Project Title:
Soil Landscape Model for Suitable Cropping Pattern in Tripura

Thematic Area:
Natural Resource Management

Location:
* Latitude: 22o57’ -- 24o32’ N 
* Longitude: 91o09’ -- 92o20’ E
* Tripura state 

Objective:
* To generate & document natural resource data base (soil, climate & crops) of Tripura
* To develop a model understanding of soil-landscape relationship for various land use options in the state.

Abstract:
Soil-acidity is one of the major factors regulating the species composition of ecosystem and influencing crop production. As such it has attracted the attention of different group of scientists with various specialization since long. In Tripura, irrespective of topographic positions soils are acidic. Factors relating to the genesis of the soils are not precisely known yet. Understanding the role of these factors is, therefore, vital in formulating a soil-landscape model that will help in land use planning.
There is a set of informations on natural resources of Tripura in the areas such as:
* Generation and documentation of data sets consisting of soils, climate and land use 
* Studying soils in toposequence in different districts 
* Modeling the concept of soil-landscape relation 
* To link the soil series occurring in a particular landscape with a type of land use with special reference to a particular crop or a host of crops.
In view of the above the present project on “Soil landscape model for suitable cropping pattern in Tripura” was formulated with the specific objectives:
* To identify factors and processes related to the development of soil acidity, 
* To study the effect of acidity on finer soil fractions,
* To study the formation of acid soils in a sequence Ultisols/Alfisols-Inceptisols-Inceptisols,
* To develop a soil-landscape model in the study area and
* To validate the developed model in similar areas occurring elsewhere.

Highlights/Findings:
The soil resource database earlier available indicates the soil information at family level of Soil Taxonomy. The state of knowledge on soils has been furthered to the level of soil series through this project. Besides, a model of understanding has been developed in terms of landscape-soil forming factors using Jenny’s state factors of soil formation. 
Through this Project a humble effort has been made to link a specific soil series with the dominant and popular crop in a particular study area. This has been carried out in all the 19 study areas spread over 4 districts of the state. The report focuses on the fact that soil parameters such as KCl-extractable Al and clay CEC have an important bearing on the selection of land use and cropping pattern in the model study areas at different elevation. This has also been elucidated while studying the mineralogy of soil clays in terms of the tendency of dominant vermiculite minerals to sequester Al in the interlayer spaces and thus minimizing the chance of Al toxicity for the crops. Through this project an effort has been made to highlight the model that is existing in relation to soil-landscape and crop. 
The database generated in terms of Natural Resources of Tripura including soils, soil landscape-model relation and soil landscape-crop model for individual district as well as 19 study areas may help to develop the perspective planning for Tripura state in terms of agricultural crops, horticultural crops and plantation crops. This could be the source book for the future developmental programme.

Data Used:
* Soil Data
* Land Use Data
* Climatic Data

Output:
The project report describes the present state of art on soil and natural resources of Tripura state (Part I) and the soil-landscape-crop models for 4 districts of the state (Part II). The maps have been generated for the project using GIS techniques. Part I of the project report details the soil information of the state. Total 48 soil series identified in the state have been described in terms of their morphological, physical and chemical properties. Dominant soil-series association and prominent soil series occurring on the most extensive landscapes at different elevation have been explained in terms of soil forming factors for all the 4 districts. The climatic parameters were utilized to calculate the PET, ½ PET and length of growing period (LGP) for 3 different stations in the state. Part II of the project report describes the soil-landscape models for 19 model study areas (3 in North Tripura district, 4 in Dhalai district, 7 in West Tripura district and 4 in South Tripura district). Each study area has been selected as a model for soil-landscape-crop relation. The dominant soils (series) occurring in the landscape has been linked with the popularly grown crop (agriculture, plantation and horticulture) on the basis of field experience. The data indicate that the soil parameters viz. KCl-extractable Al and clay CEC have an important bearing on the selection of land use and cropping pattern in the model study areas at different elevations.
* The landscapes, soil-series association, land use and crops are shown in terms of their area and extent in (Table 1).
* West tract of alluvial plain in south Tripura District, Belowbasket for Tripura District. (Figure 1)
* Radhakishorepur paddy model showing characteristics of Goachand soils suitable for paddy. (Figure 2) 


Date of project completion:
31/3/2003

Project Investigator:
Dr. Tapas Bhattacharyya
Senior Scientist,
National Bureau of Soil Survey and Land Use Planning,
Amravati Road, Nagpur - 440 010
E-mail: tapasnbsslup[at]mah[dot]nic[dot]in, tapas11156[at]yahoo[dot]com
Phone: (0712) 2500545 (O), (0712) 2232114 (R)