Phosphorus Fertilizer Research Articles

Long‐term comparison of targeted soil test values and crop removal as a phosphorus fertilization strategy in corn

AbstractFinding effective phosphorus (P) recommendation strategies to optimize corn (Zea mays L.) yield under varying yield levels and environmental conditions is continuously sought after. A 16‐year study was conducted in Concord, NE, on Nora silt loam soil initially measuring 16 ± 3 mg kg−1 Bray‐1 P. The study evaluated the impact of different P fertilization strategies on corn yield across various growing conditions (dry, normal, and wet years). Treatments included no P or N (NPNN), no P (NP), P applied at crop removal phosphorus (CRP), and maintaining soil P at 15 (B15), 30 (B30), and 45 (B45) mg kg−1 Bray‐1 P, with similar nitrogen (N) rates except for NPNN. Results showed a 25% and 33% reduction in soil test phosphorus (STP) for NPNN and NP treatments, respectively. The total P required by B30 and B45 treatments was 1.8 times more than that for CRP and B15. Although B30 and B45 treatments increased corn grain P concentration by 6%–12% compared to B15 and CRP, they did not increase yields in normal and dry years. The NP led to yield reductions of 9% and 12% in normal and wet years, respectively. In contrast, CRP achieved an 8% higher yield than B15 during wet years. Economic analysis revealed that B45 yielded a 56% higher net return in normal years, while CRP offered the highest return on investment (ROI) at 4.9. This study highlights the complexity of managing soil P under varying environmental conditions, emphasizing that while maintaining higher STP levels (B30 and B45) can enhance grain P concentration, it does not significantly boost yield and ROI compared to CRP and B15.

Biochar application affected biochemical properties, yield and nutrient content of safflower under water stress

A two-year field trial was set up to investigate the effects of applying 3 tons ha-1 of wheat (3WB) and cotton biochar (3CB) alone or in combination with chemical nitrogen (N) and phosphorus (P) fertilizers on biochemical properties, yield and nutrient content of safflower under normal irrigation and water stress (irrigation cut-off at flowering stage) conditions. The total water applied in the chemical treatments [150 kg ha−1 N + 50 kg ha−1 P (100% of the recommended dose) and 112.5N + 37.5P (75% of the recommended dose)] under water stress, was significantly higher than other treatments. Application of 112.5N + 37.5P + 3CB increased RWC from 57.5 to 59.4% and the total chlorophyll content from 80.7 to 128.1%, compared to the control. The carotenoid content, catalase and peroxidase in 112.5N + 37.5P + 3CB were lower than chemical fertilizers. Under water stress, the seed yield of 112.5N + 37.5P + 3CB was 10.2–12.6% higher than 112.5N + 37.5P + 3WB. The higher chlorophyll content, RWC, remobilization efficiency and nutrient content in 112.5N + 37.5P + 3CB compared to other treatments was associated with seed yield enhancement. The findings indicate that the combination of CB with 75% recommended dosage of N and P, may be the optimal approach for enhancing safflower production under water stress conditions.

Polystyrene microplastics as carriers for nano-hydroxyapatite particles: Impact of surface functionalization and mechanistic insights

The potential of microplastics (MPs) to act as carriers for contaminants or engineered nanomaterials is of rising concern. However, directly determining the vector effect of polystyrene (PS) MPs towards nano-hydroxyapatite (nHAP) particles, a typical nano phosphorus fertilizer and soil remediation material, has been rarely studied. In this study, the interaction of differentially surface functionalized PS MPs with nHAP were investigated through batch experiments under different solution chemistry conditions. The results demonstrated that nHAP had the highest attachment/adsorption affinity onto carboxyl-functionalized PS, followed by bare PS and amino-functionalized PS under near-neutral pH conditions. Adsorption of nHAP exhibited a strong pH-dependent behavior with PS MPs, increasing under acidic-neutral pH (3−7) and decreasing at higher pH values. The presence of humic acid and NaCl hindered the adsorption of nHAP onto MPs. Scanning electron microscopy observations revealed a rod-like morphology for adsorbed nHAP, which was randomly distributed on MPs surface. Surface complexation and cation-π interaction were mainly responsible for the adsorption of nHAP as revealed by multiple spectroscopic analyses. These results provide mechanistic insights into nHAP-PS interactions and expound the effect of surface functionalization of PS on binding mechanisms, and thus bring important clues for better understanding the vector effects of MPs towards nanoparticles.

Estimation of phosphorus input on county-based scale is more appropriate to formulate phosphorus management policies

The excessive phosphorus input generated by human activities has broken the nutritional balance of ecosystem. This study focused on the Three Gorges Reservoir Region, where human activities are concentrated. It involved the innovative selection of county subunits to provide a clearer analysis of different components contributing to net anthropogenic phosphorus input (NAPI) and factors impacting it on a smaller scale, opening up a new horizon for more accurately formulating phosphorus management policies. The results showed that NAPI of the reservoir region maintained a high level (2641.84 kg·km−2·a−1), while showing significant spatial variation due to high input (>4200 kg·km−2·a−1) at an urban agglomeration in the reservoir region. Phosphorus fertiliser made the largest (63 %–64 %) contribution to NAPI in the reservoir region, but different compositions of the component determining NAPI were shown among the counties. The sensitive coefficient (2.36) of phosphorus fertiliser in the reservoir region was the largest, the sensitive coefficients and proportional contributions in counties also varied among the counties. The findings of this study showed that reducing the input of phosphorus fertiliser and improving the utilization rate of phosphorus are direct methods for reducing NAPI in the Three Gorges Reservoir Region. Furthermore, improving the methods of treating human domestic waste and sewage can alleviate the high input pressure of phosphorus. The spatial differentiation of NAPI in the analyzed counties was mainly affected by the increase in phosphorus fertiliser and gross output value of agriculture, along with increasing urbanization, population densification, and greater economic activity in Chongqing compared with the other counties. Moreover, the components, sensitivities, contributions and impact factors in the counties were heterogeneous due to socio-economic, agricultural, and geographical characteristics, so it might be more appropriate to formulate phosphorus management policies on a smaller county-based scale.

Can earthworms and root traits improve plant struvite-P uptake? A field mesocosm study

The availability of conventional linear mineral phosphorus (P) fertilization will become lower as phosphate rock stocks are limited and strongly concentrated in a few locations. Therefore, we need to increase agronomic P use efficiency and find alternative, recycled, sources of P. Two possible solutions mentioned in the literature are (i) using struvite, a mineral circular P fertilizer; and (ii) making use of earthworm activity, which has been shown to increase P availability. Here, we study the interaction between these two approaches, with the hypothesis that earthworms could increase the P availability from the poorly soluble struvite. We set up a field-based mesocosm experiment in a sandy soil with a low agronomic P status with 13 different treatments combining three earthworms species (Lumbricus rubellus Hoffmeister, Aporrectodea caliginosa Savigny and A. longa Ude alone or in a threes species mixture), different P fertilizers (no P, Triple Super Phosphate (TSP) and struvite). The experiment lasted 13 months (five fertilisation-harvest cycles). We found that, in field conditions, the yield and P uptake of Lolium perenne did not differ between fertilization with struvite or TSP. Earthworms only played a minor role in explaining ryegrass P uptake compared to fertilisation. We did not see either positive nor negative interactions between earthworms and struvite, meaning that earthworms did not further increase the P availability from struvite. The equal performances of struvite and TSP are explained by an enhanced effort from plants to actively take up P through a modification of root traits. This includes increased arbuscular mycorrhizal fungi colonisation and the production of finer and longer roots. Our results show that struvite performs comparably to TSP under realistic field conditions, making it a viable alternative to phosphate rock-based fertilizers.

Evaluating the Impacts of Fertilization and Rainfall on Multi-Form Phosphorus Losses from Agricultural Fields: A Case Study on the North China Plain

Excessive fertilizer application increases the risk of eutrophication and agricultural non-point source pollution (ANPS) in rivers near farmland. However, the processes and mechanisms of runoff and phosphorus losses, particularly in the interflow, under various fertilizer treatments and rainfall scenarios are not well understood. This study used orthogonal experimental methods to investigate the combined effects of fertilization schemes and rainfall intensity on multi-form phosphorus runoff losses and to establish statistical relationships and regression models between phosphorus losses and environmental factors in surface runoff and interflow. The results indicated that (1) the optimized fertilization scheme, compared with conventional fertilization, enhanced pak choi (Brassica rapa) growth while reducing phosphorus runoff losses. By reducing phosphorus fertilization by 35.7%, total phosphorus losses decreased by 29.3%, 34.2%, and 29.8% under light, moderate, and heavy rainfall, respectively. (2) Different fertilizer applications and rainfall intensities had varying effects on phosphorus losses through different pathways. Fertilizer application was the primary factor affecting phosphorus losses in surface runoff, while rainfall intensity mainly influenced phosphorus losses through interflow. (3) Surface runoff was the dominant pathway for phosphorus losses from farmland (>92.0%), with particulate phosphorus (>89.4%) being the predominant form. However, under high-intensity and long-duration rainfall, interflow became a significant pathway for phosphorus losses. This study highlights the importance of optimized fertilization in reducing phosphorus losses and improving fertilizer efficiency in agricultural fields. The findings will help develop strategies to mitigate ANPS and soil nutrient losses in the North China Plain.

Phosphorus recovery potential revealed by substance flow analysis of the Indian food, agricultural and sanitation system

Phosphorus is a finite resource that is in high demand due to its essential role as a fertiliser. We undertook a substance flow analysis of phosphorus for India's agri-food system to identify where the biggest losses of phosphorus occur and which flows could be targeted to move phosphorus from a linear use and waste approach to a circular approach encompassing recovery and re-use. A novel aspect of the analysis was the inclusion of sanitation systems in India. National phosphorus flows were calculated annually for the five years 2015–2019, and the mean was then used to provide a representative annual flow. The analysis showed that India is dependent on imports for 95% of applied mineral phosphorus fertiliser and has a low phosphorus-use efficiency of 32%. The largest recoverable flow is human excreta (urine and faeces), equivalent to 21% of the current phosphorus applied in mineral fertiliser in India. Phosphorus recovery from septic tanks, the most prevalent sanitation system in India, could alone replace 8% of phosphorus applied in mineral fertiliser in India. Alongside the ongoing development of sanitation systems in India this provides an opportunity to ensure that nutrient recovery is included in sanitation developments.

Response of oilseed flax to different level of mineral nutrition in the forest-steppe of Western Siberia

The article presents the results of studying the influence of nitrogen and phosphorus fertilizers on the water regime of meadow-chernozem soil, yield and oil content of flax seeds in 2022–2023. on a stationary experiment at the field forage production laboratory of the Federal State Budgetary Institution “Omsk ASC” in the conditions of the southern forest-steppe of the Omsk region. The objects of observation are oilseed flax of the Northern variety and meado-chernozem soil. The scheme of the experiment included the following options: factor A — medium soil availability of mobile phosphorus (50-100 mg/kg according to F.V. Chirikov, background 0), increased (100–120 mg/kg, background I and 140–150 mg/kg, background II), high (150– 200 mg/kg, background III); factor B — phosphorus fertilizer (P0, P60); factor C — nitrogen fertilizer (N0, N30, N60). In this case, nitrogen and phosphorus fertilizers were superimposed on backgrounds of varying soil phosphorus supply. Climatic factors (temperature and precipitation) determined the initial reserve of total moisture in the soil when sowing oil flax, which was at the level of 82% of the lowest moisture capacity in a meter layer and did not depend on the background phosphorus supply. Mineral fertilizers increased crop productivity. Its highest yield was observed against the background of an increased supply of soil with mobile phosphorus (1.71 t/ha) with the pre-sowing application of ammonium nitrate and ammophos. The oil content of flax, on the contrary, decreased when using fertilizers. Its highest indicators (39.5%) were observed against background II when using phosphorus fertilizers.

Response of Starter Nitrogen and Phosphorus Fertilizer Rates to Nodulation, Nitrogen Fixation, and Net Nitrogen Balance on Groundnut (Arachis hypogaea L.) in the Semi-arid Tigray Region of Ethiopia

Response of Starter Nitrogen and Phosphorus Fertilizer Rates to Nodulation, Nitrogen Fixation, and Net Nitrogen Balance on Groundnut (Arachis hypogaea L.) in the Semi-arid Tigray Region of Ethiopia

A method for high value-added utilization of BOF slag: Towards slag recycling and phosphorus recovery

Basic oxygen furnace (BOF) slag is a bulk solid waste generated in steelmaking process, containing large amounts of valuable components. However, its utilization ratio is not high in China, resulting in serious environmental pollution and resource waste. To realize the high value-added utilization of BOF slag, selective leaching was adopted to separate the P-bearing dicalcium silicate from slag. The leaching ratios of Si and P were much higher than those of Fe and Mn. The oxidized BOF slag exhibited a superior leaching of P. 85.6 % of P and 68.0 % of Si was separated from BOF slag while the leaching ratio of Fe was negligible in the HCl solution at pH 3. Almost all the dicalcium silicate was removed by leaching whereas the dicalcium ferrite remained. The tailing containing 46.1 % Fe2O3 and 32.9 % CaO can be reused as a steelmaking feedstock. The leachate was treated to extract phosphates by chemical precipitation. Approximately 98 % of phosphate ions was precipitated in the leachate when the pH increased to 8. Some silica gel was removed from the precipitate via alkaline wash and a phosphate containing 28.4 % P2O5 was recovered, which could be used as a phosphorus fertilizer. This study provided a method for BOF slag recycling in steelmaking process and phosphorus recovery.

The Use Efficiency of Phosphorus in Organomineral Fertilization Systems

ABSTRACT Aim The aim of this study was to determine the agronomic, physiological and recovery efficiency of phosphorus in the transition from conventional agriculture to organic agriculture of organomineral fertilizers, which are formed by combining different levels of phosphorus fertilizers and dairy manures at different rates. Materials and Methods The study was carried out between 2019 and 2021 during the two wheat growing season in Söke county of Aydın province in the Southwest of Türkiye. In the study, excluding the control (P0), 4 different levels of phosphorus (P1:10, P2:20, P3:30, and P4:40 kg P ha−1) and 4 different doses of dairy manure (DM1:10, DM2:20, DM3:30, and DM4:40 t ha−1) and 16 different organomineral fertilizer combinations were composed. The fertilizer combinations composed were divided into four sub-organomineral fertilization systems (OMF1, OMF2, OMF3, and OMF4). The study was carried out in three replications according to the randomized block design. Results In the study, according to the averages of both years, the highest agronomic, physiological and recovery efficiency (AE, PE, and RE) was determined as 29.5 kg kg−1, 175.0 kg kg−1 and 16.9% in DM1P1 application (OMF1 system), respectively. The lowest agronomic, physiological and recovery efficiency were recorded as 21.2 kg kg−1, 163.4 kg kg−1 and 13.0% in DM4P4 application (OMF4 system), respectively. As a result, organomineral fertilizers reduced the agronomic, physiological and recovery efficiency of phosphorus by 28.1%, 8.2% and 23.1%, respectively. Conclusions Finally, it was concluded that the fertilizer use efficiency increased as the amount of phosphorus applied to compose with organomineral fertilizers decreased.

Phosphorus fertiliser is associated with reduced grass grub (Costelytra giveni) fitness in Epichloë endophyte-infected meadow fescue and perennial ryegrass.

Fertiliser applications are well-established tools in pasture-based agricultural landscapes. This study focuses on the impact of phosphorus (P) fertiliser on grass grub (Costelytra giveni), a major pasture pest. This research investigates the interplay between P, plant growth, and grass grub fitness in Epichloë endophyte-infected perennial ryegrass (Epichloë sp. LpTG-3 strain AR37) and meadow fescue infected with E. uncinata (strain MaxR; AR1017), alongside their endophyte-free counterparts. In a glasshouse trial, plants were grown in P-enriched soil with varying Olsen P levels (9, 18, 28 or 78 mg L-1), and grass grubs were introduced. Their survival and weight gain, and plant performance were measured. In a bioassay, grass grubs were placed in specimen vials with P-enriched soils (Olsen P levels 9, 18, 28 and 78 mg L-1) and provided with identical plant material to assess their diet consumption and weight gain. In the glasshouse trial, results highlighted a notable decrease in the survival of grass grub on plants infected with MaxR endophyte, but not with AR37, as well as increasing soil Olsen P levels in both plant species. While grass grub decreased plant performance at the low Olsen P level (9 mg L-1), this effect diminished with increasing P. Likewise, results from the bioassay showed a decrease in diet consumption with increasing soil Olsen P levels. In both trials increasing Olsen P levels correlated with diminished grass grub performance, revealing a nuanced relationship between soil fertility and pest dynamics. The study underscores the pivotal role of selected Epichloë endophyte-grass associations in mitigating grass grub damage across varying phosphorus levels. This study highlights the potential to integrate P applications for sustainable pest control against grass grub. Further field trials are required to validate these findings. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Phosphorus use efficiency in common bean genotypes

Phosphorus absorption in plants can vary depending on the genotypes, mineral levels, and environmental conditions. Thus, this study aimed to evaluate phosphorus use efficiency and the response capacity of five common bean genotypes in two cultivation cycles. A 2x5 factorial scheme was used with three replicates. Factor A consisted of using and not phosphorus fertilization, and factor B consisted of five common bean genotypes (BRS Expedito, Iraí, Pérola, Maronze, and Vermelho). The evaluated yield components were the number of pods per plant (NPP), the number of grains per plant (NGP), and the mass of 1000 grains (M1000G). The yield was calculated and extrapolated to kg ha-1. We also evaluated the phosphorus levels accumulated in the leaves and grains (mg and %) and estimated the use efficiency of using phosphorus in the grains. The data obtained were subjected to analysis of variance and compared using the Scott-Knott test at a 5% significance level. There was a significant interaction for all studied variables, indicating the interference of phosphorus fertilization in the behavior of the genotypes. The growing season influenced the genotypes' responses regarding phosphorus use. Yields increased with phosphorus fertilization and changed according to genotype. The phosphorus accumulated in the leaves and grains showed little divergence. The Iraí, Pérola, and Maronze genotypes stand out for their efficient use of phosphorus, presenting an increase above 50% when grown in soil with phosphorus fertilization. When fertilized, the Vermelho variety most accumulated phosphorus in the grains in the first season. In the second season, it showed a significant change in its response when using the phosphate fertilizer, indicating a change in behavior due to the environmental component.

Improving restoration outcomes of boreal Sphagnum-dominated peatlands after peat-extraction: The key role of phosphorus fertilization

Fertilization is a common and effective restoration practice for some ecosystems. However, there are still knowledge gaps about the long-term effectiveness and impact of phosphorus fertilization during the restoration of degraded boreal Sphagnum peatlands using the Moss Layer Transfer Technique. Data gathered from 114 peatland sectors restored 1 to 25 years ago, encompassing around 2900 surveyed plots in Eastern Canada, were analyzed to investigate the influence of fertilization on plant re-establishment (cover, height, and aboveground biomass accumulation) and community composition. Fertilization with a low phosphorus dosage (1.64 g P m−2) of granular phosphate rock (P2O5; NPK 0–13-0) proved to accelerate peatland vegetation recovery by favoring a shift in plant community composition towards a Sphagnum dominance. This shift was encouraged by the fast colonization of Polytrichum strictum after fertilization, a nurse plant that stabilizes the peat substrate and facilitates the subsequent establishment of Sphagnum. Phosphorus fertilization increased by 42 % Sphagnum cover 25-year post-restoration and increased approximately by 15 % aboveground biomass accumulation 20-year post-restoration. Conversely, without fertilization, the success of restoration and long-term vegetation trajectories were uncertain. Phosphorus fertilization led to an increase in plant richness in the first 5 to 10 years after restoration and enhanced spatial heterogeneity in species composition throughout the later stages of restoration (20–25 years), suggesting that fertilization may foster dynamic, diverse plant communities. This study emphasizes fertilization's key role in restoring boreal Sphagnum peatland plant communities, especially in areas prone to episodes of freeze-thaw cycles, strongly advocating for the mandatory inclusion of phosphorus fertilization in the restoration process.

Pre Extension Demonstration of Soil Test Crop Response Based Recommended Phosphorus Fertilizer for Maize in Bako Tibe and Gobu Sayo Districts of Western Oromia, Ethiopia

Pre-extension demonstration of soil test crop response based phosphorus fertilizer recommendation for maize was conducted in Bako Tibe and Gobu Sayo districts with the objective of participatory demonstration of soil test crop response based phosphorus recommendation under farmers’ condition in 2022 cropping season. Two treatments were applied (T<sub>1</sub>) blanket Recommendation (T<sub>2</sub>) Soil Test crop response based recommended phosphorus fertilizer with improved maize (BH-661) variety. The trial was conducted on eleven farmers’ fields which were used as replications. Plot size for each treatment was 10m x 20m with the spacing of 35cm and 75cm between plants and rows respectively using seed rate of 25 kg ha<sup>-1</sup> and with recommended optimum N-fertilizer rate of 110 kg ha<sup>-1</sup>. In each PAs, one FREG unit comprising of 20 farmers were established. About 185 (139 male and 46 female) participants were take part on field visit based training held during physiological maturity of maize. The average total biomass with soil test crop response based Recommended phosphorus fertilizer was 32,385 kgha<sup>-1</sup> while blanket recommendation was 27,730 kgha<sup>-1</sup>. Again the average grain yield for STCRBPR was 7,205kg ha<sup>-1</sup> while blanket recommendation was 4,641kg ha<sup>-1</sup>. Similarly, the results of the economic analysis indicated that the use of p-fertilizer based on soil test crop response and the blanket suggestion with MRR 500.93% could yield net returns of 188,029.36 and 119348 ETB per hectare, respectively. As a result, the suggested phosphorus fertilizer based on soil test crop response should be expanded/scaled up to include additional maize producer farmers in the region and surrounding districts.

Postponed Application of Phosphorus and Potassium Fertilizers Mitigates the Damage of Late Spring Coldness by Improving Winter Wheat Root Physiology.

Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of phosphorus (P) and potassium (K), effectively strengthening wheat's defense against LSC. This experiment used the winter cultivar "Yannong19" (YN 19) as plant material for two consecutive years (2021-2022 and 2022-2023). Two fertilizer treatments were used: traditional P and K fertilizers application (R1: base fertilizer: jointing fertilizer = 10:0) and postponed P and K fertilizers application (R2: base fertilizer: jointing fertilizer = 5:5); wheat plants at the anther connective formation stage shifted to temperature-controlled phytotrons for normal (T0, 11 °C/4 h) and low temperatures (T1, 4 °C/4 h; T2, -4 °C/4 h) as treatments of LSC. The results showed that under low temperature (LT) treatment, compared with R1, the R2 treatment increased the concentrations of osmotic adjustment substances (soluble sugars and soluble protein contents by 6.2-8.7% and 3.0-8.9%), enhanced activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase activities by 2.2-9.1%, 6.2-9.7% and 4.2-8.4%), balanced the hormone concentrations (increased IAA and GA3 contents by 2.8-17.5% and 10.4-14.1% and decreased ABA contents by 7.2-14.3%), and reduced the toxicity (malondialdehyde, hydrogen peroxide content and O2·- production rate by 5.7-12.4%, 17.7-22.8% and 19.1-19.1%) of the cellular membranes. Furthermore, the wheat root physiology in R2 significantly improved as the root surface area and dry weight increased by 5.0-6.6% and 4.7-6.6%, and P and K accumulation increased by 7.4-11.3% and 12.2-15.4% compared to R1, respectively. Overall, the postponed application of P and K fertilizers enhanced the physiological function of the root system, maintained root morphology, and promoted the accumulation of wheat nutrients under the stress of LSC.

Updating soil organic carbon for wheat production with high yield and grain protein

Soil organic carbon (SOC) is crucial for mitigating global warming and significantly impacts crop production. While the relationship between SOC and wheat yield is well-documented, its effect on wheat grain protein content, which is essential for food security and human health, remains unclear. This study gathered management data from wheat farmers and collected plant and soil samples in the Huang-Huai winter wheat region, China’s primary wheat-growing area, from 2015 to 2022. Boundary line analysis was used to quantify the responses of wheat yield and protein content to variations in SOC. Our findings reveal that increases in SOC significantly enhance wheat yield and protein content. The highest yields, reaching up to 10,848 kg ha–1, and a maximum protein content of 17.3 % were observed in soils with SOC ranging from 7.8–18.1 g kg–1, and high-yielding, high-protein wheat exhibited higher spike numbers and grain weights and more efficient nutrient accumulation from soil or fertilizer to shoots. Optimizing SOC levels to produce high-yielding, high-protein wheat could substantially reduce nitrogen (N), phosphorus (P), and potassium (K) fertilizer use by 9.42×104, 0.70×104, and 3.66×104 Mg per year, decrease greenhouse gas emissions by 3.36 Mt CO2 eq and generate an economic benefit of 2.77 billion USD. In conclusion, our study expands the understanding of SOC’s role in crop production beyond crop yield, providing valuable insights for producing high-yielding, high-protein wheat.

Improved Straw Decomposition Products Promote Peanut Growth by Changing Soil Chemical Properties and Microbial Diversity

The ameliorative effects of straw decomposition products on soil acidification have been extensively studied. However, the impact of chemically treated straw decomposition products on crop productivity and the underlying microbial mechanisms remain unclear. This study aimed to investigate the effects of two dosages of Ca(OH)2-treated straw decomposition products of peanuts on red soil acidity, fertility, and bacterial and fungal diversity through a pot experiment. The pot experiment included four treatments: chemical nitrogen, phosphorus, and potassium (NPK) fertilization alone (CK), NPK chemical fertilization combined with peanut straw decomposition products (PS), NPK chemical fertilization combined with 4% Ca(OH)2-treated peanut straw decomposition products (PS4Ca), and NPK chemical fertilization combined with 8% Ca(OH)2-treated straw decomposition products (PS8Ca). High-throughput sequencing was performed to investigate the effects of these treatments on soil microbial diversity. The treatments with PS, PS4Ca, and PS8Ca significantly increased soil pH, exchangeable base cations, and nutrient content, whereas they decreased the exchangeable acid, especially exchangeable aluminum. The peanut growth improved substantially with the application of straw decomposition products. Specifically, PS4Ca significantly increased the Shannon and Richness indices of fungi. The principal coordinate analysis showed that the soil microbial communities in the straw decomposition product treatments were significantly different from CK. Linear discriminant analysis effect size identified unique bacteria and fungi between treatments. The Mantel test indicated that exchangeable base cations and pH were significantly positively correlated with bacterial communities, whereas available potassium was positively correlated with fungal communities. The partial least squares path modeling revealed that the bacterial communities positively and directly affected all peanut agronomic traits. In contrast, the fungal communities had a negative and direct effect only on peanut 100-pod weight. Therefore, adding Ca(OH)2-treated straw decomposition products could effectively improve crop productivity by alleviating soil acidification, increasing soil nutrients, and subsequently changing microorganisms.

The Crop Phosphorus Uptake, Use Efficiency, and Budget under Long-Term Manure and Fertilizer Application in a Rice–Wheat Planting System

Little is known about the effect of the long-term application of organic and inorganic fertilizers on P-use efficiency, P budget, and the residual effect of P fertilizer. To clarify the effect of different fertilization on soil P balance in a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) rotation system is helpful to promote the sustainable development of agriculture. Thus, a thirty-five-year fertilizer experiment was conducted with eight treatments, including an unfertilized control (CK); chemical nitrogen (N), phosphorus (P), and potassium (K) fertilizers; and organic manure (M) either alone or in combination treatments (N, NP, NPK, M, MN, MNP, and MNPK). The results indicated that crop yields and P uptake were higher in the combined application of manure and chemical fertilizer treatments than in the manure or chemical fertilizer alone treatments. Soil P budget indicated a 23.4–55.4 kg P ha−1 yr−1 surplus in the organic combined with or without mineral fertilizer treatments, but the soil P budget indicated a 20.0 and 21.9 kg P ha−1 yr−1 deficit in the control and N treatments. The proportion of residual fertilizer P converted to soil available P in NP, NPK, M, MN, MNP, and MNPK treatments was 4.5%, 4.8%, 19.1%, 19.0%, 11.5%, and 13.3%, respectively, over a 35-year period. Furthermore, according to the higher P content and crop uptake in organic manure treatment compared with chemical P fertilizer alone, an organic addition could effectively reduce the use of chemical fertilizer and become an effective way of sustainable development in practice. Therefore, the combined application of organic and inorganic fertilizer will be a practical method to increase crop yields and soil P status in a rice–wheat planting system.

Soybean responds infrequently to phosphorus fertilization in Manitoba

Soybean ( Glycine max (L.) Merr.) production in Manitoba has increased substantially over the last 20 years, raising questions about phosphorus (P) fertilization in this region. Between 2013 and 2015, a study was conducted across 28 sites in Manitoba to evaluate the effect of P fertilizer rate and placement on soybean plant stand and seed yield. Treatments were 22.5, 45, and 90 kg P2O5 ha−1 applied as monoammonium phosphate, seed-placed, side-banded or broadcast, plus an unfertilized control treatment. Plant stand reduction due to seed-placed fertilizer toxicity was observed at five of 28 site-years, typically at the rate of 90 kg P2O5 ha−1. Stand reduction was most frequent on medium- to coarse-textured soils, dry soils or when seeding equipment had low seedbed utilization. Seed yield was reduced at two site-years due to seed placing 90 kg P2O5 ha−1, which reduced plant stands below the recommended threshold of 247 000 plants ha−1. Phosphorus fertilization did not increase seed yield, regardless of P rate, P placement, or Olsen soil test P level, except for one site-year where 45 and 90 kg P2O5 ha−1 increased seed yield by 343 and 430 kg ha−1, respectively. The extremely infrequent response to P fertilizer in combination with the high rate of P removal indicates that soybeans can use soil P reservoirs that are less available to other crops. Nevertheless, soybean growers in Manitoba should consider strategies for applying supplemental P to soybean or other crops in their rotation to maintain P fertility in soil.