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BACKGROUND: Efficient utilization of phosphorus (P) has been a major challenge for sustainable agriculture. However, the responses of fertilizer rate, region, soil properties, cropping systems and genotypes to P have not been investigated comprehensively and systematically. RESULTS: A comprehensive analysis of 9863 fertilizer‐P experiments on rice cultivation in China showed that rice yield increased first and then fell down with the addition of P fertilizer, and the highest yield of 7963 kg ha−1 was observed under 100% P treatment. Under 100% P treatment, the yield response of applied P (YRP) and agronomic efficiency of applied P (AEP) were 12.8% and 30.1 kg ha−1, respectively. Lower soil pH (< 5.5) and organic matter (< 30.0 g kg−1) were associated with lower YRP and AEP. By contrast, soil available P < 25.0 mg kg−1 resulted in decreased YRP (15.3 to 11.4%) and AEP (32.3 kg kg−1 to 26.2 kg kg−1), whereas soil available P > 25.0 mg kg−1 maintained the relatively stable YRP and AEP. Also, the YRP and AEP were significantly higher for single‐cropping rice compared to other cropping systems. Moreover, the rice genotypes such as 'Longdun', 'Kendao' and 'Jigeng' had higher YRP and AEP than the average value. Overall, the fertilizer‐P rate was the primary factor affecting YRP and AEP, and the recommended P fertilizer rate can be reduced by 9–21 kg P ha−1 compared to existing expert recommendations. CONCLUSION: The present study highlights the role of fertilizer‐P rate in maximizing the YRP and AEP, thereby providing a strong basis for future fertilizer management in rice cultivation systems. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity is one of the most serious hazards of soil acidification, which limits root formation and hinders crop growth. Soil acidification in orchards has been widely reported. However, there is little information about the effect of Al3+ on citrus roots in acidified red soil. Taking pomelo (Citrus grandis), the main citrus variety in Southeast China, as an example, soil surveys were conducted to analyze the status and characteristics of acidification in pomelo orchards. Subsequently, we explored whether optimized fertilization and liming can effectively reduce Al toxicity in roots and increase yield by three treatments, including farmer fertilization practice (FFP), NPK optimization (OPT), and OPT combined with lime (OPT+L). The results showed that (1) rapid soil acidification occurred in pomelo orchards in the past 40 years (with a decrease of 0.81 units). The severity of soil acidification increases with orchard age. In addition, the soil pH and base saturation (BS) at the drip line (DL; i.e., fertilization site) were the lowest, while the concentration of exchangeable acid (Ex.Acid) and exchangeable Al (Ex.Al), and the ratio of Ex.Al to cation exchange capacity (Ex.Al%) was highest compared to other locations away from DL. Random forest analysis indicated Ex.Al was the most important factor to reflect soil acidification. (2) Under the OPT+L treatment, the concentrations of soil Ex.Acid and Ex.Al decreased, and BS increased, which markedly reduced the Al3+ concentration in the roots and promoted root growth. OPT+L significantly decreased the Al concentrations in soils (by 71.3%) and roots (by 47.8%) but increased root activity, root length, root tips and root surface area by 119.2%, 80.3%, 124.6% and 136.6%, respectively. In addition, structural equation modeling further proved that increasing soil pH and BS while decreasing Ex.Al was beneficial to citrus production in acidic soil, and optimized fertilization and lime application are necessary. [ABSTRACT FROM AUTHOR]

Hyphae of arbuscular mycorrhizal fungi (AMF) in soil often form complex mycorrhizal networks among roots of same or different plant species for transfer of nutrients from one plant to another. However, the effect of soil nitrogen (N) availability on nutrient transfer between different plant species via common mycorrhizal networks (CMNs) has not been experimentally examined. In order to quantify CMN-mediated nutrient transfer between Leymus chinensis (LC) and Cleistogene squarrosa (CS), two systems, i.e. the CS–LC system (CS and LC were donor and recipient, respectively) and the LC–CS system (LC and CS were donor and recipient, respectively) were established. Stable isotopic 15N was applied to track N transfer between heterospecific seedlings connected by CMNs under three levels of soil N additions: no N addition control (N0), N addition with 7 mg/kg (N1) and N addition with 14 mg/kg (N2). In the CS–LC system, the highest rate of AMF colonization and hyphal length density (HLD) were found at N1. In contrast, maximum AMF colonization rate and HLD were recorded at N2 in LC–CS system. Consequently, plant biomass was significantly higher under N1 and N2 levels in CS–LC and LC–CS systems, respectively. Moreover, in CS–LC system, 15N transfer rate ranged from 16% to 61%, with maximum transfer rate at N1. For LC–CS system, 15N transfer rate was much lower, with the maximum occurring at N0. These findings suggest that CMNs could potentially regulate N transfer from a donor to recipient plant depending upon the strength of individual plant carbon sink. [ABSTRACT FROM AUTHOR]

Introduction: Intensive plum production usually involves high yields but also high environmental costs due to excessive fertilizer inputs. Quantitative analysis of the environmental effects of plum production is thereby required in the development of optimum strategies to promote sustainable fruit production. Methods: We collected survey questionnaires from 254 plum production farms in Zhao'an county, Fujian province, southeast China to assess the environmental impacts by life cycle assessment (LCA) methodology. The farms were categorized into four groups based on yield and environmental impacts, i.e., LL (low yield and low environmental impact), LH (low yield but high environmental impact), HL (high yield but low environmental impact), and HH (high yield and high environmental impact). Results: The environmental impacts, i.e., average energy depletion, global warming, acidification, and eutrophication potential in plum production were 18.17 GJ ha-1, 3.63 t CO2 eq ha-1, 42.18 kg SO2 eq ha-1, and 25.06 kg PO4 eq ha-1, respectively. Only 19.7% of farmers were in the HL group, with 13.3% in the HH group, 39.0% in LL, and 28.0% LH. Plum yields of the HL group were 109-114% higher than the mean value of all 254 farms. Additionally, the HL group had a lower environmental impact per unit area compared to the overall mean value, with a reduction ranging from 31.9% to 36.7%. Furthermore, on a per tonne of plum production basis, the energy depletion, global warming potential, acidification potential, and eutrophication potential of HL farms were lower by 75.4%, 75.0%, 75.6%, and 75.8%, respectively. Overall, the total environmental impact index of LL, LH, HL, and HH groups were 0.26, 0.42, 0.06, and 0.21, respectively. Discussion: Excessive fertilizer N application was the main source of the environmental impacts, the potential to reduce fertilizer N rate can be achieved without compromising plum yield by studying the HH group. The results provide an important foundation for enhancing the management of plum production, in order to promote 'green' agricultural development by reducing environmental impacts. [ABSTRACT FROM AUTHOR]

Cold stress is one of the major constraints limiting the productivity of many important crops, including tobacco (Nicotiana tabacum L.) production and quality worldwide. However, the role of magnesium (Mg) nutrition in plants has been frequently overlooked, especially under cold stress, and Mg deficiency adversely affects plant growth and development. Here, we evaluated the influence of Mg under cold stress on tobacco morphology, nutrient uptake, photosynthetic and quality attributes. The tobacco plants were grown under different levels of cold stress, i.e., 8°C, 12°C, 16°C, including with a controlled temperature of 25°C, and evaluated their effects with Mg (+Mg) and without Mg (-Mg) application. Cold stress resulted in reduced plant growth. However, the +Mg alleviated the cold stress and significantly increased the plant biomass on an average of 17.8% for shoot fresh weight, 20.9% for root fresh weight, 15.7% for shoot dry weight, and 15.5% for root dry weight. Similarly, the nutrients uptake also increased on average for shoot-N (28.7%), root-N (22.4%), shoot-P (46.9%), root-P (7.2%), shoot-K (5.4%), root-K (28.9%), shoot-Mg (191.4%), root-Mg (187.2%) under cold stress with +Mg compared to Mg. Mg application significantly boosted the photosynthetic activity (Pn 24.6%) and increased the chlorophyll contents (Chl-a (18.8%), Chl-b (25%), carotenoids (22.2%)) in the leaves under cold stress in comparison with Mg treatment. Meanwhile, Mg application also improved the quality of tobacco, including starch and sucrose contents, on an average of 18.3% and 20.8%, respectively, compared to Mg. The principal component analysis revealed that tobacco performance was optimum under +Mg treatment at 16°C. This study confirms that Mg application alleviates cold stress and substantially improves tobacco morphological indices, nutrient absorption, photosynthetic traits, and quality attributes. In short, the current findings suggest that Mg application may alleviate cold stress and improve tobacco growth and quality. [ABSTRACT FROM AUTHOR]

Fusarium solani (F. solani) is one of the most important pathogenic fungi, that cause Fusarium dry rot and Fusarium wilt in potato, responsible for low potato yield globally. However, the mechanistic understanding regarding the biocontrol of F. solani remains largely unknown. Here, we investigated the plant growth-promoting and antagonistic capability of Bacillus sp. PM31 against phytopathogen F. solani. The Bacillus sp. PM31, isolated from field-grown potato was analyzed for plant growth-promoting and extracellular enzyme activities. The strain PM31 exhibited phosphate, zinc, and potassium solubilization, nitrogen fixation, siderophore, exopolysaccharides production, and extracellular enzyme activities. The mycelial growth of F. solani was inhibited by strain PM31 with inhibition coefficient of 47.5. Under the storage conditions, inoculation of strain PM31 minimized the development of dry rot symptoms by 57% as compared to uninoculated diseased tubers. Under greenhouse conditions, inoculation of strain PM31 enhanced potato plant growth under fungal stress, while reduced the development of wilting, foot rot, chlorosis, and necrosis of inoculated potato plants by 92%, 75%, 64%, and 82%, respectively, as compared to diseased plants. Results inferred that the inoculation of native antagonistic Bacillus sp., PM31, could aid in global food security through biocontrol of important potato diseases viz. Fusarium dry rot and Fusarium wilt. [ABSTRACT FROM AUTHOR]

Large quantities of fertilizers, mainly nitrogen (N), phosphorus (P), and potassium (K), are used in China's crop production; however, whether N, P, and K still limit yield under the current high input remains unknown. In addition, it is not clear whether magnesium (Mg) potentially limits crop production. To address these issues, a national survey of the soil nutrient status and farmers' fertilization practices was conducted in China to determine the soil N, P, K, and Mg status and current fertilization practices. In addition, various experiments, including optimized NPK (OPTNPK) and Mg fertilizer combined with OPTNPK (OPTNPK + Mg) in comparison with farmers' practices (FFP), were performed across China to identify the potential for reducing NPK application and the need for Mg application in crop production. The survey data from 2699 questionnaires indicated that (1) all soil samples were not deficient in NPK, but 73.0% were limited by Mg. (2) The average N, P (in P2O5), K (in K2O), and Mg (in MgO) balances were 422.6, 334.1, 326.3, and −22.6 kg ha−1, respectively. Only 15.7% of all farmers applied Mg fertilizer. (3) NPK fertilization can be reduced by an average of 28.8% without reducing the crop yield and quality. (4) For most crops, the application of Mg fertilizer increased the crop yield by 5.5–40.6% and improved the quality. However, different crops under different conditions had different responses to Mg fertilization. These results indicate that reduced NPK inputs and increased Mg inputs are equally important for the healthy development and sustainability of China's agriculture. [ABSTRACT FROM AUTHOR]