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Background: Potassium (K) is an essential nutrient for plant growth and development. Maize (Zea mays) is a widely planted crops in the world and requires a huge amount of K fertilizer. Arbuscular mycorrhizal fungi (AMF) are closely related to the K uptake of maize. Genetic improvement of maize K utilization efficiency will require elucidating the molecular mechanisms of maize K uptake through the mycorrhizal pathway. Here, we employed transcriptome and gene family analysis to elucidate the mechanism influencing the K uptake and utilization efficiency of mycorrhizal maize. Methods and results: The transcriptomes of maize were studied with and without AMF inoculation and under different K conditions. AM symbiosis increased the K concentration and dry weight of maize plants. RNA sequencing revealed that genes associated with the activity of the apoplast and nutrient reservoir were significantly enriched in mycorrhizal roots under low-K conditions but not under high-K conditions. Weighted gene correlation network analysis revealed that three modules were strongly correlated with K content. Twenty-one hub genes enriched in pathways associated with glycerophospholipid metabolism, glycerolipid metabolism, starch and sucrose metabolism, and anthocyanin biosynthesis were further identified. In general, these hub genes were upregulated in AMF-colonized roots under low-K conditions. Additionally, the members of 14 gene families associated with K obtain were identified (ARF: 38, ILK: 4, RBOH: 12, RUPO: 20, MAPKK: 89, CBL: 14, CIPK: 44, CPK: 40, PIN: 10, MYB: 174, NPF: 79, KT: 19, HAK/HKT/KUP: 38, and CPA: 8) from maize. The transcript levels of these genes showed that 92 genes (ARF:6, CBL:5, CIPK:13, CPK:2, HAK/HKT/KUP:7, PIN:2, MYB:26, NPF:16, RBOH:1, MAPKK:12 and RUPO:2) were upregulated with AM symbiosis under low-K conditions. Conclusions: This study indicated that AMF increase the resistance of maize to low-K stress by regulating K uptake at the gene transcription level. Our findings provide a genome-level resource for the functional assignment of genes regulated by K treatment and AM symbiosis in K uptake-related gene families in maize. This may contribute to elucidate the molecular mechanisms of maize response to low K stress with AMF inoculation, and provided a theoretical basis for AMF application in the crop field. [ABSTRACT FROM AUTHOR]

The present experiment was undertaken to characterize the K releasing pattern as well as the bioavailability of K in nine soils under three dominant soil orders of eastern India. Soils were extracted with 0.2 M sodium tetraphenyl boron (NaTPB) and perennial ryegrass (Lolium perenne L.) was grown repeatedly with and without the addition of K fertilizer to study the K release kinetics and bioavailability. The highest K release by 0.2 M NaTPB at 144 h incubation was recorded in Entisols, while the least in Alfisols. Cumulative K released was mathematically best described by a parabolic diffusion equation and the empirical constants up to a 2 h incubation period was significantly related to relative biomass yield and K uptake by ryegrass. Considering relative biomass yield and K uptake as indices of plant K availability, the sequence of K supplying capacity of the soils under different orders was: Entisols>Inceptisols>Alfisols. The K-release rate of 30.8 mg kg-1 h-1 and the ryegrass leaf K concentration of 32.1 g kg-1 were found to be critical for this experiment. Based on the critical K release rate, the maximum amount of K released for plant uptake before showing any K deficiency symptom ranged from 179.3 mg kg-1 to 596 mg kg-1 for soils under the order Entisols, 247.9 mg kg-1 to 687.84 mg kg-1 for soils under Inceptisols and 118.67 mg kg-1 to 184.25 mg kg-1 for soils under Alfisols. [ABSTRACT FROM AUTHOR]

Objective: This study aims to evaluate the effectiveness of Integrated Soil-Crop System Management (ISSM) and provide technical support for sustainable high yield and efficiency in regional agriculture. Methods: The study compared the effects of no fertilization (Control), conventional farmer practices (FP), high-yield management (HY), and ISSM on maize yield and plant nutrient uptake. Measurements included grain yield, plant biomass, plant nutrient absorption, and soil nutrient content across different management strategies. Results: Over the 12-year experimental period, a significant decline in grain yield was observed under the Control treatment, with a slight decrease in the FP treatment. In contrast, consistent yield increases were noted for the HY and ISSM treatments. The ISSM approach significantly enhanced the average yield and plant uptake of P and K by 26%, 24%, and 32%, respectively, approaching 98%, 91%, and 85% of the levels achieved in the HY treatment. Furthermore, the average use efficiency of P and K fertilizers in the ISSM treatment exceeded those in the FP treatment by 18.7% and 1.2%, respectively, and those in the HY treatment by 17.4% and 24.8%, respectively. The adoption of ISSM led to a significant increase in total and available P and K content within the 0-20 cm and 20-40 cm soil layers and enhanced the available P and K content across all aggregate size fractions within the 0-20 cm soil layer. Conclusion: ISSM is capable of achieving long-term high and stable yields for spring maize, enhancing the uptake and utilization of P and K in plants, and bolstering the soil's capacity to supply these nutrients, thereby fostering the sustainable development of the entire soil-crop system. [ABSTRACT FROM AUTHOR]

No-tillage is one of the most important technologies in conservation agriculture. It is also crucial to understand the impact of no-tillage on grain crop yields, in order to promote the no-tillage application for food security. In this study, a metaanalysis was carried out to determine the regional yield and influencing factors of no-tillage on the three major crops in China. The data was collected from the published literature in Chinese (English) between 1995 and 2023. Conventional tillage (plowing, rotary tillage, or harrowing, depth < 18 cm) was taken as a control. Meta-analysis was employed to quantitatively investigate the overall and regional effects of no-tillage on the yield and yield components of three major grain crops (wheat, maize, and rice). Results showed that there was no significant effect of no-tillage on the regional yields of wheat, maize, and rice on the national scale. However, the regional analysis revealed that the no-tillage significantly increased the wheat yield by 4.1% and 2.2% in the Southwest and Northwest, respectively. There was a significant decrease in the maize yield by 2.4%, 2.6%, and 3.5% in the Northeast, Northwest, and Southeast, respectively. The rice yield was reduced by 1.0% in the Southeast. No significant effects were observed on the wheat and maize yields in North China, or on the wheat and rice yield in the rest regions. The yield components showed that the primary yield effect of no-tillage was attributed to the variation in the effective spikes. The influencing factors were examined on the regional crop yield. The mean annual precipitation was the main contributor to the wheat and maize yield, with the contribution rates of 12.7% and 13.6%, respectively. Soil organic carbon (SOC) content was the primary influencing factor (approximately 16.2%) on regional rice yield under no-tillage. The northwest region was characterized by mean annual temperatures <10 °C, annual precipitation <400 mm, and low soil nutrient content (SOC <10 g/kg, and total nitrogen <1 g/kg). Furthermore, no-tillage significantly increased the wheat yield under single and continuous cropping. Low annual precipitation (< 400 mm) promoted the maize yield in the Northwest, while the high soil pH (>8) and single or triple cropping in two years significantly reduced the crop yield. Specifically, the maize yield decreased in the Northeast and Southeast, which were influenced by the low (< 10 °C) and high (> 15 °C) temperatures, respectively. In the Southeast, the rice yield effects were influenced by the high annual precipitation (>800 mm), soil nutrient content (SOC >15 g/kg, and total nitrogen >1.5 g/kg), as well as the nitrogen and potassium fertilizer inputs. No-tillage was combined with the straw returning and scientific fertilization, in order to minimize the negative yield effect or even increase crop yield. The notillage technology was required to fully consider the crop types, regional climate, soil fertility, and cropping systems. These findings can provide a scientific basis to promote no-tillage technology in different agricultural regions in China. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The effect of long-term use of mineral fertilizers on changes in the content of total phosphorus and its organic, mineral, and mobile compounds in soddy-podzolic heavy loamy soil (Albiс Retisol (Abruptic, Aric, Loamic)) was analyzed. The studies were performed in a long-term stationary experiment initiated in Perm krai in 1978. The variants were: 0 (without fertilizers), N90, P90, K90, N90P90, N90K90, P90K90, N90P90K90, N30P30K30, N60P60K60, N120P120K120, and N150P150K150. Ammonium nitrate or urea, double or simple superphosphate, and potassium chloride were used in the experiment. It was established that long-term use of superphosphate during five eight-field crop rotations (P90, P90K90, N90P90, and N90P90K90) resulted in a significant increase in the contents of the total phosphorus, mineral phosphorus (by 1.3–1.8 times), and mobile phosphorus (by 1.9–2.7 times) compounds in the plow layer (0–20 cm). The use of nitrogen fertilizers (N90, N90K90, N90Р90, and N90Р90K90) affected the accumulation of organic phosphorus compounds in the soil. The increase in the content and reserves of both mineral and organic phosphorus compounds was significant only in the case of using complete mineral fertilizer N90P90K90. Different combinations of superphosphate with nitrogen fertilizers and potassium chloride, as well as the rate of fertilizer application, affected the accumulation intensity of mobile phosphorus compounds in the soil during rotations and the changes in their contents in the soil profile. The application of low fertilizer rates ((NPK)30–60) resulted in an increase in the content of mobile phosphorus compounds mainly in the plow layer, whereas higher rates ((NPK)90–150) caused changes in the 80-cm-thick soil layer. Long-term use of nitrogen and potassium fertilizers resulted in an increase in the content of mobile phosphorus compounds in the plow layer over time. [ABSTRACT FROM AUTHOR]

Soybean is a crucial crop utilized for both food and oil production, with balanced crop nutrition being a key determinant of soybean yield throughout its growth cycle. Sulfur, an essential nutrient for crop growth, substantially impacts soybean yield. In this study, two soybean cultivars, Laidou 2 and Hefeng 55, were used to study the changes in nitrogen, phosphorus, potassium, and sulfur contents in soybean plants at different growth stages. Additionally, the effects of dry matter accumulation under five different sulfur levels were examined. The results showed that the sulfur levels had varying effects on the nitrogen, phosphorus, potassium, and sulfur contents and accumulation in different parts of the soybean plants. There were marked differences in the accumulation and distribution of dry matter in different parts of the soybean plant. Soybean dry matter weight shows the best overall performance under the S80 treatment. With increasing sulfur nutrition, the nitrogen, phosphorus, potassium, and sulfur contents in various plant parts exhibited an unimodal trend, reaching maximum values when the sulfur content was 80 mg/L. This study elucidates the dynamic changes in nutrient elements in soybeans under different sulfur levels and is important in guiding the rational application of sulfur fertilizers in agricultural production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plants acquire potassium (K) not only from exchangeable K fractions but also from non-exchangeable K fractions. However, factors affecting the amount of K supplied from the non-exchangeable K fraction have not been well understood. In this study, the effects of soils and exchangeable K on the amount of K supplied to rice from the non-exchangeable K fraction were investigated for six Japanese paddy soils diluted with different rates of quartz sand. The amounts of K supplied from the non-exchangeable K fractions (recharged K) ranged from 14.4 to 137 mg K2O kg−1, equivalent to 10 to 61% of the total K acquired by rice. The amounts of recharged K were affected by the exchangeable K levels in three out of six soils. Although the cultivation experiments were conducted under various K conditions including severe K deficiency, exchangeable K was detected after cultivation in all soils, and the contents of exchangeable K were almost identical for each soil regardless of the dilution ratio of soil with quartz sand. Accordingly, there would be at least three types of non-exchangeable K fractions which dissolve into soil solution to attain a specific level of exchangeable K: (i) a non-exchangeable K fraction that releases K regardless of the exchangeable K level; (ii) a non-exchangeable K fraction that easily releases K with the decrease in exchangeable K under sufficient K conditions without inducing K-deficient symptoms in rice; and (iii) a non-exchangeable K fraction that releases K with the decrease in exchangeable K only under severe K-deficient conditions with accompanying deficient symptoms in rice. The application of K fertilizer would reduce the amount of recharged K acquired by rice from fractions (ii) and (iii), whereas fraction (i) would remain unaffected by the fertilized K until the level of exchangeable K reaches a specific level for each soil. The release of K from a fraction (iii) only occurred under conditions of severe K deficiency; hence, farmers should not rely on this fraction for K supply. [ABSTRACT FROM AUTHOR]

The online detection of fertilizer solution information is a crucial link in the implementation of intelligent and precise variable fertilization techniques. However, achieving simultaneous rapid online detection of multiple fertilizer components is still challenging. Therefore, a rapid detection method based on spectrophotometry for qualitative and quantitative identification of four fertilizers (typical N, P, and K fertilizers: KNO3, (NH4)2SO4, KH2PO4, and K2SO4) was proposed in this work. Full-scan absorption spectra of fertilizer solutions at varying concentrations were obtained using a UV–visible/near-infrared spectrophotometer. By assessing the linear fit between fertilizer concentration and absorbance at each wavelength within the characteristic band, the characteristic wavelengths for KNO3, (NH4)2SO4, KH2PO4, and K2SO4 were identified as 214 nm, 410 nm, 712 nm, and 1708 nm, respectively. The identification method of fertilizer type and the prediction model of concentration were constructed based on characteristic wavelength and the Lambert–Beer law. Based on the above analysis, a four-channel photoelectric sensor was designed with four LEDs emitting wavelengths closely matched to characteristic wavelengths for fertilizer detection. A detection strategy of "qualitative analysis followed by quantitative detection" was proposed to realize the online detection of four fertilizer types and their concentrations. Evaluation of the sensor's performance showed its high stability, with an accuracy of 81.5% in recognizing fertilizer types. Furthermore, the relative error of the sensor detection was substantially less than ±15% for the fertilizer concentrations not exceeding 80 mg/L. These results confirm the capability of the sensor to meet the practical requirements for online detection of four fertilizer types and concentrations in the field of agricultural engineering. [ABSTRACT FROM AUTHOR]

Plant nutrition through fertilizer application plays a crucial role in enhancing crop quality and yield, necessitating a balanced fertilization approach. Sweet cherry, esteemed as one of the most prized crops worldwide, was the focus of this three-year study spanning from 2019 to 2021, involving the sweet cherry cultivar Burlat. This study investigated the foliar application of magnesium (Mg) and potassium (K) to enhance fruit quality parameters. Different doses of Mg (250 g hL−1 and 125 g hL−1) and K (100 g hL−1 and 50 g hL−1) and a control treatment were administered to sweet cherry trees to assess their impact on fruit quality. At the commercial ripening stage, fruits from each treatment were harvested for comprehensive evaluation, including biometric and chromatic parameters, fruit firmness, routine parameters, sensory profile, and nutrient content analysis. Results from the study revealed notable enhancements in fruit weight and dimensions, particularly in the control treatment in 2020. Furthermore, Mg125 and Mg250 treatments exhibited improved color development and accelerated maturity by increasing the total soluble solids content while decreasing titratable acidity. Sensorial profiling indicated that Mg125 and Mg250 treatments intensified color intensity and sweet taste while mitigating sour taste perceptions. Conversely, potassium fertilization, especially the K50 treatment, led to increased fruit firmness and nutrient content. These findings offer valuable insights into optimizing sweet cherry production practices globally. [ABSTRACT FROM AUTHOR]

To assess the effect of pure castor meal and a mixture of castor meal with ground hydrothermalized phonolite rock (CM+HP mixture) in providing nutrients, particularly N and K, and optimizing yield and quality of sweet potato, a field experiment was conducted using a randomized block design. Treatments were the absence and presence of synthetic N and K fertilizers (ammonium nitrate and KCl) combined with rates of organic fertilizers (1.2 and 2.4 Mg ha−1 of castor meal, 2.25 and 4.5 Mg ha−1 of CM+HP mixture, plus a treatment without organic fertilizers). The CM+HP mixture maintained adequate N and K status in plant leaves. Organic fertilizers increased the number of storage roots per plant and the sweetness of the storage roots, while synthetic fertilizers increased the storage root mean weight. Castor meal combined with synthetic fertilizers improved soil health (increased organic matter and enzyme activity in the soil). The combined application of synthetic fertilizers with 2.4 Mg ha−1 of castor meal or 4.5 Mg ha−1 of CM+HP mixture had the greatest benefit on storage root yield, with an average increase of 128% (10.9 Mg ha−1) on marketable storage root yield, and the nutrient removal compared with the sole application of organic fertilizers. [ABSTRACT FROM AUTHOR]

Potassium (K) is the primary limiting nutrient for cassava, being essential to achieve sustainably satisfactory cassava yields in low K reserve sandy soils that require proper K fertilization to avoid depleting the soil K reserve. Soil K dynamics, the growth, and yield responses of cassava were investigated using varying K fertilizer rates (0, 25, 50, 75, 100, and 125 kg K2O/ha). Four on-farm experiments were conducted in major cassava-producing areas, Northeast Thailand during 2019–2021 year. Cassava responded positively to K, producing yield increases up to 132%, with the highest tuber yield obtained being in the range 100–125 kg K2O/ha. Mineral K was the main K source for cassava grown without K fertilization, which resulted in the poorest growth and yield quantities. Potassium fertilization significantly promoted the uptake of K by cassava, especially in the tuber, causing a negative K balance due to the large removal from the soil, even when the K fertilizer compensated to some degree. Potassium use efficiency of cassava was low, particularly with K fertilization at the highest rate, which reflected intense leaching of the soil. The critical level of soil-available K, identified using a linear-plateau model, was 40.55 mg/kg for 90% relative yield, suggesting the potential to increase K use efficiency through better fertilization guidelines. Our findings suggested that K fertilization of cassava annually is advisable for better yields and to avoid progressive depletion of the soil K capital, even though the residual K from K fertilizer contributed to available K in soils. [ABSTRACT FROM AUTHOR]

Background: Striga asiatica (L.) O. Kuntze is a traditional medicinal plant rich in flavonoids, which has various pharmacological effects such as anti-hepatitis and antioxidant activities. However, there is a scarcity of resources, and artificial cultivation has not yet been achieved. This study explored the association between flavonoid metabolites and soil physicochemical properties and trace elements in different habitats, with the aim of offering theoretical guidance for the high-quality artificial cultivation of S. asiatica. Results: The results showed that S. asiatica has low requirements for soil fertility and prefers to grow in acidic soil with high contents of potassium and available potassium, while low contents of phosphorus, nitrogen and alkali hydrolyzed nitrogen. Additionally, 1592 kinds of metabolites were identified from S. asiatica, including 78 flavonoids. Conclusions: The flavonoid metabolites were strongly related to soil factors. Reasonable application of nitrogen and potassium fertilizers as well as controlling the contents of sodium, manganese and boron in the soil, can promote the synthesis of flavonoid metabolites in the plant. Moreover, kaempferide, glycitein, luteolin, apigenin and genistein may be the metabolic markers for identifying different regions. [ABSTRACT FROM AUTHOR]

AbstractCoffee in Western Ghats grown under shade, soils are enriched with all the nutrients except phosphorus. The areas receive high rainfall, which leads to leaching loss and surface runoff of applied nutrients causing low fertilizer use efficiency. Improved agronomic practices are essential to address these issues. Fertigation is one such practice, having the potential to reduce extra chemical load by improving nutrient use efficiency. Hence, an attempt was made to study the impact of long-term fertigation on soil-plant nutrition and productivity of Robusta coffee. The trial was laid out in randomized complete block design (RCBD) with six treatments and four replications. Data on yield parameters and coffee yield indicated that significantly higher total number of nodes/branches, number of bearing nodes/branches, number of fruits/branches and coffee yield (49.1, 35.0, 758, and 2117 kg ha−1, respectively) were recorded in fertigation block supplied with 100% recommended dose of fertilizer (RDF) as water soluble fertilizer (WSF) which were statistically on par with 75% RDF (44.1, 29.4, 679, and 1821 kg ha−1, respectively). Similarly, higher major, secondary, and micro-nutrient content were noticed in leaf with fertigation at 75 and 100% RDF and also it was observed that, leaf Nitrogen (N), Phosphorus (P), and Potassium (K) content played a highly significant role in increasing coffee yield. The study results revealed that the quantum of N, P, and K fertilizer requirement could be brought down to the tune of 25% through fertigation as compared to the conventional soil application. [ABSTRACT FROM AUTHOR]

The bacterial communities that harbour the pyrroloquinoline quinone gene (pqqC‐harbouring bacteria communities) play a pivotal role in the mobilization of inorganic phosphorus (Pi). However, there is limited knowledge regarding the connection between soil pqqC‐harbouring bacterial communities and Pi fractions, as well as the factors that can regulate them, particularly under different fertilization strategies in the agricultural soil. High‐throughput sequencing was used to investigate the pqqC‐harbouring communities from the wheat (Triticum aestivum L.)–sweet potato (Ipomoea batatas L.) season in a 9‐year field experiment, including without fertilization (control), nitrogen (N) and potassium (K) fertilization (NK), NPK fertilization (NPK) and the combined application of chemical NPK and organic fertilizer (NPKM), and to explore their relationships with Pi fractions and their regulatory factors. Long‐term N fertilization and crop type substantially changed the community composition of pqqC‐harbouring bacteria but had no effect on their diversity. In two crop seasons, long‐term N fertilization significantly increased the content and proportion of moderately labile Pi (aluminium‐ and iron‐bound P) and available P (AP) and significantly decreased the proportion of recalcitrant Pi (calcium‐bound P) compared with the control. Specifically, AP increased by 79%–778%, Fe‐P by 64%–88%, and Al‐P by 71%–308%, while Ca‐P decreased by 10%–59%. N fertilization increased the relative abundance of Micromonospora, which was significantly positively correlated with moderately labile Pi and AP. Moreover, the relative abundance of some Streptomyces increased by 391% in the sweet potato season, and they were positively correlated with AP. Structural equation modelling revealed that the interplay between the pqqC‐harbouring community composition and Pi mobilization was mainly governed by pH, underscoring the role of pH in shaping the communities of Pi‐mobilizing microbes and their effect on Pi mobilization processes. This study emphasized how N fertilization and crops reshape Pi‐mobilizing microbial communities, which in turn affects Pi mobilization and P availability. Overall, these findings offer valuable insights into optimizing P cycles and availability through N fertilization strategies. [ABSTRACT FROM AUTHOR]

Tree species can have great impacts on soil. Since the rhizosphere is more responsive to external inputs than the surrounding bulk soil, we investigated the rhizosphere effect of the exotic slash pine and the native araucaria in long‐term conifer monocultures in southern Brazil. Araucaria trees in a natural section of a nearby mixed araucaria forest were taken as the control. We assessed physical, chemical, and mineralogical properties of the underlying subtropical highly weathered soil. We did not find rhizosphere effects for most chemical and physical soil attributes, yet principal component analysis clearly distinguished the effects of the exotic and native conifers on rhizosphere properties by separating slash pine cluster from reforested and native araucaria clusters. Reductions in silt and sand contents under slash pine reforestation led to increases in clay and well‐crystallized iron oxides contents. The clay mineralogy comprised kaolinite, mica/illite, and hydroxy‐interlayered minerals, with kaolinite enrichment in the rhizospheres of both araucaria sites, mica/illite depletion in the rhizospheres of both araucaria and pine monocultures, and prevalence of well‐crystallized iron oxyhydroxides in the slash pine rhizosphere. This study demonstrates a tendency toward increasing soil weathering in the conifer monocultures, potential negative impacts of the faster growing slash pine reforestation on soil organic carbon, available P, and total K possibly by mica/illite depletion, while araucaria had lower impacts on soil properties. These results show long‐term potential loss of soil fertility and quality, which should be considered when monitoring soil changes in human modified ecosystems. Core Ideas: Monoculture of conifers slightly increased soil particle fragmentation.Conifer monocultures that had not received K fertilizers promoted mica/illite depletion in the rhizospheres.Monoculture of slash pine caused more negative impact on soil in the long term than did monoculture of araucaria. [ABSTRACT FROM AUTHOR]

Background: Green manure is an important source of organic fertilizer. Exploring green fertilizer and nitrogen fertilizer reduction is important for agricultural production. However, few studies have been conducted, especially on the effects of different green fertilizers along with reduced nitrogen fertilizer application on soil ammonia volatilization emissions, rice yield, and nitrogen fertilizer uptake and utilization. Methods: In this study, the effects of different types of green manure and reduced nitrogen fertilizer application on soil ammonia volatilization emissions, aboveground population characteristics of rice, and nitrogen fertilizer uptake and utilization were explored. This study was based on a field-positioning experiment conducted between 2020 and 2022. Six treatments were established: no nitrogen fertilizer application (CK), conventional fertilization in wheat-rice (WR), villous villosa-rice (VvR), vetch sativa-rice (VsR), rapeseed seed-rice (RR), and milk vetch-rice (GR), with a 20% reduction in nitrogen fertilizer application. The amounts of phosphorus and potassium fertilizers remained unchanged. The characteristics of ammonia volatilization loss in rice fields, agronomic traits of rice, yield traits, and nitrogen uptake and utilization were investigated. Results: The results indicated a significant difference (P < 0.05) in the impact of different treatments on ammonia volatilization emissions from rice in the two-year experiment. Compared with WR treatment, VvR, VsR, RR, and GR treatments reduced the total ammonia volatilization loss by 23.58 to 39.21 kg ha−1, respectively. Compared with the conventional WR treatment, other treatments increased rice yield by 0.09 to 0.83 t ha−1. GR treatment was significantly higher than other green fertilizer treatments, except for VsR (P < 0.05). It increased the nitrogen uptake of rice by an average of 4.24%–22.24% and 13.08%–33.21% over the two years, respectively. The impact of different types of green manure on the nitrogen uptake and utilization of rice varied greatly, indicating that the combination of green manure and fertilizer is a sustainable fertilization model for crops to achieve high yields. In particular, the Chinese milk vetch as green manure was more beneficial for ammonia volatilization reduction in paddy field and stable grain production of rice. [ABSTRACT FROM AUTHOR]

Potassium (K) is an essential macronutrient for the healthy growth and development of crops but their conventional resources are only limited to a few countries. Deficiency of potash fertilizer in soil is a widespread problem for countries with no such potash deposits to meet the present as well as future food demands. In view of this, the present work investigates a novel interdisciplinary approach for the recovery of potash fertilizer from widely available glauconitic rocks. The rock sample containing ~ 6–8% K2O can be considered a potential alternative source of K-fertilizer. The characterization study revealed that the quartz, glauconite and K-feldspar are the major mineral phases, and the glauconite occurs in the form of ovoidal-shaped pellets. As potassium is trapped between di-octahedral T-O-T stable structure of glauconite, a combined process involving hydrogen gas reduction followed by mild hydrochloric acid leaching was developed to enhance the effective recovery of potassium. More than 99% of potassium dissolution was achieved with 20% (v/v) hydrochloric acid leaching at 80ºC for the sample reduced at 500ºC in the presence of 20 mL/min of H2 gas flow rate for 2 h. The leach liquor was further treated to recover potassium as muriate of potash (MOP). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Researchers have extensively studied and documented the effects of potassium (K) fertility on alfalfa (Medicago sativa L.). Yet, additional research is needed to determine how interactions of K, cultivar, and harvest management influence the K needs of alfalfa. To explore these interactions, we conducted 5 years of field research at the University of Wyoming James C. Hageman Sustainable Agriculture Research and Extension Center in Lingle, WY. Treatments were (a) four K rates (0, 56, 112, and 168 kg K2O ha−1 year−1) applied before planting in the fall of 2016 and after the final harvest in the fall of 2017–2020, (b) two cultivars (Hi‐Gest 360 and AFX 457), and (c) two harvest times (early harvest, late bud to early [10%] bloom, and late harvest, 7 days after early harvest), arranged in a 4 × 2 × 2 factorial under random complete blocks with four replications. At 168 kg K2O ha−1 year−1 and early harvest, a consistently significant (p < 0.05) higher yield response was observed. The same response was seen at 112 kg K2O ha−1 year−1 and late harvest. This occurred at a site with moderate‐to‐high soil K levels throughout the study period. There was a linear (p < 0.001, R2 = 0.66) and quadratic (p = 0.006, R2 = 0.61) response of forage accumulation to K rate at early and late harvest, respectively. Similar trends were also seen for stem count, relative water content, root uptake of K, and tissue K. Time of harvest showed immense potential for optimizing K's effect for a consistent high‐yield response. However, fertilizing alfalfa with 112 kg K2O ha−1 year−1 gave the most profitable production under both harvest times. If K fertilizer prices drop over time, high profits could be attained with higher K fertilization rates. After 3 years of production, average forage accumulation increased under an early harvest system and decreased under a late harvest system. Growers in Wyoming and similar regions are encouraged to consider fertilizing alfalfa with moderate K rates (∼112 kg K2O ha−1 year−1) on soils testing moderate‐to‐high in soil test K, implement a late harvest system for the first 3 years after planting, and transition to an early harvest system after the initial 3 years to maximize alfalfa profits. Core Ideas: There have been conflicting reports on the effect of potassium (K) fertilizer on alfalfa (Medicago sativa L.) production.Research is needed to quantify the K needs of alfalfa as influenced by the interactions of K rates, cultivar, and harvest time.Alfalfa responded significantly to K fertilizer even in a moderate‐to‐high exchangeable K soil environment.Alfalfa cultivar did not influence K requirements, and late harvest reduced K requirements by 56 kg K2O ha−1 year−1 for optimal yield response.The 112 kg K2O ha−1 year−1 rate was most economically optimal for both early and late harvests, suggesting that K rates can be similar for both harvest times. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Potassium (K) is one of the essential nutrients that play a crucial role in rice fields; however, its availability, transport, and balance components can be influenced by alternating wetting and drying (AWD) irrigation practice. This study used the Hydrus-1D solute transport model to simulate K transport and balance components in AWD irrigated rice fields. Thirty lysimeter field experiment plots with three different irrigation treatments (No: no soil water stress, MS: mild soil water stress (400 cm), and SS: severe soil water stress (750 cm)) were used for rice cultivation. Daily measurements of soil matric potential head (SMPH) and ponding water depth (PWD) were recorded. Throughout the rice-growing season, leachate water samples from the surface (ponding water) and soil profiles were collected to measure K content. Using the lysimeter field experiment data, the Hydrus-1D model simulated K transport in the AWD rice field. The simulation results indicate that the K distribution predominantly occurred within the top puddled soil layer (0–20 cm) in AWD practice. This suggests that the recommended K fertilizer dose with a 4–5 cm PWD and SMPH of 400 cm optimizes K availability for rice while limiting K leaching loss. The Hydrus-1D model proves to be a valuable management tool, aiding in determining optimal K application rates and ponding water depths for AWD irrigation, ensuring sufficient K nutrients for rice, and controlling K loss for sustainable rice production. [ABSTRACT FROM AUTHOR]

This article explores the impact of boron contamination on spinach plants and the potential mitigating effects of silicon and NPK fertilizer. The study found that increasing levels of boron in the soil led to a decrease in plant growth and various physiological parameters. However, the addition of silicon and fertilizer helped alleviate the negative effects of boron toxicity and improved plant growth. The research suggests that silicon and NPK application can be effective in reducing boron toxicity in spinach plants. [Extracted from the article]

Potassium (K) fertilization guidelines often oversimplify, overlooking factors like soil mineralogy and K application methods. This study aimed to evaluate the influence of K fertilizer rates and application methods on crop yields and the forms of K in soils with different textural and mineralogical features. In 2020, two field trials were conducted to evaluate the impact of varying K rates, added through band or broadcast methods, in Planosol and in Ferralsol. Soybean yield was evaluated in both trials, while flooded rice yield was evaluated only in the Planosol. Soil samples collected from the 0–10 and 10–20 cm layers and soil K content was determined using Mehlich-1, nitric acid (HNO3), and sodium tetraphenylborate. In the Ferralsol, K desorption by HNO3 in the 10–20 cm soil layer was 1.4 times higher the in band application (171 mg kg−1) compared to broadcast method (92 mg kg−1). The Mehlich-1 extractor proved insensitive to detecting K rates in the Planosol (91 and 43 mg kg−1 in the 0–10 and 10–20 cm layers, respectively), while it exhibited responsiveness in the Ferralsol, demonstrating positive increases with K rates. Using a proper chemical extractor is crucial for accurate detection and recovery of applied K in the soil. Grain yields were 4.50 Mg ha−1 for soybeans in the Ferralsol and 9.72 and 5.55 Mg ha−1 for rice and soybeans, respectively, in the Planosol. The findings reveal that applied K distributes into preexisting pools, persisting in the applied location, thereby reducing the anthropogenic K gradient with band reapplication. [ABSTRACT FROM AUTHOR]

The application of potassium fertilizer application and straw return are effective agronomic measures for increasing crop productivity; however, information on how straw return—when substituting potassium fertilizer—affects crop yield, efficiency, and quality in dryland remains limited. In this study, an experiment on a dryland summer maize and winter wheat rotation system was initiated in 2007. This study included four treatments: CK (no fertilizer and no straw return), NP (nitrogen and phosphorus fertilizer application without straw return), NPK (nitrogen, phosphorus, and potassium fertilizer application without straw return), and NPS (NP treatment with straw return, substituting potassium fertilizer as used in the NPK treatment). These treatments were employed to assess grain yield and fertilizer agronomic efficiency in 2015–2020. Additionally, we evaluated the content of nitrogen (N), phosphorus (P), and potassium (K), as well as the protein content and protein yield in maize and wheat grains and the protein components in wheat grains in 2019–2020. The results showed that compared to the CK treatment, NP, NPK, and NPS treatments not only significantly increased the yield, protein yield, and fertilizer agronomic efficiency in both maize and wheat but also increased the content of protein and protein components in wheat grains. Compared to the NP treatment, the NPK treatment significantly increased the contents of N, K, globulin, and gluten in wheat grains by 5.11%, 21.59%, 10.06%, and 15.14%. Compared to NPK treatment, NPS treatment significantly increased the average yield of summer maize by 21.33% and 20.91%, respectively, as well as the annual yield by 9.99% and 13.59%, the N fertilizer agronomic efficiency of summer maize by 132.47%, and the annual N and P fertilizer agronomic efficiency by 42.83% and 64.36%, over the five-year period. The NPS treatment also significantly increased the summer maize protein yield and annual protein yield by 10.43% and 23.08%, as well as the content of protein components, the protein content, and P content in wheat grains by 4.93–13.58%, 7.81%, and 28.89%, respectively. In conclusion, NPS treatment can not only enhance crop yield, protein yield, and fertilizer agronomic efficiency in summer maize annually but also has the advantage of promoting wheat quality. NPS is an efficient strategy to improve crop yield, efficiency, and quality in a dryland maize–wheat rotation system. [ABSTRACT FROM AUTHOR]

To compare the differences in the soil microbial community structure in yellow soil paddy fields after the long-term application of chemical fertilizer, the role and mechanism of chemical fertilizer in maintaining soil microbial diversity were analyzed, and a theoretical basis for fertilization management in farmlands was provided. In this study, long-term experiments were conducted at the Scientific Observation and Experimental Station of the Arable Land Conservation and Agricultural Environment (Guizhou), Ministry of Agriculture and Rural Affairs. Soil samples were collected from five treatments: fertilizer N, P, and K (NPK); fertilizer P and K (PK); fertilizer N and K (NK); fertilizer N and P (NP); and no fertilizer (CK). High-throughput sequencing technology was used to analyze the microbial composition and diversity of the colonies, and the influencing factors are discussed. An analysis of the soil bacterial α diversity indices under the different fertilization treatments revealed that the long-term application of NPK fertilizers had less of an effect on the soil bacterial α diversity indices than did the CK. The long-term application of chemical fertilizers significantly reduced the soil bacterial Chao1, Shannon, and Simpson indices, while there was no significant difference in the bacterial Pielou e index among the treatments. The long-term application of chemical fertilizers significantly increased the soil fungal Chao1 index, but the effects on the other indices were not significant (p < 0.05). An analysis of the bacterial and fungal species under different fertilization treatments showed found that compared with CK, the long-term application of chemical fertilizer increased the relative abundance of Proteobacteria to varying degrees while reducing the relative abundance of Chloroflexi. The impact of other phyla was relatively small, and the difference in the relative abundance of fungi was not significant (p < 0.05). Principal component analysis revealed that, at the genus level, the bacterial and fungal community structures in the CK and NK treatments were relatively independent, while those in the NPK, PK, and NP treatments were similar. Random forest analysis revealed that OM, TP, and TK are the dominant factors that affect soil bacteria α diversity. The dominant factors affecting fungi α diversity are pH, OM, and AK. Redundancy analysis indicated that AK and TP were the main factors affecting bacterial community structure, while AP, AK, and pH were the main factors affecting fungal community structure. The conclusion drawn from this study is that the long-term application of nitrogen, phosphorus, and potassium fertilizer; phosphorus and potassium fertilizer; and nitrogen and phosphorus fertilizer can improve soil fertility, alter the soil environment, enhance microbial diversity, and improve the microbial community structure in yellow soil paddy fields, promoting soil ecosystem stability and health. [ABSTRACT FROM AUTHOR]

To reach the target yield of crops, nutrient management is essential. Selecting the appropriate prediction model and adjusting the nutrient supply based on the actual situation can effectively improve the nutrient utilization efficiency, crop yield, and product quality. Therefore, a prediction model of the NPK fertilizer application rate for greenhouse tomatoes under the target yield was studied in this study. Under low, medium, and high soil fertility conditions, a neural network prediction model based on the sparrow search algorithm (SSA-NN), a neural network prediction model based on the improved sparrow search algorithm (ISSA-NN), and a neural network prediction model based on the hybrid algorithm (HA-NN) were used to predict the NPK fertilizer application rate for greenhouse tomatoes. The experimental results indicated that the evaluation indexes (i.e., the mean square error (MSE), explained variance score (EVS), and coefficient of determination (R2)) of the HA-NN prediction model proposed in this study were superior than the SSA-NN and ISSA-NN prediction models under three different soil fertility conditions. Under high soil fertility, compared with the SSA-NN prediction model, the MSE of the ISSA-NN and HA-NN prediction models decreased to 0.007 and 0.005, respectively; the EVS increased to 0.871 and 0.908, respectively; and the R2 increased to 0.862 and 0.899, respectively. This study showed that the HA–NN prediction model was superior in predicting the NPK fertilizer application rate for greenhouse tomatoes under three different soil fertility conditions. Due to the significance of NPK fertilizer application rate prediction for greenhouse tomatoes, this technique is expected to bring benefits to agricultural production management and decision support. [ABSTRACT FROM AUTHOR]

Background: Wheat is staple diet for majority of people of world and requires several nutrients for optimum growth like Nitrogen, Potassium and Zinc etc. These nutrients when added in the form of chemical fertilizers definitely increase production but at the cost of negative impact on soil, air, water and living beings. Nanoformulations can provide a possible solution to this problem. The current study tried to assess the impact of foliar application of Nano-N, K, Zn on morphological and yield related parameters of wheat. Methods: Wheat plants were grown up to harvesting stage for two consecutive years from 2018 to 2020. Pots grown plants were treated with three different concentrations of Nano-N, K, Zn and bulk/chemical N, K, Zn along-with a control setup having no external nutrients supplement. Several morphological and yield related parameters were recorded. Result: Application of Nano-N, K, Zn resulted in statistically significant increase in plant height, seeds per spike, root length, 100 seed weight, yield and biomass accumulation compared to the control and bulk/chemical N, K, Zn. Highest yield per pot of 23.87 g was obtained under nano-N, K, Zn treatment while yield under bulk fertilizers and control setup was only 7.54 g and 4.38 g respectively. Our work presents a novel combination of nitrogen, potassium and zinc nanofertilizers which not only increase quality of wheat produce but also environment friendly too. [ABSTRACT FROM AUTHOR]

This study assesses the elemental composition of Egyptian glauconite sediments, focusing on potentially toxic elements (PTEs) and macronutrients. The primary aim is to evaluate the feasibility of utilizing these sediments as a natural source of potassium for agricultural purposes, besides conventional chemical fertilizers like potassium sulfate. To quantify elemental content, chemical analysis was employed across five distinct grain size fractions after grinding glauconite rock. The assessment included potassium, calcium, sodium, and PTE concentrations, utilizing potassium chloride (KCl) and ammonium acetate lactate (AL Solution) as single extractants, and the BCR extraction protocol, in addition to measuring the pseudo-total content of these elements. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) facilitated a comparative analysis of elemental concentrations. Results indicate PTE concentrations within European Union regulations, with an absence of cadmium. Glauconite samples contain approximately 3–3.3% potassium by weight, alongside significant amounts of essential macronutrients (calcium, magnesium) and micronutrients (copper, nickel, zinc) crucial for agriculture. BCR sequential extraction protocol results closely align with or slightly surpass pseudo-total content results. Notably, the AL Solution demonstrates high efficiency compared to KCl or acetic acid in the first step of the BCR method. BCR sequential protocol provides valuable insights into various elemental forms and potential mobility. Overall, this study reveals that glauconite has the potential to serve as a promising alternative potassium fertilizer without causing adverse environmental impacts. [ABSTRACT FROM AUTHOR]

The essential role of fertilization in the management of oil palm plantations cannot be overstated, with the understanding that effective strategies must be finetuned to accommodate the diversity of soil types present. The nuanced response of oil palm to fertilization under different soil conditions underscores the critical nature of this research. This study investigates the relationship between oil palm farming practices and agro-environmental performance of plantations. This research aims to understand the complex mechanisms influencing plantation productivity. Five agronomic field experiments were carried out on various soil types (Podzol, Inceptisol, Peat) during 2022. These experiments involved various types of soil and used different plant materials in a total land area of 33 hectares. The results of the peat soil trials revealed a positive effect of RP fertilizer on leaf phosphorus (P) content and a visible gradient in potassium (K) content with different doses of KCl. Average plantation yields peaked in 2022, showing the best yields ever recorded. On the contrary, experiments in podzolic soils showed that oil palm responded better to organic fertilizers than to mineral fertilizers in podzolic soils. The inceptisol soil revealed a significant increase in leaf potassium (K) content with KCl dose, confirming the positive effect of fresh oil palm empty fruit bunches (EFB) on potassium levels. In particular, EFB acts as a good K fertilizer, positively influencing the K content but negatively affecting the calcium content (Ca) due to K/Ca antagonism. These findings emphasize the need for diversified agricultural strategies to optimize oil palm cultivation, increase productivity, and reduce dependence on external input. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coastal regions provide excellent ambience for agricultural practices in terms of their weather conditions. However, the presence of salinity in such areas affects crop growth and productivity by restricting the accessibility to vital nutrients. Potassium (K) is one such key nutrient, whose absorption, transport, and distribution to crops are greatly affected by salinity. Conventional use of huge amounts of potash fertilizers in such areas failed to serve the purpose due to their poor mobility, non-availability to the crops and soil precipitation leading to the search for alternate and sustainable approaches. One such approach is the use of potassium-solubilizing microorganisms (KSMs) as plant prebiotics which are capable of solubilizing mineral potassium from insoluble components and thus facilitates the K intake to the crops. Many species such as Aminobacter, Bacillus, Burkholderia, Cladosporium, Enterobacter, Paenibacillus and Sphingomonas are effective K solubilizers. These groups of bacteria are primarily converting the insoluble K to its solubilized form by various mechanisms including the production of organic/inorganic acids, protons via acidolysis mechanism and hydrogen ion-facilitated cation-exchange mechanism. The present review is primarily intended to report comprehensive information on the various negative effects of salinity on crop growth and yield. Also, scientific discussions on the feasibility of sustainable agricultural practices using KSMs were systematically analyzed in the context of their role in actions along with their mechanistic elucidation. Conclusively, this review has critically identified the potential challenges/gaps in the augmentation of KSMs in the coastal regions and provided significant research hotspots to be addressed in future prospects. [ABSTRACT FROM AUTHOR]

Endophytic bacteria, recognized as eco-friendly biofertilizers, have demonstrated the potential to enhance crop growth and yield. While the plant growth-promoting effects of endophytic bacteria have been extensively studied, the impact of weed endophytes remains less explored. In this study, we aimed to isolate endophytic bacteria from native weeds and assess their plant growth-promoting abilities in rice under varying chemical fertilization. The evaluation encompassed measurements of mineral phosphate and potash solubilization, as well as indole-3-acetic acid (IAA) production activity by the selected isolates. Two promising strains, tentatively identified as Alcaligenes faecalis (BTCP01) from Eleusine indica (Goose grass) and Metabacillus indicus (BTDR03) from Cynodon dactylon (Bermuda grass) based on 16S rRNA gene phylogeny, exhibited noteworthy phosphate and potassium solubilization activity, respectively. BTCP01 demonstrated superior phosphate solubilizing activity, while BTDR03 exhibited the highest potassium (K) solubilizing activity. Both isolates synthesized IAA in the presence of L-tryptophan, with the detection of nifH and ipdC genes in their genomes. Application of isolates BTCP01 and BTDR03 through root dipping and spraying at the flowering stage significantly enhanced the agronomic performance of rice variety CV. BRRI dhan29. Notably, combining both strains with 50% of recommended N, P, and K fertilizer doses led to a substantial increase in rice grain yields compared to control plants receiving 100% of recommended doses. Taken together, our results indicate that weed endophytic bacterial strains BTCP01 and BTDR03 hold promise as biofertilizers, potentially reducing the dependency on chemical fertilizers by up to 50%, thereby fostering sustainable rice production. [ABSTRACT FROM AUTHOR]

The application rate of potassium fertilizer is closely related to the yield of crops. Thin-shelled Tartary buckwheat is a new variety of Tartary buckwheat with the advantages of thin shell and easy shelling. However, little is known about application rate of potassium fertilizer on the yield formation of thin-shelled Tartary buckwheat. This study aimed to clarify the effect of potassium fertilizer on the growth and yield of thin-shelled Tartary buckwheat. A field experiment to investigate the characteristics was conducted across two years using thinshelled Tartary buckwheat (Miku 18) with four potassium fertilizer applications including 0 (no potassium fertilizer, CK), 15 (low-concentration potassium fertilizer, LK), 30 (medium-concentration potassium fertilizer, MK), and 45 kg·ha-1 (high-concentration potassium fertilizer, HK). The maximum and average grain filling rates; starch synthase activity; superoxide dismutase and peroxidase activities in leaves; root morphological indices and activities; available nitrogen, phosphorus, and organic matter content in rhizosphere soil; urease and alkaline phosphatase activities in rhizosphere soil; plant height, main stem node number, main stem branch number, leaf number; grain number per plant, grain weight per plant, and 100-grain weight increased first and then decreased with the increase in potassium fertilizer application rate and reached the maximum at MK treatment. The content of malondialdehyde was significantly lower in MK treatment than in other three treatments. The yields of thin-shelled Tartary buckwheat treated with LK, MK, and HK were 1.22, 1.37, and 1.07 times that of CK, respectively. In summary, an appropriate potassium fertilizer treatment (30kg·ha-1) can delay the senescence, promote the grain filling, and increase the grain weight and final yield of thin-shelled Tartary buckwheat. This treatment is recommended to be used in production to achieve high-yield cultivation of thin-shelled Tartary buckwheat. [ABSTRACT FROM AUTHOR]

Background: Pulses are commonly known as food legumes, next to cereals in production and consumption in India. India is the leading producer of pulses in the world. In spite of being a leading producer, India is still importing pulses to meet consumer demand, due to low productivity of pulses due to various reasons. Hence, there is a need to improve the productivity in pulses. Potassium application in pulse crops have been paid less attention, among different nutrients. Methods: A field experiment was conducted in a randomized block design with factorial concept (FRBD) during Rabi, 2021-22 to enhance the productivity and quality of blackgram with potassium fertilization. Result: The present study revealed that among different potassium levels, soil application of 40 kg K2O ha-1 improved the growth parameters, yield attributes, seed and haulm yields and economic returns of blackgram, which was statistically at par with soil application of 30 kg K2O ha-1. With regard to different foliar sprays tried, foliar application of 1% KH2PO4 at flowering and pod development stages recorded higher growth parameters, yield attributes, seed and haulm yields, protein content and economic returns of blackgram, which was statistically on par with foliar application of 1% KCl or 0.5% KNO3 at flowering and pod development stages. The interaction effect between soil application of potassium and foliar fertilization of potassium could not exert any significant influence on any of the parameters studied in the present investigation. [ABSTRACT FROM AUTHOR]

This study explored the mechanisms underlying the release and transformation of potassium from potassium‐rich minerals in paddy soils derived from purple soils. While potassium is abundant in these minerals, it is typically insoluble and inaccessible to plants. The agricultural practices employed in paddy soils may activate insoluble mineral potassium, potentially reducing potassium fertilizer applications. The activation of mineral potassium not only helps alleviate the dependence on soluble potassium fertilizers in rice cultivation, but also contributes to enhancing food security and sustainable agricultural development. Despite these potential benefits, the transformation pathways of mineral potassium in paddy soils remain unclear, posing an important science question that requires further investigation. This study collected data from a long‐term fertilizer experiment of paddy soils derived from purple soils with abundant potassium‐rich minerals (1982–2019, rice‐wheat rotation). The results revealed that paddy management could drive the transformation of potassium in illite minerals in paddy soils and meet the long‐term growth needs of crops. Submergence reduction significantly increased the concentration of positive ions such as Fe2+ and Ca2+ and provided a pathway for the free movement of ions, promoting the substitution of these ions with interlayer potassium of minerals. This substitution and alternating reduction and oxidation conditions played an important role in the transformation of potassium in illite minerals. The study indicates the promising potential for using crushed illite rocks in rice paddies as a substitute for traditional potassium fertilizers. [ABSTRACT FROM AUTHOR]

To explore how endophytic microbial compositions in amaranth roots are influenced by various fertilization methods and to determine whether these microbes are associated with amaranthin formation, we conducted an analysis of the endophytic microbial community structure. The roots of amaranth plants subjected to different fertilization treatments—conventional fertilization without potassium (NP), conventional fertilization without phosphorus (NK), conventional fertilization without nitrogen (PK), and balanced fertilization (NPK)—were examined. The results showed that the proportions of Streptomyces, Actinospica, and Burkholderia-Caballeronia-Paraburkholderia in the amaranth roots under the balanced fertilization (NPK) treatment were all greater than those in the amaranth roots under the nitrogen (PK), phosphorus (NK), and potassium (NP) deficiency fertilization treatments. In contrast, the proportions of Phenylobacterium, Acrocalymma, Neocosmospora, Fusarium, Acidovorax, Gibellulopsis, Cladosporium, Dactylonectria, and Gibberella in the amaranth roots under the nutrient deficiency fertilization (NP, NK, and PK) treatments were higher than those in the amaranth roots under the balanced fertilization treatment. Additionally, a significantly positive correlation was found between Streptomyces and the amaranthin content. Furthermore, Acrocalymma, Neocosmospora, and Fusarium exhibited significantly negative correlations with the amaranthin content. The above results suggested that endophytes could easily colonize in amaranth roots as beneficial microorganisms under balanced fertilization conditions. In other words, the balanced fertilization (N, P and K fertilizers are 188.0, 53.0 and 50.0 kg·hm−2, respectively) could recruit more beneficial endogenous microorganisms in amaranth roots for improving their growth and quality. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) requires potassium (K) in large amounts for crop growth and development and is more sensitive to low K availability in soils than other agronomic crops. Low K concentrations within the plant may decrease the rate of photosynthesis, which will impact plant growth and development. Cotton yield potential has increased due to genetic improvements, which may have increased the quantity and rate at which cotton takes up K. This research aimed to determine the effect of K fertilizer rates within irrigation level on boll distribution and yield contribution from specific node zones. This study was conducted at New Deal, TX in 2016 and 2017. Muriate of potash (KCl) was applied using knife injection at rates of 0, 45, 90, 135, and 180 kg K h−1 with 80% and 30% evapotranspiration (ET) irrigation levels. Differences were not noted for estimated box mapping yield between K rates in 2016 (p = 0.3996). When 180 kg K ha−1 was applied, total bolls and estimated box mapping yield within 30% ET increased in the early and middle node zones and total nodes over all other K application rates in 2017. It was observed with box mapping that the early and middle node zones were able to utilize applied K more effectively due to the increase in bolls and yield compared to the late and vegetative node zones. Our results suggest that K is an important nutrient in cotton production due to the impacts it has on the early and middle node zones. Core Ideas: Potassium impacts cotton boll distribution and yield contribution from specific node zones within irrigation levels.The early and middle node zones for yield were the greatest with the 180 kg K ha−1 rate within 30% evapotranspiration.The early and middle node zones benefited from added potassium through increased boll formation and yield. [ABSTRACT FROM AUTHOR]

Aims: Green manuring exhibits strong positive effects on soil fertility and crop yield, while its effects on agro-ecosystem multifunctionality (agro-EMF) and the underlying mechanisms are poorly understood. Methods: Based on a 7-year potato cropping field experiment, we conducted a holistic survey of soil and rhizosphere microbiomes, plant performance (i.e. yield and disease resistance) and soil functions, and assessed agro-EMF under conventional chemical potassium (K) fertilization and green manure (GM) amendment practices. Results: We demonstrated that GM application significantly promoted agro-EMF compared to chemical K fertilizer, as indicated by improved crop yield (5.8%-20.6%), reduction in potato late blight incidence (2.8%-46.2%), and increased soil nutrient contents. GM amendment drastically altered microbial community composition, especially in the rhizosphere. Intriguingly, agro-EMF was primarily predicted by microbial community composition, rather than microbial diversity, with a higher agro-EMF variation explained by the rhizosphere microbiome. In comparison to chemical K fertilizer, GM treatments greatly improved the complexity (58.5%-125.8%) and stability (8.2%-21.5%) of the microbial inter-kingdom network. Correspondingly, GM amendment significantly enriched keystone taxa, including the bacterial taxa Xanthomonadaceae, Rhizobiaceae and Sphingobacteriaceae, the fungal taxon Chaetomiaceae and the protistan taxon Cercozoa in the rhizosphere, of which are closely associated with soil nutrient cycling, plant growth promotion, and disease resistance. Conclusion: Taken together, our study revealed that green manuring greatly promoted agro-EMF via coordinating soil nutrient cycling, rhizosphere microbiome and microbial network interactions for greater crop yield, disease resistance and soil functions. This study provides critical information on the mechanisms of ecosystem functions maintenance in agro-ecosystems and presents a basis towards developing conservation farming practices for agricultural sustainability. [ABSTRACT FROM AUTHOR]

The scarcity of irrigation water and nutrients poses a serious challenge to the production of pigeonpea in the changing climate. Despite largest producer of pigeonpea, India is still not meeting the domestic pulses requirement. Exploiting the ratoon ability of pigeonpea in rainy and post-rainy seasons would produce higher grains with limited resources in shorter periods due to multiple harvests. Therefore, the present study was conducted to know the resource requirement of ratoon pigeonpea, partial factor productivity (PFP), and water use efficiency (WUE). Two irrigation levels (I1= 0.50 and I2=0.75 Crop Pan Evaporation), three nutrient levels (F1 = 100%, F2 = 75%, and F3 = 50% of recommended dose of fertilizers; 25:50:25 kg N:P2O5:K2O ha−1) and two mulching levels (M0 = without mulching, and M1 = with mulching) were laid out in split-split plot design at University of Agricultural Sciences, GKVK, Bengaluru. Results revealed that a combination (I2F1M1) of a higher level of irrigation (0.75 CPE) and 100% of recommended fertilizer through fertigation with mulching produced higher dry matter accumulation (190.16 g plant−1 at harvest) and nutrients (82.08, 17.37, and 78.35 kg total N, P, and K ha−1, respectively) uptake. Whereas, higher PFP of nutrients (58.12, 29.06, and 58.12 kg grain kg−1 of N, P, and K fertilizer nutrient, respectively) and WUE (21.07 kg ha-cm−1) were observed in higher irrigation with 50% of required fertilizer and mulching (I1F3M1) as a result of higher yield and lesser resources used. Therefore, a concurrent supply of optimum irrigation and mulching could improve the PFP and WUE of ratoon pigeonpea even under reduced fertilizer application. [ABSTRACT FROM AUTHOR]

Two filed experiments were performed in a sandy soil private farm located in ElQassasin, Fakous District, Sharqia Governorate, Egypt, along the two winter seasons of 2020/21 and 2021/22, to investigate the influence of spraying three aqueous extracts from three plant species besides their mix, as well as the efficacy of the three plant extract concentration alongside spraying with distilled water as control treatment. Additionally, the effect of three potassium application times on bread wheat yield and its attributes as well as grains content of both crude protein and carbohydrates were studied. The impact of the above mentioned factors on weed suppression (weeds number and dry weight) was assessed. Split-split plot design in three replicates was applied. Results displayed that spraying wheat plants with plant extracts had significant effects on all recorded traits except No. of tillers/m², No. of grains/spike, and Total Carbohydrates. Chinopodium extract produced higher biological yield and seed index. Lantana extract also achieved higher yield. Moringa oleifera extract had the highest value for each of biological yield and seed index. Foliar spraying with these extracts stimulated dry matter accumulation. Moringa and Chinopodium extracts produced the highest grain protein content. Foliar spraying with these extracts suppressed weeds number and dry weight. The concentration of plant extracts significantly impacted biological yield in wheat plants. A 75% concentration of sprayed extracts reduced weeds number and their dry weight; leading to higher grain yield, harvest index, and crude protein content. Fairly Potassium addition (pre-sowing) hampered weeds number and dry weight (combined analysis) while enhanced wheat yields and most of their attributes. Potassium played a crucial role in weed suppression, making wheat plants more competitive to weed plants. Adding potassium at early stages of growth is recommended. The interaction between extracts and concentrations significantly affected biological and grain yields, harvest index, and crude protein content. However, the interaction was ineffective on other traits. The interaction between extracts and potassium timing was also effective. The study found that spraying wheat plants with a mixed extract from three plant spices (C. album, M. olefeira, and L. camara) resulted in the highest reduction percentage in weed components, with C. album extract ranking second in suppressing weed components. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microbial-driven N turnover is important in regulating N fertilizer use efficiency through the secretion of metabolites like glycolipids. Currently, our understanding of the potential of glycolipids to partially reduce N fertilizer use and the effects of glycolipids on crop yield and N use efficiency is still limited. Here, a three-year in situ field experiment was conducted with seven treatments: no fertilization (CK); chemical N, phosphorus and potassium (NPK); NPK plus glycolipids (N+PKT); and PK plus glycolipids with 10% (0.9 N+PKT), 20% (0.8 N+PKT), 30% (0.7 N+PKT), and 100% (PKT) N reduction. Compared with NPK, glycolipids with 0–20% N reduction did not significantly reduce maize yields, and also increased N uptake by 6.26–11.07%, but no significant changes in grain or straw N uptake. The N resorption efficiency under 0.9 N+PKT was significantly greater than that under NPK, while the apparent utilization rates of N fertilizer and partial factor productivity of N under 0.9 N+PKT were significantly greater than those under NPK. Although 0.9 N+PKT led to additional labor and input costs, compared with NPK, it had a greater net economic benefit. Our study demonstrates the potential for using glycolipids in agroecosystem management and provides theoretical support for optimizing fertilization strategies. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) cultivars vary in their response to environmental factors. Recently, interest in cotton cultivars' response to varying potassium (K) fertilizer application rates and irrigation has increased. As such, the effect of cotton varieties (early and mid‐maturing), K fertilizer application rates, and irrigation on cotton growth, development, and yield were investigated in Starkville, MS, on two soil mapping units (SMUs): a Leeper silty clay loam (LSCL) and a Marietta fine sandy loam (MFSL). Cotton plant height was positively correlated with SMU, especially LSCL, reaching 60–110 cm on average, in both irrigated and rainfed conditions. Cotton lint yield, fiber quality, and leaf K concentration responded to K and irrigation, and these responses were SMU specific. Particularly, in LSCL, the early‐maturing cultivar, DP 1518 B2XF, responded to K application rate in a positive linear manner in terms of lint yield under both irrigated and rainfed conditions, whereas mid‐maturing DP 1646 B2XF did not. Moreover, lint yield in irrigated MFSL soil increased with K application rate, whereas no responses were observed in rainfed conditions. These data suggest that irrigation, SMU, and cultivar combination could have an impact on K response of cotton and should be considered when making fertility recommendations or decisions. Core Ideas: Potassium application rate and irrigation effects on early and mid‐maturing cotton varieties were tested.Response to potassium and irrigation were soil mapping unit specific.Early and mid‐maturing varieties responded differently to potassium application based on irrigation status. [ABSTRACT FROM AUTHOR]

Salinity stress significantly constrains agricultural productivity and vegetation decline worldwide, particularly in Iran. Potassium, the second most prevalent nutrient in plants, is well known to be essential for cell metabolism. Here, the effects of potassium fertilizer in two biogenic nanoparticles (K-NPs) and conventional (potassium sulfate) forms (0.1 mg/ml) on Melissa officinalis L. under salinity (0, 50, 100, and 150 mM) were investigated. The results demonstrated that stress markers (electrolyte leakage, malondialdehyde, and hydrogen peroxide) increased as salinity levels increased. Plant growth parameters (shoot and root length, fresh and dry weight of shoot and root) and physiological and photosynthetic parameters (stomatal conductance, relative water content, chlorophyll fluorescence, and photosynthetic pigments) were reduced in salinized plants. The highest reduction in fresh weight root, dry weight root, fresh weight shoot, dry weight shoot, root length, and shoot length was recorded under 150 mM NaCl by 30.2%, 51.6%, 30.5%, 24.7%, 26.4%, and 21%, respectively. In contrast, bulk potassium sulfate and K-NPs increased these parameters. Furthermore, K-NPs improved M. officinalis tolerance to NaCl toxicity by enhancing the content of osmolytes such as proline, soluble sugars, and antioxidant enzymes, improving antioxidant contents such as phenols, tannins, anthocyanins, and flavonoids; increasing total protein; and lowering stress markers in plant tissues. Given the results of the physiological, biochemical, and phytochemical parameters obtained from this study, it can be stated that K-NPs, in comparison to the conventional form of potassium fertilizer, exhibit a greater potential to mitigate damages caused by salinity stress in M. officinalis plants. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate how different mixtures of urine and chemical fertilizer impact the quality and characteristics of lettuce, as well as the soil's microbial community, a study was conducted using lettuce as the focus. The study employed potted cultivation to explore the best combination of urine and chemical fertilizer for optimal lettuce growth. The treatments were as CK (no fertilizer), T1 (1.0 g urea + 3.3 g monocalcium phosphate + 0.9 g potassium sulfate), T2 (0.235 gN equivalent of human urine + 0.5 g urea + 3.19 g monocalcium phosphate + 0.75 g potassium sulfate), and T3 (0.47 gN equivalent of human urine + 3.05 g monocalcium phosphate + 0.6 g potassium sulfate). The study also examined the effects of different ratios of urine and chemical fertilizer on soil's physical and chemical properties, soil microbial diversity, and soil microbial community structure. The results indicated that combining urine and chemical fertilizer could boost the weight and height of lettuce. At the T2 level, lettuce has the highest plant height and fresh weight, with a 25.01% and 138.89% increase in plant height compared to T1 and T3, respectively. The fresh weight increased by 48.81% and 67.79% compared to T1 and T3, respectively. Various soil proper ties like total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), available potassium (AK), ammonium nitrogen (NH4 +-N), soil organic matter (SOM), and electrical conductivity (EC) all showed improvements under different urine fertilizer ratios, with T3 demonstrating the most significant increases. Applying human urine and chemical fertilizer together was found to decrease the abundance of bacteria in the lettuce soil. This effect was more pronounced with higher proportions of urine application, particularly affecting the Proteobacteria phylum. Treatments T1 and T2 increased the relative abundance of Proteobacteria by 27.54% and 6.68% respectively, while T3 reduced Proteobacteria abundance by 8.32%. In conclusion, com bining urine and chemical fertilizer can enhance both lettuce quality and soil health. However, excessive use of urine can reduce the abundance of microorganisms in the soil. Under normal phosphorus and potassium fertilizer usage, the best ratio for application is 65 mL of urine combined with 0.5 g of urea (in a 11 ratio based on nitrogen content). [ABSTRACT FROM AUTHOR]