') were considered efficient to P because produced similar shoot biomass with the low and high P treatments. In the third and fourth experiments, the treatments consisted of two P sources (monosodium phosphate (NaH2PO4) and tricalcium phosphate [TCP; Ca3(PO4)2]. Initially, extra 5 mM of calcium (Ca) was added to the TCP solution to reduce the TCP solubility and, hence, P bioavailability to plants. All accessions produced similar shoot and root weight with both treatments, indicating that the TCP treatment did not cause low-P stress to the plants. After, the extra Ca concentration added to TCP was increased to 10 mM, resulting in low-P stress and a significant reduction in shoot weight of all accessions. Despite the severe P stress, 'Little Gem' and 60183 were among the accessions with the least shoot weight reduction in the TCP treatment. Variability was observed in root biomass root-shoot ratio among accessions under the TCP treatment, suggesting that lettuce accessions responded differently to P stress conditions. The genetic variation for P use efficiency (PUE) and PUE-related traits in lettuce grown hydroponically suggests the feasibility of breeding new lettuce cultivars from elite lettuce germplasm adapted to low P availability in hydroponics. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is a vital macronutrient required for soybean growth and development but is a finite resource in agriculture worldwide. Low inorganic P availability in soil is often a significant constraint for soybean production. However, little is known about the response of P supply on agronomic, root morphology, and physiological mechanisms of contrasting soybean genotypes at various growth stages and the possible effects of different P on soybean yield and yield components. Therefore, we conducted two concurrent experiments using the soil-filled pots with six genotypes (deep-root system: PI 647960, PI 398595, PI 561271, PI 654356; and shallow-root system: PI 595362, PI 597387) and two P levels [0 (P0) and 60 (P60) mg P kg−1 dry soil] and deep PVC columns with two genotypes (PI 561271 and PI 595362) and three P levels [0 (P0), 60 (P60), and 120 (P120) mg P kg−1 dry soil] in a temperature-controlled glasshouse. The genotype × P level interaction showed that increased higher P supply increased leaf area, shoot and root dry weights, total root length, shoot, root, and seed P concentrations and contents, P use efficiency (PUE), root exudation, and seed yield at different growth stages in both experiments. At the vegetative stage (Experiment 1), shallow-rooted genotypes with shorter life cycles had more root dry weight (39%) and total root length (38%) than deep-rooted genotypes with longer life cycles under different P levels. Genotype PI 654356 produced significantly higher (22% more) total carboxylates than PI 647960 and PI 597387 under P60 but not at P0. Total carboxylates positively correlated with root dry weight, total root length, shoot and root P contents, and physiological PUE. The deep-rooted genotypes (PI 398595, PI 647960, PI 654356, and PI 561271) had the highest PUE and root P contents. In Experiment 2, at the flowering stage, genotype PI 561271 had the greatest leaf area (202%), shoot dry weight (113%), root dry weight (143%), and root length (83%) relative to the short-duration, shallow-rooted genotype PI 595362 with external P applied (P60 and P120), with similar trends at maturity. PI 595362 had a greater proportion of carboxylates as malonate (248%), malate (58%), and total carboxylates (82%) than PI 561271 under P60 and P120 but no differences at P0. At maturity, the deep-rooted genotype PI 561271 had greater shoot, root, and seed P contents and PUE than the shallow-rooted genotype PI 595362 under increased P rates but no differences at P0. Further, the genotype PI 561271 had higher shoot (53%), root (165%), and seed yield (47%) than PI 595362 with P60 and P120 than P0. Therefore, inorganic P application enhances plant resistance to the soil P pool and maintains high soybean biomass production and seed yield. [ABSTRACT FROM AUTHOR]

Key message: Short-term nitrogen (N) deposition stimulates phosphorus (P) demand owing to the growth improvment of Phyllostachys edulis seedlings. Increased N loads led to the acquisition and utilization of sufficient P, while the limitation of P starvation could be alleviated by the higher activity of soil acid phosphatase and P use efficiency rather than P resorption from senescent organs. Context: Plants in most terrestrial ecosystems are usually subjected to natural phosphorus (P) deficiency or surplus by overfertilization associated with increasing global nitrogen (N) deposition. As the widely distributed gramineous plant in Southern China, moso bamboo (Phyllostachys edulis (Carrière) J. Houz) grows fast and it also shows a relatively good growth performance under the variable N and P conditions. However, few studies focus on the special mechanism of P mobilization and utilization of moso bamboo, especially with the N loads. Aims: The objective of this study was to figure out the mechanisms of P mobilization and utilization in P. edulis seedlings under varying levels of soil P and N deposition conditions in the subtropical region of China. Methods: We grew P. edulis seedlings under 3 experimental N deposition rates (0 (N −), 30 (N +), and 60 (N + +) kg N ha−1·a−1) and 3 levels of soil P (2.99 mg·kg−1, soil available P content under natural conditions, denoted as P1; 20 mg·kg−1, P2; and 40 mg·kg−1, P3). We measured growth traits and analyzed the related P use indices. Results: Dry weight and P accumulation of new leaves and stems increased with increasing N loads under the 3 P treatments, with the positive effects of N deposition being stronger in the P2 and P3 treatments. Compared with N − , N + , and N + + significantly increased P use efficiency (PUE) (+ 15.54% and + 12.47%, respectively) regardless of soil P conditions. The P resorption efficiency showed a decreasing tendency under variable P conditions with increasing N, whereas PUE was further increased. Acid phosphatase (APase) activity and soil available P content were significantly improved by N loads in P1. Conclusion: Phyllostachys edulis seedlings showed high growth plasticity and P mobilization mechanisms under different soil P availability with N loads. In general, N addition stimulated P demand of P. edulis seedlings owing to the growth promotion in the short period of experiment. A special P use mechanism in P deficiency conditions was that the limitation of P starvation was alleviated by the higher soil APase activity and PUE instead of P resorption from senescent organs. The long-term effect of N deposition on P mobilization and utilization in P. edulis forests requires further monitoring. [ABSTRACT FROM AUTHOR]

Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plant-available P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical ‘catch and release’ wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify ‘phosphorus use efficiency’ using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype.

Phosphorus (P) deficiency and low P use efficiency (PUE) are limiting factors in rice (Oryza sativa L.) production. Understanding the agronomic and physiological traits of P-tolerant rice varieties is crucial for improving PUE. However, the agronomic and physiological traits of rice varieties differing in tolerance to low P have not been fully studied or comprehensively explored. Two varieties with strong tolerance to low P (STVs, low P tolerance index > 0.9) and two with weak tolerance to Low P (WTVs, low P tolerance index < 0.5) were grown hydroponically with normal P level (NP, 8.02 mg L−1) and low P level (LP, 0.401 mg L−1) in year 2020 and 2021. Results showed that, compared with NP, the LP significantly decreased grain yield, but enhanced P translocation efficiency (PTE), internal P use efficiency (IPE), and P harvest index (PHI) in all the varieties. The STVs showed better performance than the WTVs. Specifically, the STVs exhibited a 131.33% higher grain yield, 15.95% higher PTE, 41.6% higher IPE, and 8.84% higher PHI compared to the WTVs. The STVs also exhibited superior shoot traits, including increased productive tillers, leaf area index (LAI), leaf photosynthetic rate, shoot biomass, contents of indole-3-acetic acid (IAA) and zeatin (Z) and zeatin riboside (ZR) in leaves, non-structural carbohydrates (NSC) remobilization during grain filling, and content of NSC per spikelet, when compared to the WTVs under the LP treatment. Additionally, the STVs demonstrated better root traits, such as higher root biomass, root oxidative activity (ROA), root acid phosphatase (RAP) activity, and greater root IAA and Z + ZR contents. These shoot and root traits exhibited highly positive correlations with grain yield, PTE, and IPE. In conclusion, the STVs maintain higher grain yield and PUE under the LP treatment, due mainly to their improved root and shoot agronomic and physiological traits, which provide valuable references for selecting for P-efficient rice varieties.