Carrier-based and liquid bioinoculants of Azotobacter and PSB saved chemical fertilizers in wheat (Triticum aestivum L.) and enhanced soil biological properties in Mollisols

Abstract

The increasing cost and imbalanced use of chemical fertilizers in wheat (Triticum aestivum L.) stressed the need to explore the potential of bioinoculants of Azotobacter and PSB for saving fertilizer N and P. Field experiments conducted for two years in a Mollisol at Pantnagar revealed maximum plant height, grain and straw yields and nutrient uptake by wheat with application of 100% NP. However, soil application of carrier-based biofertilizer at 10?kg?ha^?1 and liquid-based biofertilizers at 625 and 1250?mL?ha^?1 rates in combination of 75% NP were at par with 100% NP by recording significantly more mean plant height at different intervals, grain yield, by 10.9, 10.5 and 10.8%, and straw yield, by 8.6, 8.2 and 9.1%, over 75% NP, respectively. These treatments also accumulated significantly more N, P and K in plant at different age and; grain and straw. An application of liquid biofertilizer at 1250?mL?ha^?1 with 75% NP gave maximum population of Azotobacter and PSB, microbial biomass C and activities of acid and alkaline phosphatase in soil at different crop age. The carrier and liquid formulations of the biofertilizers were comparable in their performance. Irrespective of formulation and doses, application of biofertilizers in soil was found better than seed treatment for different recorded parameters. An application of 625?mL?ha^?1 liquid biofertilizers in soil with 75% NP was found optimum for the growth, yield and nutrients uptake and soil biological properties.     

Contribution of Biofertilizers and Fertilizer Nitrogen to Nutrient Uptake and Yield of Egyptian Winter Wheat

ABSTRACT

Nutrient uptake and grain and straw yield of Egyptian winter wheat (Triticum aestivum L. Merr.) were evaluated for two site-years after the seed inoculation with two biofertilizer products, Phosphorien, containing the phosphorus (P)-solubilizing bacteria Bacillus megatherium, and Nitrobien, containing a combination of nitrogen (N)-fixing bacteria Azotobacter chroococcum and Azospirillum liposerum. Ammonium nitrate and polymer-coated urea fertilizers were applied to plots alone and together with the biofertilizers at rates of either 83 kg N ha^?1 or 186 kg N ha^?1 for comparison. The highest grain yield (5.76–6.74 Mg ha^?1) and straw yield (11.49–13.32 Mg ha^?1) occurred at the highest fertilizer rates with N fertilizer. There was a slight additional increase in grain and straw yields when a biofertilizer was applied along with N fertilizer. A slightly higher grain and straw yield was measured with the polymer-coated urea treatment than with the ammonium nitrate treatment. The biofertilizer materials were not as effective as N fertilizers in producing grain (4.02–4.09 Mg ha^?1) or straw (7.71–8.11 Mg ha^?1) for either year, although the Nitrobien + Phosphorien combination increased these parameters over the N-fertilizer control. The effect of the Nitrobien biofertilizer in increasing grain yields was equivalent to a urea application rate of about 13 kg N ha^?1. Biofertilizer inoculations increased iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations in wheat tissue (at boot stage), but these higher levels did not influence grain or straw yield.     

Effects of Organic Amendments on Productivity and Profitability of Bell Pepper–French Bean–Garden Pea System and on Soil Properties during Transition to Organic Production

A transition period of at least 2 years is required for annual crops before the produce may be certified as organically grown. There is a need to better understand the various management options for a smooth transition from conventional to organic production. The purpose of this study was to evaluate the effects of different organic amendments and biofertilizers (BFs) on productivity and profitability of a bell pepper–french bean–garden pea system as well as soil fertility and enzymatic activities during conversion to organic production. For this, the following six treatments were established in fixed plots: composted farmyard manure (FYMC, T₁); vermicompost (VC, T₂); poultry manure (PM, T₃) along with biofertilizers (BF) [Rhizobium/Azotobacter + phosphorus solubilizing bacteria (Pseudomonas striata)]; mix of three amendments (FYMC + PM + VC + BF, T₄); integrated nutrient management (FYMC + NPK, T₅); and unamended control (T₆). The yields of bell pepper and french bean under organic nutrient management were markedly lower (25.2–45.9% and 29.5–46.2%, respectively) than with the integrated nutrient management (INM). Among the organic treatments, T₄ and T₁ produced greater yields of both bell pepper (27.96 Mg ha^?1) and french bean (3.87 Mg ha^?1) compared with other treatments. In garden pea, however, T₄ gave the greatest pod yield (7.27 Mg ha^?1) and was significantly superior to other treatments except T₅ and T₁. The latter treatment resulted in the lowest soil bulk density (1.19 Mg m^?3) compared with other treatments. Similarly, soil organic C was significantly greater in all the treatments (1.21–1.30%) except T₂ compared to T₆ (1.06%). Plots under INM, however, had greater levels of available nitrogen–phosphorus–potassium (NPK) than those under organic amendments. T₁ plots showed greater dehydrogenase and acid phosphatase activities compared with other treatments. However, T₄ and T₅ plots had greater activities of β-glucosidase and urease activities, respectively. The cost of cultivation was greater under organic nutrient management (except T₂) compared with INM. The latter treatment gave greater gross margin and benefit/cost (B/C) ratio for all vegetables, except that T₂ gave greater B/C ratio in garden pea compared with other treatments. We conclude that T₁ and T₄ were more suitable for enhancing the productivity of bell pepper–french bean–garden pea system, through improved soil properties, during transition to organic production.     

Microbial Dynamics,Root Colonization,and Nutrient Availability as Influenced by Inoculation of Liquid Bioinoculants in Cultivars of Apple Seedlings

The present study investigates the performance of recommended doses of chemical fertilizer (RDF) and locally isolated strains of Azotobacter, Azospirillum, and arbuscular mycorrhizal fungi (AMF) inoculated either solely or in combination with seedlings of Red Delicious and Lal Ambri cultivars. The RDF (T₇) treatment recorded significantly greater vegetative growth and leaf nitrogen (N), phosphorus (P), and potassium (K) contents over multi-inoculation of Azotobacter + Azospirillum + AMF (T₆) but root colonization and microbial counts decreased significantly. Inoculation of Azotobacter + Azospirillum + AMF (T₆) was superior over sole and dual inoculation with respect to vegetative growth and nutrient contents in leaves and soil but had significant greater counts of Azotobacter, Azospirillum, and Pseudomonas than RDF. Greatest root colonization (34.0 and 35.1%) was recorded in Azotobacter + Azospirillum + AMF (T₆) followed by AMF (T₄) treatment (29.3 and 32.0%) in Red Delicious and Lal Ambri seedlings, respectively. Overall, it can be inferred that multiinoculation of synergistically interacting bioinoculants may be helpful in the establishment of healthy organic apple orchards.     

Effect of biofertilizers application on the growth of Eucalyptus grandis seedlings under greenhouse conditions

Abstract

To investigate the effect of biofertilizers on the growth and yield of Eucalyptus grandis seedlings, greenhouse experiments were performed applying fertilizers based on agricultural byproducts, inoculated with nitrogen-fixing bacteria of the genera Azotobacter spp and Azospirillum spp. For the biofertilizers formulation, a nitrogen-fixing bacteria consortium was inoculated, and the experimental design was a 2?×?2 × 2 factorial arrangement, the factors were nitrogen source (NS: chicken manure), source of carbon (CS: eucalyptus leaf litter) and source of micronutrients (RS: rhizospheric soil) with two dose levels, inoculated with a consortium of Azotobacter spp and Azospirillum spp. The optimal time production of the best biofertilizers was 30?days, with the highest density of Azospirillum (9.23 × 10⁶ CFU·g^?1) and Azotobacter (19.3 × 10⁶ CFU·g^?1), and total nitrogen contents in the range of 2.15-5.64%, released into the biofertilizers with chicken manure and bioaugmented with the bacterium consortium. The treatment with the highest dose of biofertilizer, 500?g, showed the most significant effect on seedling development, increasing growth, stimulating rooting and the highest increase in leaf number. The results show that biofertilizers contributed to Eucalyptus grandis crop yield, and biofertilizers are proposed as an alternative for implementing sustainable soil management in the forest sector.     

Substitution of mineral fertilizers with biofertilizer: an alternate to improve the growth,yield and functional biochemical properties of strawberry (Fragaria × ananassa Duch.) cv. Camarosa

Abstract

An experiment was conducted to substitute mineral fertilizers with biofertilizers in strawberry to work out the yield, quality of strawberry and soil fertility. A 25% substitution of mineral fertilizer with biofertilizer increased the number of fruits/plant along with improving Juice content (89.55%), Total soluble solids (10.35°B), total sugar (6.69%), ascorbic acid (43.80?mg 100?g^?1), anthocyanin content (81.05?mg 100?g^?1), total phenol (5.97?mg Gallic acid equiv. g^?1), flavonoids (0.12?mg g^?1) and antioxidant capacity (2.13?µmol. Trolox equiv. 100?g^?1). The available N and K content in post-harvest soils were improved significantly with 75% RDF + Azospirillium @ 2?g plant^?1 + PSB @ 2?g plant^?1 + topdressing of 25% K treatments (200.10 and 211.70?kg ha^?1, respectively). Viable count of soil microorganisms (Bacteria, actinomycetes and fungi) was also estimated maximum (4066, 190 and 11.33?×?10⁴ cfu g^?1?dry soil, respectively) with substitution of 25% of mineral fertilizer either with Azotobacter or Azospirillum.     

Effect of Long-Term Integrated Nutrient Management (INM) Practices on Soil Nutrients Availability and Enzymatic Activity under Acidic Inceptisol of North-Eastern Region of India

ABSTRACT

Soil acidity is one of the main limitations for optimal use of land resources for better crop production. And, long-term fertilization experiments found to be helpful in increasing the nutrient supply in these acidic soils. Keeping this in view, a field experiment on rice was carried out by applying biofertilizers and enriched compost in an acidic Inceptisol of Assam over 10 successive years (2006–15) to examine its effects on nutrient availability and soil enzymatic activity. This experiment had five treatments viz. absolute control (T₁), 100% recommended doses (RD) of inorganic NPK (T₂), 50% RD of inorganic NP + 100% K +biofertilizers (T₃), 50% RD of inorganic NP + 100% K +1 tonne enriched compost ha^?1 (T₄) and 25% RD of inorganic NP + 100% K +2 tonnes enriched compost ha^?1 (T₅) under randomized block design with four replications. After completing 10 years of experiment, it was observed that integrated use of enriched compost and biofertilizers with reduced doses of inorganic fertilizers enhanced the soil enzymatic activity as well as nutrient availability in rice grown in acidic clay loam soils of Assam. Application of biofertilizers and enriched compost had positive impact on plant accessible nitrogen, phosphorus and potassium in soil as compared to inorganic fertilizers. Also soil organic matter content increased considerably by these treatment. Integrated nutrient management practice in rice had also significantly enhanced the dehydrogenase, fluorescein diacetate and phospho-monoesterase activity in soil.     

Evaluation of inoculation with nitrogen and phosphorus biofertilizers on yield and radiation use efficiency of black cumin (Nigella sativa L.) under Mashhad climatic conditions

The purposes of this study were evaluate the effects of biofertilizers inoculation on growth indices, yield and radiation use efficiency (RUE) in black cumin under Mashhad climatic conditions. This field experiment was carried out based on a randomized complete block design with three replications. This experiment was performed at Agricultural Research Station, Ferdowsi University of Mashhad, Iran, during two growing seasons 2007–2008 and 2008–2009. Treatments were (A) Azotobacter paspali, (B) Azospirillum brasilense, (C) Rhizophagus irregularis, A + C, B + C, A + B, A + B + C and control. In all treatments, except control, 100 g of seeds were inoculated with15 mg of each biofertilizer. Results indicated that leaf area index (LAI) and accumulative dry matter (DM) showed an increasing trend up to 1863°Cd and a short declining trend afterwards. The relation between accumulative DM and absorbed photosynthesis active radiation (PARa) was linear. Radiation use efficiency (RUE) fluctuated from 0.55 gMJ^?1 (control) to 0.89 gMJ^?1 (B+C). Inoculation with biofertilizers enhanced root development and hence availability of moisture and nutrients, particularly nitrogen and phosphorus. Since these ecological fertilizers produce many growth regulators for the plant which promote LAI and accumulative DM and therefore yield, PARa and RUE enhanced.     

Symbiotic parameters,growth, nutrient accumulation,productivity and profitability as influenced by integrated nutrient management in lentil (Lens culinaris)

Field experiments evaluated the effects of integrated nutrient management on symbiotic parameters, growth, nutrient accumulation, productivity and profitability of lentil (Lens culinaris Medikus). Application of recommended dose of nutrients (RDN, 12.5 kg N ha^?1 + 40 kg P₂O₅ ha^?1) + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers [Rhizobium + phosphate solubilizing bacteria (PSB) + plant growth promoting rhizobacteria (PGPR)] + 1.0 g ammonium molybdate kg^?1 seed recorded the highest number & dry weight of nodules, leghaemoglobin content, root & shoot dry weight, plant height, number of pods plant^?1 and 100-seed weight. The next best treatment was RDN + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed. On the basis of mean of three-year data, the treatment of RDN + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed proved the best in realizing the highest grain yield (34.0%), gross returns (34.0%) and net returns (54.8% higher over control). Nitrogen, phosphorus and potassium in the grains and straw were significantly improved where RDN was applied in combination with seed inoculation, basal application of ZnSO₄ and seed treatment with 1 g ammonium molybdate than their single applications.     

Effect of Predominant Integrated Nutrient Management Practices on Soil Quality Indicators and Soil Quality Indices under Post Monsoon (Rabi) Sorghum (Sorghum Bicolor) in Rainfed Black Soils (Vertisols) of Western India

A long-term study was conducted to study the impact of integrated nutrient management on soil quality in post-monsoon sorghum (Sorghum bicolor) at Solapur in Maharashtra State in Western India under All India Coordinated Research Project for Dryland Agriculture. The experiment was laid out with ten Integrated Nutrient Management Treatments in a randomized block design with three replications. The results of the study indicated that among all the integrated nutrient management treatments practiced, the application of 25 kg nitrogen (N) ha^?1 through crop residue (CR) + 25 kg N ha^?1 (urea) showed the highest soil quality index of 2.36, which was at par with other treatments receiving farmyard manure (FYM) and crop residues along with urea. The relative order of performance of the integrated nutrient management treatments in influencing soil quality was: T₆: 25 kg N ha^?1 (CR) + 25 kg N ha^?1 (urea) (2.36) >T₅: 25 kg N ha^?1 (FYM) (2.31) > T₇: 25 kg N ha^?1 (FYM) +25 kg N ha^?1 (urea) (2.30) = T₈: 25 kg N ha^?1 (CR) +25 kg N ha^?1 (Leucaena loppings) (2.30) > T₁₀: 25 kg N ha^?1 (Leucaena loppings) +25 kg N ha^?1 (urea) (2.17) > T₄: 25 kg N ha^?1 (CR:crop residues) (2.16) > T₉: 25 kg N ha^?1 (Leucaena loppings) (2.15) > T₃: 50 kg N ha^?1 (urea) (2.10) > T₂: 25 kg N ha^?1 (urea) (1.99) > T_1: 0 kg N ha^?1 (control) (1.77). The results of the study also indicated that average percent contribution of each soil key indicator towards soil quality indices was: pH (3.97%), EC (1.94%), organic carbon (18.6%), available P (2.80%), available K (6.57%), exchangeable Ca (7.02%), available S (3.45%), Available Zn (17.9%), dehydrogenase (DHA) (16.2%), microbial biomass carbon (MBC) (18.5%) and mean weight diameter (MWD) (3.14%). Thus, the results of the present study will be highly useful to the land managers in planning effective management of soil quality.     

Integrated Nutrient Management Affects Fruit Yield of Sapota (Achras zapota L.) and Nutrient Availability in a Vertisol

ABSTRACT

We studied the effect of integrated nutrient management (INM) combinations on supplement of plant nutrient for quantitative and qualitative fruit production in sapota. Thus, 17 combinations of INM practices were evaluated on fruit yield of sapota and nutrient availability in a Vertisol of Chambal region, India. The results demonstrated that almost all treatment combinations comprised of recommended dose of fertilizer (RDF), i.e. 1,000:500:500 g NPK plant^?1 with application of organic and inorganic sources of nutrients had a significant effect on the fruit yield of sapota, soil microbial biomass, NPK content of leaf, fruit and soil over control (T₁). Among different treatments, application of 2/3rd part of RDF + 50 kg FYM + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₁) significantly enhanced the number of fruits plant^?1 (327.88), yield plant^?1 (29.03 kg) and yield ha^?1 (4.52 t). However, the soil microbial count of fungi (8.89 cfu g^?1 soil), bacteria (11.19 cfu g^?1 soil) and actinomycetes (5.60 cfu g^?1 soil) at fruit harvest was higher under the 2/3 of RDF +10 kg vermicompost + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₅). The leaf nitrogen content (N, 2.03%) was higher in T_15, while phosphorus (P, 0.28%) and potassium (K, 1.80%) content were higher in T₁₁. It is evident that treatment T₁₁ increased fruit yield by 32% in Sapota cv. Kalipatti compared to control. Therefore, combined application of nutrient sources proved not only beneficial for enhancing fruit yield of sapota but also sustaining soil health in Chambal region of south-eastern Rajasthan.     

Poultry manure and banana waste are effective biofertilizer carriers for promoting plant growth and soil sustainability in banana crops

The aims of our study were to compare the effectiveness of poultry manure (PM) and banana waste (BW), with regard to their use as inoculant carriers of a bacterial consortium constituted by strains of Azospirillum, Azotobacter and P-solubiliser bacteria and to establish the most efficient dose of biofertilizer for a soil cultivated with banana (Musa paradisiaca AAA Simmonds), with respect to improving plant performance and soil physical and microbiological properties. Six months after planting, plant growth had increased with increase in dose of the biofertilizers applied. The biofertilizer prepared on BW enhanced the density of P-solubiliser bacteria, the concentrations of available P and foliar P to a greater extent than with the biofertilizer prepared on PM. The increases produced by the biofertilizer prepared on PM for the soil aggregate stability, enzymatic activities and the labile carbon fractions were highly correlated to the dose applied. Both biofertilizers can be considered potentially useful as inoculant carriers of PGPR but the usefulness of BW appears to be restricted to moderate doses of application (≤3%).     

Inoculation of rapeseed under different rates of inorganic nitrogen and sulfur fertilizer: impact on water relations,cell membrane stability,chlorophyll content and yield

It is important to develop integrated fertilization strategies for various crops that enhance the competitive ability of the crop, maximize crop production and reduce the risk of nonpoint source pollution from fertilizers. In order to study the effects of mineral nitrogen fertilization and biofertilizer inoculation on yield and some physiological traits of rapeseed (Brassica napus L.) under different levels of sulfur fertilizer, field experiments in factorial scheme based on randomized complete block design were conducted with three replications in 2012 and 2013. Experimental factors were: (1) four levels of chemical nitrogen fertilizer (0, 100, 150 and 200 kg N ha^?1), (2) two levels of biofertilizer (with and without inoculation) consisting Azotobacter sp. and Azospirillum sp. and (3) two levels of sulfur application (0 and 50 kg S ha^?1). Rapeseed yield, oil content of grains and studied physiological traits had a strong association with the N fertilization, biofertilizer inoculation and sulfur (S) application. Higher rates of N fertilization, biofertilizer inoculation and S application increased the grain yield of rapeseed. In the case of physiological traits, the highest value of relative water content (RWC) was recorded in 100 kg N ha^?1 that was statistically in par with 150 kg N ha^?1 application, while usage of 150 kg N ha^?1 showed the maximum cell membrane stability (CMS). Inoculation with biofertilizer and S fertilization resulted in higher RWC and CMS in rapeseed plants. The chlorophyll content showed its maximum values in the highest level of N fertilization, biofertilizer inoculation and S application. The usage of 200 kg N ha^?1 significantly decreased the oil content of rapeseed grains, but the highest grain oil content was obtained from the application of 150 kg N ha^?1, Azotobacter sp. and Azospirillum sp. inoculation and S fertilization. It seems that moderate N rate (about 150 kg N ha^?1) and S application (about 50 kg S ha^?1) can prove to be beneficial in improving growth, development and total yield of inoculated rapeseed plants.     

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

In 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 organic amendments on nodulation and nitrogen fixation by cowpea

Cornstover, garbage compost, and cowdung were added to an Alfisol (Iwo series) at the rates of 0, 23, 69, and 115 Mg ha^‐1 and incubated for 4 weeks in the greenhouse prior to sowing cowpea [Vigna unguiculata (L.) var. Ife Brown]. Two successive plantings were made per pot. Harvesting of the plants was at onset of flowering, 42 days after planting. Nitrogen (N) fixed was assessed using the N₂ difference method. Soil reaction (pH), organic carbon (C), and tissue N contents were increased by all the organic amendments. At both harvests, dry matter yields were significantly enhanced by garbage compost and cowdung. While garbage compost and cowdung increased the amounts of N₂ fixed, the efficiency of N₂ fixation was higher in the cornstover treatments. The cornstover additions also significantly increased nodule size and number. These results suggest that organic amendments would benefit N₂ fixation especially in soils low in indigenous organic matter. The beneficial effects were in the order: cowdung > garbage compost > cornstover. To enhance N₂ fixation in cowpea, a rate of 23 Mg ha^‐1 of these organic amendments is suggested.     

Introduction of composted rock phosphate and poultry manure enhances winter wheat phosphorus use efficiency,grain yield and soil quality

This field study evaluates the integrated impact of poultry manure (PM), rock phosphate (RP), composted rock phosphate (CRP) and single super phosphate (SSP) on the growth, yield, and phosphorus use efficiency (PUE) of winter wheat and their effect on postharvest soil characteristics. The seven treatments were as follows: T₁ = control; T₂ = SSP full; T₃ = PM full; T₄ = RP full; T₅ = CRP full; T₆ = 50% SSP + 50% CRP (50:50); T₇ = 50% PM + 50% CRP (50:50) at a recommended P rate of 90 kg ha^?1. The combined treatment with PM + CRP produced the highest straw yield of 3582 kg ha^?1, grain yield of 2226 kg ha^?1, P uptake of 21.3 kg ha^?1, and PUE of 18%. The postharvest soil organic carbon, total nitrogen and soil available phosphorus were sig-nificantly higher in integrated treatments.     

Non-isotopic method for the quantification of biological nitrogen fixation and wheat production under field conditions

 A field experiment was conducted in the Inshas area (Sharkeia governorate) to study the potential of biofertilizers, when the quantities of commercial fertilizers were reduced, for optimal wheat production. The different treatments were arranged in a completely randomized block design with seven replicates. N fertilizer was applied in three treatments with one control, i.e. zero, full, half and one-fourth rates, in the presence or absence of inocula. Azospirillum brasilense strain Sp245 was used as a biofertilizer. Generally, inoculation increased the accumulation of shoot dry matter and grain yield by about 35%, relative to the control treatment. Similar trends were observed in the case of N and P uptake by shoots and grains, as well as the efficient use of both, where inoculation increased the acquisition of the two elements as compared with the uninoculated plants. The obtained data showed that N₂ fixed by shoots and grains ranged from 2 to 10 kg N ha^–1 and from 8 to 19 kg N ha^–1, respectively. With respect to fixed N₂, the best treatment was inoculation combined with the one-fourth dose of N, followed by inoculation combined with half of the recommended N dose. Most of the fixed N was utilized by grains and the results clearly reflected the negative effect of high N fertilizer rates on biological N fixation. It is obvious that inoculation, in general, enhanced the N fertilizer utilized by both shoots and grains of wheat plants. In conclusion, the application of biofertilization technology to a light-textured soil with low fertility had a positive effect on plant growth, N gained from the air and enhancement of fertilizer N uptake (apparent recovery fraction). Received: 22 April 1999     

Yield enhancement and phosphorus economy in lentil (Lens culinaris Medikus) with integrated use of phosphorus,Rhizobium and plant growth promoting rhizobacteria

The study evaluated the effects of phosphorus (0, 20, 30, and 40 kg P₂O₅ ha^?1) and biofertilizers [Rhizobium (Rhizobium leguminosarum bv viciae), plant growth promoting rhizobacteria (PGPR) (Pseudomonas fluorescens), Rhizobium + PGPR, and uninoculated control] in lentil. Application of 40 kg P₂O₅ ha^?1 resulted in the highest number of nodules, nodule dry weight, leghemoglobin content in nodules, chlorophyll content, yield attributes, and grain yield. Coinoculated treatment performed better than uninoculated control, and individual inoculations of Rhizobium and PGPR in terms of all above mentioned parameters. Application of 20 kg P₂O₅ ha^?1 + Rhizobium inoculation gave statistically similar and 20 kg P₂O₅ ha^?1 + Rhizobium + PGPR inoculation gave significantly higher grain yield than that by 40 kg P₂O₅ ha^?1 alone. The use of Rhizobium alone and Rhizobium + PGPR consortium can save not only 20 kg P₂O₅ ha^?1 but also increase the grain yield of lentil.     

Nitrogen use Rationalization and Boosting Wheat Productivity by Applying Packages ‎of Humic,Amino Acids,and Microorganisms

ABSTRACT

Integrated management of soil organic matter and nutritional status of crop plants is essential to sustain the production of organic farming systems. Thus, a 2–year field experiment was conducted to examine the effects of soil additions (192 kg N ha^–1, humic+192 kg N ha^–1, humic+144 kg N ha^–1 and humic+96 kg N ha^–1) and foliar applications (amino acids, Azotobacter+yeast, and amino acids plus Azotobacter+yeast) as various fertilizer resources on growth and yield of wheat. Results showed that humic+192 kg N ha^–1 × amino acids plus Azotobacter+yeast were the effective combination for producing the highest values of flag leaf area, total dry weight, tiller number m^–2, spike weight m^–2, and grain yield ha^–1. Under foliar application of amino acids plus Azotobacter+yeast, reducing N supply from recommended rate (192 kg N ha^–1) to 144 kg N ha^–1+ humic achieved higher values of all yield traits, with a saving of 25% of applied mineral nitrogen as well as enhancing nitrogen use efficiency.     

Effects of Fertilizers on Yield,Sustainability, and Soil Fertility under Rainfed Pigeon pea + Rice System in Subhumid Oxisol Soils

A long-term field experiment was conducted at the research farm of the All-India Coordinated Research Project for Dryland Agriculture, Phulbani, Orissa, India, from 2001 to 2006 to identify the best integrated nutrient-use treatments for ensuring greater productivity, profitability, sustainability, and improved soil quality in pigeon pea + rice (two rows of pigeon pea followed by five rows of rice alternately) intercropping system. In all, nine treatments, eight comprising integrated nutrient-use practices, chemical fertilizer (CF), farmyard manure (FYM), and green leaf manure (GLM) to supply nitrogen (N) at 45 kg N ha^–1 and one farmer's practice equivalent to 25 kg N ha^–1 (FYM 5 t ha^–1), were tested on a long-term basis. Results of the study revealed that 20 kg N ha^–1 (FYM) + 25 kg N (CF) gave maximum mean rice grain yield of 1.52 t ha^–1, followed by 20 kg N (GLM) + 25 kg N (urea) with grain yield of 1.51 t ha^–1. In the case of pigeon pea, 30 kg N (FYM) +15 kg N (urea) gave maximum pigeon pea grain yield of 0.94 t ha^–1, which was 34% greater than the sole application of chemical fertilizer. Pigeon pea grain yield tended to increase with increasing proportion of organic N in FYM + CF or GLM + CF combinations. Application of 20 kg N (FYM) + 25 kg N (urea) recorded maximum mean rice equivalent yield of 3.59 t ha^–1 and sustainability yield index of 59%. While studying profitability, application of 20 kg N (FYM) + 25 kg N (CF) gave maximum net returns of US$168.94 ha^–1. Impact of treatments on soil quality as assessed in terms of relative soil quality indices (RSQI) increased with increasing proportion of organic sources of N. Using an innovative and new approach, an index of integrated productivity–sustainability–profitability–soil quality performance index (I _P,S,Pr,SQ) was computed to make a precise evaluation of the treatments. Based on this index, the order of performance of the treatments was T₆ [20 N (FYM) + 25 N (CF)] (7.7) > T₇ [30 N (FYM) + 15 N (CF) (6.9)] > T₃ [20 N (GL) + 25 N (CF)] (6.8) > T₅ [10 N (FYM) + 35 N (CF) (6.6)] > T₉ [GL] (6.5) > T₈ [CF] (6.2) > T₄ [30 N (GL) + 15 N (CF)] (6.0) > T₂ [10 N (GL) + 35 N (CF)] (5.7) > T₁ [FYM at 5 t ha^–1] (4.1). Thus, the results and the methodology adopted in this study using long-term data would be very useful to researchers, farmers, land managers, and other stakeholders not only in India but also across the world under similar climatic and edaphic situations.