Biofertilizer Treatments Research Articles

Integration of EM-X Biofertilization and Sowing Methods on Encouragement of Sunflower Productivity and Charcoal Rot Control under Reclaimed Soil Conditions

Two field experiments were carried out at 6 October farm, El-Nubaria Province, the desert backyard of El-Behaira Governorate- Egypt during the two successive summer seasons (2010 and 2011) to study the effect of the integration between different sowing methods and different bio fertilization treatments on sunflower (Helianthus annuus L.) var. Giza-102 productivity and charcoal rot disease management caused by Macrophomina phaseolina (Tassi) Goidunder the reclaimed soil conditions. Rides sowing methods were found to be more effective in reducing M.phaseolina population and charcoal rot, therefore enhance sunflower productivity compared to the other examined sowing methods. EM-X { EM1 + Bacillus subtilis + mycorrhiza + Azotobacter sp.} was found to be more effective in reducing M.phaseolina population and charcoal rot, therefore enhance sunflower productivity compared to the other examined biofertilization treatments including the conventional chemical fertilization as the control treatment. The integration between ridges sowing method with tillage and EM-X{ EM1 + B. subtilis + mycorrhiza + Azotobacter sp.} was found to be the furthermost advised agricultural practices under these conditions as land degradation neutrality (LDN) technology that enhances land cover and area unit productivity under these conditions.

Alleviation of heavy metals toxicity by the application of plant growth promoting rhizobacteria and effects on wheat grown in saline sodic field

ABSTRACTThe aim of the study was to determine tolerance of plant growth promoting rhizobacteria (PGPR) in different concentrations of Cu, Cr, Co, Cd, Ni, Mn, and Pb and to evaluate the PGPR-modulated bioavailability of different heavy metals in the rhizosphere soil and wheat tissues, grown in saline sodic soil. Bacillus cereus and Pseudomonas moraviensis were isolated from Cenchrus ciliaris L. growing in the Khewra salt range. Seven-day-old cultures of PGPR were applied on wheat as single inoculum, co-inoculation and carrier-based biofertilizer (using maize straw and sugarcane husk as carrier). At 100 ppm of Cr and Cu, the survival rates of rhizobacteria were decreased by 40%. Single inoculation of PGPR decreased 50% of Co, Ni, Cr and Mn concentrations in the rhizosphere soil. Co-inoculation of PGPR and biofertilizer treatment further augmented the decreases by 15% in Co, Ni, Cr and Mn over single inoculation except Pb and Co where decreases were 40% and 77%, respectively. The maximum decrease in biological concentration factor (BCF) was observed for Cd, Co, Cr, and Mn. P. moraviensis inoculation decreases the biological accumulation coefficient (BAC) as well as translocation factor (TF) for Cd, Cr, Cu Mn, and Ni. The PGPR inoculation minimized the deleterious effects of heavy metals, and the addition of carriers further assisted the PGPR.

Role of Bio-Fertilizer Treatments in Alleviating the Adverse Effect of Water Stress in Mangifera indica

WATER stress is one of the most important abiotic stresses that…….....may limit agriculture production worldwide. This work wascarried out on mango trees (Mangifera indica L.) tostudy the effect of exposure to different levels of drought stress (65, 75,85 and 100 % of full irrigation requirements), in addition, to evaluatingthe role of using some plant growth promoting rhizobacteria (PGRP);such as Azospirillum and Azotobacter, in alleviating drought-inducedchanges. Physiological and biochemical changes were determined inmango leaves after two seasons of different treatments. Resultsindicated that membrane stability, photosynthetic pigments andinsoluble sugar contents were significantly decreased with increasingdrought levels, while electrolyte leakage, soluble sugars, totalcarbohydrates and proline content were sharply increased compared tocontrol. Lipid peroxidation level and the activities of superoxidedismutase (SOD), peroxidase (POD) and catalase (CAT) enzymesshowed progressive increases with drought levels. Application of biofertilizersmay be effective in alleviating the adverse effect of waterstress. Bio-fertilizers caused marked increase in photosyntheticpigments and carbohydrate contents and a decrease in proline contentcompared to control.

Effect of sources and levels of sulphur and bio-fertilizer on growth, yield and quality of summer groundnut

A field experiment was conducted during summer season of 2015 to study the effect of sources and levels of sulphur and bio-fertilizer on growth, yield and quality of summer groundnut ( Arachis hypogaea L.) at Anand Agricultural University, Anand. The experiment was conducted in a loamy sand soil with 12 treatment combinations (2 source of sulphur, 3 levels of sulphur and 2 levels of bio-fertilizer). The study revealed that sources and level of sulphur as well as biofertilizer treatment significantly influenced all the yield attributing characters , pod and haulm yield. Sulphur applied @ 40 kg ha -1 through gypsum recorded an increase in pod and haulm yield to the tune of 11.51 and 9.69 per cent, respectively over elemental sulphur.

The role of organic/bio–fertilizer amendment on aggregate stability and organic carbon content in different aggregate scales

This study investigated the effects of different organic and bio–fertilizer (alone or in combination) applications on aggregate stability and organic carbon (OC) content in macro (2–1mm) and micro (0.25–0.050mm) aggregate sizes of clay loam (Typic Xerofluvent) textured soil. In addition, correlation between OC content and aggregate stability was determined. The study was conducted as a pot experiment under greenhouse conditions and was arranged in a completely randomized design with three replications. The treatments were: control (no fertilizer) (C), inorganic fertilizer (15:15:15 compound fertilizer+ammonium nitrate, 33% N) (F), mycorrhizal fungi (Glomus spp.) (M), microalgae (Chlorella spp.) (A), bacteria (Bacillus megaterium KBA–10+Pantoea agglomerans RK–134+Pseudomonas fluorescens FDG–37) (BMF), bacteria (Bacillus subtilis PA1+Paenibacillus azotofixans PA2) (BCP), vermicompost (V), vermicompost+mycorrhizal fungi (VM), vermicompost+microalgae (VA), vermicompost+bacteria (VBMF) and vermicompost+bacteria (VBCP) applied in 90days incubation period. At the end of the 90-day incubation period, organic and bio–fertilizer amendments had an increasing impact on aggregate stability and OC content in macro– and micro– aggregate scale. Especially, bio–fertilizers in combination with vermicompost mostly had stronger effects on stability and OC content of aggregates of both size classes in comparison with control and bio–fertilizer treatments alone. In addition, significant (p<0.05) and positive correlations were observed between stability and OC contents of macro (2–1mm) and micro (0.25–0.050mm) aggregates size classes in each treatment.

Effect of inorganic, organic and integrated nutrient management on productivity, profitability and soil health in maize (Zea mays)-potato (Solanum tuberosum)-onion (Allium cepa) cropping system in central plain zone of Uttar Pradesh

A field experiment on critical evaluation of inorganic, organic and integrated use of nutrient in terms of yield and soil health of maize (Zea mays) - potato (Solanum tuberosum) - onion (Allium cepa) cropping system was conducted at Kanpur during six consecutive years (2003–04 to 2008–09). The experiment was comprised of seven treatments, out of them one inorganic, one integrated, three organic and two were organic + bio-fertilizer. The highest productivity of maize cob, potato tuber and onion bulb was recorded with the application of 100% inorganic fertilizer, followed by integrated, organic and organic + bio-fertilizer treatments. In the initial year, the yield differences between inorganic and integrated and among integrated and organic treatment was wider and became narrower year after year of crop production. Potato equivalent yield was higher under 100% inorganic treatment (T7) and found comparable to T6(organic + bio-fertilizer) treatment. Soil properties after six crop cycle showed maximum improvement in organic carbon content and available status of nitrogen with organic and organic treatments, followed by integrated and inorganic treatment; while maximum improvement in available status of phosphorus and potassium were recorded with inorganic treatment, followed by integrated and organic

Effect of Azotobacter and Phosphobacteria on Yield of Wheat (Triticum aestivum)

The effect of inoculation by Azotobacter and Phosphobacteria regarding biofertilizer on growth and yield of wheat (Triticum aestivum) was studied in experimental field of K.V.K. Allahabad (U.P) during the rabi season of 2011-12. The field trial consisted of 9 bio-fertilizer treatments viz., seed treatment with liquid PSB (Phosphate Solubilizing Bacteria) inoculants (T1 ), seed treatment with powder PSB inoculants (T2 ), soil treatment with liquid PSB inoculants (T3 ), soil treatment with powder PSB inoculants (T4 ), soil treatment with liquid Azotobacter inoculants (T5 ), soil treatment with powder Azotobacter inoculants (T6 ), seed treatment with liquid Azotobacter inoculants (T7 ), seed treatment with powder Azotobacter inoculants(T8 ) & un-inoculated(Control)(T9 ). Results showed that plant height, number of tillers/plant, number of spikes/ plant, spike length, no. of grains/spike, grain yield (kg/ha) and straw yield (kg/ha) were significantly higher in plants inoculated with seed treatment especially PSB in liquid form. Interaction effect of liquid phosphobacteria with seed treatment was a good combination. However, the maximum grain yield was recorded with application of liquid phosphobacteria followed by Azotobacter. The highest gross return (Rs. 72832/ha) and net return (Rs.64532/ha) was obtained with liquid phosphobacteria seed treatment combination.

Biofertilizers as agent against the harmful effect of salinity on wheat

The objective of this study was to investigate the ability of Biogen and Cyanobacteria as biofertilizers for substitution the normally used chemical fertilizer (Urea), and to ameliorate the harmful effect induced by salinity on two wheat cultivars Sakha 93 (salt tolerant) and Gemiza 10 (salt sensitive). The results showed that application of two salinity levels (100 and 200mM NaCl) caused reductions in the germination percentage and the other measured growth parameters (plant height, No of leaves, leaf area, No of internodes and fresh and dry weights) and in the rate of different measured metabolic processes (pigment content, photosynthetic activity, total soluble carbohydrates and protein content) and most yield parameters (plant height, no of spike/m2, spike length, no of grain/spike, grain weight/spike, 1000-grain weight, carbohydrates, protein content, wet, dry gluten and ash content, N, P and K content in seed). The results showed that application of both biofertilizers could reduce the recommended dose of urea by about 50%. On the other hand application of each biofertilizers significantly ameliorated the harmful effect induced by salinity on both wheat cultivars. However, the ameliorative effect was more significant in biogen than cyanobacterial fertilizers for both cultivars. The amelioration effect could be attributed to change in the antioxidant enzyme activity and appearance of some protein bands in response to the different biofertilizer treatment. Accordingly, we recommend the use of the two biofertilizers for partial substitution (50%) of the normally used chemical fertilizer (urea). Furthermore, we recommend the use of both biofertilizer for the salty land (100-200mM NaCl).

Effect of Some Macro Elements and Bio Fertilization on The Growth, Yield and Chemical Composition of Coriander Plant (Coriandrum sativum L.)

Coriander (Coriandrum sativum, L.) is an important medicinal herbs worldaride. The objective of this study was to investigate the effect of mineral and bio fertilization on vegetative growth, yield, and chemical composition including essential oil; as well as, major compounds of Coriandrum sativum L. Therefore, two filed experiments were conducted at the Experimental Farm of the Nubaria station-ELbeharia, Egypt during 2013/2014 and 2014/2015 growing seasons. The experimental design was split plot design with three replicates. Mineral fertilizer levels (control, 50% NPK, 75% NPK and 100% NPK) occupied the main plots. The sub plot was assigned to five bio-fertilizer treatments, i.e.,uninoculation, phosphorein, cerealine, potassomage and mixed bio-fertilizer). Theresultsobtained could be summarized as follows: (1) the addition of mineral fertilizer at rate of 100% resulted in a significant increment in vegetative growth,yield and chemical composition of coriander plants during both seasons, (2) the application of 100%NPK with mixture of biofertilizers (phosphorein +cerealine + potasisomage) was the best combination to obtain the highest mean values of plant height, number of branches/plant, fresh and dry weights of herb/plant, number of umbels/plant, 100-seed weight and seed yield/fed, as well as, oil %, but major compounds resulted fromcombination of 75 % NPK with potassomage and mix of biofertilizers for the coriander were tested in this study. However, of traits under study increased significantly, due to inoculation treatments over the uninoculation (control) one and the mixture of biofertilizers was the best treatment. This investigation suggests the need for more studies concerning the effect of NPK fertilizer rates and biofertilizers on coriander plants under different environments using different types of soil in order to reach the optimum combination to achieve the best yield.

Effect of Some Organic, Inorganic and Biofertilization Treatments on Fruiting of Early Sweet Grapevines

Effect of Some Organic, Inorganic and Biofertilization Treatments on Fruiting of Early Sweet Grapevines

Growth of lentil (Lens culinaris Medikus) as influenced by phosphorus, Rhizobium and plant growth promoting rhizobacteria

The experiment was conducted to study the effect of four levels of phosphorus (0, 20, 30 and 40 kg P2O5 ha-1) and four biofertilizer treatments [uninoculated control, Rhizobium, plant growth promoting rhizobacteria (PGPR) and Rhizobium + PGPR] on growth and grain yield of lentil. The experiment was conducted in factorial randomized complete block design (RCBD) with three replications. The periodic data recorded at 30, 60, 90, 120 days after sowing (DAS) and at harvest showed that the highest growth in various parameters i.e. plant height, branches plant-1 and shoot dry matter accumulation was recorded with application of 40 kg P2O5 ha-1, however, it was at par with 30 P2O5 ha-1. Among the biofertilizers, Rhizobium + PGPR treatment gave maximum values of growth parameters like plant height, branches plant-1 and shoot dry matter accumulation at all the stages. At 30-60 DAS, the maximum crop growth rate (CGR) was recorded with the application of 40 kg P2O5 ha-1 (71.3 kg ha-1 day-1) and co-inoculation of Rhizobium and PGPR (72.0 kg ha-1 day-1). Application of 40 P2O5 ha-1 and use of coinoculation (Rhizobium + PGPR) provided the highest grain yields. The study highlights the importance of phosphorus application and biofertilizers inoculation for improving the growth and grain yield of lentil.

Effect of biofertilizer and some plant growth hormones on germination and seedling character of Sesame (Sesamum indicum (L.)

In this study, the effect of plant growth regulators (IAA and GA3 ) and living bacteria containing (Azospirillam) biofertilizer were investigated on the germination, root length and shoot length. The seeds of sesame variety TMV – 7 were treated with different concentration of gibberlic acid (1.0mgL-1, 1.5 mgL-1, 2.0 mgL-1 and 2.5 mgL-1) and indole acetic acid(1.0mgL-1, 1.5 mgL-1, 2.0 mgL-1 and 2.5 mgL-1). The biofertilizer, Azospirillam was mixed with rice Starch in a container to form slurry . Germination, root length and shoot length were evaluated. From the results, it was observed that the biofertilizer had regulatory effect on seed germination, root length and shoot length over control. In plant growth hormones treated plants, 2.0mg/l of GA3 shows maximum effect compared to IAA. It can be concluded that, the biofertilizer treatment stimulated the germination and growth by excreting phytohormones and enhancing the nutrient mobilization from the seed.

Effects of biofertilizers and cycocel on some physiological and biochemical traits of wheat (Triticum aestivum L.) under salinity stress

ABSTRACTIn order to study the effects of biofertilizers and cycocel on some physiological and biochemical characteristics of wheat (Triticum aestivum L.) under salinity condition, a factorial experiment was conducted based on randomized complete block design with three replications under greenhouse condition in 2015. Treatments were included salinity in four levels [no salt (control or S0), salinity 30 (S1), 60 (S2) and 90 (S3) mM NaCl equivalent of 2.76, 5.53 and 8.3 dS m−1, respectively], four biofertilizers levels [no biofertilizer (F0), seed inoculation by Azotobacter chrocoocum strain 5 (F1), Pseudomonas putida strain 186 (F2), both inoculation Azotobacter + Pseudomonas (F3)] and three cycocel levels [without cycocel as control (C0), application of 600 (C1) and 1000 (C2) mg L−1]. Results showed that salinity severe stress (90 mM) decreased chlorophyll content, relative water content (RWC), total chlorophyll, photochemical efficiency of PSII and yield of wheat. Whereas, soluble sugars and proline content, electrical conductivity (EC), the activity of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) enzymes were increased. Similar results were observed in CAT, POD and PPO activities due to inoculation by biofertilizers and cycocel. Salinity at 30 mM increased the photochemical efficiency of PSII and chlorophyll content in plants grown under biofertilizer and cycocel treatment but with increasing salinity up to 90 mM mentioned parameters were decreased. The highest proline and soluble carbohydrate at all salinity levels were observed in plants treated in the highest cycocel level and Azotobacter+ Pseudomonas application. Generally, it was concluded that biofertilizers and cycocel can be used as a proper tool for increasing wheat yield under salinity condition.

Effect of Mineral, Organic and Bio-fertilization on Growth and Production of Moringa (Moringa oleifera, L.) Plants

Two filed experiments were carried out at the Experimental Farm, Faculty of Agriculture (Saba Basha), Alexandria University at Abees region, Alexandria, Egypt during the two growing seasons of 2014 and 2015 to study theeffect of mineral, organic and bio-fertilization on growth and productivity of moringa plants (Moringa oleifera, Lam).The experimental design was split plot were three replicates. The main plot were conducted for the five combination of organic manure plus mineral fertilizer of (100% organic, 75% organic manure + 25% mineral, 50% organic manure + 50% mineral, 25% organic manure + 75% mineral and 100% mineral), while, the four bio-fertilization treatments were uninoculation, phosphorein, A- mycorrhizal and cerealine were arranged in the sub-plot. The main results could be summarized as follows: (1) The application of 75% organic manure + 25% mineral; gave the highest mean values of all studied characters, (2) the application of 75% organic manure + 25% mineral with A- mycorrhizal inoculation was the best combination to obtain the highest mean values of plant height, stem length, stem diameter, number of branches /plant, fresh and dry weights/plant, K (%), total carbohydrate (%) and vitamin (C). However, all traits under study increased significantly due to inoculation treatments over the application 100% mineral with uninoculation treatments.

Interactive Effect of Different Phosphoure Levels, Biofertilizer and Organic Fertilization on Phosphorus Availability and Uptake in Corn Plant (Zea mays L.)

This experiment aims at testing the activity of biofertilizer, level of phosphorus and humic acid on P availability in the soil. The experiment has been executed in wood shade house of Soil and Water Resource Department College of Agriculture, Abu-Ghraib. Soil is collected from the soil surface (0-30 cm) of the field experiment, passed through the sieve of 4 mm then sterilized with methylbromide and packed at the rate of 5 kg soil / plastic pot. The experiment involves three levels of P fertilizer (0 , 30 and 60 kg P ha-1) P0, P1 , P2, three levels of humic acid (0 , 20 and 40 kg H.A. ha-1), and two levels of biofertilizer BO (seed not inoculated) and B1 (seed inoculated with biofertilizer) and all possible combinations among these variables. There are 18 treatments each replicated three times. The N and K fertilizers were added to all experiment units at the rate of 240 kg N and 120 kg K . ha-1 . The RCD is adopted. P fertilizer and humic acid are added and mixed with soil surface in pots, and corn seed of biofertilizer treatments inoculated. Corn seeds of Var. 5018 are planted at the rate of 8 seeds pot-1 in 10-5-2013, then seedling thinned to 4 plant pot-1 after 10 days from planting. The results can be summarized as following: 1. The results from pot experiment show active biofertilizer as there is an increase in availability of P in the soil and its uptake by corn plant. Moreover, there are significant increases in dry weight, weight of corn roots by inoculating corn seed with biofertilizer. 2.There is no significant difference between 30 kg P ha-1 and 60 kg P ha-1 on the most of the studies variables (above).

Response of Sesame Plants Productivity and Seed Quality to Different Fertilization Methods

Two filed experiments were conducted at the Experimental Station Farm of Faculty of Agriculture (Saba Basha), Alexandria University during 2014 and 2015 seasons. The objective of this study was to investigate the response of sesame plants productivity and seed quality to different fertilization methods. The results could be summarized as follows: Foliar spraying of amino acid gave higher plant height, number of pods/plant, weight of pods (g), number of seeds/pods, 1000-seed weight (g), seed yield (g/plant), seed, straw and biological yields (ton/ha), as well as, oil yield (t/ha) in both seasons. Whereas, phosphorus fertilizer at 30 unit resulted in a significant increment in yield components and chemical composition of sesame seed in both seasons. Significant variation was recorded between the tested biofertilizer treatments for yield, yield components and percentages of oil, N, P and K of sesame seeds in both seasons. The effective treatments for all characters and chemical composition were obtained from foliar spraying of amino acid with phosphorein inoculation in both seasons. The effective treatments for oil percentage, phosphorus percentage and potassium percentage in both seasons were obtained from applying phosphorus at 30 units with phosphorein inoculation.

Effect of Potassium, Phosphorus and Bio- fertilization on Barley Productivity

This study was carried out at theExperimental Farm of Faculty of Agriculture (Saba-Basha), Alexandria University, Egypt ,at Abees region during 2013/2014 and 2014/2015 seasons to study the effect of phosphorus and potassium fertilizer rates and different biofertilization treatments on growth, yield, yield components and chemical grain contents of six rows barley (Hordeum vulgare, L.) variety Giza 123.The experimental design used was a split- split plot with three replicates, where the three phosphorus application rates (0, 37.2 and 74.4 kg P2O5 /ha) were randomly distributed on main plot, three potassium fertilizer levels (0, 57.6 and 115.2 kg K2O/ha) were located in sub-plots, whereas the three biofertilization treatments i.e. uninoculation, inoculation with phosphorein and inoculation with potassmage were occupied the sub-sub plots. Application of 74.4 kg P2O5 /ha significantly gave the highest value of yield and its attributes i.e. plant height (cm), number of tillers/m2, spike length (cm), number of spikes/m2, number of grains /spike, spike weight/m2, 1000-grain weight (g), grains yield (t/ha), biological yield (t/ha) and harvest index (%) and N, P, K and protein percentages in grains. Increasing potassium application of 115.2 kg K2O/ha increased the yield and its components, as well as, all chemical composition in grains. Inoculation potassmage gave the highest yield and its components, also N, P, K and protein in grains. Also, the obtained results indicated that the favorable effect of the highest levels of the studied factors, i.e., 74.4 kg P2O5 /ha, 115.2 kg K2O/ha and inoculation with potassmage on barley plant growth, yield and its attributes and grain chemical contents in grains.

EFFECT OF MINERAL AND BIOFERTILIZATION TREATMENTS ON: 1- VEGETATIVE GROWTH AND FLOWERING OF GLADIOLUS PLANTS

A field experiment was carried out at Nursery of Ornamental Plants, Fac. Agric., Minia Univ., Egypt during the two successive seasons of 2013/2014 and 2014/2015 to investigate the effect of NPK (0, 50, 75 and 100% of recommended dose) and biofertilization (phosphorein and/or E.M.) treatments on growth and flowering of Gladiolus grandiflorus cv. White Prosperity. Results showed that vegetative growth traits (leaf length, number of leaves/plant and leaves dry weight/plant) and flowering parameters (length of spike, rachis length, number of florets/spike, first floret diameter and fresh weight) were gradually increased by increasing the levels of NPK fertilizer. Also, all biofertilization treatments significantly increased all vegetative growth parameters as well as all flowering characters in comparison with the control. Phosphorein plus effective microorganisms (E.M.) treatment was more effective in this concern. It was found that the use of NPK (75% from the recommended dose) plus phosphorein + E.M. improved the growth and flower production of gladiolus plants compared with the other treatments.

Effect of nitrogen fertilization and Bacillus licheniformis biofertilizer addition on the antioxidants compounds and antioxidant activity of greenhouse cultivated tomato fruits (Solanum lycopersicum L. var. Sheva)

Tomato is one of the principal crops worldwide due to its large consumption. In this work, biofertilization treatments, based on Bacillus licheniformis, with different nitrogen fertilization doses were investigated to improve the functional quality of tomato under greenhouse conditions. Treatments tested used nitrogen fertilization only (NF) or nitrogen combined with biofertilization (BF) with the following nitrogen doses: 0, 25, 50, 75 and 100% of the recommended nitrogen dose. The lycopene content increased with the nitrogen dose with the BF treatments resulting in lower lycopene contents in comparison with the NF counterparts. The contents of hydrophilic antioxidant compounds (vitamin C and total phenols), as well as antioxidant activity (DPPH scavenging capacity and FRAP) increased as the nitrogen dose was reduced. The biosynthesis of the hydrophilic antioxidant compounds appears to be an induced resistance mechanism caused by the nitrogen-deficiency stress. In addition, B. licheniformis had a positive net effect on the synthesis of flavonoids by the plant at a 75% nitrogen dose. A two-factorial ANOVA (nitrogen fertilizer dose×biofertilizer addition) evidenced that the greatest contribution of the nitrogen fertilizer dose was to the total phenols content and antioxidant activity, while the biofertilizer mainly contributed to the vitamin C and lycopene contents. In general, the content of antioxidant compounds was affected by the interaction of the two factors. Significantly, this is the first report about the combined effect of the nitrogen fertilization dose and biofertilization addition during tomato cultivation, on the content of antioxidant compounds in tomato fruits.

Organic plum cultivation in the Mediterranean region: The medium-term effect of five different organic soil management practices on crop production and microbiological soil quality

Organic farming practices recommended by European regulations offer an alternative to conventional soil management, but these practices should be analyzed in greater depth to assess their effectiveness on different plants and in different local conditions. Accordingly, this study evaluates the efficacy of five different organic management strategies on an organic plum farm in Southeastern Spain. This study was conducted for a period of six years and the five different organic treatments were applied in triplicate in 256m2 plots randomly distributed in three blocks (15 plots in total); each plot had 16 plum trees. Every year crushed pruning wastes were incorporated into the soil in all the experimental plots. One triplicated plot only received this aforementioned treatment (crop biomass treatment, CB). The rest of the plots also received one of the following treatments: (i) the addition of a commercial product for organic agriculture based on bacteria (biofertilizer), composed of Azospirillum brasilense (bacteria fixing N) and Pantoea dispersa (bacteria with a capacity for solubilising phosphates and stimulating plant growth) (biofertilizer treatment, B); (ii) the annual addition of 20t/ha of certified commercial organic compost (annual compost treatment, AC); (iii) the biennial addition of 20t/ha of certified commercial organic compost (biennial compost treatment, BC); and (iv) the sowing and subsequent incorporation of a mixture of 60% Avena sativa and 40% Vicia sativa (green manure treatment, GM). Each year the following indicators of ecosystem sustainability related to soil microbiological characteristics and carbon fixation were measured after harvest, in addition to plum yield: organic carbon (Corg), water soluble C, humic substances and humic acid C, microbial biomass C, respiration, ATP, dehydrogenase activity and hydrolase enzymes (alkaline phosphatase, urease and beta-glucosidase) activities. The two way ANOVA of the results indicated that all the above parameters were significantly affected (p≤0.001) by both, treatment and time. The interaction of treatment and time also significantly affected all of these parameters, except for yield and dehydrogenase activity. Composts not only produced better results than green manure cover crops and biofertilizer treatments in terms of plum yields, but they also brought about higher increases in the soil C pool and greater improvements in soil microbiological characteristics. In the six years of the study, compost-treated soils showed higher average plum yields and higher organic carbon, humic substance and humic acid contents than the rest of treatments. The size and activity of microbial population was also greater in the compost-treated soils, reflected in the higher values found in these soils for microbial biomass C, soil respiration, ATP (adenosine-tri-phosphate) content and dehydrogenase and hydrolases activity. Nevertheless, yields when compost was added biennially (BC) tended to be higher than in the annual compost treatment (AC) in most years as well as on average, although the differences were usually not significant. Yields in the sixth crop showed a high positive correlation with soil humic substances and humic C content (p≤0.01), as well as with Corg, microbial biomass C and phosphatase and urease activity (p≤0.05).