B0 Treatments Research Articles

Biochar Improves Yield by Reducing Saline-Alkaline Stress, Enhancing Filling Rate of Rice in Soda Saline-Alkaline Paddy Fields.

Soda saline-alkaline stress significantly impedes the rice grain filling process and ultimately impacts rice yield. Biochar has been shown to mitigate the negative impacts of saline-alkaline stress on plants. However, the exact mechanism by which biochar influences the rice grain-filling rate in soda saline-alkaline soil is still not fully understood. A two-year field experiment was conducted with two nitrogen fertilizer levels (0 and 225 kg ha-1) and five biochar application rates [0% (B0), 0.5% (B1), 1.5% (B2), 3.0% (B3), and 4.5% (B4) biochar, w/w]. The results demonstrated that biochar had a significant impact on reducing the Na+ concentration and Na+/K+ ratio in rice grown in soda saline-alkaline lands, while also improving its stress physiological conditions. B1, B2, B3, and B4 showed a notable increase in the average grain-filling rate by 5.76%, 6.59%, 9.80%, and 10.79%, respectively, compared to B0; the time to reach the maximum grain-filling rate and the maximum grain weight saw increases ranging from 6.02% to 12.47% and from 7.85% to 14.68%, respectively. Meanwhile, biochar, particularly when used in conjunction with nitrogen fertilizer, notably enhanced the activities of sucrose synthase (SuSase), ADPG pyrophosphorylase (AGPase), starch synthase (StSase), and starch branching enzyme (SBE) of rice grains in soda saline-alkaline lands. Furthermore, rice yield increased by 11.95-42.74% in the B1, B2, B3, and B4 treatments compared to the B0 treatment. These findings showed that biochar improves yield by regulating ionic balance, physiological indicators, starch synthesis key enzyme activities, and the grain-filling rate in soda saline-alkaline paddy fields.

The Biochar Amendment Improves Tomato Growth and Yield under Deficit Irrigation in Sandy Loam Soil in Senegal.

Poor agricultural soil management practices and water use optimisation in irrigation are major challenges facing crop production in Senegal. To address these problems, a factorial experiment was conducted in 2021 and 2022 to investigate the effects of biochar on tomato growth and yield in sandy loam soil under different irrigation levels. Treatments included three biochar treatments (B2 = 30 t·ha-1, B1 = 15 t·ha-1, and B0 = 0 t·ha-1) and three irrigation levels (full irrigation, W0 = 8 L·m-2·day-1; medium deficit irrigation, W1 = 6 L·m-2·day-1, which is 75% of W0; and deficit irrigation, W2 = 4 L·m-2·day-1, 50% of W0). The results showed that using biochar at 30 t·ha-1 significantly (P < 0.05) reduced the bulk density of the soil by up to 8.3% under W1. In addition, biochar at 15 t·ha-1 and 30 t·ha-1 enhanced, regardless of the amount of water applied, the growth of tomato plants by at least 14% compared to that in the B0 treatment. Furthermore, the tomatoes' yields in biochar treatments B1 (12.58 t·ha-1) and B2 (12.45 t·ha-1) under W2 were greater than those under B0 (9.27 t·ha-1) under full irrigation. The combinations of biochar and the lowest irrigation water level (W2 and B1 or W2 and B2) can therefore allow a water economy of up to 50% of full irrigation without compromising yield. Our study concluded that biochar could sustainably reduce agricultural water consumption while increasing yields. To further understand the influence of biochar on sandy loam soil, more research is needed on its effects on soil moisture content at permanent wilting points and field capacity.

Effects of biochar treatments on the elemental composition of tobacco (Nicotiana tabacum L.) leaves based on the priming period

This study determined the effects of different doses of biochars (B) on Virginia tobacco (Nicotiana tabacum L.) cultivar, on first and second harvest dependent change in plant nutrients (N, P, K, Ca, Mg, Cl, Zn, Fe, Mn, Cu, and B), leaf color parameters (L*, a*, and b*), chlorophyll value (SPAD), electrolyte leakage (EL), crude ash, number of leaves, and plant height. Pot experiments were conducted with biochar treatments of 10 tons ha−1 (B1), 20 tons ha−1 (B2), 40 tons ha−1 (B3), and 80 tons ha−1 (B4). Tobacco leaf macroelement (N, P, K, Ca, and Mg) levels increased with increasing biochar doses. The highest values were obtained for B4 treatments (80 tons ha−1) and the lowest for control (B0) treatments. Microelements (Fe, Zn, Mn, and B) exhibited a non linear change, while Cl and Cu exhibited a linear change. Color parameters (L*, a*, and b*) for the first and second priming showed the highest L* and b* values for B2 and B3 treatments, respectively, and the highest a* values for the B2 treatment. Leaf SPAD values increased with increasing biochar doses; further, the obtained SPAD values were ordered as B4 > B3 > B2 > B1 > B0. Leaf electrolyte leakage values were 25.90 %–37.25 % in the first priming and 26.90 %–40.59 % in the second priming. For both the primings, the highest crude ash values (21.94 % and 19.05 %) were observed for the B4 treatments, whereas the lowest values (17.89 % and 17.01 %) were observed for the B0 treatments. the tallest plant height (121.9 cm) and the highest number of leaves (45.3) were determined in B4 applications. Overall, considering the nutrition and quality of tobacco, B2 application is recommended.

Effects of Biochar Application on Soil Bacterial Community Diversity and Winter Wheat Growth in Wheat Fields

A long-term field experiment was conducted to study the diversity of soil bacterial communities and the response of crop growth to biochar application, in order to provide a scientific basis for the rational application of biochar in agricultural fields. Four treatments were applied at 0 (B0 blank), 5 (B1), 10 (B2), and 20 t·hm-2(B3) to investigate the effects of biochar on soil physical and chemical properties, soil bacterial community diversity, and growth of winter wheat using Illumina MiSeq high-throughput sequencing technology. The results showed that soil water content, pH value, soil organic carbon, total nitrogen, nitrate nitrogen content, winter wheat biomass, nitrogen uptake, and yield showed an increasing trend with the increase in biochar amount. The high-throughput sequencing results showed that the B2 treatment significantly reduced the alpha diversity of the bacterial community at the flowering stage. The overall response of soil bacterial community composition to different application rates of biochar and phenological phases was taxonomically consistent. In this study, Proteobacteria, Acidobacteria, Planctomycetes, Gemmatimonadetes, and Actinobacteria were the dominant bacterial phyla. The relative abundance of Acidobacteria decreased, but the relative abundance of Proteobacteria and Planctomycetes increased with biochar application. The results of redundancy analysis, co-occurrence network analysis, and PLS-PM analysis indicated that bacterial community compositions were closely associated with soil parameters such as soil nitrate and total nitrogen. The average connectivity between 16S OTUs was higher under the B2 and B3 treatments (16.966 and 14.600) than under the B0 treatment. The variation in soil bacterial community (89.1%) was regulated by biochar and sampling period and partly explained the changes in the growth dynamics of winter wheat (0.077). In conclusion, biochar application could regulate the changes in the soil bacterial community and promote crop growth after seven years of application. It is suggested that 10-20 t·hm-2 biochar should be applied in semi-arid agricultural areas to achieve sustainable agricultural development.

Olive Yield and Physicochemical Properties of Olives and Oil in Response to Nutrient Application under Rainfed Conditions.

The effects of mineral fertilizers on the physicochemical properties of olives and oil under rainfed conditions is scarce. In this three-year study, the results of a nitrogen (N), phosphorus (P), potassium (K) and boron (B) fertilization trial carried out in a young rainfed olive grove and arranged as a nutrient omission trial are reported. The control consisted of the application of N, P, K and B (NPKB) and four other treatments corresponded to the removal of one of them (N0, P0, K0 and B0). Olive yield and several variables associated with the physicochemical properties of olives and oil were evaluated. The NPKB treatment increased olive yield compared to the treatment that did not receive N (N0). Although dependent on the climate conditions of the crop season, the NPKB treatment increased fruit weight and the pulp/pit ratio and its fruits tended to accumulate more oil than K0. However, the phenolics concentrations on fruits and oil tended to be lower. All olive oil samples were classified in the "extra virgin" category and all showed a decrease in its stability between 3 and 15 months of storage, regardless of treatment, especially in N0, P0 and B0 treatments. The results of the sensorial analysis indicate that all the oils fell into the medium fruitiness and greenly-fruity category. Only in P0 and B0 were defects detected, namely muddy sediment. Thus, this study seems to indicate the importance of N application, but also a balanced nutrient application and that further studies are needed, given the difficulty in finding clear trends in the response of measured variables to fertilizer treatments.

Effects of biochar combined with nitrogen reduction on the soil microbial community of rapeseed

ABSTRACT Excessive N critically depresses soil properties. Biochar has the potential to enhance soil health. A two-year field experiment was conducted to analyze the effects of biochar (0, 10, 20 and 40 t ha−1, namely, B0, B10, B20 and B40) combined with N (180, 144 and 108 kg ha−1, namely, N100, N80 and N60) on soil microorganisms. Results showed that B10 significantly promoted soil microbial biomass and had a strong correlation with most microbial groups, mainly reflected in a15:00, 10Me17:0, i18:0, i19:0, i16:0, 16:1w5c, 10Me18:0, 18:0 2OH and 18:00, while N60 decreased fungi and actinomycete content. Soil microbial functional activity was also significantly increased under B10 and B20 treatments and decreased under N80 and N60 treatments, compared to B0 treatment and N100 treatment, respectively. Microbial functional composition was also changed greatly by biochar, and B10 and B20 were closely related to most carbon sources. The combination of B10 and N80 significantly increased soil microbial biomass (total PLFA by 1.4 nM kg−1) and functional activity (Shannon index and Evenness index by 0.8%) compared with conventional N management (N100B0). Our findings reveal that biochar can achieve N reduction and enhance soil microbial diversity and community stability in purple soil regions of southwest China.

Biochar changed the distribution of imidacloprid in a plant–soil–groundwater system

The use of biochar has increased, as its physicochemical properties reduce the adverse effects of pesticides. However, few studies have comprehensively investigated the effects of biochar on the distribution of pesticides in a plant–soil–groundwater system. In this study, a biochar produced from rice straw at 550 °C was chosen, and column experiments with five rated of biochar application (application rates = 0.0, 1.0, 2.0, 3.0, and 4.0% w/w for B0–B4, respectively) were conducted to investigate the capacity of biochar to immobilize imidacloprid (IMI) in soil, thereby decreasing its uptake by plants and leaching from soil into groundwater. Our results showed that IMI in plants, leached from soil, and detected in soil accounted for 3.78, 1.76, and 36.4% of the total IMI input, respectively, and the biochar treatments dramatically decreased the IMI distribution to 0.57, 0.11, and 13.4%, respectively. By contrast, the percentage of undetected IMI increased from 58.1% in the B0 treatment to an average of 86.0% in the biochar treatments. Biochar treatments increased IMI immobilization in soil, which could be related to the increased soil carbon content, surface area, cation exchange capacity. This study indicates that biochar with characters of high surface area and porosity can stabilize IMI and reduce its potential to harm plants and groundwater.

Changes in the chemical characteristics of acid sulfate soil applied to oyster mushroom baglog waste compost

Acid sulfate soils are one of the potential lands for agriculture with appropriate treatment. The main problem in these soils is the chemical properties, which is high in acidity and limited nutrients availability and Fe and Al toxicity. Amelioration techniques are needed to improve the chemical properties of the soil, which is oyster mushroom baglog waste compost. This research aims to study the effect of oyster mushroom baglog waste (OMBW) compost to soil chemical properties, also to know the best dosage which affects chemical properties. The research was conducted at the greenhouse of the Agroecotechnology Department and the Laboratory of the Soil Department, Faculty of Agriculture, Lambung Mangkurat University, Banjarbaru. The research was started from August-October 2020. One-factor completely randomized design (CRD) with five treatments and five replications was used, the b0 treatment was not OMBW compost, b1 was 5 t ha-1, b2 was 10 t ha-1, b3 was 15 t ha-1, and b4 was 20 t ha-1. The application of the OMBW compost significantly affected the soil pH and decreased soluble-Fe and Al, but did not significantly affect the Eh value at 2 WAA (Week After Application). The best concentration of dose of OMBW compost was 10 t ha-1 which improved soil pH, decreased soluble-Fe and Al.

Biochar application enhances microbial interactions in mega-aggregates of farmland black soil

Soil microbial community diversity and composition are responsive to biochar application. However, the impacts of biochar application on soil microbial community structure and interactions in different aggregate fractions are poorly understood. We conducted a 3-year field trial involving biochar application to black soil in northeastern China. Four biochar treatments were applied: 0 (B0, control), 10 (B10), 30 (B30) and 50 (B50) t ha−1 biochar. Compared to the B0 treatment, biochar application significantly decreased the diversity of bacterial and fungal communities. In addition, biochar application significantly increased the relative abundances (RAs) of Bacteroidetes and Proteobacteria and significantly decreased those of Actinobacteria, Chloroflexi, Planctomycetes and Verrucomicrobia. Moreover, the B30 and B50 treatments significantly increased and decreased the RA of Nitrospirae, respectively. Moreover, the RA trends of Acidobacteria, Nitrospirae and Planctomycetes among different aggregate fractions was mega-aggregates (ME; > 2 mm) > macroaggregates (MA; 0.25–2 mm) > microaggregates (MI; < 0.25 mm); the RAs of Basidiomycota and Glomeromycota in ME were higher than those in MA and MI. The RA of Ascomycota in MI was the highest among the different aggregate fractions. The co-occurrence networks showed that the B30 treatment enhanced microbial interactions in terms of the number of links, average degree, and modularity, while the B50 treatment reduced these interactions. Additionally, co-inertia analysis demonstrated that the microbial interactions in ME were enhanced by biochar application. Thus, an appropriate biochar application (e.g., 30 t ha−1 used in the present study area) can enhance soil microbial interactions, especially in ME.

Effects of Biochar on Sediment Transport and Rill Erosion after Two Consecutive Years of Seasonal Freezing and Thawing

This research explored the effects of biochar on slope runoff and sediment transport processes and the hydrodynamic mechanism of rill erosion under the seasonal freeze–thaw climate in the black soil area of Northeast China. The four slopes of 1.8, 3.6, 5.4 and 7.2° were set, corn straw biochar was used, and three biochar contents of 0 kg m−2 (B0 treatment), 6 kg m−2 (B6 treatment) and 12 kg m−2 (B12 treatment) were applied. The experimental plot was placed outdoors to simulate the freeze–thaw cycle of sloping farmland under natural conditions. Three artificial simulated rainfall tests were carried out before the end of seasonal freeze–thaw cycles and spring sowing date (May) in 2018 and 2019. The sediment transport process of runoff and the variation of hydrodynamic parameters in rills were analyzed under one and two seasons of freezing and thawing in natural outdoor conditions. The results show that biochar has a positive effect on reducing rainfall runoff and soil loss after one year and two years of seasonal freezing and thawing. The effect of biochar on the sediment concentration of slope runoff increased with increasing application time; in the second year, the B6 and B12 treatments reduced the sediment concentration by 5.5–14.8% and 3.3–13.6%, respectively, compared with the values of the first year. The Reynolds number (Re) in the rill flow after the B6 and B12 treatments decreased with increasing duration, which effectively reduced the turbulence degree of the flow on the rill of the slope. With the increase in duration, the rill critical erosion power increased; in 2018 and 2019, the critical shear force, critical runoff power and critical unit runoff power were 0.403 Pa, 0.098 m s−1, and 0.002 N m−1 and 0.497 Pa, 0.124 m s−1, and 0.003 N m−1, respectively. This result indicates that increasing the duration and number of seasonal freeze–thaws can promote the development of biochar control of the runoff and sediment processes on slope and rill development.

Effects of biochar amendment on soil carbon dioxide emission and carbon budget in the karst region of southwest China

Knowledge about the influence of tobacco biochar (BC) on soil carbon dioxide (CO2) emissions and carbon (C) budget in a karst region of southwest China is limited. The karst field experiment was conducted in randomly arranged plots and evaluated five treatments: a plot without BC addition (B0), with 1.0 t BC ha−1 (B1C1), 10 t BC ha−1 (B10C10), 25 t BC ha−1 (B25C25) and 50 t BC ha−1 (B50C50). Soil CO2 emissions were assessed using closed chambers at 10-day intervals during a tobacco-growing season. Soil temperature and moisture were simultaneously measured at 5-, 10-, and 20-cm depths. BC amendment increased tobacco productivity, soil organic matter, total nitrogen, available phosphorus, and available potassium contents but decreased total sulfur content. Compared with the control (B0), daily average soil CO2 fluxes significantly increased by 20.0%, 26.3%, 39.4% and 50.2% in the B1, B10, B25, and B50 treatments, respectively. The cumulative soil CO2 emissions for the entire tobacco-growing season were significantly higher in BC amendments than in the control. Furthermore, soil CO2 fluxes were observed to be positively correlated with soil temperature but negatively correlated with soil moisture. Soil respiration sensitivity to temperature (Q10) significantly increased at greater soil depths, whereas decreased in BC-amended soils. Moreover, the BC amendments significantly increased C gain from −1.17 t ha−1 in the B0 treatment to 19.48 t ha−1 in the B50 treatment. Based on C budget, the increase in CO2 emissions in the BC-treated soil was compensated by the higher tobacco biomass and soil C storages. These results suggest that the application of tobacco BC to karst farmland enhances the soil C sequestration.

Effects of a Salicylic Acid Analog on Aphis gossypii and Its Predator Chrysoperla carnea on Melon Plants

The salicylic acid analog BTH (benzo-(1,2,3)-thiadiazole-7-carbothioic-acid S-methyl ester) induces systemic acquired resistance by promoting plant resistance against numerous plant pathogens and some insect pests. The objective of the research was to evaluate the activation of plant defenses with BTH on melon (Cucumis melo L., Cucurbitaceae) and its effects on the herbivore Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) and on the aphid predator Chrysoperla carnea (Stephens, 1836) (Neuroptera: Chrysopidae). Under laboratory conditions, plants were sprayed with BTH (50 g/ha) zero (B0), four (B4), and seven (B7) days prior exposure to insects. B0 treatment resulted in 100% mortality of aphid nymphs and disrupted adult feeding behavior (recorded by electrical-penetration-graphs technique), by prolonging the time to reach the phloem, requiring more probes to first salivation and reducing ingestion activities. There were no effects on feeding behavior of A. gossypii fed on B4 plants but on its life history because fewer nymphs were born, intrinsic rate of natural growth decreased, and mortality increased. There were no effects on biological parameters of aphids reared on B7 plants. Prey consumption by C. carnea larvae when predated A. gossypii fed on BTH-treated plants was not different among treatments. Therefore, BTH enhances the suppression of A. gossypii in the short term, without negative effects on the predatory larva C. carnea, which makes this plant strengthener a useful tool to be considered in integrated pest management programs.

Archaeal and methanogenic communities in the rice field under different fertilizer applications

Abstract. Fatma YS, Rusmana I, Wahyudi AT, Hamim. 2019. Archaeal and methanogenic communities in the rice field under different fertilizer applications. Biodiversitas 20: 3667-3675. The archaeal community in the soil surrounding rice roots plays key roles in biogeochemical cycles. Methanogenic archaea contribute to CH4 production in the rice field and control CH4 emission rates; an important greenhouse gas significantly emitted from the rice field. Characteristic of archaeal and methanogenic community in Indonesian rice field has not been well documented. In this study, rice plants grown in the rice field were treated with two different fertilizer applications, i.e., 100% urea without biofertilizer (250 kg ha-1) (B0), and 50% urea (125 kg ha-1) with biofertilizer consisted of methanotrophic bacteria and N2O-reducing bacteria (B1). Soil archaeal community of the two types of fertilization was characterized over the rice-growing period using 16S rRNA amplicon sequencing. The succession and dynamic of the archaeal population were detected in each of the two treatments before fertilizer application (0 days after transplanting [DAT]) until the rice generative phase (69 DAT). During the period, the archaeal soil community in both treatments was dominated by Crenarchaeota. The relative abundance of putative methanogens was higher in the B0 treatment than that of B1 treatment. Within the methanogenic community, Methanosarcinaceae and Methanomassiliicoccaceae which found as most dominant group in both treatments were presumably to be important contributors to CH4 emission. The application of 50% urea with biofertilizer (B1) changed the structure of the archaeal and methanogenic community in the rice field compared to the application of 100% urea (B0).

Interactions between biochar and nitrogen impact soil carbon mineralization and the microbial community

Adding biochar (BC) to soils is proposed to enhance carbon sequestration in agricultural soils. However, there is limited knowledge regarding the effects of the interactions between BC and nitrogen (N) on soil organic carbon (SOC) mineralization at an interannual scale. We conducted a three-year field experiment to systematically reveal the impacts of BC combined with N fertilizer on a silty clay soil, including its physicochemical properties, soil respiration characteristics and microbial community. BC applied once at 0, 20 and 40 t ha−1 (B0, B1 and B2, respectively) was combined with three N fertilization levels (0, 120 and 240 kg N ha−1; N0, N1 and N2, respectively). Only winter wheat (Triticum aestivum L.) was cultivated, and it was cultivated in a winter wheat-summer fallow crop system. BC application persistently increased the SOC content by 36.3–91.6% over three years. Several soil parameters were also improved by BC combined with N after one year, such as bulk density, NO3- and available P content. Compared with its values with B0 treatments with N1 or N2, the total soil CO2 emitted decreased by 6.7–8.9% in response to BC combined with N1 but increased by 5.9–7.5% in response to BC combined with N2. B1N1 not only significantly increased microbial biomass but also decreased qCO2. In addition, B1N1 in particular increased the relative abundances of members of the microbial population associated with increased microbial C use efficiency, such as Rhizopus and Helotiaceae. However, B2N1 and B2N2 strongly disturbed the soil microbial ecosystem; moreover, the lowest alpha diversity of the bacterial community was observed in B2N2 soils. In summary, adding BC at a high rate to N-fertilized soil strongly disturbs the soil microbial ecosystem and reduces the C-sequestering potential of soil, while B1N1 treatment is recommended to enhance soil C sequestration and improve soil fertility under dryland farming.

Substitution of mineral fertilizers with biogas digestate plus biochar increases physically stabilized soil carbon but not crop biomass in a field trial

Various organic amendments are scrutinized as potential agricultural management strategies to ensure soil productivity while mitigating climate change due to the accumulation of soil organic matter (OM). The objectives of this experiment were to study the effects of biochar and biogas digestate versus mineral fertilizer on crop aboveground biomass as well as fractions and mineralization of soil organic carbon (SOC). Samples of a sandy Cambisol were taken 14 months after establishment of a field experiment in Germany. Treatments included application of equal nitrogen in the form of mineral fertilizer or liquid biogas digestate without biochar (B0), with 1 Mg biochar ha−1season−1 for two growing seasons (B2), or with 40 Mg biochar ha−1 application (B40). Soil fractionation in water separated water-extractable and free particulate (fPOM) OM, followed by sonification and sieving to isolate occluded particulate (oPOM) and < 20 μm aggregate-occluded and mineral-associated OM. CO2 emissions were measured during 92-day laboratory incubations at 10 and 20 °C. Analysis of variance found digestate lowered (p < 0.05) rye aboveground biomass compared to mineral fertilizer (9.3 vs. 10.6 Mg ha−1), while biochar had no effect. B40 treatments increased C mineralization during incubation by 16% and contained 3.8 times more SOC than B0 treatments. This additional SOC was allocated to fPOM (52%), oPOM (22%), and the <20 μm fraction (26%). Digestate application increased SOC content of oPOM by 11% compared to mineral fertilizer. Furthermore, combined application of 40 Mg biochar ha−1 with digestate resulted in 20% more SOC in the <20 μm fraction than biochar with mineral fertilizer. The lack of a significant fertilizer or biochar-fertilizer interaction effect on C mineralization during incubation demonstrates the stability of SOC from digestate alone or in combination with biochar. The absence of significant differences in SOC content between B0 and B2 treatments demonstrates the difficulty of documenting SOC sequestration in the field at low biochar application rates.

Effect of Organic Decayed Material (or Bokashi Fertilizer ) and Varietas on the Grwoth and Yield of Sweet Corn ( Zea mays saccharata Sturt).

The aims of research were to determine the effect Bokashi fertilizers and varietas as well as their interaction on the growth and yield of sweet corn, and to determine the proper dosage of Bokashi fertilizer to produce maximum production on certain varieties.The research was conducted starting from March 2016 to July 2016, from land preparation up to the last data collection. It was carried out at Jl. Pendidikan, North Sangatta sub district, East Kutai District. The research using Random Block Design (RBD), with 2 factorial and 3 replications. The first factor was Bokashi Fertilizers (B), consisting of four levels, namaly : no Bokashi application or control (b0), 10 tons/ha equal to 3,5 kg/plot (b1), 15 tons/ha equal to 5,25 kg/plot (b2), and 20 ton/ha equal to 7 kg/plot (b3). The second factor was the maize varieties (V), consisting of there varieties, namaly : Bonanza F1 (v1), Sweet Boy (v2), and Sweet Corn (v3).Results of the research showed that the Bokashi fertilizer treatment has no significant effect on the age of male flowers and female flowers emerge. But it had significant effect on the production of cobs per hectare. And it had very significant effect on the plant height at ages 15 days, 30 days and 45 days affer planting, cob lenght and cob diameter. The highest cobs production was attained at the b1 treatment with 7,68 tonnes/ha, while the lowest one was attained at the b0 treatment with only 7,48 tonnes/ha.Treatment of varieties did not affect significanttly on the plant height at ages of 15 days, 30 days and 45 days after planting, age of male flowers and female flowers emerge, cob length, cob diameter and production of cobs per hectare.Interaction treatment had no significand effect on the plant height at ages of 15 days, 30 days and 45 days after planting, age of male flowers and female flowers emerge, cob lenght, cob diameter and production of cobs per hectare.

Persistent effects of biochar on soil organic carbon mineralization and resistant carbon pool in upland red soil, China

Biochar as a soil ameliorant has generated great interest for scientists in improving soil quality and carbon sequestration. The objective of this study was to investigate the persistent effects of biochar application on soil organic carbon (SOC) mineralization and soil-resistant carbon (Cr) in upland red soil. This experiment was conducted from September 2011 to May 2016. Biochar was applied only once in September 2011 at rates of 0, 2.5, 5, 10, 20, 30 and 40 t/ha in the field experiment, designated as treatments B0, B1, B2, B3, B4, B5 and B6. The chemical properties, dynamics of SOC mineralization and soil-resistant carbon (Cr) were measured at the 1st and 6th year after biochar application. The results were as follows: biochar application at rates of 30 and 40 t/ha (B5 and B6 treatments) distinctly increased soil pH value and available P relative to B0 in 2011. The pH value, available P, SOC, total N and C/N ratio in B4, B5 and B6 treatments were significantly higher compared with the B0 treatment, where the B6 treatment increased the pH value by 0.80 and C/N ratio by 3.88 while increasing available P, SOC and total N by 24.18, 76.29 and 19.78%, respectively, compared with the B0 treatment in 2016. The cumulative SOC mineralization (Cm) occupied around 4.62–6.91% of total organic carbon (Ct), which showed a declining trend in 2016 as compared to 2011. The Cm/Ct ratio also showed a declining trend with biochar amendment at both samplings. The Cr occupied around 26–46% of SOC and showed obviously increasing trends both in 2011 and 2016. We further found that Cm/Ct showed highly significant (p < 0.01) negative correlations with the rates of biochar application both in 2011 and 2016. The Cr, however, showed very significant (p < 0.01) positive correlations with the rates of biochar application both in 2011 and 2016. This study suggested that biochar application to upland red soil persistently improved soil properties and resistant carbon. Cumulative SOC mineralization was clearly restrained by biochar amendment. This study can provide scientific support for improving soil fertility and enhancing carbon sequestration by application of large amount of biochar (40 t/ha) in upland red soil.

Biochar application constrained native soil organic carbon accumulation from wheat residue inputs in a long-term wheat-maize cropping system

An understanding of the influence of biochar on soil organic carbon (SOC) formed from different carbon (C) sources, other than biochar, at field scale is required to accurately assess and predict the C sequestration potential of biochar. For this study, we set up a field experiment in 2009, including four treatments (i.e. B0, B30, B60, and B90, where the biochar application rates were 0, 30, 60, and 90tha−1, respectively). We then assessed the impact of biochar after five years (i.e. in 2014) on native SOC derived from C3 (wheat) and C4 (maize) crop residues, and also changes in relatively labile and stable SOC fractions. After five years, the content of native SOC derived from crop residues increased by 81% (from 4.32 to 7.84gkg−1) in the B0 treatment, while the increases of native SOC were relatively lower in the B30 (61%), B60 (43%), and B90 (26%) treatments. Thus biochar decreased the content of native SOC compared to the B0. Additionally, biochar decreased “labile pool I” (first-step, weak acid hydrolysable) of native SOC by 11.2–47.7%, compared to the B0, but did not influence “labile pool II” (second-step, strong acid hydolysable) and “recalcitrant pool” (acid non-hydolysable). Using the natural abundance 13C, our results showed that 62–74% of the native SOC was derived from wheat across all the treatments. Biochar application decreased the contribution of wheat-derived C to native SOC by 14.7, 29.0, and 41.5% in the B30, B60, and B90 treatments, respectively, while the content of maize-derived native SOC did not change, relative to the B0. In conclusion, although wheat-derived native SOC was higher than maize-derived native SOC, biochar application decreased the contribution of wheat residue to native SOC, possibly by enhancing its degradation, thus decreasing wheat-derived native SOC storage in an agricultural system.