Effects of Biochar-based Organic Fertilizer on Accumulation of Total Flavonoid Contents in Dandelion

In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),and the base fertilizer that only applied conventional chemical fertilizer was used as the control.The total flavonoid contents and physiological indices of dandelion in different growth periods were determined.The results showed that the accumulation of the total flavonoid contents in leaves and roots of dandelion improved significantly by applying biochar-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),with the highest total flavonoid occurred in the 0.45 kg•m^(-2) biochar-based organic fertilizer treatment.Along with dandelion growing,the total flavonoid contents in leaves were first elevated,and then decreased,with the maximum reached at 95 days after sowing(anthesis).While the total flavonoid contents in roots were elevated constantly.The total flavonoid contents accumulation in dandelion were positively correlated with net photosynthetic rate,stomatal conductance,transpiration rate,soluble sugar content,soluble protein,nitrate nitrogen,and available potassium,while negatively correlated with intercellular CO_(2) concentration.

Effects of Biological Organic Fertilizer on Flue-cured Tobacco Chemical Composition

Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the increase of biological organic fertilizer would significantly improve soil nutrient supplying capacity.Compared with conventional fertilization,the contents of reducing sugar,total sugar and starch in different parts of tobaccos which were applied with biological organic fertilizer were closer to standards of excellent tobacco.In the treatment,the ratio of reducing sugar and nicotine in tobacco was more suitable in middle and lower parts of the plant and the contents of total N,nicotine and chlorine in tobacco were lowered,improving tobacco quality.

Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions

Colored rice is a type of high-quality,high-added-value rice that has attracted increasing attention in recent years.The use of large amounts of inorganic nitrogen fertilizer in rice fields results in low fertilizer use efficiency and high environmental pollution.Organic fertilizer is a promising way to improve soil quality and sustain high yields.However,most studies focus on the effect of animal-based organic fertilizers.The effects of different ratios of plantbased organic fertilizer and inorganic fertilizer on the grain yield and quality of colored rice have rarely been reported.Therefore,a two-year field experiment was conducted in 2020 and 2021 to study the effects of replacing inorganic N fertilizers with plant-based organic fertilizers on the yield,nitrogen use efficiency(NUE),and anthocyanin content of two colored rice varieties in a tropical region in China.The experimental treatments included no nitrogen fertilization(T1),100% inorganic nitrogen fertilizer(T2),30%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T3),60%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T4),and 100% plantbased organic fertilizer(T5).The total nitrogen provided to all the treatments except T1 was the same at 120 kg ha-1.Our results showed that the T3 treatment enhanced the grain yield and anthocyanin content of colored rice by increasing nitrogen use efficiency compared with T2.On average,grain yields were increased by 9 and 8%,while the anthocyanin content increased by 16 and 10% in the two colored rice varieties under T3 across the two years,respectively,as compared with T2.Further study of the residual effect of partial substitution of inorganic fertilizers showed that the substitution of inorganic fertilizer with plant-based organic fertilizer improved the soil physiochemical properties,and thus increased the rice grain yield,in the subsequent seasons.The highest grain yield of the subsequent rice crop was observed under the T5 treatment.Our results suggested that the application of plantbased organic fertilizers can sustain the production of colored rice with high anthocyanin content in tropical regions,which is beneficial in reconciling the relationship between rice production and environmental protection.

Mitigation of N_(2)O emissions in water-saving paddy fields:Evaluating organic fertilizer substitution and microbial mechanisms

Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.

Combined application of organic fertilizer and chemical fertilizer alleviates the kernel position effect in summer maize by promoting post-silking nitrogen uptake and dry matter accumulation

Adjusting agronomic measures to alleviate the kernel position effect in maize is important for ensuring high yields.In order to clarify whether the combined application of organic fertilizer and chemical fertilizer(CAOFCF)can alleviate the kernel position effect of summer maize,field experiments were conducted during the 2019 and 2020 growing seasons,and five treatments were assessed:CF,100%chemical fertilizer;OFCF1,15%organic fertilizer+85%chemical fertilizer;OFCF2,30%organic fertilizer+70%chemical fertilizer;OFCF3,45%organic fertilizer+55%chemical fertilizer;and OFCF4,60%organic fertilizer+40%chemical fertilizer.Compared with the CF treatment,the OFCF1 and OFCF2 treatments significantly alleviated the kernel position effect by increasing the weight ratio of inferior kernels to superior kernels and reducing the weight gap between the superior and inferior kernels.These effects were largely due to the improved filling and starch accumulation of inferior kernels.However,there were no obvious differences in the kernel position effect among plants treated with CF,OFCF3,or OFCF4 in most cases.Leaf area indexes,post-silking photosynthetic rates,and net assimilation rates were higher in plants treated with OFCF1 or OFCF2 than in those treated with CF,reflecting an enhanced photosynthetic capacity and improved postsilking dry matter accumulation(DMA)in the plants treated with OFCF1 or OFCF2.Compared with the CF treatment,the OFCF1 and OFCF2 treatments increased post-silking N uptake by 66.3 and 75.5%,respectively,which was the major factor driving post-silking photosynthetic capacity and DMA.Moreover,the increases in root DMA and zeatin riboside content observed following the OFCF1 and OFCF2 treatments resulted in reduced root senescence,which is associated with an increased post-silking N uptake.Analyses showed that post-silking N uptake,DMA,and grain yield in summer maize were negatively correlated with the kernel position effect.In conclusion,the combined application of 15-30%organic fertilizer and 70-85%chemical fertilizer alleviated the kernel position effect in summer maize by improving post-silking N uptake and DMA.These results provide new insights into how CAOFCF can be used to improve maize productivity.

Comparative Analysis of Organic and Compound Fertilizers on the Yield and Metabolites of Platostoma palustre

To explore the effect of fertilizers on the yield and quality of Platostoma palustre,in this study,P.palustre was utilized as the research material,and field experiments were conducted with different application rates of compound fertilizer and organic fertilizer and non-targeted metabolomics analysis was further employed to compare and analyze the differences in the metabolic components between the compound fertilizer and organic fertilizer treatments.The results of field experiments demonstrated that both compound and organic fertilizers could promote the fresh weight,shade dry weight,and dry weight of P.palustre,with 450 kg hm−2 compound fertilizer and 4500 kg hm−2 organic fertilizer presenting the optimum effects.Non-targeted metabolomics revealed that 1096 metabolites were identified in 450 kg hm−2 compound fertilizer and 4500 kg hm−2 organic fertilizer,and 885 metabolites were annotated in the Human Metabolome Database(HMDB).There were 318 differential metabolites(DMs)found between the two treatments,and 263 metabolites were annotated in HMDB.The abundance of 2 phenolic compounds and 12 organic oxygen compounds in the treatment of 4500 kg hm−2 organic fertilizer was significantly higher than that of the 450 kg hm−2 compound fertilizer,while the abundance of 21 organic oxygen compounds,14 flavonoids,3 phenolic compounds,and 5 cinnamic acids and their derivatives was significantly up-regulated in 450 kg hm−2 compound fertilizer treatment.In addition,5 metabolic pathways were significantly enriched,and the flavone and flavonol biosynthesis was the most significantly differential metabolic pathway.These results suggested that the application of both compound fertilizers and organic fertilizers can increase the yield of P.palustre,but their effects on metabolites were different.This study has considerable implications for the planting and cultivation of P.palustre,furnishing a scientific foundation for an efficient and rational application of fertilizer.

Application of organic fertilizer for improving soybean production under acidic stress

The presence of acidic soil in rural areas poses difficulties for agricultural production.One factor regulating soil pH is the overuse of inorganic fertilizer.The increased use of fertilizers in soybean production not only raises sustainability concerns but also contributes to soil acidity.Therefore,the use of organic fertilizer could offer a solution for addressing both issues related to soil acidity and sustainability.The purpose of this study was to investigate the manipulation of soil pH using organic fertilizer for soybean production under acidic stress.The planting medium,consisting of a mixture of topsoil,rice husk charcoal,and organic fertilizer(in a ratio of 2:1:1),was supplemented with 0.5 g of NPK fertilizer as a basal treatment in each planting medium.To regulate the soil acidity to pH 4,we added FeSO_(4) and allowed the mixture to incubate for 30 days.The results demonstrate that the application of three types of organic fertilizers chicken manure(P1),oil palm empty bunch fertilizer(P2),and vermicompost(P3)positively impacts the growth of three soybean varieties.The findings indicate that the application of P2 organic fertilizer can increase vegetative growth almost 50%in soybeans on acidic soil,including plant height,leaf count,and root length.Meanwhile,applying P3 organic fertilizer can boost reproductive growth responses in soybeans on acidic soil,such as pod number(from around 0-4 unit to 42-51 unit),grain number(from around 0-5 unit to 88-90 unit),and grain weight(from around 0-0.37 g to 12-25 g).Organic fertilizer has the potential to regulate soil pH,promoting higher yields of soybeans under acidic stress.

Improvement of Wolfberry(Lycium barbarum L.)Fruit Yield and Quality and Enhancement of Soil Fertility by Nitrogen Reduction Combined with Organic Fertilizers

Excessive amounts of nitrogen(N)fertilizers are applied during wolfberry production,resulting in some soil problems as well as potential environmental risks in the Qinghai-Tibet Plateau.In this study,organic fertilizers were used to replace part of the N fertilizer in wolfberry fields with different fertility levels.N fertilizer rates had 0,50,100,150,200,and 250 g N/plant.Organic fertilizer rates had 0,2,4,6,8,and 10 kg organic fertilizer/plant.The experimental treatments included 6 combinations of N0M10,N50M8,N100M6,N150M4,N200M2,and control was N250M0.The results showed that in the high-fertility soils,combinations of N150M4,N100M6 and N50M8 treatments were increased in yields,fruit shape index,flavonoid content,total phenol content,mineral nutrient content,and antioxidant activity of wolfberry fruits.Also they were improved in soil fertility and decreased in residual nitrate through the soil depth of 0-300 cm.In the soil with less fertility,fruit yield,amino acid contents,flavonoids,total phenols,mineral nutrients and antioxidant activity of fruits were increased by the N200M2,N150M4 and N100M6 treatments and soil fertility was improved as well.Also more residual nitrate was found in the depth of 0-100 cm of soil with both chemical and organic fertilizer compared with the control.Therefore,in the Qinghai-Tibet Plateau,combining decreased N fertilizer with organic fertilizer rather than chemical fertilizer alone could help farmers achieve satisfactory yields and quality of wolfberry fruits and reduce the risk of nitrate leaching.In conclusion,50-150 g/plant of N fertilizer combined with 4-8 kg/plant of organic fertilizer in high-fertility gardens and 100-200 g/plant of N fertilizer combined with 2-6 kg/plant of organic fertilizer in low-fertility gardens are recommended for wolfberry cultivation.

The Impacts on Spinach Growth and Yield by Biological Organic Fertilizer

To decrease fertilization amount of chemical fertilizer and improve the quality of vegetable crops,spinach was taken as the test material,and the impact of different fertilizer on spinach growth and yield was studied via the manners of biological organic fertilizer and organic fertilizer + chemical fertilizer. Experimental results showed that in the formula of organic fertilizer + chemical fertilizer,chlorophyll and nitrogen contents in spinach leaves obviously increased; in the formula of only adding organic fertilizer,spinach leaf temperature,leaf width,root length,plant height and fresh weight were all better than those in the formula of organic fertilizer + chemical fertilizer,and better formulas were A_5,E_5,F_3 and I_5,in which spinach plant height in E_5 was 5. 63 times higher than G_5,root length in E_5 was 2. 67 times higher than G_5,and fresh weight in G_5 was 32. 6 times higher than G_5. By comprehensive analysis,the most suitable formula for spinach production was E_5,and the research could provide theoretic basis for fertilization amount of organic fertilizer required by spinach growth and development.

Biochar Applied with Organic Fertilizer Improves Alkaline Soil Properties and Crop Yield

Biochar(BC)is widely applied in agricultural production for its multiple uses such as carbon sequestration.However,application of BC alone has limited effect on soil fertility and crop yield,especially alkaline soil.Therefore,a pot experiment on Chinese cabbage(Brassica rapa var.glabra)was carried out in this study to investigate the effect of BC applied with organic fertilizer(OF)on alkaline soil properties and crop yield.To be specific,BC and OF were respectively applied at 0,1%,2%,and 3%,and Chinese cabbage was transplanted and cultivated for 2.5 months.Results showed that BC and OF increased the content of both organic matter and available P in alkaline soil(P<0.05).Moreover,the application of OF alone decreased the pH value but raised available N content of alkaline soil,and the application of only BC demonstrated the contrary effect(P<0.05).OF significantly improved crop yield(P<0.05),but the effect of BC was insignificant.Crop yield was the highest under the treatment of 1%BC and 3%OF.Thus,BC had limited effect on alkaline soil fertility and crop yield,but the application with OF was a good option for ameliorating alkaline soil and raising crop yield.

Effects of Bio-organic Fertilizer with Antagonistic Bacteria against Tobacco Bacterial Wilt on Soil Microbial Communities and Disease Resistance of Tobacco

In this study, the effects of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt on soil microbial communities and disease resist- ance of tobacco were investigated by field experiment. The results showed that the incidence of tobacco bacterial wilt in bio-organic fertilizer treatments （T3 and T4） decreased remarkably among four treatments in the field. Compared with the local conventional fertilization group, the incidence of tobacco bacterial wilt was re- duced by 21.9% and 25.0% in T3 and T4, respectively ; the yield of flue-cured tobacco was improved by 5.7% and 5.3%, respectively ; the proportion of mid- high grade tobacco leaves increased by 2.3% and 2.6%, respectively. After application of bio-organie fertilizer with antagonistic bacteria against tobacco bacterial wilt, rhizosphere soil microbial communities exhibited vast amount and abundant species ; the amount of rhizosphere soil bacteria of infected tobacco plants was im- proved by 218.5% with fewer species. It could be concluded that the application of bio-organic fertilizer with antagonistic bacteria against tobacco bacterial wilt could improve the ecological environment of tobacco field, inhibit the growth of pathogenic bacteria, decrease the incidence of tobacco bacterial wilt, and enhance the quality of flue-cured tobacco. This study laid the foundation for further ecological prevention and control of soil-borne diseases of tobacco.

Sustainable Bio-Conversion of Rice Straw Waste into High Quality Organic Fertilizer

The aim of this study is to investigate the effect of different additives including biochar, effective micro-organisms (EM), animal manure and commercial microbial inoculants on the bioconversion of rice straw. Different compost piles were constructed, and each contained 50 kg of rice straw and mixture of natural rocks to enrich the compost nutritional value. The physical, chemical and biological parameters indicating the decomposition of organic material, maturation and quality of the organic fertilizer product were investigated during the composting process. A rapid increase in compost temperature was obtained in inoculated piles. All piles reached maturation after around 42 days. All analysis of the properties of the final compost products indicated that it was in the range of the matured level and can be used as organic fertilizer without limitation. The highest decomposition rate and highest organic fertilizer quality were obtained in the pile inoculated with EM and 10% biochar compared to other treatments.

Effect of Organic and Chemical Fertilizer Application on Growth, Yield, and Soil Biochemical Properties of Landrace <i>Brassica napus</i>L. Leaf-and-Stem Vegetable and Landrace (Norabona)

Norabona is generally cultivated in Japan under management systems that use chemical fertilizers and synthetic chemical pesticides. However, the continuous use of these fertilizers and pesticides damages the soil environment and reduces the number of soil microorganisms. There has been little research investigating the effect of organic and chemical fertilizer applications on soil biochemistry and the growth and yield of norabona. In this study, we investigated the effect of organic and chemical fertilizer application on these factors during the norabona growing season from September 2019 to May 2020. Leaf length, shoot height, and shoot width were significantly higher under organic fertilizer management in the early stage of cultivation (in March) than under chemical fertilizer management. However, there was no significant difference between treatments for these growth parameters in later months, nor for any other parameters. Soil TN, and TP contents were significantly higher in the organic fertilizer treatment after harvest than prior to cultivation or after the chemical fertilizer treatment. In addition, soil TC, and volumetric water content were significantly higher in the organic fertilizer treatment than in chemical fertilizer treatment. The higher TC, TN, and C/N ratio in organic fertilizer treated soil appeared to increase the bacterial biomass, leading to enhanced nutrient circulation via N and P circulation activity, producing a rich soil environment with active soil microorganisms.

Application of Bio-organic Fertilizer Containing High-efficient Nitrogen-fixing Bacillus amyloliquefaciens on Strawberry

With strawberry as a test material,the effects of the bio-organic fertilizer containing high-efficiency nitrogen-fixing Bacillus amyloliquefaciens on nutrient contents in strawberry-planted soil,wilt occurrence and strawberry yield and quality were studied by a plot experiment,so as to provide reference for scientific use of the bio-organic fertilizer and green production of strawberry.The results showed that after hole-applying the bio-organic fertilizer at a rate of 22.5 t/hm^2,the contents of NH^+_4-N,available P,available K and organic matter did not change much with time;and when replacing 50%of chemical fertilizers with the bio-organic fertilizer at a rate of 11.25 t/hm^2(K_3),the contents of NH^+_4-N and available P in the soil did not change much with time,and the contents of available K and organic matter decreased slightly with time,but were both higher than the CK(the unfertilized treatment).Meanwhile,the disease index values of strawberry wilt disease in treatments K_2 and K_3were significantly lower than those of the CK and the conventional fertilization treatment(K_1),and the vitamin C contents of strawberry fruit in the two treatments were significantly higher than that of the CK.The yield determination showed that the cumulative yields of treatments K_2 and K_3 increased by 9.8% and 3.3%,respectively,and the increase rates of the early yields(before the Spring Festival)were 30.6% and 21.9%,respectively.Therefore,the application of the bio-organic fertilizer can replace chemical fertilizers,and can achieve the effects of reducing the occurrence of wilt,improving the early yield of fruit commodity and improving fruit quality.

Treatments Comparison of Mineral and Bio Fertilizers in the Apple and Sour Cherry Organic Nursery

Maiden trees of apple cultivars ＇Topaz＇ and ＇Ariwa＇ grafted on M26 rootstock and of sour cherry cultivars ＇Debreceni Botermo and ＇Sabina＇ on mahaleb cherry （Prunus mahaleb L.） were fertilized with bioproducts such as： Fertigo-granulated manure, Micosat-microbial inoculum consisting of mycorrhizal fungi; Humus UP-an extract from vermicompost; Humus Active ＋ Aktywit PM-an extract from vermicomposts with PM （Positive Microorganism）; BioFeed Amin--a plant extract reinforced with amino acids; BioFeed Quality-a seaweed extract reinforced with humic and fulvic acids; Tytanit-titanium; Vinassa-molasses residue from yeast production; Florovit Eko-composed of many environmentally-friendly products. Control maidens were fertilized with mineral fertilizers containing mainly NPK. The maiden trees fertilized with the preparations Tytanit and Humus UP grew less vigorously and produced smaller increases in the length of lateral shoots than those fertilized with mineral fertilizers. On the other hand, bio preparations such as BF Amin, BF Quality, Micosat and Vinassa promoted tree branching and intensified the growth of lateral shoots, stimulating tree growth to a greater extent than the mineral fertilizers.

Effects of Applying Organic Fertilizer on Rice Lodging Resistance and Yield

[Objective]The aim was to provide a scientific basis for the reasonable application of organic fertilizer to improve lodging resistance and yield of rice.[Method]The application of four different kinds of organic fertilizer was applied to study their effects on rice lodging resistance and yield of late rice Yuzhengxiang that with high quality.[Result] The effect of applying organic fertilizer for improving rice lodging resistance capability was:biogas residues> chicken manure > rapeseed cake> tobac...

Investigation on the Accumulation of Heavy Metals from Organic Fertilizer in Soil and Plant

ObjectiveThis study aimed to investigate the accumulation of heavy metals from organic fertilizer in soil and plant. MethodThree plots were chosen in Shanghai suburb to measure the heavy metal accumulation by monitoring their concentrations in soil and plant after organic fertilizer was applied. We also analyzed the correlations of the heavy metals in soil and plants. Single-factor pollution index and Nemerow’s synthetical pollution index were adopted to evaluate the heavy metal contamination in soils. Moreover, how many years before the heavy metal accumulation will exceed the environmental capability if 45 t/hm 2 organic fertilizer is applied every year was also estimated in the present study. ResultThe rules of heavy metals’ accumulation in soil changed with the various soil characters and pH. The average concentrations of Pb, Cd and As in the tested plants exceeded the limits. The average concentration of Cu in the tested soil shared positive correlation with that in the tested plants. The average concentration of Pb in the tested soil was negatively correlated with that in the tested plant while the other heavy metals didn’t show the rule like that. Organic fertilizer application caused no obvious pollution to the soils. Cu would exceed the standard environmental capacity within 15 years if 45 t/hm 2 organic fertilizer is applied every year, while for Hg, it will be 2 000 years. ConclusionWhen the excessive organic fertilizer is put into the land, the heavy metals from organic fertilizer would accumulate in soil and plant. With continued excessive fertilization, the heavy metals especially Cu would exceed the stan- dard environmental capacity. More attention should be paid to the inputting amount of the organic fertilizer.

Determinants of Marketability for Organic Biomass Liquid Fertilizer from Human Waste in Da Nang City, Vietnam

Recently, 90 tons of human waste per day are collected from private residences, offices, and public facilities in Da Nang City. Meanwhile, farmers in this region have to allocate 10% - 20% of rice sales for purchasing chemical fertilizer. Therefore, it is essential to be adopted more inexpensive organic fertilizer. To deal with these problems, Japan International Cooperation Agency (JICA) has signed a contract with Da Nang city government about human waste treatment and production of organic biomass liquid fertilizer (OBLF) in 2015. The aims of this project are to promote the use of OBLF in farming and improve public awareness of environmental protection. 530 respondents were interviewed at Hoa Vang districts of Da Nang city, and data was analyzed by Contingent Valuation Method (CVM) under double bounded dichotomous choice approach. The results have revealed that 436 respondents (82%) agreed to use OBLF. The farmers’ WTP depends on factors including household income, experience in using organic fertilizer, awareness of environment and training of organic fertilizer in the past. The estimated price for OBLF was 94,856 VND (4.0 USD)/ton. The cost that farmers paid for OBLF was lower than that of current available chemical fertilizers in Da Nang city. This proves that marketability seems to be existed for OBLF product in Da Nang city. From these findings, the government should have policies to support and subsidize the farmers to encourage them to use OBLF in a large scale of cultivation. Furthermore, establishment of a market to consume the organic products harvested from cultivated areas using OBLF is also recommended.

Effects of Combined Application of Biochar-based Organic Fertilizer and Reduced Nitrogen Fertilizer on Soil Enzyme Activity and Yield of Purple Cabbage(Brassica oleracea var.capita rubra)in Yuanmou County

[Objectives]In response to the issue of soil improvement in Yuanmou County,the effects of combined application of biochar-based organic fertilizer and reduced nitrogen fertilizer on soil nutrients,soil enzyme activity,and yield of purple cabbage(Brassica oleracea var.capita rubra)were investigated in the field base of Institute of Thermal Zone Ecological Agriculture,Yunnan Academy of Agricultural Sciences in Yuanmou County.[Methods]A total of 13 treatments were set up by applying biochar-based organic fertilizer at three levels of 15,30 and 45 t/hm^(2)(T_(1),T_(2),T_(3)),combined with top application of nitrogen fertilizer(urea)at four levels:375(N_1),300(N_(2)),225(N_(3))and 0 kg/hm^(2),with non-fertilizing treatment as control check(CK),in order to explore the optimal ratio for the combined application of biochar-based organic fertilizer with nitrogen fertilizer.[Results]The application of biochar-based organic fertilizer could significantly improve soil nutrients,enzyme activity,and purple cabbage yield.The improvement effect of combined application with nitrogen fertilizer was higher than that of single application of biochar-based organic fertilizer,and the improvement effect was enhanced with the application amount of biochar-based organic fertilizer increasing.The contents of organic matter and total nitrogen were the highest in treatment T_(3)N_(3),of which the values increased by 81.39%and 56.09%compared with the CK,respectively.The contents of soil hydrolyzable nitrogen,available phosphorus,and available potassium were all the highest under treatment T_(3)N_(2),with increases of 92.76%,171.01%and 235.50%,respectively.There was a significant positive correlation between the activity of soil catalase,urease,and sucrase and organic matter,total nitrogen,and available nutrients.The overall soil enzyme activity was relatively higher in treatment T_(3)N_(2).The yield of purple cabbage treated with biochar-based organic fertilizer combined with nitrogen fertilizer could reach 85750 kg/hm^(2),which was 94.78%higher than that treated with biochar-based organic fertilizer alone.Based on comprehensive analysis,the optimal combination ratio was 45 t/hm^(2)of biochar-based organic fertilizer and 300 kg/hm^(2)of urea(T_(3)N_(2)).[Conclusions]This study provides data support for the promotion of biochar-based organic fertilizers and reduced fertilizer in agricultural soil in the Dam area of Yuanmou County.

Yield, Growth and Vegetative Development Parameters Response of Dry Beans to Organic and Inorganic Fertilizers and Biofertilizer

As part of the promotion of common bean cultivation, fertilization methods will have to be proposed to growers. The aim of this study is therefore to develop a technical itinerary for dry bean fertilization. To this end, different types of chemical and organic fertilizers were evaluated on three dry bean varieties (HARI25/GHA19, HARI35/GHA19 and HARI36/GUI21). Seven (7) doses of chemical and organic fertilizers were used, including two controls (D0 with no fertilizer and D1, the reference dose using NPK base and cover fertilizers in the form of urea). The fertilization trial was set up as a Split-Plot design, with variety as the primary factor and dose as the secondary factor. The experiment was repeated three (3) times. The results showed that vegetative development parameters and fruit set rate varied according to the variety studied. For yield and its components, the treatments had a significant effect. Indeed, the response of varieties to fertilizers was specific. For each variety used, the optimum yield was obtained with a different treatment, thus highlighting the genotype effect of the dry bean varieties studied. Among the treatments tested, D4 (5 t organic fertilizer/ha) performed best in all three varieties, generating yield increases of 20%, 46% and 91% respectively.