An experiment was conducted at Zonal Agricultural Research Station, VC farm, Mandya to assess the effect of long term soil fertility management on behaviour of potassium with respect to different forms and distribution pattern in rice-cowpea cropping system. Soil of the study area belong to sandy loam texture having initial pH (6.28), EC (0.14 dSm-1), CEC (9.60 cmol (p+) kg-1), MWHC (20.70%) and bulk density (1.67 g cc-1). The organic carbon (0.34 %), available nitrogen (163 kg ha-1), available potassium (134 kg ha-1) were low and medium in available phosphorus (29.20 kg ha-1). Results indicated that the water soluble K content of soils varied from 8 to 16 mg K kg-1 in the surface layer and 5 to 14 mg K kg-1 in the sub surface layer in the plots treated with different fertilizer, manure and their combinations. Exchangeable K also ranged between 59 and 116 mg K kg-1 in the surface layer and 58 to 98 mg K kg-1 in the sub surface layer. The non-exchangeable K content ranged from 111 to 874 mg K kg-1 and from 160 to 880 mg K kg-1 , respectively in the upper and the lower layers. The total K content varied from 792 to 3017 mg K kg-1 at 0-15 cm depth and from 874 to 3318 mg K kg-1 at 15-30 cm depth.

SummaryDuring Kharif 2012, a field experiment was conducted in an alfisol of Mandya with different levels of potassium under irrigated maize to know the impact of application of potassium on various soil properties. The study involved nine treatments viz., Recommended NPK as per UAS (B) package, rec. NPK 15 DAS, NP + 75, 100, 125 per cent rec. K in splits, NP only and absolute control, replicated thrice and the statistical design was RCBD. The results of the experiment indicated that, soil pH and EC not varied much due to application of graded levels of potassium in maize. Highest organic carbon content was recorded in the treatment of recommended dose of NP + recommended dose of K in two splits (basal and at the time of topdressing). The soil available NPK content after the harvest of maize crop differed due to application of graded levels of potassium and the highest NPK content was recoded with the application of recommended NPK as per UAS (B) package and lowest available nitrogen was registered in the control. Similar trend was also observed with respect to exchangeable Ca, Mg and available sulphur. Application of recommended NP + 125 per cent of recommended K in two splits recorded the higher values for the various soil properties studied.

A flood is an overflow of water that submerges land which is usually dry. Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. This results in causing damage to human and property if they are in the natural flood plains of rivers or settled on the banks of rivers. To facilitate the appropriate measures for effective flood mitigation in advance, there is a need to model the flood plain which facilitates to locate the flood plain and its extent for effective flood mitigation measures. By understanding the extent of flooding and floodwater inundation, decision makers are able to make choices about how to best allocate resources to prepare for emergencies and to generally improve the quality of life. This research presents a straightforward approach for processing output of the HEC-RAS hydraulic model, to enable two and three dimensional floodplain mapping and analysis in the ArcView geographic information system. The methodology is applied to a stretch of river Krishna from downstream of Nagarjuna Sagar project to Kummaripalem which is located on upstream of Prakasam Barrage. The flood plain maps are developed for the flows corresponding to 2, 10, 25, 50 and 100 year return periods. The resulting surface model provides a good representation of the general landscape and contains additional detail within the stream channel. Overall, the results of the research indicate that GIS is an effective environment for floodplain mapping and analysis.

Soil indeed alive and dynamic system consisting of minerals and microorganisms, the top-most layer of soil is comparatively richer in nutrients and supports maximum bio-resource. The profile character varies distinctly from place to place, particularly with respect to their depth, colour and composition. The mineral composition of the soil, organic matter within it and environment, all these are resolute by chemical, physical and biological properties of soil. Soil organic carbon is necessary for improving soil quality, sustaining food production and sinking CO 2 in the atmosphere, whereas its inorganic counterpart (free CaCO 3 ) is the cause of organic carbon decomposition, restricting root proliferation, developing salinity (Eswaran and Van den

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