Sole Application Research Articles

Effect of Chinese Milk Vetch on Zinc Content and Zinc Absorption of Rice in Purple Tidal Mud Soil

Rice is a staple food crop that feeds billions globally. Addressing Zn deficiency in rice is crucial for improving nutrition and food security. Zn deficiency in rice is a widespread issue, especially in purple tidal mud substrates, which often exhibit low Zn availability. The objective of this two-year pot study was to explore the relationship between Zn content, yield components, and Zn absorption in rice grown in purple tidal mud substrate with varying amounts of Chinese milk vetch (Astragalus sinicus L.) incorporation. The experimental design consisted of seven treatments: an unfertilized control, a Chinese milk vetch control, a chemical fertilizer control, and four treatment variations incorporating Chinese milk vetch alongside chemical fertilizer applications. The results indicated that planting and applying Chinese milk vetch improved the grain yield of rice in purple tidal mud substrate, and the yield increased with higher levels of Chinese milk vetch applied. The increased grain yield resulted in higher Zn absorption in rice grains. The application of Chinese milk vetch, both solely and in combination with chemical fertilizers, had varying effects on zinc uptake and grain zinc formation efficiency in early and late rice, with the control and low-level Chinese milk vetch treatments generally exhibiting the highest performance across the two-year period. By introducing Chinese milkvetch following the use of chemical fertilizers, the Zn content in rice grains increased starting from the second year. The treatment with Chinese milkvetch applied at a rate of 2.25 t/hm2 showed the best results in increasing the Zn content in rice grains. The increase in Zn content and Zn uptake by the rice plants gave rise to a lowering of the DTPA-extractable Zn content in the purple tidal mud substrate. Sole Chinese milk vetch application and using Chinese milk vetch following chemical fertilizer application both increased Zn content extracted by DTPA in purple tidal mud substrate.

The long-term nitrogen fertilizer management strategy based on straw return can improve the productivity of wheat-maize rotation system and reduce carbon emissions by increasing soil carbon and nitrogen sequestration

ProblemFacing the multiple objectives of increasing production, carbon sequestration, and nitrogen reduction in farmland, optimizing straw and nitrogen fertilizer management to achieve a balance between grain production and ecological safety in the wheat-maize rotation system has become increasingly critical and urgent. MethodsThis study conducted a five-year field experiment in the Guanzhong Plain of China from 2017 to 2021 to investigate the effects and synergistic regulatory mechanisms of straw disposal methods (straw return, no-straw return) and nitrogen application rates (0, 150, 225, 300 kg ha−1) during the maize season on soil greenhouse gas (GHG) emissions, crop yield, and soil organic carbon (SOC) and soil toatl nitrogen (STN) content. ResultsThe results showed that under the scenario of no-straw return, fertilization increased soil nitrous oxide (N2O) emissions by 35.9–64.0 %, and annual total crop yield by 16.4–22.8 %; however, under the straw return scenario, the increase in soil N2O emissions due to fertilization decreased to 26.7–62.0 %, while the yield increase rose to 19.5–25.9 %. The interaction effect between straw return and nitrogen application was significant, with straw return boosting the contribution rate of nitrogen application to yield (2.2–4.4 %) and simultaneously reducing the contribution rate of nitrogen application to N2O emissions (3.0–27.5 %). The study also indicated that the yield-increasing effect of straw return continued to increase with the duration of straw return, with the contribution rate to yield reaching 9.9 % after three years of continuous straw return, while the contribution rate of nitrogen application to yield increased by an average of 3.0 % per year. This suggests that there is significant potential for coupling straw return with reduced nitrogen application. Straw return combined with nitrogen fertilizer increased SOC content by 7.9–40.1 % and 3.7–12.5 %, STN content by 1.0–22.8 % and 6.1–13.9 %, respectively, compared to sole nitrogen application and sole straw return. Pathway analysis indicated that straw return combined with nitrogen fertilizer mainly enhanced soil carbon-nitrogen sequestration, improved fertilizer utilization efficiency and crop nutrition levels, reduced net global warming potential (GWP) and greenhouse gas intensity (GHGI), and synergistically regulated to increase yield while reducing GHG emissions. ConclusionThe study highlights that straw return lowers the threshold for nitrogen application levels, suggesting that regulating nitrogen application levels between 224 and 256 kg ha−1 during the maize season, and maintaining a nitrogen application level of 195 kg ha−1 during the wheat season, is beneficial for long-term stable production and emission reduction in the wheat-maize rotation system farmland.

Combined inoculation of arbuscular mycorrhiza fungi with Meso‐rhizobium improves nutrient uptake, growth performance, and moisture stress tolerance of chickpea (Cicer arietinum L.)

AbstractBiofertilizers can be better alternatives to chemical fertilizers to enhance plant nutrition and productivity as they improve the soil fertility and crop productivity in an eco‐friendly and cost‐effective manner. A pot experiment was conducted between December 2018 and March 2019 in southern Ethiopia to evaluate the combined inoculation of arbuscular mycorrhizal fungi (AMF) and Meso‐rhizobium (MR) on biomass yield, nutrient uptake, and moisture stress tolerance of chickpea (Cicer arietinum L.) (variety: Habru). The experiment was executed as a factorial arrangement using a completely randomized design with three replications. The treatments were control (non‐fertilized), sole AM fungi inoculation, AM fungi inoculation with phosphorus fertilizer (20 kg P ha−1) and MR, and sole inorganic fertilizers (20 kg P;10 kg N ha−1) at four different moisture levels (optimum throughout the growing season, stressed at vegetative, flowering, and seed filling stages). The results demonstrated that biomass yields were limited by moisture stress, especially at vegetative and flowering stages of chickpea. Sole and co‐application of AMF with MR and inorganic P increased biomass yields on average by 19%, 39%, and 33% under water stress conditions, respectively, compared to the non‐inoculated control. The application of AMF with MR and inorganic P also significantly increased nodulation, AMF colonization, and nutrient uptake, but these effects were dependent on soil moisture status. In conclusion, there are potential advantages to be gained from sole and combined AMF application with rhizobium to improve growth and productivity of chickpea through enhanced nutrient and water uptake, though the results of this pot experiment should be validated through field trials.

Sustainable soil health and agricultural productivity with biochar-based indigenous organic fertilizers in acidic soils: insights from Northwestern Highlands of Ethiopia

Depletion of soil fertility in tropical regions is a pressing concern contributing to lower crop yields. This study aimed to evaluate the effects of biochar and co-composted biochar on acidic soil and the growth performance of teff (Eragrotis teff (Zucc.)) in the sub-tropical highlands of Ethiopia. Co-composted biochar was produced by mixing Acacia decurrens biochar with chicken litter and cow dung manure at different ratios of 100:0:0, 25:75:0, 15:85:0, and 25:0:75. Treatment impact on soil properties and crop yields were evaluated with applications of 0, 5, 10, and 20 t ha–1 in field trials. The study shows interaction effects of biochar-based amendments significantly (P < 0.001) improved soil bulk density (g/cm3), moisture content (%), pH, total nitrogen (%), total organic carbon (%), available phosphorus (mg/kg), cation exchange capacity (cmol ( +)/kg)) and teff yield. The application of 20 t ha–1 sole biochar significantly improved soil acidity by 0.99 units. Soil treated with 20 t ha–1 of BCLL and BCM resulted in notable increases in soil pH, ranging from 0.12 to 0.83 units for BCLL and 0.15 to 0.81 units for BCM. Soil treated with 20 t ha–1 BCLL showed a significant increase in tef grain yield, with improvements of 315%, 48%, 48%, and 84% compared to the control, compost, inorganic fertilizer, and sole biochar application, respectively. In conclusion, the application of 20 t ha–1 BCLL has significantly improved soil properties and crop yield. This emphasizes the need to expand the intervention to assist farmers facing similar soil fertility challenges.

Integrated Management of Collar Rot of Chickpea (Cicer arietinum) Caused by Sclerotium rolfsii under Greenhouse Conditions

Collar rot, one of the major soil borne diseases of chickpea incited by Sclerotium rolfsii causes significant economic losses in chickpea crop. The present study was undertaken to identify the eco-friendly management of this soil borne disease in chickpea. In this study, the efficacy of chemical, biocontrol and biofumigation to manage the chickpea collar rot disease was tested under Greenhouse conditions. Our results revealed that the treatments involving the sole application of chemical fungicide Tebuconazole 60 FS (as seed treatment or soil application) or in combination with other treatments resulted in 100% germination of chickpea seeds. Two treatments namely T5 (SA of Tebuconazole 60 FS) and T12 (ST with Tebuconazole and SA of mustard seed cake) recorded 0.00% total mortality and hence found to be highly effective in protecting chickpea seeds from both pre emergence seed rot and post emergence seedling mortality.The results on the percent disease incidence revealed that, T10 (ST with Trichoderma spp and SA of mustard seed cake) provided maximum disease reduction of 81.93 per cent (PDI 12.04%) and 75.93 (PDI 24.07% ) per cent over the control at 30 and 45 DAS respectively. This was followed by Treatment T7 which exhibited 72.22 % (PDI 18.52%) and 69.45 % (PDI 30.55%) disease reduction over the control at 30 and 45 DAS respectively. Overall, the results of our study (considering both germination and percent disease incidence percentages), revealed that T7 (ST and SA of Trichoderma spp.) was the most effective treatment in managing the collar rot disease of chickpeas.

Soil properties and nutrient uptake of maize (Zea mays) as influenced by mixed manure and blended inorganic fertilizer in Haramaya district, eastern Ethiopia

The deteriorating state of soil fertility and low agricultural productivity in Ethiopia can be traced to the lack of equivalent consideration given to the soil's biological, chemical, and physical properties. A pot experiment was conducted to investigate the effect of mixed manure and blended nitrogen, phosphorus, sulfur and boron (NPSB) fertilizer on phosphorus adsorption, and other properties of Vertisols, nutrient uptake, and growth performance of maize. The study findings indicate that the combined application of mixed manure and blended NPSB significantly reduced soil pH from 7.87 to 7.68, phosphorus adsorption efficiency from 93 to 88.5 %, and Freundlich adsorption capacity from 194 to 100.75 mg kg−1 , intensity from 1.96 to 1.27 compared to control. However, combined application of these two treatments significantly increased the organic carbon from 0.81 to 1.64 %, total nitrogen from 0.04 to 0.13 %, and available phosphorus from 6.96 to 73.82 g kg−1. The study further revealed that mixed manure and blended NPSB resulted in significantly (p ≤ 0.05) higher contents of nitrogen and phosphorus in the maize leaves as well as their uptake compared to their sole application and control. The highest values of these parameters were observed in plots treated with a combined application of 15 t ha−1 mixed manure with each rate of 100 and 150 kg ha−1 blended NPSB. Additionally, the maize plant height (p ≤ 0.05) and above-ground biomass (p ≤ 0.01) also exhibited significant increase. Compared to the control and full dose of NPSB, all the treatments that received a combined application of 15 t ha−1 mixed manure with blended NPSB ranging from 50 to 150 kg ha−1 resulted in significantly higher above-ground biomass of maize. The results suggest that the combined use of mixed manure and blended NPSB could be a practical and effective approach to improve soil properties and maize above-ground biomass yield.

Castor Meal and Ground Hydrothermalized Phonolite Optimize Sweet Potato Nutrition, Yield, and Quality

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.

The effects of drought and salinity on KS and RAW managerial coefficients in the efficient water management in maize farms

This study aimed to investigate the simultaneous effects of drought and salinity on irrigation management coefficients in maize farms. A three-year field research was conducted in the form of a 3 × 3 factorial experiment with a randomized complete block design and three replications from 2020 to 2022 in a maize farm, in Aliabad Fashafoye, Qom province, Iran. The applied treatments included three levels of salinity (S0 = 1.8, S1 = 5.2, and S2 = 8.6 dS/m) and three levels of irrigation (W0 = 100%, W1 = 75%, and W2 = 50% of field capacity). Evapotranspiration stress coefficient (KS) due to W0S1 and W0S2 treatments was (0.975 and 0.934), (0.974 and 0.932), and (0.962 and 0.935) in 2020, 2021, and 2022, respectively. According to the results, KS decreased by increasing the salinity level of irrigation water, so a 1-unit increase in salinity level above the tolerance threshold of the crop to salinity decreased KS by 0.78 and 1.76% for S1 and S2, respectively. Moreover, each percent of volumetric moisture decrease from field capacity decreased KS by 5.9 and 13.3% in W1 and W2, respectively. Also, with the increase in the intensity of the stresses, the readily available water (RAW) of treatments decreased. The sole application of salinity stress decreased the decreasing slope of RAW by 3.2%, while the application of both stresses resulted in the decreasing slopes of 4.9, 5.7, and 7.8% at the salinity levels of S0, S1, and S2, respectively, compared to the control. The findings of this study show that the accurate estimation of crop evapotranspiration and RAW can help to improve the irrigation schedule, and the amount of irrigation water used is less than in non-stress conditions due to the reduction of total evapotranspiration and less water uptake in environmental stresses in maize farms.

Effect of biochar and inorganic fertilizer on the quality of beetroot (Beta vulgaris L.) in Kenya

Despite its health benefits, the production and quality of beetroot is still low in Kenya due to the application of non-recommended rates of fertiliser and soil amendment. This research aimed at contributing to the improvement of the beetroot quality in Kenya. It was designed to determine the effects of biochar and NPK (17-17-17) on the quality of beetroot in Kenya. An RCBD factorial experiment was conducted at Egerton University farm, Kenya, for two seasons. Biochar (0, 5, 10 t/ha) and NPK (0, 200, 300 and 400 kg/ha) were applied together before planting. Data were collected on beetroot diameter, total phenolics, total soluble solids, calcium, iron and phosphorus contents and analysed using SAS statistical software. The co-application of biochar and NPK significantly (p≤0.05) increased the beetroot diameter, iron, calcium, phosphorus, TSS and phenolics content in season two and not in season one. The sole application of biochar showed a significant increase in the iron content of beetroot in season one. However, biochar did not have a significant effect on beetroot diameter, mineral content, TSS and phenolics content of beetroot in season two. The sole application of NPK at 200, 300 and 400 kg/ha significantly (p≤0.05) increased the diameter of beetroot and iron content in both seasons one and two and also significantly improved the calcium and phosphorus content in season two. These NPK levels were not statistically different from each other, but different from the control. It is therefore recommended to apply NPK and biochar for quality beetroot.

Long-term different fertilization practices restructured the functional carbon pools in a paddy soil through distinct mechanisms

Fertilization is a common management practice for improving soil organic matter (SOM), which is a crucial indicator of soil fertility. Nevertheless, how long-term fertilization affects functional SOM fractions and its mechanisms remain unclear. In this study, a 12-year field experiment, initiated in 2011, was conducted in Xinzhu village, Zhejiang province, China. Four different fertilizer treatments (without any fertilizers application, Control; sole application of inorganic fertilizers, NPK; combined application of NPK with cattle manure, NPKM; and combination of NPK fertilizers and return of rice straw, NPKS) were selected in this field trial. Functional carbon (C) pools, microbial community structure and SOM composition in both topsoil (0−15 cm) and subsoil (15−30 cm) were explored using the physical and chemical fractionation, phospholipid fatty acids (PLFA) analysis and solid-state 13C-Nuclear Magnetic Resonance Spectrometry (13C NMR) assays. Compared to the control, the NPK combined with organic amendments had significantly higher organic carbon contents of unprotected pools (cPOM and fPOM) in both topsoil (39−277 %) and subsoil (43.1−91.3 %), respectively. Organic carbon accumulated the most within iPOM (1.99 g kg−1 soil) and H-d(Silt+Clay) fractions (1.41 g kg−1 soil) under NPKM in the topsoil, suggesting that physical and chemical protection played the pivotal role after manure addition. Furthermore, NPKM increased the abundance of bacterial and fungal PLFAs in both topsoil (31.4 % and 24.5 %) and subsoil (173 % and 175 %), while NPKS elevated the alkyl/O-alkyl C ratio but reduced the aromaticity in topsoil, compared to inorganic fertilization alone. Partial least squares path modelling showed that fertilization had a direct impact on silt+clay associated C (0.6) in topsoil, POM-C (0.76) in subsoil, and microbial community structure (0.88 and 0.87) in both soil layers. Redundancy analysis revealed that in the NPKM treatment, the key factors affecting functional carbon pools were the total PLFA and the ratio of gram-positive to gram-negative bacterial PLFA, while for the NPKS treatment, it was the alkyl C/O-alkyl C ratio. In conclusion, long-term fertilization had a strong effect on functional carbon fractions through multiple mechanisms in different soil layers, involving changing microbial community and SOM composition.

Effect of Epidermal Mucous Secretion of Earthworms and other Selected Organic Substances on Rooting of Semi-Hardwood Cuttings of &lt;em&gt;Citrus aurantifolia&lt;/em&gt; and Top Cuttings of &lt;em&gt;Dracaena sanderiana&lt;/em&gt;

A recent trend in plant growth and propagation is to use natural substances rather than synthetic plant growth regulators. Two experiments were conducted to find out the effect of epidermal mucous secretion (EMS) of earthworms and other organic substances including Aloe vera gel, coconut water and ripe banana on rooting of semi-hardwood cuttings of Citrus aurantifolia and top cuttings of Dracaena sanderiana compared to commercially available plant growth regulators (PGRs). Eleven treatments were prepared using sole application of EMS solution, Aloe vera gel, coconut water and ripe banana, and mixtures of EMS and other organic substances in two different ratios by allocating equal and more inputs from EMS. The present experiments were set up adopting a completely randomized design. The number of roots per cutting, total root length per cutting (cm), length of the longest root per cutting (cm) and root vigor score were recorded for both plant species where destructive sampling was done at two months after planting for C. aurantifolia and one and two months after planting for D. sanderiana. The number of roots per cutting, length of the longest root per cutting and the root vigor score were significantly greater in the control treatment that used commercially available PGR and the cuttings treated with EMS: coconut water (1:1) for C. aurantifolia suggesting the possibility to us EMS and coconut water mixture to substitute the PGR for root induction in C. aurantifolia. The number of roots, total root length and the length of the longest root per cutting were significantly high in the treatments administrated with Aloe vera gel, ripe banana, and a mixture of EMS: ripe bananas (1:1) together with the PGR at two months after planting for D. sanderiana. Hence, the ingredients listed above could be utilized as alternative organic substances to produce adventurous roots in D. sanderiana top cuttings as same as the PGR. The results of the present study could be extremely valuable for developing a unique organic rooting replacement for the synthetic root inducing materials for C. aurantifolia and D. sanderiana. Nonetheless, additional research is required to validate the results of this study.

Evaluation the efficacy of NB-UVB treatment alone in comparison with combination therapy of NB-UVB and oral prednisolone in treatment of vitiligo

Background: The treatment landscape for vitiligo has witnessed diverse approaches yielding variable outcomes. Objective: To discern the optimal approach in terms of both tolerability and efficacy by comparing Narrow Band Ultraviolet B (NB-UVB) phototherapy with adjunctive oral mini pulse (OMP) prednisolone tablets. Patients and Methods: A total of eighty-seven individuals with progressive vitiligo were enrolled in a one-year study, with participants allocated randomly across three study groups through a continuous selection method. Group 1 received a combination of NB-UVB and OMP prednisolone tablets, group 2 underwent NB-UVB treatment only, and group 3 received OMP prednisolone tablets alone. Clinical assessments were conducted at three- and six-month intervals, and statistical analyses were performed utilizing descriptive and bivariate techniques, including the chi-square test, to gauge the significance of differences between the various groups. Results: In Group 1 (NB-UVB + OMP), substantial improvement was observed in 41.4%, accompanied by moderate improvement in 44.8% of patients. Group 2 (NB-UVB) demonstrated marked improvement in 31.0% and moderate improvement in 38.0%. In Group 3 (OMP), a lower proportion experienced marked (13.8%) or moderate (3.4%) improvement. Chi-square test findings indicated that the combination of NB-UVB and OMP correlated significantly with marked and moderate improvement in contrast to OMP alone, with respective values of χ² = 6.434 (p = 0.001) and χ² = 7.831 (p = 0.015) after a six-month follow-up. Conclusion: Through a comprehensive evaluation of three treatment modalities in vitiligo patients, it was established that the sole application of oral mini pulse steroids (OMP) held an adjunctive value, lacking substantial efficacy on its own. Remarkably, the amalgamation of Narrow Band UVB and OMP presented a clear advantage over either treatment administered independently.

Evaluation the Efficacy of NB-UVB Treatment Alone in Comparison with Combination Therapy of NB-UVB and Oral Prednisolone in Treatment of Vitiligo

Background: The treatment landscape for vitiligo has witnessed diverse approaches yielding variable outcomes. Objective: To discern the optimal approach in terms of both tolerability and efficacy by comparing Narrow Band Ultraviolet B (NB-UVB) phototherapy with adjunctive oral mini pulse (OMP) prednisolone tablets. Patients and Methods: A total of eighty-seven individuals with progressive vitiligo were enrolled in a one-year study, with participants allocated randomly across three study groups through a continuous selection method. Group 1 received a combination of NB-UVB and OMP prednisolone tablets, group 2 underwent NB-UVB treatment only, and group 3 received OMP prednisolone tablets alone. Clinical assessments were conducted at three- and six-month intervals, and statistical analyses were performed utilizing descriptive and bivariate techniques, including the chi-square test, to gauge the significance of differences between the various groups. Results: In Group 1 (NB-UVB + OMP), substantial improvement was observed in 41.4%, accompanied by moderate improvement in 44.8% of patients. Group 2 (NB-UVB) demonstrated marked improvement in 31.0% and moderate improvement in 38.0%. In Group 3 (OMP), a lower proportion experienced marked (13.8%) or moderate (3.4%) improvement. Chi-square test findings indicated that the combination of NB-UVB and OMP correlated significantly with marked and moderate improvement in contrast to OMP alone, with respective values of χ² = 6.434 (p = 0.001) and χ² = 7.831 (p = 0.015) after a six-month follow-up. Conclusion: Through a comprehensive evaluation of three treatment modalities in vitiligo patients, it was established that the sole application of oral mini pulse steroids (OMP) held an adjunctive value, lacking substantial efficacy on its own. Remarkably, the amalgamation of Narrow Band UVB and OMP presented a clear advantage over either treatment administered independently. Keywords: Vitiligo, NB-UVB, OMP, Prednisolone.

Microplastic and cadmium contamination: Impact on the soil by inhibiting the growth of pak choi (Brassica rapa subsp. chinensis)

Microplastics are persistent pollutants that elicit significant environmental and health concerns; however, little is known about their interactions with cadmium (Cd) and their toxic effects on soil and plant growth. A pot study was conducted to examine the effects of polyethylene (PE; 0.05 % w/w), polylactic acid (PLA; 0.05 % w/w), and Cd application (5 mg kg−1 soil) in a soil-plant system. Sole application of PE and soil contamination with Cd negatively influenced the biomass, soil properties, Cd accumulation, photosynthetic properties, chlorophyll content, root growth traits, and antioxidant enzyme activity. PE+Cd exerted stronger adverse effects on biomass, soil properties, Cd accumulation, photosynthetic properties, chlorophyll content, root growth traits, and antioxidant enzyme activity. PLA+Cd decreased Cd uptake and accumulation in leaves and roots. PE+Cd upregulated the antioxidant activities (APX, CAT, POD, and SOD contents) in the root and leaves, compared to that by PLA. Both types of microplastics, especially PE, are affected by oxidative stress caused by Cd-contaminated soil. In conclusion, PE+Cd had stronger adverse effects on soil health and pak choi physiology, thereby affecting roots and leaf biomass. Long-term experiments are required to enhance our understanding of microplastic in bioremediation.

Minimization of heavy metal toxicity in radish (Raphanus sativus) by strigolactone and biochar

Due to the high solubility of Cd in water, it is considered a potential toxin which can cause cancer in humans. In plants, it is associated with the development of oxidative stress due to the generation of reactive oxygen species. To overcome this issue, the roles of different plant hormones are vital. Strigolactones, one of such natural plant hormones, show promise in alleviating cadmium toxicity by mitigating its harmful effects. Acidified biochar (AB) can also effectively mitigate cadmium toxicity via ion adsorption and pH buffering. However, the combined effects of strigolactone and AB still need in-depth investigations in the context of existing literature. This study aimed to assess the individual and combined impacts of SLs (0 and 25 µM) and AB (0 and 0.75% w/w) on radish growth under Cd toxicity, i.e., 0 and 20 mg Cd/kg soil. Using a fully randomized design (CRD), each treatment was administered in four replicates. In comparison to the control under 20 mg Cd/kg soil contamination, the results showed that 25 µM strigolactone + 0.75% AB significantly improved the following: radish shoot length (~ 17%), root length (~ 47%), plant fresh weight (~ 28%), plant dry weight (~ 96%), chlorophyll a (~ 43%), chlorophyll b (~ 31%), and total chlorophyll (~ 37%). It was also noted that 0.75% AB was more pronounced in decreasing antioxidant activities than 25 µM strigolactone under 20 mg Cd/ kg soil toxicity. However, performing 25 µM strigolactone + 0.75% AB was far better than the sole application of 25 µM strigolactone and 0.75% AB in decreasing antioxidant activities in radish plants. In conclusion, by regulating antioxidant activities, 25 µM strigolactone + 0.75% AB can increase radish growth in cadmium-contaminated soils.

Impacts of long-term chemical nitrogen fertilization on soil quality, crop yield, and greenhouse gas emissions: With insights into post-lime application responses

The improvement in the agricultural production through continuous and heavy nutrient input like nitrogen fertilizer under the upland red soil of south China deteriorates soil quality, and this practice in the future could threaten future food production and cause serious environmental problems in China. This research is initiated with the objectives of evaluating the impacts of long-term chemical nitrogen fertilization on soil quality, crop yield, and greenhouse gas emissions, with insights into post-lime application responses. Compared to sole application of chemical nitrogen fertilization, combined application with lime increased soil indicators (pH by 6.30 %–7.76 %, Ca2+ by 90.06 %–252.77 %, Mg2+ by 184.47 %–358.05 %, available P by 5.05 %–30.04 %, and soil alkali hydrolysable N by 23.49 %–41.55 %. Combined application of chemical nitrogen fertilization with lime (NPCa (0.59), NPKCa (0.61), and NKCa (0.27) significantly improved soil quality index compared to the sole application of chemical nitrogen fertilization (NP (0.31), NPK (0.36), and NK (0.16). Compared to sole application of chemical nitrogen fertilization, combined application with lime increased grain yield by 48.36 %–61.49 %. Structural equation modeling elucidated that combined application of chemical nitrogen fertilization and lime improved wheat grain yield by improving soil quality. Exchangeable Ca2+, exchangeable Mg2+, pH, and exchangeable Al3+ were the most influential factors of wheat grain yield. Overall, the combined application of chemical nitrogen fertilization and lime decreased global warming potential (calculated from N2O and CO2) by 16.92 % emissions compared to the sole application of chemical nitrogen fertilization. Therefore, liming acidic soil in upland red soil of South China is a promising management option for improved soil quality, wheat grain yield, and mitigation of greenhouse gas emissions.

Zinc and nitrogen mediate the regulation of growth, leading to the upregulation of antioxidant aptitude, physio-biochemical traits, and yield in wheat plants

An ample amount of water and soil nutrients is required for economic wheat production to meet the current food demands. Nitrogen (N) and zinc (Zn) fertigation in soils can produce a substantial wheat yield for a rapidly increasing population and bring a limelight to researchers. The present study was designed to ascertain N and Zn’s synergistic role in wheat growth, yield, and physio-biochemical traits. A pot experiment was laid out under a complete randomized design with four N levels (N1-0, N2-60, N3- 120, and N4-180 kg ha−1), Zn (T1-0, T2-5, T3-10, and T4-15 kg ha−1) with four replications. After the emergence of the plants, N and Zn fertigation was applied in the soil. The growth traits were considerably increased by combined applications as compared to the sole applications of the N and Zn. The photosynthetic pigments were found maximum due to combined applications of N and Zn, which were positively associated with biomass, growth, yield, and wheat grain quality. The combined application also substantially enhances the antioxidant enzyme activities to scavenge the ROS as H2O2 and reduce lipid peroxidation to protect the permeability of the biologic membranes. The combined higher applications of N and Zn were more responsive to ionic balance in a shoot by maintaining the Na+ for osmotic adjustments, accumulating more Ca2+ for cellular signaling; but, combined applications resulted in K+ reduction. Our present results suggest that appropriate sole or combined applications of N and Zn improve wheat's growth, yield, and antioxidant mechanisms. Previous studies lack sufficient information on N and Zn combined fertigation. We intend to investigate both the sole and combined roles of N and Zn to exploit their potential synergistic effects on wheat.

Bioactivation of Legacy Phosphorus in Calcareous Soil by P-Activators and Its Effect on Maize Growth

ABSTRACT Soil legacy phosphorus (P) accumulated due to the long-term continuous application of P fertilizers in agricultural fields accumulated in the soil for years, as sparingly soluble forms. This can be made as a possible soil P source using P-activators. In this study, a laboratory incubation and a pot experiment were conducted to evaluate the potential of some P activators (Phosphorus solubilizing bacteria, phytase, humic acid, oxalic acid) in increasing the availability of residual phosphorus in calcareous soil. For the incubation experiment, the P activators were applied alone and in combination. Soil samples were analyzed at subsequent intervals for soil available P, alkaline phosphatase activity, and sequential P fractions. The results showed that phytase application with humic acid (HA) increased the available soil P (12.4 kg ha−1) and alkaline phosphatase activity (47.42 µg p-nitrophenol released g−1 soil hr−1) followed by phosphorus solubilizing Bacteria (PSB) with humic acid and PSB with phytase treatments. All treatments have a significant effect on different soil P-fractions. A greater reduction in calcium phosphate fraction was noted in phytase and humic acid application. The combined application of P-activators performed better than their sole application. The best three treatments selected from the laboratory incubated experiment were used for the pot experiment with maize, along with the different dosages of P fertilizer. The morphological parameters were observed on the 30th and 60th days of the maize crop. The results of plant height, chlorophyll index, and dry matter production showed that the application of phytase and HA with 100% recommended dose of P was statistically comparable with phytase and HA with 75% recommended dose of P. The findings have illustrated the extent of P release by different P activators in increasing the legacy P availability. The application of phytase and HA with 25% reduced dose of P fertilizers will promote the availability of legacy P in calcareous soils through solubilization.

Effects of Returning Green Manure-Chinese Milk Vetch on the Availability and Transformation of Zinc in Purple Tidal Mud Soil under Rice Cultivation

This study aimed to investigate the impact of different levels of Chinese milk vetch (Astragalus sinicus L.) incorporation on the availability and transformation of zinc in purple tidal mud soil under rice cultivation. A two-year pot experiment was conducted, comprising seven treatments: a control group without fertilizer, a control group with Chinese milk vetch application, a control group with chemical fertilizer application, and four treatment groups with varying levels of Chinese milk vetch application following chemical fertilizer application. Results showed that Chinese milk vetch application increased the content of available zinc (DTPA-Zn) in purple tidal mud soil. Sole application of Chinese milk vetch ultimately enhanced the transfer factor of zinc in purple tidal mud soil and reduced the distribution index. However, applying Chinese milk vetch after chemical fertilizer application ultimately decreased the transfer factor of zinc and increased the distribution index. Furthermore, sole application of Chinese milk vetch facilitated the conversion of zinc in purple tidal mud soil into available forms, while applying it after chemical fertilizer application promoted the transformation of zinc into ineffective forms, with a greater conversion observed at higher levels of Chinese milk vetch application.

Individual and interactive effects of amino acid and paracetamol on growth, physiological and biochemical aspects of Brassica napus L. under drought conditions

Drought stress poses a significant threat to Brassica napus (L.), impacting its growth, yield, and profitability. This study investigates the effects of foliar application of individual and interactive pharmaceutical (Paracetamol; 0 and 250 mg L−1) and amino acid (0 and 4 ml/L) on the growth, physiology, and yield of B. napus under drought stress. Seedlings were subjected to varying levels of drought stress (100% field capacity (FC; control) and 50% FC). Sole amino acid application significantly improved chlorophyll content, proline content, and relative water contents, as well as the activities of antioxidative enzymes (such as superoxide dismutase and catalase) while potentially decreased malondialdehyde and hydrogen peroxide contents under drought stress conditions. Pearson correlation analysis revealed strong positive correlations between these parameters and seed yield (R2 = 0.8–1), indicating their potential to enhance seed yield. On the contrary, sole application of paracetamol exhibited toxic effects on seedling growth and physiological aspects of B. napus. Furthermore, the combined application of paracetamol and amino acids disrupted physio-biochemical functions, leading to reduced yield. Overall, sole application of amino acids proves to be more effective in ameliorating the negative effects of drought on B. napus.