Soil Science and Agricultural Chemistry

Soil organic matter (SOM) and its fractions play an important role in many soil chemical, physical, and biological properties. We studied functional groups of SOM fraction using a physical and chemical fractionation scheme in long-term application of a fertilization in a rice-rice system, which started in 2005 (sandy loam). Replicated soil samples of experimental plots of four different manure and fertilizer treatments and one unfertilized control were evaluated. The unprotected coarse particulate organic matter (POM) (cPOM), pure physical protected POM (iPOM), and the biochemically silt-sized fractions (NH-dSilt) contributed the major carbon storage fractions constituting 32.16-40.37%, 13.78-23.32%, and 14.44-28.66% of the total soil organic carbon (SOC) content, respectively. Combined application of organic manure like farmyard manure along with fertilizer improved the SOC content in all unprotected, physically protected, and chemically protected, silt and clay-associated physico-biochemically, clay-associated physicochemically protected and siltassociated biochemically protected fractions compared to control. Besides, the SOC increase expressed as SOC content per unit of total SOC for iPOM, cPOM, silt associated physicochemically and physico-biochemically protected fractions (H-µSilt and NH-µSilt) were the highest and as large as 70%, 60%, 45%, 38%, respectively. Our study indicates that long-term addition of manure with fertilizer for a long period of soil submergence under rice cultivation promoted the formation of more stabilized pools of C through physical and chemical protection mechanism.

Soil carbon sequestration is a complex process influenced by agricultural practices, climate and soil conditions. Labile organic carbon is sensitive to soil management practices and thus provides better management of carbon dynamics than total carbon alone. Thus, an attempt is made here to investigate the Carbon sequestration potential and labile pool of soil organic carbon (SOC) in post kharif-2014 in flooded tropical rice (Oryza sativa L.) under long-term fertilizer experiment started in the year 2005-06 in the central farm of Odisha University of Agriculture and Technology (OUAT) under All India Coordinated Research Project (AICRP) taking rice as a test crop. The experiment was laid out in a Randomized Block Design with quadruplicated treatments. The treatments include no fertilization, 100% N, 100% NP, 100% NPK, 150% NPK and 100% NPK+FYM. The results revealed that cultivation over the years caused a 14% decrease in SOC in unfertilized control over uncultivated soil. The carbon sequestration potential (1.77 Mg ha −1) was highest in 100%NPK +FYM treatment. The greater accumulation of microbial biomass C, water and extractable carbon (WEO-C), potassium permanganate oxidizable C (KMnO4-C) was recorded in 100%NPK + FYM treatment. The highest carbon management index (CMI) was computed in 100%NPK with FYM. CMI can be used as a more sensitive indicator of the rate of change of SOC in response to soil management changes. Results suggested that 100% NPK+ FYM are adequate for maintaining SOC stock and this practice may help in maintaining the sustainability of rice-rice cropping system.

Rice-rice is an important production system for eastern India. Soil organisms play important role in the functioning of rice field ecosystem. Fertilizer and manures directly or indirectly influence soil biota particularly faunal community and their functioning. The present investigation was undertaken to study nematode population and diversity under the influence of long term fertilizer experiment conducted on an acidic sandy loam Inceptisols of Bhubaneswar with eight numbers of manurial treatments. Nematode population and diversity studies were made on soils of pre planting, tillering and flowering stages of kharif 2017 taking treatment combinations of balanced nutrition (100%NPK), super optimal dose of balanced nutrition, secondary and micronutrient, organic manure (FYM) and soil conditioner (lime). The plant parasitic nematode population varied from 64 to 324/ 200 g soil. FYM @ 5t/ha and lime @ 1t/ha significantly reduced the parasitic nematode population at all growth stages of ...

Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741 252, Nadia, West Bengal, India <em>E-mail</em> : [email protected], dkdas 1231 @rediffmail. com <em>Manuscript received 13 December 2011, revised 10 December 2012. accepted 07 January 2013</em> The adsorption study of boron was conducted in two soils (inceptisol and alfisol) of Indian sub-tropics with the addition of graded doses of boron amended with and without organic matter. The results reveal that the amount of boron adsorbed was recorded an increase with increasing concentration of applied boron as well as equilibrium concentration of boron (8) in soils of alfisol and inceptisol treated with organic matter, but the percentage adsorption decreased with an increasing equilibrium concentration of B. The ratio of concentration in equilibrium to the amount adsorbed of 8 was recorded relatively higher in an alfisol compared to inceptisol. The m...

Department of Agricultural Chemistry & Soil Science, Institute of Agricultural Science, University of Calcutta,<br> 51/2, Hazra Road, Kolkata-700 019, India<br> E-mail : [email protected]<br> College of Agriculture, Orissa University of Agriculture and Technology, Bhubaneshwar-751 003,<br> Odisha, India<br> Water Management Research Centre, Department of Agriculture, Ranaghat,<br> Government of West Bengal, India<br> Manuscript received 08 April 2015, revised 24 June 2015, accepted 01 July 2015 The interaction study between potassium and zinc was conducted with an inceptisol under submerged soil<br> condition at ambient laboratory conditions with their nine different treatment combinations. It was found that exchangeable<br> K increased gradually till 42 days of incubation before decreasing and was maintained highest (189.20 mg kg<sup>–1</sup>) in<br> the treatment T<sub>6</sub> where both K and Z...

The goal of the study was to determine how long-term fertilizer management of a rice-rice production system affected the buildup or depletion of surface soil phosphorus (P) in a subtropical climate. The results showed that using FYM @ 5t ha-1 season-1 in conjunction with optimal NPK doses (80-40-60 kg ha-1 season-1