Pabitra Banik

Fractionation and bioavailability of metals and their impacts on microbial properties in sewage irrigated soil

A study was conducted to evaluate the effect of long-term irrigation of sewage contaminated with heavy metals like Cd, Cr, Cu and Pb on microbial and biochemical parameters of soils of West Bengal, India. The microbial parameters included microbial biomass carbon (MBC), microbial metabolic quotient; the biochemical parameters included fluorescein diacetate hydrolyzing activity, beta-glucosidase, urease, phosphatase, and aryl sulphatase activities. A sequential extraction technique was used to quantify water soluble, exchangeable, carbonate bound, Fe/Mn-oxide bound, organically bound, and residual metal fractions. Metal concentrations in the two most labile fractions (i.e., water soluble and exchangeable fractions) were generally low. Total metal concentrations at each site seemed to be associated with soil amorphous Fe and Al minerals. The MBC and the enzymes studied were significantly and negatively correlated with water soluble and exchangeable metals but not significantly correlated with other forms, indicating that water soluble and exchangeable forms exerted a strong inhibitory effect on the soil microbial and biochemical parameters. It was concluded that irrigating soils with metal contaminated sewage seemed to damage soil quality in the long term.

Effect of microbial inoculation during vermicomposting of different organic substrates on microbial status and quantification and documentation of acid phosphatase.

In this experiment, three microbial strains were inoculated in two different organic wastes to study their effect on the humic acids content, acid phosphatase activity and microbial properties of the final stabilized products. Pyrophosphate extract of vermicomposts were analyzed through polyacrylamide gel electrophoresis to study the nature of a isozymes in different treatments. Results suggested that vermicomposting increased humic acids content and acid phosphatase activity in organic substrates and microbial inoculation further enhanced the rate of humification and enzyme activity. Although humic acids content in different microorganism-inoculated vermicomposts were statistically at par, acid phosphatase activity in these treatments was significantly (P<0.05) different. Results revealed that microbial respiration was increased due to vermicomposting, but a reduction in microbial biomass was recorded after stabilization of organic wastes. Although vermicomposting increased the value of microbial quotient (qCO(2)), microbial inoculation did not show any significant effect on qCO(2). The zymogram revealed that two isozymes of acid phosphatase (group II and group III) were present in all vermicompost samples and higher acid phosphatase activity in fungi-inoculated vermicomposts might be due to the presence of an additional isozyme (group I) of acid phosphatase.

Yield and Resource Utilization Efficiency in Baby Corn—Legume-Intercropping System in the Eastern Plateau of India

Cereal-legume intercropping plays a pivotal role for increasing land use efficiency and atmospheric nitrogen fixation. A field experiment was carried out on a baby corn–legume intercropping system in 2:1 and 2:2 additive series in the eastern plateau region of India over two consecutive rainy seasons (2003/2004). The experimental design was a randomized complete block with 13 treatments replicated thrice. Significant (p ≤ 0.05) differences were observed in grain yield with 2:1 and 2:2 intercropping treatments. Legumes yield was significantly reduced when intercropped with baby corn. However, total productivity in terms of baby corn yield equivalent (7063 kg ha−1) was highest under the baby corn–groundnut intercropping system, and land use efficiency was higher under the intercropping system as compared with monocrops of either species. There was a significant increase in atmospheric nitrogen fixation by the legumes for the intercropping system over monocrops. Baby corn facilitated an increase in nodule number and dry weight in legumes under intercropping over monocrops; moreover, root length of legumes was greater when intercropped with baby corn. These findings suggest that intercropping baby corn and legumes, particularly groundnut, can increase total productivity per unit area, improve land use efficiency, and increase atmospheric nitrogen fixing ability.

Vermicompost and Fertilizer Application: Effect on Productivity and Profitability of Baby Corn (Zea Mays L.) and Soil Health

ABSTRACT Earthworm digested wastes (vermicompost) are being produced in increasing quantities to make farming sustainable. A study was carried out for two consecutive years (2007–09) at the Agricultural Experimental Farm of Indian Statistical Institute, Giridih, India on sandy loam soil in factorial randomized block design with three replications. Baby corn (cv. Early Composite) was grown without vermicompost (V0) or with vermicompost (V1: @ 10 Mg ha−1) in combination with three recommended doses of fertilizers [F1: 50%, F2: 100% (N:P2O5:K2O = 150:60:60 kg ha−1) and F3: 150% RDF] besides an absolute control (F0: no-NPK) to assess their effect on baby corn productivity and soil health. Vermicompost applied plots recorded considerably higher cob (0.717 Mg ha−1) and green fodder (17.58 Mg ha−1) yield. Among the fertilizers, baby corn grown with F3 yielded maximum cob (0.759 Mg ha−1) and green fodder (18.46 Mg ha−1). Vermicompost application built-up soil nutrient like nitrogen (145 kg ha−1), phosphorus (16 kg ha−1), potassium (190 kg ha−1), organic carbon (0.78%), and enhanced cation exchange capacity (12.19 Cmol+ kg−1), microbial [basal soil respiration, microbial biomass carbon, microbial quotient, and metabolic quotient] and enzyme activities (urease and acid phosphatase). However, microbial and enzyme activities were minimum with F3. Vermicompost and F2 treatments were most remunerative. Use of vermicompost not only reduces the requirement of chemical fertilizers but also supplements important all essential nutrients to increase crop yield besides improving the soil properties and processes.

Direct and Residual Effect of Organic and Inorganic Sources of Nutrients on Rice-Based Cropping Systems in the Sub-humid Tropics of India

An experiment was conducted at an experimental farm in Giridih, India, to investigate the direct effect of organic and inorganic sources of nutrients on the production potential of upland rice (Oryza sativa L.) and to assess their residual effect on succeeding winter crops viz. linseed (Linum usitatissimum L.), niger (Guizotia abyssinica L.) and barley (Hordeum vulgare L.). The objective was to maximize the nutrient use efficiency and productivity of the cropping system in a sustainable way. The maximum grain yield, biomass production, and nitrogen (N) and phosphorus (P) uptake of rice were recorded when grown with the application of 100% NPK through fertilizers. Among the succeeding winter crops, linseed registered the maximum rice-equivalent yield. Irrespective of winter crops, 100% N supplied through vermicompost alone treatment recorded the highest value of rice-equivalent yield of winter crops. The maximum nutrient (NPK) uptake values were recorded for the cropping system grown under the treatment of 25% VC + 75% NPK supplied through fertilizers while the paddy-linseed system removed the maximum amount of nutrients from the soil. The paddy-barley system recorded the highest gross return, net return and benefit cost ratio.

Effect of organic and inorganic sources of nutrients on the winter crops-rice cropping system in sub-humid tropics of India

A field experiment was conducted during 2005–2006 and 2006–2007 on a winter crops-rice (Oryza sativa L.) cropping system at the Agricultural Experimental Farm of the Indian Statistical Institute, Giridih, Jharkhand, to evaluate nutrient management packages on yield and soil fertility status. Eight nutrient management practices were evaluated on three cropping sequences: linseed-rice, niger-rice and barley-rice. Significantly, a higher seed yield of winter crops was recorded where 100% nutrient through inorganic fertilizers was applied. Total biomass yield, barley equivalent yield, nitrogen and potassium uptake were also highest in this treatment. Maximum grain yield and harvest index of rice grown after the harvest of winter crops on residual soil fertility was registered where 100% nutrient was applied through organic manure to the previous winter crops. Lentil-rice grown on 25% N nutrient supplied through VC and 75% through inorganic fertilizers recorded the highest rice equivalent yield. The maximum economic return value was registered under the barley-rice sequence. Among the different sequences lentil-rice recorded maximum nutrients uptake values. Linseed-rice sequence built up the residual soil nitrogen maximum and barley-rice sequence increased the residual soil phosphorus content.

Effect of vermicomposting on calcium, sulphur and some heavy metal content of different biodegradable organic wastes under liming and microbial inoculation

A study was conducted to evaluate the changes in total calcium and sulphur and some heavy metal (Zn, Cu, and Pb) concentration of different organic wastes affected by liming and microorganism inoculation. Vermicomposting was an effective technology for disposal of organic substrates like municipal solid wastes (MSW), possessing comparatively higher concentration of heavy metals. The addition of lime in initial organic substrates significantly (P ≤ 0.05) increased total calcium and total sulphur content of vermicomposts. Inoculation of microorganisms significantly (P ≤ 0.05) reduced the heavy metal content of final products as compared to control. Fungal strains were comparatively more effective in detoxification of heavy metals than B. polymyxa.

A mathematical model on the effect of M. denticulata weed on different winter crops.

Many weeds interfere with the productivity of wheat and other winter annual crops; however, one common weed Medicago denticulata, appears to have a beneficial effect. An experiment was conducted at Agricultural Experimental Farm of the Indian Statistical Institute, Giridih, Jharkhand to observe the effect of M. denticulata (a legume) on different crops yield of barley (Hordeum vulgare Sensu lato), linseed (Linum usitatissimum L.), Indian mustard [Brassica juncea (L.) Czernj. & Cosson] and wheat (Triticum aestivum L.). The commensalisms interaction was studied, in which one species benefits, while the other is unaffected, between the crops, M. denticulata and other weeds, to observe the role of medicago as biological control agent of other weeds for enhancement of crop productivity. Further, a statistical test was performed to establish the effect of M. denticulata and weed infestations based on one-step Markov structure of the covariance matrix of the biomass. This permitted development of a mathematical model of a crop-M. denticulata-other weeds system and their interactions through direct and indirect competition for resources. Crops yield decreased considerably due to the presence of other weeds, while it increased due to introduction of medicago and hence medicago acted as a controlling agent in a crop-M. denticulata-other weeds system. Our mathematical analysis supported the experimental findings. The model parameters are estimated through a nonlinear least square and stochastic differential equations. Moreover, some thresholds for the growth of medicago population came out from our analysis that may be used as a biological control threshold for the enhancement of crop productivity.

Multi-criteria land evaluation for suitability analysis of wheat: a case study of a watershed in eastern plateau region, India

Improper land use results in land degradation as well as decline in agricultural productivity. To obtain optimum benefit from the land, proper utilization of its resources is necessary. Land suitability analysis is the evaluation and grouping of specific areas of land in terms of their suitability for a defined use, which is a precondition for sustainable land use planning. This study investigated the applicability of Geographical Information System (GIS) techniques in combination with multi-criteria land evaluation for analysing land suitability. The study used the weighted overlay technique for multi-criteria evaluation with GIS for the assessment of suitability of wheat cultivation in Beko watershed (Purulia, India). The watershed area is moderately suitable for wheat crop production, with constraints like imperfect drainage and poor soil depth.

Effect of new organic supplement (Panchgavya) on seed germination and soil quality

We studied the suitability of Panchgavya (five products of cow), new organic amendment, application on seed germination, plant growth, and soil health. After characterization, Panchgavya was mixed with water to form different concentration and was tested for seed germination, germination index, and root and shoot growth of different seedlings. Four percent solution of Panchgavya was applied to different plants to test its efficacy. Panchgavya and other two organic amendments were incorporated in soil to test the change of soil chemical and microbiological parameters. Panchgavya contained higher nutrients as compared to farm yard manure (FYM) and vermicompost. Its application on different seeds has positively influenced germination percentage, germination index, root and shoot length, and fresh and dry weight of the seedling. Water-soluble macronutrients including pH and metal were positively and negatively correlated with the growth parameters, respectively. Four percent solution of Panchgavya application on some plants showed superiority in terms of plant height and chlorophyll content. Panchgavya-applied soil had higher values of macro and micronutrients (zinc, copper, and manganese), microbial activity as compared to FYM, and vermicompost applied soils. Application of Panchgavya can be gainfully used as an alternative organic supplement in agriculture.