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Biochar for sustainable soil management

Organic and inorganic fertilizers are used primarily to increase nutrient availability to plants. Monitoring balanced versus unbalanced fertilization effects on soil microbes could improve our understanding of soil biochemical processes and thus help us to develop sound management strategies. The objective of this study was to investigate the effects of long-term fertilization regimes on soil microbial community functional diversity, metabolic activity, and metabolic quotient and to find out the main factors that influence these parameters. A long-term fertilization experiment established in a sandy loam soil at northern China has received continuous fertilization treatments for more than 20 years, including control, mineral fertilizers of NK, PK, NP, and NPK, organic amendment (OA), and half organic amendment plus half mineral fertilizer (1/2 OM). Top soil samples (0–15 cm) from four individual plots per treatment were collected for the analysis of chemical properties and microbial parameters. Microbial biomass C was analyzed using the fumigation–extraction method. Invertase activity and basal respiration were determined based on incubation method. Then, the microbial metabolic quotient was calculated as the ratio of basal respiration to microbial biomass C. To this end, microbial functional diversity was evaluated using the community level physiological profile method by Biolog Eco-microplate. Higher microbial biomass C, invertase activity, and basal respiration, but lower microbial metabolic quotient, were observed in P-fertilized soils, and OA had significantly greater (P < 0.05) impacts on the biomass, activity, and quotient compared with mineral fertilizers. Both the sole-carbon-source utilization activity and the functional diversity of soil microbial community were significantly increased (P < 0.05) by balanced fertilization (NPK, OA, or 1/2 OM), and species richness of community and relative abundance of the most common species in the K-deficient (NP) treatment were also significantly increased (P < 0.05). Principal component analysis and redundancy analysis showed that both organic and mineral fertilizers could affect microbial parameters by increasing soil organic C contents, and P was the key factor to increase soil microbial diversity and soil fertility. Long-term balanced fertilization greatly increased soil microbial biomass, functional diversity, and invertase activity and played an important role in decreasing soil microbial metabolic quotient, while P could be considered as the key factor to control soil microbial diversity as well as soil fertility. With regard to the different effects of OA and mineral fertilizer on soil organic C contents and root exudates, combined application of mineral and organic fertilizers is recommended in the region.

Organic and mineral fertilizers are widely used to address low soil fertility in increasing yield of tomato. The study was conducted at Tanzania Agricultural Research Institute, Makutupora, Dodoma in Tanzania to evaluate the effect of two organic fertilizers and their combinations with mineral fertilizers on improving tomato production and its subsequent nutrients availability in the soil for two consecutive cropping seasons of 2019/2020 and 2020/2021. Experimental treatments consisted of: - Organic fertilizers with; i) Chicken manure with effective microorganism alone, ii) Combination of chicken manure with effective microorganism and mineral fertilizer, iii) Cattle manure alone, iv) Combination of cattle manure and mineral fertilizer) Mineral fertilizers; Nitrogen, Phosphorus and Potassium (17:17:17), Calcium Ammonium Nitrate (27% N, 8% Ca), and control. The treatments were replicated thrice to a test crop Rio-Grande tomato variety in a complete randomized block design. Data were analyzed using Genstat version 15 software. The results showed a significant difference in fertilizers (p≤0.05) on the growth and yield of tomatoes where chicken manure with effective microorganisms resulted in taller plants than cattle manure. Combinations of chicken manure with effective microorganisms and mineral fertilizer resulted in a higher number of branches, clusters and fruits than the sole cattle manure or in combination with mineral fertilizers. Based on the results, this study, recommends the use of chicken manure with effective microorganism combined with mineral fertilizers for improved tomato fruit yield while maintaining high soil fertility.

A field experiment was conducted in Shiravan, Iran, during 2005 in order to investigate the effects of organic amendments, synthetic fertilizers and compost extracts on crop health, productivity and storability of commonly used tomato (Lycopersicon esculentum Mill.). Treatments included different fertilizers of cattle, sheep and poultry manures, house-hold compost and chemical fertilizers, and five aqueous extracts from cattle manure, poultry manures, green-waste and house-hold composts and water as control. The effect of fertilizer type on tomato yield and marketable yield was significant (P

Aqularia malaccensis or commonly known as ‘Gaharu’ is famous for its heartwood that is fragrant and highly valuable. Since 2018, the International Union for Conservation of Nature (IUCN) has reported a decline in the A. malaccensis population caused by agricultural and heartwood activities. Reforestation and transplanting of the A. malaccensis is essential to preserve the genetic diversity at the species level. Previous studies on the production growth of A. malaccensis have been focussing on using different types and fertilizer regimes to enhance its growth for conservation and restoration effort. However, knowledge on the potential of enhancing the growth of A. malaccensis using soil amendments derived from organic sources is limited. Therefore, this study aims to compare the effect of organic soil amendments derived from four different sources on the growth of A. malaccensis. Saplings of A. malaccensis were employed in a glasshouse experiment following a complete randomized block design with 5 treatments × 4 replicates to ensure validity and minimise variability within treatments. The five treatments were saplings grown with no addition of organic amendments serving as control (C), forest litter (FL), chicken manure (CM), insect frass (IF) and empty fruit bunch mixed with Azolla sp. (EFBA). The saplings grown in polybags were placed randomly on a 9 x 9 grid within the nursery, 0.2 m apart and watered daily using an automatic sprinkler system. Physical characteristics of the saplings and other environmental parameters were measured. The saplings of A. malaccensis increased in mean height when grown in soil amended with CM, IF and EFBA. In contrast, there were no significant effect of organic amendments of plant stem diameter, number of shoots and leaves. In addition, the stem diameter for saplings grown in soil with organic amendments were weakly and negatively correlated to soil temperature. This study indicated that that the organic soil amendments derived from different sources had a significant role in the plant’s resource allocation during the saplings stage. Further studies on the plant, organic amendments and soil physicochemical traits are needed to explain the interaction between these components for the better conservation effort.

به منظور بررسی اثرات کود‌‌های آلی و شیمیایی بر برخی ویژگی‌های کمی و کیفی چای ترش آزمایشی در قالب طرح بلوک‌های کامل تصادفی با 10 تیمار و 4 تکرار در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه زابل انجام شد. تیمار‌ها شامل: (T1) عدم مصرف کود (شاهد)، (T2) 300 کیلوگرم کود نیتروژن، فسفر و پتاسیم در هکتار به نسبت 2:1:1، (T3) 20 تن کود گاوی در هکتار، (T4) 10 تن کمپوست در هکتار، (T5) 5 تن ورمی‌کمپوست در هکتار، (T6) محلول پاشی اسید هیومیک به نسبت 5/1 در هزار، (T7) 50 درصد T2 + T6، (T8) 50 درصد T3 + T6، (T9) 50 درصد T4 +T6 و (T10) 50 درصد T5 + T6 بودند. نتایج نشان داد در اکثر صفات مورد بررسی اختلاف معنی‌داری بین تیمارهای اعمال شده و شاهد وجود داشت، به طوری که بیشترین مقدار ارتفاع و تعداد شاخه‌های جانبی و قطر ساقه در نتیجه کاربرد تیمار کودهای آلی توأم با اسید هیومیک (T8، T9 و T10) حاصل شد. تأثیر کود‌ کمپوست توأم با اسید هیومیک (T9) بر وزن‌تر و خشک کاسبرگ (31/157، 69/22 گرم در بوته)، تعداد میوه در بوته، وزن میوه، تعداد دانه در بوته، و در مورد میزان آنتوسیانین، تأثیر کود گاوی توأم با اسید هیومیک (T8) نسبت به سایر تیمارها بیشتر بود. نتایج این تحقیق نشان داد که کاربرد کودهای آلی در بهبود عملکرد کمی و کیفی گیاه دارویی چای ترش و همچنین در جهت پایداری تولید و حفظ محیط زیست تأثیر مثبتی داشته و به نظر می‌رسد کودهای آلی جایگزین مناسبی برای کودهای شیمیایی باشند.

Salvia (Salvia fruticosa Mill) is used in traditional medicine and in food and pharmacological industries, and as organically grown plants are preferred it is important to understand how organic soil fertilisation regimes affect the nutritional status and quality of the plant. To address this, an experiment was conducted testing the direct (in the first year) and residual (in the second year) effects of different organic nutrient inputs; control (C: untreated plants), farmyard manure (FYM), chicken manure (CM), vermicompost (VC), and spent mushroom compost (SMC). In the first year, N concentrations in the salvia were increased by 15%–46% and 8%–16%, at beginning of flowering and at full flowering, respectively, indicating a direct effect of the organic amendments. In the second year, the residual effects of the organic amendments increased N concentrations by 8%–37% at beginning of flowering. The organic amendments also affected concentrations of P at full flowering and caused increases of 6%–23% in the first year and by 6%–18% in the second year. Soil organic matter increased by 13%–16% as direct effects of the organic amendments and by 14%–24% as residual effects. Antioxidant activity, total flavonoid and phenolic concentrations of the salvia increased with applications of organic amendments. Total phenolic concentration and antioxidant activity were positively correlated with N, Mn and Mg and negatively correlated with K, Ca and P in the plant leaves. VC and SMC were the most effective amendments for enhancing total flavonoid content, antioxidant activity and plant nutrient concentrations.

Organic amendments supply essential nutrients to crops and act as effective soil conditioners. This study investigates the effects and mechanisms of organic amendments on soil physicochemical properties and microbial diversity, aiming to provide technical solutions for alleviating continuous cropping obstacles. A three-year field experiment was conducted with four types of organic amendments: biological organic fertilizer (BF), carbon-polymerized organic water-soluble fertilizer (CF), potassium fulvate from mineral sources (PF), and microbial fertilizer (MF). The control group received no organic fertilizer application. Results showed that compared to the control, organic amendments significantly increased soil organic matter and available nutrient contents, organic matter and available phosphorus under BF (22.5 and 43.2 mg/kg, respectively) showed increases of 129.6% and 53.7%, respectively. Similarly, available potassium in PF (286.6mg/kg) was elevated by 47.3%. Additionally, soil pH was increased (shifting from 5.4 to 6.0), thereby alleviating soil acidification. 16S rRNA and ITS sequencing revealed that organic amendments markedly influenced soil microbial abundance and diversity, increasing the relative abundance of beneficial bacteria (e.g., The abundance of Gemmatimonas rose from 10.0% in control to 19.2% in MF.) while suppressing pathogenic bacteria (e.g., The abundance of Ralstonia decreased from 10.5% in control to 2.5% in MF.). In terms of tobacco growth, organic amendments enhanced root length, surface area, volume, and branching number; Significant increases were observed in α-amylase activity (from 0.6 to 1.6 mg/min/g)) and nitrate reductase activity (from 0.15 to 0.21 U/g) in leaves following the treatment.; and reduced the incidence of bacterial wilt and black shank diseases. Specifically, BF, CF, PF, and MF achieved relative control efficacies of 66.7%, 56.0%, 44.0%, and 61.9% against bacterial wilt, and 66.0%, 52.6%, 42.3%, and 55.7% against black shank, respectively. In conclusion, the application of organic amendments can alleviate continuous cropping barriers by improving the soil micro-environment, promoting tobacco growth, and providing certain control over soil-borne diseases. Overall, the BF treatment showed the most comprehensive improvement effect, and to a lesser extent, PF and MF.

This trial was conducted under commercial field conditions in Dakhla Oasis, New Valley Governorate- Egypt, in order to investigate the influence of two irrigation systems (flood and drip irrigation), combinations of organic and inorganic fertilizers and different date palm (Phoenix dactylifera) cultivars (i.e. Barhi, Sagae. Khadry and Majdool) in sandy soil during the study season (2013 - 2014). Four different combinations of organic and mineral fertilizers were evaluated as compared to the control (i.e. 100% mineral). The treatments include (1)100% mineral; (2) 100% cattle manure; (3) 100% chicken manure; (4) 50% mineral plus 50% cattle and (5) 50% mineral plus 50% chicken manure. . All treatments were arranged in a split-split plot design with three replicates; irrigation systems were arranged in the main plot while the combination of organic and inorganic fertilizers were arranged in sub plot, and date palm cultivars were arrange in sub-sub plot. Vegetative growth parameters (Plant length and number of leaves) were measured as well as physical and chemical characteristics of soil before and after application were analyzed. The results showed that application of different organic manures to the sandy soil improved its physical properties including soil field capacity, wilting point conductivity as well as available water compared to the soil without organic manures (control). The chemical analysis of soil indicated that, flood irrigation led to decrease soil pH; the 100% of manure fertilizer decreased soil pH more than other fertilizers combinations. The cation exchange capacity (CEC) showed similar trend as that of pH. In contrast, the soil EC had different trend; the 100% mineral fertilizers gave the lowest EC values followed by 50% mineral plus 50% organic fertilizers; the highest soil EC was obtained by 100% cattle or chicken manure. The pH, CEC and EC of soil were higher under drip irrigation as compared to flood irrigation system. Date palm plant growth was influenced by increasing organic manure under irrigation system. Plant length and number of leaves per plant were increased by 50% mineral and 50% cattle under drip irrigation as compared to other treatments. The highest plant growth parameter was obtained by 50% mineral and 50% cattle combined with drip irrigation system for Majdool cultivar during the experimental season.

Understanding of relations and interactions between ecosystem’s components and plants is one of the main conditions for sustainable production of medicinal plants. To study the effect of simultaneous application of organic and biological fertilizers on yield and yield components of zucchini squash, a split plot arrangement of factors based on randomized complete block design with tree replications was used during 2009-10 growing season. The mainplot factor was the type of organic fertilizers, including 1-cow manure, 2-sheep manure, 3-chicken manure, 4-vermicompost and 5-control. The subplot factor was the biofertilizer (namely Nitragin, containing Azotobacter sp. , Azospirillum sp. and Pseudomonas sp.), utilization. The results showed the positive but non significant effect of organic and biological fertilizers on yield and yield components of zucchini squash. Amongst the organic fertilizers, cow and chicken manure, have superiority compared the others. The highest seed oil and protein percent resulted in chicken manure, although there was not significant different between treatments due to seed oil percent. The positive effect of organic and biological fertilizers on seed yield was higher than fruit yield. Positive correlations found between fruit and seed yield, and between one fruit weight and one fruit seed weight (R2=0.72** and 0.56**, respectively). At a glance, cow manure solely application was better than its application with nitragin. Nitragin application has no significant effect on some traits, when utilized with sheep manure and vermicompost. The possibilities of antagonistic effect among organic and biological fertilizers needs to be more studied.

Soil pollution with potentially toxic elements is a significant environmental problem worldwide. Such soils need reclamation, utilizing environmentally friendly and cost-effective techniques. Therefore, a study was performed with an aim to evaluate the effect of different organic amendments on bioaccumulation of potentially toxic elements in spinach grown on contaminated soils. For the experiment, soils from various mines (manganese mine (MM), chromite mine (CM), quartz mine (QM), and soap stone mine (SSM)) were amended with organic fertilizers including spent mushroom compost (SMC), vermicompost (VC), and leaf compost (LC). Spinach was grown in pots containing 5 kg growing media at 1:1:1 by weight (garden soil:mining soil:organic fertilizer). Results indicated that mining soils and organic amendments significantly affected plant growth and yield parameters and potentially toxic elements’ content in spinach. Organic fertilizers amendment reduced potentially toxic elements’ availability, increased spinach growth, and reduced their related health risk indices (HRI). Among organic fertilizers, VC was more effective in reducing uptake of lead (Pb), manganese (Mn), chromium (Cr), and cadmium (Cd) by 81%, 59%, 74%, and 45%, respectively; improving spinach growth and yield; and reducing HRI.

Organic fertilization can promote greater production of cladodes as well as increase phytomass production and the quality and content of bioactive compounds. Thus, the aim of this study was to evaluate the sources and doses of organic fertilizer on the production and quality of forage palm cladodes. A completely randomized experimental design in a 3 × 3 factorial scheme with five replications was used. Three sources of organic fertilizer (chicken manure, cattle manure, and goat manure) and three concentrations of each source (0, 10, and 20%) were studied. Cladodes fresh mass, pH, soluble solids, titratable acidity, soluble solids/titratable acidity ratio, ascorbic acid, chlorophyll, carotenoids, phenolic compounds, flavonoids, and anthocyanins were evaluated. Palm cladodes fertilized with 20% chicken manure produce the highest biomass, while cladodes fertilized with 10% chicken manure have the highest palatability and content of bioactive compounds. Thus, fertilization with 10% chicken manure is the most promising and economically viable way to increase the production and quality of palm cladodes. The research demonstrated that fertilization with chicken, cattle, and goat manure increases the productivity, nutritional quality, and palatability of the cladodes intended for human consumption, providing a sustainable and healthy alternative for the region.

To investigate the effect of typical manure application on soil microbes in paddy fields, a field experiment on manure application in Chongming Island was carried out. The composition and variety of soil microorganisms in rice paddy fields were analyzed using high-throughput theory (CK), chicken manure (CM), pig manure (PM), and organic fertilizer (OF). The results showed that compared with CK, the application of organic manure increased soil organic matter (SOM), and the application of chicken manure significantly increased the soil ammonia nitrogen (NH4+-N) and total nitrogen (TN) contents (P<0.05). Soil microbial diversity in the PM group was significantly higher than that in the CK group (P<0.05), and the soil microbial community richness in the OF group was significantly higher than that in the CM group (P<0.05). pH, total phosphorus (TP), total nitrogen, and Pb were the important factors affecting the composition of soil microbial communities in paddy fields. The microbial community structure in the CM group was significantly different from those in the other three groups. Compared with CK, the OF group increased the relative abundance of Nitrospira, and the CM group significantly reduced the relative abundance of the denitrifying bacteria Ignavibacteriae (P<0.01) to 40.56%, but significantly increased the relative abundance of nitrifying bacteria Thauera(P<0.05) to 203.00%. The PM group significantly increased the relative abundance of ammoniated bacteria Armatimonadetes (P<0.05) to 57.51% and the anaerobic strain Anaerolinea to 102.00%. The application of chicken manure and pig manure significantly increased the relative abundance of pathogens Pseudomonas and Flavisolibacter (P<0.05), respectively, while the application of organic manure reduced the relative abundance of Flavisolibacter. Overall, the application of manure increased the abundance of bacteria involved in the nitrogen cycle of paddy soils and played a positive role in regulating the nitrogen balance in paddy soils. However, direct application of chicken manure and fresh pig manure increased the abundance of pathogenic bacteria, which had a certain degree of stress on the soil health in the paddy field.

Biochar ( BC ) application to agricultural soil has been proposed as an effective countermeasure to mitigate climate change. A laboratory incubation experiment was carried out to gain insight into the effectiveness of BC on methane ( CH 4 ) consumption in a tropical clayey vertisol. Except for the control treatment, BC of two different sizes (&lt;0.25 or 0.25–2.00 mm) was mixed with vermicompost ( VC ), poultry manure ( PM ) or farmyard manure ( FYM ). BC and organic amendment were added to soil at 10% w/w and 80 kg N/ha, respectively. BC increased CH 4 consumption rate, k , in soil, irrespective of organic amendment type. The CH 4 consumption potential of soil was greater with the smaller size BC (&lt;0.25 mm). Of the three organic amendments, VC exhibited the highest k (0.105) followed by FYM (0.093) and PM (0.072). BC (&lt;0.25 mm) + PM was the most effective of the organic amendments in enhancing CH 4 consumption ( k = 0.242). The lag phase varied between 7.3 day (control) and 1.0 day (soil + VC ). Results revealed that there was a significant ( P &lt; 0.0001) effect of organic amendment and BC on CH 4 consumption, CO 2 production and microbial abundance. Cumulative CO 2 production (mg/g soil) varied between 2.15 (control) and 8.77 (soil + PM + BC &lt; 0.25 mm). Pearson's correlation analysis showed significant correlation between CH 4 consumption and methanotrophs abundance ( P &lt; 0.001). The study shows that BC enhanced CH 4 consumption potential in agricultural land on a tropical vertisol, particularly using the smaller size (&lt;0.25 mm), and could be an effective strategy to mitigate atmospheric CH 4 .

Application of organic waste products as amendments has been proposed as a management option whereby soil quality of Vertisols could be improved. An incubation experiment was, therefore, conducted for 4 weeks under controlled temperature conditions (30 degrees C) to identify those potential organic amendments that might improve the quality of a Vertisol. Twelve organic amendments were investigated: cotton gin trash from three sources, cattle manure from two sources, green waste compost, chicken manure from three sources including a commercial product, biosolids and two commercial liquefied vermicomposts. Except for the biosolids, no other organic amendments had any effect on soil microbial biomass and respiration. Compared with NO3-N levels in the control, there was a 50% decrease in soil amended with 10 t ha(-1) green waste compost (65 microg g(-1)). The three different types of chicken manures increased the NO3-N concentration from 75% (228 microg g(-1)) to 226% (424 microg g(- 1)) over the control. Approximate recovery of P added by the amendment as resin-extractable soil P was 53% for cattle manure and 39% for chicken manure. Application of cattle manure resulted in a 22% increase in soil-exchangeable K over levels found in control. Organic amendments application also resulted in a significant increase in exchangeable Na concentration. Some of the organic wastes, viz. cotton gin trash (10 t ha(-1)), cattle manure (10 t ha(-1)), biosolids (10 t ha(-1)) and composted chicken manure (3 t ha(-1)) have value as a source of nutrients to soil and hence showed potential to improve Vertisol properties.