Ha-1 Biochar Research Articles

Impact of supplemental irrigation and organic manure on growth and yield performance of rice variety BRRI dhan103 under terminal drought condition in Aman season

BRRI dhan103 is a transplanting Aman (T. Aman) rice variety that demands sufficient organic manure and supplemental irrigation to ensure successful production. Seven treatments, viz., T1= rainfed control; T2= one supplemental irrigation at 80 days after transplanting (DAT); T3= two supplemental irrigations at 70 and 80 DAT; T4= additional 5 t ha-1 poultry compost under rainfed condition; T5= additional 10 t ha-1 poultry compost under rainfed condition; T6= additional 2.5 t ha-1 biochar under rainfed condition; and T7= additional 5 t ha-1 biochar under rainfed condition, were evaluated against BRRI dhan103 to assess the impact of supplemental irrigation and manuring under terminal drought conditions. It was revealed that supplemental irrigation and manuring significantly improved all growth parameters and yield attributes compared to the rainfed control. Notably, T5 treatment provided its greatest performance statistically in respect of SPAD value (36.13), root dry weight (12.43 g), number of tillers hill-1 (13.22), panicle length (28.87 cm), panicles hill-1 at harvest (9.13), total spikelet (194.53), spikelet panicle-1 (197.63), filled spikelet panicle-1 (197.63), thousand grain weight (33.78 g), grain weight panicle-1 (28.70 g), grain yield hill-1 (31.97 g), and above-ground biological yield (3043.35 g m-2). The highest tiller hill-1 at harvest (9.53) was achieved when an additional 10 t ha-1 of poultry compost was applied under rainfed conditions. This study suggested that additional 10 t ha-1 poultry compost under rainfed conditions performed best to enhance the growth and yield of BRRI dhan103.

Lactuca sativa Growth and Yield as Affected by Cashew Nut Shells Biochar, Cattle Manure and Urea in Northern and Central Benin

Aims: This study aims to identify good combinations of cashew nut shell biochar, cattle manure, and urea for enhancing lettuce (Lactuca sativa L.) growth and yield in the North and Central regions of Benin. Place and Duration of Study: Two agronomic trials were conducted: one in Tchaourou, Borgou department (2022), and another in Dassa, Colline department (2023). Methodology: A Fisher experimental design with three replications was used at each site, focusing on fertilization with seven treatments, including four reference treatments (local practices) and three treatments based on the reference treatments with biochar incorporation. Results: The results demonstrated significant improvements in plant growth parameters and yield, with the application of biochar combined with cattle manure and urea or with cattle manure only. The plants leaves number, height and yields obtained from the application of 10 t ha⁻¹ biochar + 20 t ha-1 cattle manure and 10 t ha-1 biochar + 0.025 t ha-1 urea +10 t ha-1 cattle manure were respectively at least 165 and 318%; 25 and 50%; 42 and 91% higher than those obtained under the producer's mineral fertilization practice at both sites. Conclusion: The findings showed that integrating cashew nut shell biochar with organic and inorganic fertilizers can significantly enhanced lettuce production, and thus overall vegetable crop yields while reducing the need for mineral fertilizers and dependence of cattle manure. Additionally, studying the best application methods and rates for different soil types and crop systems can help in maximizing the benefits of biochar.

Efektivitas Bahan Pembenah Tanah pada Dinamika Fosforus dengan Perunutan Isotop 32P dan Hasil Jagung di Ultisol Jasinga

Soil conditioners can accelerate the recovery of soil physical, chemical, and/or biological quality, thus optimizing soil productivity. The 32P isotope tracing technique was used to determine the contribution of P from soil amendments in the form of lime, biochar, and compost, as well as to study their effects on P fertilization efficiency and corn yield. The treatments included lime, biochar, compost, and combinations of these three materials. The parameters analyzed were corn yield and P contribution from P sources. This study aimed to evaluate the ability of soil amendments to increase P uptake, growth, and yield of corn, as well as to determine the P contribution from lime, biochar, and compost to corn plants using the 32P isotope tracing technique. The results on Ultisol soil from Jasinga, Bogor, showed that the combination of 3 t ha-1 lime + 15 t ha-1 biochar + 15 t ha-1 compost resulted in the highest grain weight of 45.942 g per plant; the contribution of P from the carrier materials to the grain of the combination of 3 t ha-1 lime + 15 t ha-1 biochar + 15 t ha-1 compost was 44.945 mg per plant. In conclusion, the combination of these soil conditioners can increase P availability and corn production on Ultisol soil from Jasinga, Bogor. Keywords: soil conditioner material, 32P isotope tracer technique, Ultisols

A coffee biochar-mineral NP interaction: Boon for soil health

Low soil fertility, attributed to a deficiency in multiple nutrients, is causing a decline in the productivity of potatoes (Solanum tuberosum) in the Gawata district of southwestern Ethiopia. To address this issue, a field experiment was conducted during the Belg season (February to May) and Meher season (June to October) of the year 2024. The objective was to assess the response of potatoes to the combined application of nitrogen, phosphorus, and coffee biochar (BC) in relation to specific soil physico chemical properties under rainfed conditions. The treatments comprised various combinations of biochar (2.5, 5, 7.5 t ha-1) and inorganic NP (25, 50, and 75%) of the recommended dose (165 kg N ha-1 + 60 kg P ha-1 = 100% recommended dose of fertilizer, RDF), along with 20 t ha-1 of biochar and 100% inorganic NP, with a no-fertilizer treatment serving as the control. In total, there were 12 treatments and a randomized complete block design with three replications was employed for the experiment. The results indicated that the combined application of 75% inorganic NP and 7.5 t ha-1 of biochar significantly increased pH, organic carbon, total nitrogen, available phosphorus, cation exchange capacity, and exchangeable calcium and magnesium. Additionally, it reduced bulk density, exchangeable acidity, exchangeable aluminum, and exchangeable potassium compared to the values obtained from the initial soil test. Consequently, it was concluded that the integrated use of 7.5 t ha-1 of biochar and 75% of inorganic NP during the Belg season, or 25% of it during the Meher season, represents an optimal nutrient management strategy for potato production in the study area.

Investigating the Effects of Banana-Derived Biochar and Straw Residues on Growth and Yield of Maize (Zea Mays L.) Crop

Biochar application with straw residues can enhance their rate and increase the availability of nutrients for maize crop under field conditions. Therefore, this present study was primarily aimed at exploring the combined effect of banana derived biochar and straw residues application on the biomass production and the yield components of maize crop. The experimental study was consisting of six treatments: T-1 control, T-2 Biochar (40 ha-1), T-3 12.5 tons ha-1 straw residues, T-4 25 tons ha-1 straw residues, T-5 40 tons ha-1 biochar + 25 tons ha-1 straw residues, T-6 40 tons ha-1 biochar + 12.5 tons ha-1 straw residues. Results displayed that combine application of Biochar (40 tons ha-1) and straw residues (25 tons ha-1) enhanced the shoot fresh biomass (208%), Root fresh biomass (85%), Root length (85%), Number of grains per cob (262%), Seed index (68%), cob length (79%), grain yield (120%) and leaf area (80 %) as compared to control. While, 40 tons ha-1 biochar + 12.5 tons ha-1 straw residues increased shoot fresh biomass (197%), root fresh biomass (57%), root length (41%), number of grains per cob (220%), seed index (37%), cob length (69%), grains yield (103%) and leaf area (64%) in comparison to control. Most of the growth parameters were positively correlated with yield components. Similarly, correlation coefficient indicated significant association among different morphological characteristics when subjected to these combined applications of biochar and straw residues. Hence, this study concluded that combine application of banana biochar and straw residues promoted the grain growth and yield of the maize crop under field condition.

Optimizing biochar application for enhanced cotton and sugar beet production in Xinjiang: a comprehensive study.

Optimizing biochar application is vital for enhancing crop production and ensuring sustainable agricultural production. A 3-year field experiment was established to explore the effects of varying the biochar application rate (BAR) on crop growth, quality, productivity and yields. BAR was set at 0, 10, 50 and 100 t ha-1 in 2018; 0, 10, 25, 50 and 100 t ha-1 in 2019; and 0, 10, 25 and 30 t ha-1 in 2020. Crop quality and growth status and production were evaluated using the dynamic technique for order preference by similarity to ideal solution with the entropy weighted method (DTOPSIS-EW), principal component analysis (PCA), membership function analysis (MFA), gray relation analysis (GRA) and the fuzzy Borda combination evaluation method. Low-dose BAR (≤ 25 t ha-1 for cotton; ≤ 50 t ha-1 for sugar beet) effectively increased biomass, plant height, leaf area index (LAI), water and fertility (N, P and K) productivities, and yield. Biochar application increased the salt absorption and sugar content in sugar beet, with the most notable increases being 116.45% and 20.35%, respectively. Conversely, BAR had no significant effect on cotton fiber quality. The GRA method was the most appropriate for assessing crop growth and quality. The most indicative parameters for reflecting cotton and sugarbeet growth and quality status were biomass and LAI. The 10 t ha-1 BAR consistently produced the highest scores and was the most economically viable option, as evaluated by DTOPSIS-EW. The optimal biochar application strategy for improving cotton and sugar beet cultivation in Xinjiang, China, is 10 t ha-1 biochar applied continuously. © 2024 Society of Chemical Industry.

Biochar and Manure Co-Application Increases Rice Yield in Low Productive Acid Soil by Increasing Soil pH, Organic Carbon, and Nutrient Retention and Availability.

In recent years, overuse of chemical fertilization has led to soil acidification and decreased rice yield productivity in southern China. Biochar and manure co-application remediation may have positive effects on rice yield and improve acid paddy soil fertility. This study was conducted to understand the effects of co-application of wood biochar and pig manure on rice yield and acid paddy soil quality (0-40 cm soil layers) in a 5-year field experiment. The experiment consisted of six treatments: no biochar and no fertilizer (CK); biochar only (BC); mineral fertilizer (N); mineral fertilizer combined with biochar (N + BC); manure (25% manure N replacing fertilizer N) combined with mineral fertilizer (MN); and manure combined with mineral fertilizer and biochar (MN + BC). Total nitrogen application for each treatment was the same at 270 kg nitrogen ha-1y-1, and 30 t ha-1 biochar was added to the soil only in the first year. After five years, compared with N treatments, N + BC, MN, and MN + BC treatments increased the rice yield rate to 2.8%, 4.3%, and 6.3%, respectively, by improving soil organic matter, total nitrogen, and available phosphate under a 0-40 cm soil layer. MN + BC had the strongest resistance to soil acidification among all the treatments. The interaction between fertilizers and biochar application was significant (p < 0.05) in rice yield, soil electrical conductivity (10-20 cm), and soil available phosphate (20-40 cm). Principal component analysis indicated that the effect of manure on soil property was stronger than that of biochar in the 0-40 cm soil layer. The overall rice yield and soil fertility decreased in the order of biochar + mineral fertilizer + manure > mineral fertilizer + manure > biochar + mineral fertilizer > mineral fertilizer > biochar > control. These results suggest that biochar and manure co-application is a long-term viable strategy for improving acid soil productivity due to its improvements in soil pH, organic carbon, nutrient retention, and availability.

REDUCTION OF CHEMICAL FERTILIZER APPLICATION BY USING BIOCHAR FOR THE GROWTH AND YIELD OF RICE CV. BRRI dhan 29

A field experiment was carried out at research field, Hajee Mohammad Danesh Science and Technology University, Dinajpur to assess the reduction of chemical fertilizer application by using biochar for the growth and yield of rice cv. BRRI dhan 29. The experiment was performed with five treatments viz. T1 = Recommended doses of N, P, K and S, T2 = Biochar 10 t ha-1, T3 = Biochar 7.5 t ha-1 + half recommended doses of N, P, K and S, T4 = Biochar 5 t ha-1 + half recommended doses of N, P, K and S and T5 = Biochar 2.5 t ha-1 + half recommended doses of N, P, K and S. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The highest plant height (102.35 cm) and the number of tillers hill-1 (26.35) was found in the treatment T1 which was statistically similar to the treatment T3 with the values 99.93 cm and 25.89, respectively. The panicle length (25.01 cm), number of spikelets hill-1 (14.30), number of grains panicle-1 (194.50) and 1000-grain weight (25.03 g) were found maximum in the treatment T3 which was statistically similar to the treatment T1 with the values 24.89 cm, 13.87, 193.50 and 24.37 g; respectively. The highest grain yield (7.46 t ha-1) and straw yield (9.92 t ha-1) was found on T1 treatment which was statistically similar to the treatments T3 (7.42 and 9.86 t ha-1). The highest biological yield (17.28 t ha-1) was measured in the treatment T3. These results suggest that application of 7.5 t ha-1 biochar with half recommended doses of N, P, K and S may reduce 50% of N, P, K and S for rice cultivation (cv. BRRI dhan 29) as these treatments acquire statistically similar production to solely chemical fertilizer applications. However, further research is needed on biochar production, cost efficiency for biochar application and environmental aspects of biochar application.

Biochar from Raw Materials Arundo Spp; Effect on Corn Plant Growth and Production

Biochar is widely used for water and soil remediation due to its local availability and low production costs. However, its effectiveness depends on the physicochemical properties related to the raw material and pyrolysis temperature, as well as the environmental conditions where it is used. Additionally, biochar is susceptible to natural aging caused by changes in soil or sediment moisture, which can alter its redox properties and interactions with contaminants such as arsenic. Therefore, we are interested in conducting fundamental research on raw materials from grass types and their influence on the growth and production of QPM corn plants. In this research, we carried out laboratory content tests and field experiments. The treatments were: p0 control, p1 = 3 tons ha-1 biochar, p2 = 6 tons ha-1 biochar, p3 = 9 tons ha-1, p4 = 12 tons ha-1, p5 = 15 tons ha-1. The experimental results showed that the administration of biochar made from Arundo Spp. 12 tons Ha-1 can increase the effective growth and production of corn plants

Assessing Leaching Requirement an Ameliorated Saline Soil in a Lysimeter Experiment

Soil salinity problems in the coastal hinterland region of East Java diminish agricultural development and land productivity. Soil leaching is expected to reduce soil salinity. This study investigated the effectiveness of different ameliorant compositions and leaching requirements (LR) in the leaching process. The experiment involved applying ameliorants (T) and leaching (L) treatments to lysimeters filled with saline soil. The ameliorant treatments included biochar, organic matter, and gypsum. The results showed the leaching requirement capacity to reduce electrical conductivity from 5.7 dS m-1 to below 2 dS m-1. Leaching for T0 (without ameliorants) and T1 (10 Mg ha-1 of biochar) required 943 mm of water, while T2 (20 Mg ha-1 of biochar) and T3 (40 Mg ha-1 of compost) required 1052 mm. The T4 (10 Mg ha-1 of compost and 2 Mg ha-1 of gypsum) necessitated 1154 mm of leaching water. The ameliorants’ application and assortment increased the water demand for leaching. The findings indicated a consistent relationship between TDS and salinity, indicating the soil’s dominant presence of salty ions.

Physiological responses of coffee (Coffea arabica L.) plants to biochar application under water deficit conditions

Water deficit is one of the main abiotic stressors in crop production. The development of strategies to improve plant tolerance to water deficits has gained importance. Biochar application can be considered an alternative to mitigate abiotic stress. The use of coffee pulp to produce biochar could be a novel strategy for improving drought tolerance in coffee crops. Coffer plants cv. ‘Castillo’ were grown in pots or PVC pipes filled with silt loam soil in two separate experiments to evaluate the effect of coffee pulp biochar application on physiological responses under water deficit conditions. Four different biochar doses (0, 4, 8, and 16 t · ha-1) were used. A water deficit was imposed through progressive reduction irrigation (25%, 50%, 75%, and 90% of water lost via evapotranspiration). The leaf gas exchange, maximum quantum yield of PSII (Fv/Fm), biomass, and water status were measured. Reduced irrigation negatively affected the Fv/Fm, leaf gas exchange, biomass, and water status. Biochar (8 t ha-1) increased photosynthesis in both well-irrigated plants (6 µmol m-2 s-1) and with reduced irrigation (3.5 µmol m-2 s-1) compared to 0 t ha-1 biochar (reduced irrigation: 1.8 µmol m-2 s-1 and well irrigated: 3.9 µmol m-2 s-1). In conclusion, 8 t ha-1 biochar can be a recommended practice for coffee production, not only to capture carbon and reintroduce it to the soil, but also to alleviate the effects of moderate water deficit. In future investigations, biochar application can be evaluated as an alternative to soil management or coffee plant nutrition, and its interaction with drought stress scenarios.

Impact of Varying doses of Biochar and INM Practices on Agro Physiological Performance, Yield and Economics of Maize (Zea mays L.)

A field experiment was conducted to evaluate the effect of graded doses of biochar and fertility levels with and without biofertilizer under partially reclaimed Sodic Soils on the maize crop during Kharif, 2021 and 2022 at Students Instructional Farm of Acharya Narendra Deva University of Agriculture and Technology, Kumarganj Ayodhya. The eight treatments viz. T1: Control, T2: 100% (RDF 100:60:40; N P2O5, K2O), T3: 50% RDF + 2.5 t ha-1 biochar, T4: 50% RDF + 2.5 t ha-1 biochar + ZMB Biofertilizer, T5: 50% RDF + 2.5 t ha-1 biochar + ZMB Biofertilizer + Zn, T6: 100 % RDF + 5 t ha-1 biochar, T7: 100 % RDF + 5 t ha-1 biochar + ZMB Biofertilizer, T8: 100 % RDF + 5 t ha-1 biochar + ZMB Biofertilizer + Zn were setup in a Randomized Block Design with replicated thrice. The Kanchan variety (K-25) was taken as a test crop. Significantly, maximum relative growth rate, net assimilation rate and yield were recorded with 100% RDF + 5 t ha-1 biochar + ZMB biofertilizer + Zn gave the best results. The highest gross return (₹12674) and net return (₹67162) was obtained with 100 % RDF + 5 t ha-1 biochar + ZMB biofertilizer + Zn (T8).

Effect of Biochar on Growth and Yield of Sunflower (Helianthus annus L.) in Non-saline Tidal Area of Bangladesh

Biochar is an organic amendment used for crop production. A piece of research work was conducted in the field laboratory of Patuakhali Science and Technology University, Dumki, Patuakhali to observe the effect of biochar on the growth and yield of sunflowers. There were four treatments as Control, 5 tons ha-1 biochar, 10 tons ha-1 biochar, and 20 tons ha-1 biochar. A significant difference was found in the plant height, number of leaves, length of leaves, number of seed head-1, head diameter, seed weight head-1, 1000 seed weight, yield, and stover yields when different biochar doses were applied. The highest plant height (181.37 cm), number of leaves (20.82), leaf length (45.84 cm), number of seed head-1 (677.13), head diameter (20.63 cm), total seed weight head-1 (68.19 g), 1000 seed weight (65.49 g), grain yield (3.42 tons ha-1) and stover yield (5.79 tons ha-1) was recorded from 20 tons ha-1 treatment. Biochar of 20 tons ha-1 could be recommended for higher growth and yield of sunflower.

A biochar and Fulvic Acid Usage-Based Approach to Reduce Pollution Resulting from the use of Mineral Fertilizers

Nowadays, due to pollution in world due to due to excessive consumption of mineral fertilizers, the limiting or minimizing their use has become a major strategy for environmentalists. The research work objective was to reduce quantities of mineral fertilizers, especially NPK fertilizers, by gradually replacing nitrogen fertilizers with fulvic acid and biochar. Four different combinations of mineral fertilizers were used as soil application (NPK1: 120, 160 and 143, NPK2: 180, 310 and 190, NPK3: 240, 475 and 240 and NPK4: 300, 635 and 285 kg ha-1), biochar as soil application (B0: without biochar, B1: 15 and B2: 30 Mg ha-1) and fulvic acid as foliar addition (FA0: without fulvic acid and FA1: 0.2, gL-1) were studied using pot experiment during 2017/2018 season using wheat plants. The results indicated general increment trend in almost investigated parameters with increasing fertilizers level especially that combined with biochar at any rate and fulvic acid. The highest soil N and P contents (63.59 and 38.35 mgkg-1) were reported with NPK4 + B2 + F1 while the lowest values (31.09 and 2.96 mgkg-1) were recorded under the lowest fertilization level without application of B or FA. Unlike, maximum K contents (216.79 and 214.88 mgkg-1) were reported under adding the NPK4 or with B2 without FA. The grain yield recorded maximum values (5 Mg ha-1) under combined application of maximum NPK fertilizer level, 30 Mg ha-1 of biochar and fulvic acid while applying the minimum NPK fertilization level (level 1) without any applications of biochar or fulvic acid resulted in the lowest values (2.94 Mg ha-1). The results showed that it is possible to partially reduce the quantities of mineral fertilizers used and replace them with a complementary addition from fulvic acid and biochar, and this is reflected in the reduction of environmental pollution resulting from the use of mineral fertilizers. Also, the combination of NPK and biochar led to an improvement in the productivity of wheat grown in sandy lands, as it reduced the loss of nutrients, and the addition of fulvic acid led to an increase in plant resistance to stress conditions that appear under sandy soil conditions.

Increased humic materials explain aggregate-protected carbon and nitrogen accumulation in biochar-amended tropical soils

Humic materials make important contributions to soil organic carbon (SOC) and nitrogen (TN) accumulation. However, information on the correlation between humic substances and the accumulation of aggregate-protected C and N in response to biochar application to soils under tropical agroecosystems is limited. Therefore, a replicated field trial was conducted to elucidate the effects of biochar on soil aggregate properties and humic materials, and how these humic compounds affect aggregate-protected SOC and TN in a humid tropical agroecosystem. The treatments included no biochar/ control (CT), 15-Mg biochar ha-1 (BC-15), 30-Mg biochar ha–1 (BC-30), and 30-Mg biochar ha-1 + phosphate fertilizer (BC-30+P). The BC-30 and BC-30+P treatments significantly increased the contents of humic materials (humic and fulvic acids) as compared to the CT. There was a significant increase in the mean weight diameter of soil aggregates by 3- and 4-fold in the BC-30 and BC-30+P treated soils, respectively. Similarly, the application of the BC-30 and BC-30+P treatments yielded significant increases in the soil structural coefficient by 3- and 4-fold, respectively, relative to the CT. A 10% decline in soil bulk density was observed with biochar applied at 30-Mg ha-1. Significant increases in SOC and TN accumulation were observed in the macroaggregates of the biochar-amended soils. An inverse relationship between the degree of polymerization and aggregate-protected C and N was observed, implying that low molecular weight aliphatic compounds favor SOC and TN accumulation with biochar amendments. The important soil property that contributed to SOC and TN accumulation in aggregates was FA, which could be used as an early and sensitive indicator to notice early changes in aggregate-protected C and N accumulation in soils of the humid tropics.

Indigenously produced biochar retains fertility in sandy soil through unique microbial diversity sustenance: a step toward the circular economy.

Agricultural productivity in the arid hot desert climate of UAE is limited by the unavailability of water, high temperature, and salt stresses. Growing enough food under abiotic stresses and decreasing reliance on imports in an era of global warming are a challenge. Biochar with high water and nutrient retention capacity and acid neutralization activity is an attractive soil conditioner. This study investigates the microbial community in the arid soil of Dubai under shade house conditions irrigated with saline water and the shift in the microbial community, following 1 year of amendment with indigenously prepared biochar from date palm waste. Amplicon sequencing was used to elucidate changes in bacterial, archaeal, and fungal community structures in response to long-term biochar amendment. Samples were collected from quinoa fields receiving standard NPK doses and from fields receiving 20 and 30 tons ha-1 of biochar, in addition to NPK for 1 year. Water holding capacity, pH, electrical conductivity, calcium, magnesium, chloride, potassium, sodium, phosphorus, total carbon, organic matter, and total nitrogen in the soil from biochar-treated and untreated controls were determined. The results show that soil amendment with biochar helps retain archaeal and bacterial diversity. Analysis of differentially abundant bacterial and fungal genera indicates enrichment of plant growth-promoting microorganisms. Interestingly, many of the abundant genera are known to tolerate salt stress, and some observed genera were of marine origin. Biochar application improved the mineral status and organic matter content of the soil. Various physicochemical properties of soil receiving 30 tons ha-1 of biochar improved significantly over the control soil. This study strongly suggests that biochar helps retain soil fertility through the enrichment of plant growth-promoting microorganisms.

Long-term effects of biochar application on the growth and physiological characteristics of maize.

Biochar, as a soil conditioner, has been widely used to promote the growth of maize, but most of the current research is short-term experiments, which limits the research on the long-term effects of biochar, especially the physiological mechanism of biochar on maize growth in aeolian sandy soil is still unclear. Here, we set up two groups of pot experiments, respectively after the new biochar application and one-time biochar application seven years ago (CK: 0t ha-1, C1: 15.75t ha-1, C2: 31.50t ha-1, C3: 63.00t ha-1, C4: 126.00t ha-1), and planted with maize. Subsequently, samples were collected at different periods to explore the effect of biochar on maize growth physiology and its after-effect. Results showed that the plant height, biomass, and yield of maize showed the highest rates of increase at the application rate of 31.50 t ha-1 biochar, with 22.22% increase in biomass and 8.46% increase in yield compared with control under the new application treatment. Meanwhile, the plant height and biomass of maize increased gradually with the increase of biochar application under the one-time biochar application seven years ago treatment (increased by 4.13%-14.91% and 13.83%-58.39% compared with control). Interestingly, the changes in SPAD value (leaf greenness), soluble sugar and soluble protein contents in maize leaves corresponded with the trend of maize growth. Conversely, the changes of malondialdehyde (MDA), proline (PRO), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) manifested an opposite trend to the growth of maize. In conclusion, 31.50 t ha-1 biochar application can promote the growth of maize by inducing changes in its physiological and biochemical characteristics, but excessive biochar application rates ranging from 63.00-126.00 t ha-1 inhibited the growth of maize. After seven years of field aging, the inhibitory effect of 63.00-126.00 t ha-1 biochar amount on maize growth disappeared and changed to promoting effect.

Physiological response of &amp;#8216;Castillo el Tambo&amp;#8217; coffee plants to biochar and chemical fertilization applications

The fertilizers costs are currently elevated, and it is necessary to evaluate complementary agronomic strategies. Biochar (BC) offers several potential benefits at a relatively low cost. The research aimed was to study the effect of the application of four different doses of biochar (BC) (0, 4, 8, and 16 t ha-1) and four fertilization levels (FL) (0%, 33%, 66% and 100% of the nutritional requirements). We obtained the BC from coffee (Coffea arabica L.) pulp. The selected response variables were: Stomatal conductance (gs), water use efficiency (WUE), root hydraulic conductivity (K), leaf photosynthetic pigments (Chl), and total dry weight (TDW) of coffee ‘Castillo el Tambo’. The experiment was conducted under greenhouse conditions. The results showed that plants with 0 t ha-1 and 0% FL registered low values in the physiological parameters evaluated (gs = 60.5 mmol m-2 s-1; WUE = 3.03 g DM L-1 H2O; Chl = 59.4 atLEAF readings; Kr = 9.7×10-6 kg s-1 MPa-1; TDW = 9.7 g). On the other hand, we recorded a positive effect when ‘Castillo el Tambo’ coffee plants received 8 t ha-1 BC (Kr = 11.8×10-6 kg s-1 MPa-1), especially at fertilization levels of 66% and 100% (gs = 146.7 and 167.5 mmol m-2 s-1; Chl = 72.8 and 66.6 Chl content; WUE = 4.3 and 5.0 g DM L-1 H2O; TDW = 13.6 and 16.0 g, respectively). In conclusion, the use of BC manufactured with coffee pulp, mainly at a dose of 8 t ha-1, can be an alternative to complement the chemical nutrition of coffee plants.

PENGARUH BERBAGAI JENIS BAHAN ORGANIK TERHADAP PERTUMBUHAN CABAI PADA SISTEM BUDIDAYA YANG MENGGUNAKAN MULSA ALANG-ALANG DENGAN PENGAIRAN SEPARUH DAERAH AKAR

This study aims to determine the effect of various types of organic matter on the growth of chili plants in a cultivation system using alang-alang mulch with half the root area irrigating. This research was conducted from August to November 2020 in Kambu, Kendari City. The study was arranged based on a Randomized Block Design (RAK) consisting of 4 treatments, namely without organic matter (B0), 10 t ha-1 cow dung + alang-alang mulch (B1), 10 t ha-1 rice husk biochar + alang-alang mulch (B2) and 10 t ha-1 biochar of cocoa pods + reed mulch (B3). The treatment was repeated 4 times. The results showed that the effect of organic matter significantly affected plant height, base weight, dry weight, number of leaves, leaf area, soil moisture and soil temperature. The best treatment was obtained in cow manure treatment with a percentage increase in the percentage increase. plant height 28 DAP and 42 DAP were 89.6% and 100.4%, respectively.

Effects of biochar addition on aeolian soil microbial community assembly and structure

The effects of biochar on soil improvement have been widely confirmed, but its influence on soil microorganisms is still unclear. Elucidating the complex relationship and the community assembly processes of microorganisms under biochar addition is important to understand the ecological effects of this substance. We performed a one-time addition of biochar on aeolian soils and planted maize (Zea mays L.) continuously for 7 years. Afterwards, soil samples were collected, and the 16S/ITS rRNA gene sequencing technology was used to study changes in microbial community structure, network characteristics, and community assembly processes in the aeolian soils. We found that biochar addition significantly increased the maize yield and changed the soil microbial community composition (β-diversity), but had no significant effect on the microbial α-diversity. The addition of 31.5-126.0 Mg ha-1 of biochar led to a reduction of the rhizosphere bacterial network's edge number, average degree, and robustness, but had no significant effect on the fungal network properties. The bacterial community was controlled by deterministic processes, while fungi were mainly controlled by stochastic processes. The addition of 126.0 Mg ha-1 of biochar led to a transformation of the bacterial community's assembly processes from deterministic to stochastic. These results indicate that the stability of the rhizosphere bacterial community's complex network in aeolian soils diminishes under biochar addition, together changed the bacterial community's assembly processes. Fungi can instead effectively resist the environmental changes brought by biochar addition, and their network remains unchanged. These findings help clarify the effect of biochar addition on microbial interaction and assembly processes in aeolian soils characteristic of arid regions. KEY POINTS: • Biochar addition led to changes in the microbial community composition • Biochar addition reduced the network's stability of rhizosphere bacteria • Biochar addition changed the processes of the bacterial community assembly.