Manure Application Research Articles

Drought Adaptation Strategies Among Smallholder Cereal Farmers In Makueni County, Kenya

Increasing frequency and severity of drought increase vulnerability of smallholder cereal farmers globally. Arid and Semi-Arid Lands cover 80% of Kenya and location around the equator are major factors in drought development in the country. Frequent droughts result in fluctuations in cereal yields hence food insecurity in Makueni County. This study evaluated community-based and indigenous knowledge drought adaptations practiced by smallholder cereal farmers in Makueni County, Kenya. This study adopted explanatory sequential mixed methods research design. Household surveys (N=225) and key informant interviews (N=16) were used. Descriptive techniques were used in data analysis. The study found that frequent droughts in Makueni County resulted in adoption of small farm sizes for production of maize, sorghum and finger millet. Majority of the farmers produced between 1 and 10 bags of cereals. Majority (50.2%) of the smallholder cereal farmers who adopted community-based adaptations and indigenous knowledge-based drought adaptations strategies recorded an in increase in cereal yields in Makueni County. Early planting (66.7%), timely weeding (61.4%), manure application (57.0%), improving land tillage (56.1%), seed spacing (55.3%) and planting droughtresilient seeds (44.7%) led to the high annual cereal yields ranging between 1 and 10 bags in Makueni County. The drought adaptation strategies are commendable for upscaling in agro-ecological zones with similar climatic conditions in order to improve food production in the country. Information and data generated by this study is expected to result in improvement in drought adaptation policy formulation and adaptive capacity of smallholder cereal farmers hence, improvement in food production and security.

How Pharmaceutical Residues Occur, Behave, and Affect the Soil Environment.

Many pharmaceuticals (PhMs), compounds for the treatment or prevention of diseases in humans and animals, have been identified as pollutants of emerging concern (PECs) due to their wide environmental distribution and potential adverse impact on nontarget organisms and populations. They are often found at significant levels in soils due to the continuous release of effluent and sludge from wastewater treatment plants (WWTPs), the release of which occurs much faster than the removal of PhMs. Although they are generally present at low environmental concentrations, conventional wastewater treatment cannot successfully remove PhMs from influent streams or biosolids. In addition, the soil application of animal manure can result in the pollution of soil, surface water, and groundwater with PhMs through surface runoff and leaching. In arid and semiarid regions, irrigation with reclaimed wastewater and the soil application of biosolids are usual agricultural practices, resulting in the distribution of a wide number of PhMs in agricultural soils. The ability to accurately study the fate of PhMs in soils is critical for careful risk evaluation associated with wastewater reuse or biosolid return to the environment. The behavior and fate of PhMs in soils are determined by a number of processes, including adsorption/desorption (accumulation) to soil colloids, biotic (biodegradation) and abiotic (chemical and photochemical degradation) degradation, and transfer (movement) through the soil profile. The sorption/desorption of PhMs in soils is the main determinant of the amount of organic chemicals taken up by plant roots. The magnitude of this process depends on several factors, such as crop type, the physicochemical properties of the compound, environmental properties, and soil-plant characteristics. PhMs are assumed to be readily bioavailable in soil solutions for uptake by plants, and such solutions act as carriers to transport PhMs into plants. Determining microbial responses under exposure conditions can assist in elucidating the impact of PhMs on soil microbial activity and community size. For all of the above reasons, soil remediation is critical when soil pollutants threaten the environment.

The application of organic mulch and chicken manure for improving soil water availability and yield of turmeric (Curcuma domestica Val) in an Inceptisol of Jambi, Indonesia

Turmeric (Curcuma domestica Val) is one of the agricultural commodities being developed by the Jambi Province of Indonesia. However, despite the high value of turmeric, its productivity in Jambi Province is low. This is because the crop is mostly cultivated in marginal lands dominated by Inceptisol, which has low fertility and low water availability. Organic mulch and chicken manure have the potential to be used to improve soil water availability and crop yield. This research aimed to evaluate the effect of organic mulch cover and chicken manure on soil water availability and turmeric yield. The treatments tested were combinations of various percentages of organic mulch cover (30%, 60%, and 90%, and chicken manure dosage (0, 5, 10, and 15 t ha-1). The twelve treatment combinations were arranged in a randomized block design with three replications. The results showed that the combination of the percentage of organic mulch cover and chicken manure dosage affected soil organic matter content, soil bulk density, soil pore size distribution, soil water availability, and turmeric yield. The application of 30% cover of organic mulch and 10 t ha-1 of chicken manure was found to be the best combination to improve soil available water and turmeric yield. The regression analysis results showed that soil bulk density, organic carbon, fast-drainage pores, and slow-drainage pores simultaneously affected the soil water content, with an R2 value of 0.85. The results of this study proved that soil available water is also closely correlated with turmeric yield.

Organic manures reduce the bioavailability of fluoride in soil via different mechanisms

Fluoride (F) pollution in soils, which can be caused by long-term application of phosphate fertilizers, has serious socio-economic and ecological impacts. Therefore, it is important to find economically viable and environmentally friendly remediation technologies that mitigating the potential hazards of F-contaminated soil while maintaining crop yields. In this study, a soil incubation experiment was carried out to investigate the effects of two different organic manures at various amounts on soil F content and soil properties. We demonstrated that organic manure application at a rate of 5% was optimal to control the content of available fluoride (AE-F) in soil. Organic manure decreased the AE-F content and increased the residual or organically bound content. Furthermore, organic manure application also increased the contents of carbohydrates, proteins, and amides, which can anchor AE-F to the dissolved organic matter (DOM) in soil through physicochemical reactions, thereby reducing the migration of F. Moreover, after organic manure application, complex humus compounds were formed through microbial action, thus reducing the bioavailability of soil F. In summary, the application of organic manures can reduce the accumulation of soil AE-F, thereby reducing the absorption of F by crops in F-contaminated soil and alleviating the potential risk of F contamination.

Economic optimization of sustainable soil management: a Dutch case study

Soil quality is pivotal for crop productivity and the environmental quality of agricultural ecosystems. Achieving sufficient yearly income and long-term farm continuity are key goals for farmers, making sustainable soil management an economic challenge. Existing bio-economic models often inadequately address soil quality. In this study, we apply the novel FARManalytics model, which integrates chemical, physical, and biological indicators of soil quality indicator, quantitative rules on how these indicators respond to farmers’ production management over time, and an economic calculation framework that accurately calculates the contribution of production management decisions towards farm income. This is the first study applying this model on existing arable farms. FARManalytics optimizes crop rotation design, cover crops, manure and fertilizer application and crop residue management. Nine Dutch arable farms were analyzed with a high variation in farm size, soil type, and cultivated crops. First, we assessed farm differences in soil quality and farm economics. Second, we optimized production management to maximize farm income while meeting soil quality targets using farm-specific scenarios. Third, we explored the impact of recent policy measures to preserve water quality and to increase the contribution of local protein production. The results show that the case farms already perform well regarding soil quality, with 75% of the soil quality indicators above critical levels. The main soil quality bottlenecks are subsoil compaction and soil organic matter input. We show that even in front-runner farms, bio-economic modeling with FARManalytics substantially improves economic performance while increasing soil quality. We found that farm income could be increased by up to €704 ha−1 year−1 while meeting soil quality targets. Additionally, we show that to anticipate on stricter water quality regulation and market shift for protein crops, FARManalytics is able to provide alternative production management strategies that ensure the highest farm income while preserving soil quality for a set of heterogenous farms.

Effect of Winter Sowing and Different Fertilizer Sources on Physiological Parameters and Yield Components of Dragon’s Head (Lallemantia iberica Fisch. & C.A.Mey.)

The effects of autumn sowing and chemical, organic, and biological fertilizer sources were explored on yield components and physiological traits of dragon’s head (Lallemantia iberica Fisch. & C.A.Mey). The study was conducted as a factorial experiment based on a randomized complete block design with three replications in a field experiment in the 2017-2018 crop year. The fertilizer treatments included organic fertilizers (vermicompost, manure, and humic acid), biofertilizer (Thiobacillus mixed with sulfur), chemical fertilizer (macro NPK), and control (no fertilizer). The studied traits included seed yield per ha, harvest index, biological yield per ha, chlorophyll a, chlorophyll b, carotenoid, proline, and dissolved carbohydrate. The results of the comparison of the means revealed that the winter sowing outperformed the spring sowing evidently and increased traits like seed yield per ha, biological yield per ha, and harvest index significantly. The fertilization of the plants in both sowing seasons, especially in the winter sowing, increased seed yield per ha, biological yield per ha, and harvest index so that the vermicompost-fertilized winter-sown plants produced the highest seed yield per ha (0.91 g), whereas the application of manure was related to the highest harvest index in the winter sowing (27.9%). The highest biological yield (8797 kg ha-1) was related to the treatment of Thiobacillus of the winter-sown plants. Proline content was higher in the spring sowing plants, and the control treatment in the spring sowing had the highest proline content (0.120 mg g-1). Concerning dissolved carbohydrates, the spring sowing and the unfertilized plants had the highest content (20.3 mg g-1). On the other hand, chlorophyll a, chlorophyll b, and carotenoid were higher in the treatments of Thiobacillus and vermicompost, which resulted in achieving higher yields due to the increase in photosynthesis rate. According to the results, the winter sowing of the dragon’s head in the Azerbaijan region of Iran and the use of Thiobacillus and vermicompost could be recommended for obtaining plants with optimum quality parameters.

Appropriate Amount Application of Manure is Conducive to Improve Soil Aggregate Stability in Saline-Alkaline Soil: Analyzed from Soil Organic Carbon Mediated by Microbial Necromass Carbon

Appropriate Amount Application of Manure is Conducive to Improve Soil Aggregate Stability in Saline-Alkaline Soil: Analyzed from Soil Organic Carbon Mediated by Microbial Necromass Carbon

Различные формы Sr в агротемногумусовых подбелах юга Приморского края

To assess the concentration level and identify the main phase-carriers of various forms of strontium (Sr), the total content, distribution and concentration of water-soluble forms of the element in Albic Stagnosoils, which composed the bulk of the arable fund of the region under study, were studied. Full-profile soil pits were dug at the long-term fallow, phytoreclamative, and fertilized with mineral and organic fertilizer variants of the experience. The study of the different Sr forms contents was carried out by energy dispersive X-ray fluorescence spectroscopy and atomic absorption spectrometry. The main Sr volume was immobilized in the composition of soil mineral phase in soils of all variants of the experience. The addition of mineral fertilizers to soil was accompanied by an increase in the total content (by 6.4 %) and concentration of water-soluble (by 5,7 times) Sr forms, compared to the soil of fallow, and intensification of Sr sorption by Mn-containing soil compounds. The long-term addition of different types of organic fertilizers contributed to the activation of stable Sr-organic complexes formation. Under a green manure application in conditions of soil solution acidity decrease, the increase in the influence of Ca-containing soil compounds on the distribution of Sr has been shown. The soils of all variants of the experience were characterized by the absence of factors and conditions that contributed to the Sr accumulation in profiles, it was suggested by the lower total Sr content compared to the mean background content for surface soils around the world and to the mean content in agricultural soils in Japan.

EFFECT OF RABBIT MANURE AND ROW ARRANGEMENT ON CROP YIELD UNDER FINGER MILLET AND GROUNDNUT INTERCROPPING SYSTEMS IN A SEMI-ARID NIGERIA

Field trials were conducted at the Research and Training farm of the Centre for Dryland Agriculture, Bayero University Kano (Latitude 11º 58' N and Longitude 8º26' E and 475 m above sea level) and at community-based demonstration farm, Dawakin Kudu (Latitude 11º 84 N and Longitude 8º 59” E) Kano State, Nigeria during the 2019 rainy season, to investigate the effects of rabbit manure (RM) and row arrangement (RA) on finger millet and groundnut intercropping system. The treatments consisted of six row arrangements (1:1, 1:2, 2:1, 2:2, 2:4, and alternate stand) and four levels of rabbit manure (0, 1.5, 2.5, and 3.5 t ha-1) and one level of NPK fertilizer. The treatments were laid out in a split-plot design, with row arrangement (RA) occupying the main plot and rabbit manure (RM) occupying the sub plot, which were replicated three times. Findings revealed that Rabbit manure application significantly (P < 0.05) affected most finger millet and groundnut yield parameters, except for row arrangement which had minimal impact. The optimal rate of rabbit manure application depended on the specific parameter, location, and crop. For finger millet, application of RM increased spike weight, panicle weight, 1000-grain weight, and total grain yield at Dawakin Kudu but only affected spike weight at BUK. For groundnut, RM application increased the number of pods per plant, mean pod weight, and 100-kernel weight at Dawakin Kudu, while only affecting the number of pods per plant at BUK. Intercropping was generally more productive than sole cropping, with the most productive combinations varying by location. Therefore, it could be recommended for farmers in the Sudan savanna to consider the possible adoption of the application of rabbit manure at a rate of 2.5–3.5 t ha-1 to increase finger millet and groundnut yields.

Integrated disease management strategy for stem rot of rice caused by Sclerotium oryzae Catt

Stem rot of Rice caused by Sclerotium oryzae Catt was once thought to be a minor disease, is becoming one of the major constraints of rice production currently. An experiment was conducted in split plot design with manures, bio agents, fungicide in different treatments alone or integration at Agricultural Research station, Nellore, Andhra Pradesh for three rabi seasons of consecutive years (2019-2021). Pooled analysis of two years data revealed that among all the treatments application of farm yard manure @ 4t/ac+dhaincha @10kg/ac+ 2kg Trichoderma asperellum multiplied in 90 kg farm yard manure+10kg neem cake/ac applied to one acre through soil + two sprays of propiconazole 25EC @ 1ml/l with 15 days interval from booting to panicle emergence effectively managed the diseases with significantly least stem rot incidence (11.40%) and highest grain yield (8359 kg/ha).

Comparative analysis of manures and fertilizer on okra growth, yield and its economics in Baitadi, Nepal

Embracing organic techniques can minimize environmental impacts and promote practices that enhance soil and ecological health. A field experiment to study, “Comparative Analysis of Manures and Fertilizer on Okra Growth, Yield and its Economics in Baitadi, Nepal” was conducted at Gokuleshwor Agriculture and Animal Science College in 2023. The experiment was laid out in Randomized Complete Block Design (RCBD) with 3 replications and 7 treatments. The variety used in this experiment was ‘Arka Anamika’. The treatments used in the experiment were FYM, Goat manure, Poultry manure, Vermicompost, Sesame cake, RDF, and Control (no fertilizer). The fertilizer provided the necessary nitrogen, while the insufficient phosphorus and potassium were supplemented with single super phosphate and muriate of potash, respectively. Results revealed that the application of different fertilizers significantly affected various vegetative and reproductive parameters such as germination days, plant height, stem diameter, number of leaves, number of branches, number of buds, number of open flowers, number of pods, pod’s length, girth of pods, weight of pods and yield. The results obtained were minimum germination days(4.64) for RDF. Maximum plant height(208.43cm), maximum stem diameter(9.4cm), and number of branches(24.27) were obtained by application of poultry manure at 60 DAS. A maximum number of buds, open flowers, and pods were recorded in poultry manure and RDF application at 75 DAS. The maximum length of the pod(12.52cm) in vermicompost and the maximum girth of the pod(1.59cm) in poultry manure were obtained while the maximum wt. of the pod(14.1gm) in sesame cake. The application of poultry manure obtained a maximum yield per hectare(15.51t/ha). Also in the B: C ratio, Poultry manure exhibited higher(2.65) as compared to other treatments. From this study, we can conclude that poultry manure could contribute to the higher yield and overall attributes of okra.

Effect of different organic manures on the growth and yield of Zucchini in Khotang, Nepal

This experiment was conducted from February 2022 to May 2022 in ward no 1 of Diktel Rupakot Majuwagadi Municipality, Khotang district of Nepal to evaluate the efficacy of different organic manures in the growth and yield of zucchini in Khotang. We aimed to identify the most effective organic manure (goat manure, poultry manure, farm yard manure (FYM), vermicompost experiment, and control), and the research was carried out in a Randomized Complete Block Design (RCBD) with five treatments and four replications. The Cheongma variety of zucchini was used as a test crop. The recommended dose of manure (goat manure at 20 t/ha, poultry manure at 15 t/ha, FYM at 20 t/ha, vermicompost at 6 t/ha, and control) was applied to each treatment. There is no significant difference observed between treatments and vegetative parameters but a significant difference was found in yield. Furthermore, results showed that the highest yield was obtained from the field treated with poultry manure (1.84 kg), followed by FYM (1.40 kg) and 1.38 kg on vermicompost, respectively. The minimum yield was recorded at 1.09 kg from control, followed by goat manure (1.29 kg). The study by (Farhan, 2021; Eifediyi, 2010) found that the application of poultry manure and FYM significantly increased fruit yield and our research study also demonstrated the same findings.

Life cycle assessment of biochar and cattle manure application in sugar beet cultivation – Insights into root yields, white sugar quality, environmental aspects in field and factory phases

Sugar beet (Beta vulgaris L.) is a well-known sugar crop essential for supplying the global demand for sugar. Examining how different farming techniques affect the environment may help produce a high-quality crop with the least negative environmental effects. To this, the life cycle assessment (LCA) of biochar (B) and cattle manure (CM) applications at three different rates (5, 10, and 15 tons ha−1) compared with conventional chemical fertilization (CH) in the autumn and spring sugar beet crops has been studied. The system boundaries for LCA analysis were set from the cradle to the sugar factory gate. Based on the results, the highest amounts of root yield were obtained under CM10 and CM15 treatments with 24.5% and 23.2% increase in autumn cultivation and 34.8%, and 33.9% increase in spring cultivation, compared to CH. However, CM15 resulted in significantly lower sugar content (10.9%) than B5 (17%). Also, B utilization significantly reduced molasses content in sugar beet rather than CM in both cultivation periods. Further, biochar treatments (B5, B10, B15) significantly increased the white sugar yield in both cultivation times by 43.7%, 39.2%, and 36.1%, on average. Generally, the highest and the lowest global warming potential (GWP) were obtained from CM15 and B15 with 638.5 and 437.2 CO2-eq ton−1 root/sugar yields, respectively. These findings validate the hypothesis that using biochar in sugar beet production could reduce greenhouse gas emissions while increasing the amount of white sugar produced.

Effect of Soil Application of Organic Amendments on Flowering and Yield Parameters of Chilli (Capsicum annuum L.)

The present investigation was conducted at Department of Plant physiology, College of Agriculture, Vellayani during the period from January 2023 to May 2023 with an objective to evaluate the effect of soil application of organic amendments on flowering and yield parameters of chilli (Capsicum annuum L.). Research was conducted to identify the best organic soil amendment suited to the chilli variety, Vellayani Athulya. Work consisted of 8 treatments and 3 replications with the design simple CRD. The treatments were T1-Control 1 [KAU Organic POP (OPOP) (2017) with FYM (25 t ha-1)], T2-Control 2 [KAU POP (2016)], T3-FYM substituted with vermicompost (12.5 t ha-1) as per KAU OPOP (2017), T4 -FYM substituted with goat manure (1t ha-1) as per KAU OPOP (2017), T5 -T1+ Rice husk biochar (0.5% w/w), T6- T2+ Rice husk biochar (0.5% w/w), T7- T3+ Rice husk biochar (0.5% w/w ) and T8- T4+ Rice husk biochar (0.5% w/w). The results revealed that the treatment T8-FYM substituted with goat manure (1t ha-1) as per KAU Organic POP(OPOP) (2017)+ rice husk biochar (0.5% w/w) resulted in better flowering and yield attributes in chilli. Also the same treatment showed superior performance in terms of number of flowers plant-1 (44.67), days to first flowering (22 days), days to first harvest (41 days), percentage of fruit setting (64.18%), number of fruits plant-1 (28.67), fruit length (15.30cm), fruit girth (9.30cm), fruit weight (17.70 g fruit -1) and yield (507.41 g plant-1). Thus, the combined application of goat manure (1t ha-1) as per KAU OPOP + rice husk biochar (0.5% w/w) proved to be a better soil organic amendment for chilli variety Vellayani Athulya.

Influence of Different Cow Manure Application Rates on the Growth, Yield and Indigo Blue Color of Indigofera suffruticosa Mill

Background: Indigo is a key ingredient in the natural dyeing of fabrics. However, the conventional use of chemical fertilizers in indigo cultivation has led to an increase in production costs and soil degradation. Low-fertility soils further compromise the growth and yield of indigo plants. To address these challenges, employing manure is recognized as a sustainable approach for indigo cultivation. The use of manure enhances soil nutrient levels, improves soil structure and mitigates production costs. In this study, our objectives were to compare different rates of cow manure in relation to indigo growth, yield and the effect of cow manure rate on the value of indigo blue color. Methods: The experiments were carried out at the Plant Science Field from June to October 2022. Employing a randomized complete block design (RCBD), the study featured four treatments with four replications each. The treatments included: Treatment 1: no fertilizer (control); Treatment 2: cow manure at a rate of 3,125 kg/ha; Treatment 3: cow manure at a rate of 6,250 kg/ha; and Treatment 4: cow manure at a rate of 9,375 kg/ha. Data collection included plant height, canopy width, number of branches, plant weight, indigo blue weight and indigo blue color value. The CIE color system (Commission International de l’Éclairage) determined the color value. Result: The application of cow manure at a rate of 9,375 kg/ha resulted in the highest plant height and canopy width, with the corresponding number of branches of 150.73 cm, 46.45 cm and 31.73 cm, respectively. As compared to the other treatments, these values were statistically different. The color that was associated with the indigo finished product was dark blue and the yield; plant weight and indigo blue weight were recorded as 15,663.44 kg/ha and 2,540.44 kg/ha, respectively. The color value of indigo blue showed that the L* values of 24.94, a* -9.32, b* -2.44 and C* 9.63 were not significant but h* 194.66 was statistically significant.

Combined Application of Chemical Fertilizer and Organic Amendment Improved Soil Quality in a Wheat–Sweet Potato Rotation System

The long-term excessive use of chemical fertilizers may result in soil degradation, but manure and straw application is considered to be an effective approach for alleviating this problem. The aim of this study is to examine the long-term impacts of different fertilization patterns on soil quality variables in a wheat–sweet potato rotation system. Four treatments were conducted in a field trial for a duration of twelve years, including (1) no fertilizer (control, CK); (2) application of mineral fertilizers (NPK) alone; (3) NPK with crop straw return (NPKs); (4) combined use of NPK and farmyard manure (NPKm). Thirteen physical, chemical, and biological soil parameters were measured. The results showed that the NPKm and NPKs significantly improved the proportion of macroaggregates (>0.25 mm) by 24.7% and 21.9% compared to the NPK alone, respectively. The proportion of microaggregates (0.053–0.25 mm) under the NPKm was 47.4% significantly higher than the NPKs. Additionally, the NPKm resulted in a 22.2% and 19.6% increase in the SOC content than the NPK and NPKs, respectively. In terms of soil-available K, the NPKs resulted in levels that were 42.1% and 49.6% higher than the NPKm and NPK alone, respectively. Long-term fertilization significantly decreased soil pH by 0.95–1.85 units compared to the control, whereas manure application could alleviate soil acidification, as shown when the pH increased by 10.6–18.7%. The NPKm and NPKs resulted in significantly increased soil pHs by 10.6% and 18.7% compared to the NPK alone, respectively. In addition, the NPKm and NPKs increased N-acetyl-β-D-glucosaminidase activity by 52.6% and 60.3% compared to the NPK alone. Determined by the minimum data set method, the NPKm treatment exhibited the highest soil quality index, followed by the NPKs and NPK. Our findings suggested that the combined use of chemical fertilizers with organic amendments proved beneficial for enhancing soil quality.

Composting and Liquid Formulations: Panacea to Better Yield in Agriculture: A Review

Liquid formulations, including aqueous, oil, and polymer-based products, often use polysaccharides to alter fluid properties. Liquid inoculants offer cost-effective alternatives to solid carriers, particularly benefiting small producers in India by overcoming transportation and processing challenges. Ideal liquid inoculants are non-toxic, low-cost, uniform, nutrient-supplemented, and support rapid microorganism release and growth. Effective formulations stabilize organisms, ensure easy field delivery, protect against environmental factors, and enhance microbial activity. Rich in nutrients and organic matter, compost enhances the texture, structure, and moisture retention of soil, improving soil qualities and crop productivity. It boosts soil enzyme activity and microbial populations, promoting nitrogen fixation and nutrient availability. Organic manure applications increase soil fertility, water retention, and reduce bulk density. Field and horticultural crops, such as potatoes, chillies, and tomatoes, show significant yield improvements with compost, which also suppresses plant diseases and weed populations. These findings underscore the importance of adopting liquid formulations and composting as sustainable agricultural practices.

Effects of Organic Manure on Wheat Yield and Accumulation of Heavy Metals in a Soil—Wheat System

The application of organic manure is an effective way to develop sustainable agriculture. However, the application of organic manure may be associated with a potential risk of heavy metal pollution for soil and crops. In this study, the effects of organic cow manure (T1) (as base fertilizer), organic pig manure (T2) (as base fertilizer) and chemical fertilizer (T3) on winter wheat grain yields, grain quality, heavy metal concentrations and heavy metal bioconcentration factors (BCFs) in a soil–wheat system were studied from November 2021 to June 2023. The results showed that the winter wheat grain yields in the T1 and T2 treatments were lower than those in the T3 treatment by 2.57–38.0% and 10.5–25%, respectively. There were no significant differences in quality indexes of winter wheat grain among different fertilizer treatments. The concentrations of heavy metals in topsoil and winter wheat were 0.12–76.11 μg/g and 0.01–43.25 μg/g, respectively. The BCFs of heavy mental in the soil–wheat grain system was 0–2.92. In general, there were no significant differences in heavy metals’ concentrations in topsoil and wheat grain among different fertilizer treatments. In summary, compared with chemical fertilizer, the short-term application of organic manures had no significant effect on heavy metals concentrations in topsoil and wheat.

Dissipation of AM Nitrification Inhibitor in Soil Supplemented with Organic Amendments

ABSTRACT To examine the effect of organic amendments on the dissipation and nitrification inhibition activity of 2-amino 4-chloro 6-methyl pyrimidine (AM), a laboratory study was conducted on a sandy loam soil (Typic Hapludoll) receiving no organic amendments (Control) or application of farmyard manure (FYM) or pine needles biochar (PNB) @ 5 t ha−1. Dissipation of AM was initially faster during the first 7 d, and then it slowed down. Dissipation kinetics of AM conformed to the first-order model (R2 values = 0.973 to 0.981, significant at p ≤ .01). The conventionally estimated time for the dissipation of half the amount of initially detected AM (half-life) was 15.9, 23.6, and 12.1 d for the control, FYM, and PNB treatments, respectively. All treatments receiving AM had numerically lower NO3 −–N concentrations compared to no AM but significantly lower NO3 −–N concentrations were recorded under, especially the PNB + AM treatment at 15, 30, 45, 60 and 90 d. The higher effectiveness of AM under PNB could be attributed to the sorption of AM in the micro-pores of PNB with slower release. Percent distribution of sorbed AM onto FYM and PNB revealed that desorption of sorbed AM from PNB was comparatively very limited. FTIR spectra revealed that both FYM and PNB strongly retained AM. Application of AM @1 mg kg−1 soil (equivalent to 2.24 kg ha−1) seems to effectively retard the nitrification of urea in soil amended with PNB and help reduce the leaching losses of NO3 −–N in agriculture.

Responses of soil microbial metabolism, function and soil quality to long-term addition of organic materials with different carbon sources

Biochar and green manure have been widely applied in agricultural production and are important means to achieve sustainable agriculture. However, there is limited research systematically and comprehensively exploring the response of soil microbiota and the changes in soil metabolomics after the addition of two different carbon source amendments to the soil, and the differential mechanisms of soil metabolomics between them remain unclear. In this study, a long-term field experiment (initiated in 2019) was conducted to investigate the effects of biochar and green manure application on soil nutrients and soil functions driven by soil microbes. Compared to the pure fertilizer treatment, biochar increased soil total carbon by 14.54% to 27.04% and soil available potassium by 4.67% to 27.46%. Ryegrass significantly increased soil available phosphorus and organic matter. Under different fertilization regimes, the ecological niches of soil microbes changed significantly. Network analysis revealed that long-term ryegrass returning reduced the complexity of soil microbial networks. Ryegrass and biochar increased dispersal limitation in fungal assemblages (reaching 93.33% and 86.67%, respectively), with biochar particularly enhancing variable selection in bacterial assemblages (accounting for 53.33%). Variation partitioning analysis based on redundancy analysis indicated that humic substances had the highest explanatory power for microbial community variation, with humic substances explaining 38.49% of bacteria and 52.19% of fungi variation. The ryegrass treatment mainly changed the abundance of carbohydrates (CH), amines (AM), c (AH), and lipids (LP), while the BC treatment mainly altered the abundance of organic acids (AC), amines (AM), and carbohydrates (CH). Meanwhile, both treatments significantly reduced the bisphenol A, one of the soil pollutants. Ryegrass incorporation significantly increased the abundance of genes related to soil C, N, P, and S cycling, especially genes involved in carbon decomposition, while biochar significantly enhanced the abundance of nitrogen fixation genes nifH and Hao in soil. Random forest model results indicated that carbohydrates, alcohols, aromatics (AR), and ester (ES) were the main categories of metabolites in soil influenced by differential microbes, and Finegoldia served as a common important metabolic driving species. In summary, this study reveals the processes of soil function, microbial community succession, and metabolism driven by ryegrass and biochar, providing important insights for optimizing soil management and improving soil quality.Graphical