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Mausanr. (1995), 46. !. 131-140

633 : 551.577 : 631.45

Cropping pattern of Konkan region on the basis of probabilisticrainfall and soil characteristics

B. C. BISWASMeteorological Office. Plllle·411005

a ndR. D. PIIADTARE

College 0/ Agriculture. Pune-tl I 005(Received 24 Al/glI51 1992. Modified 26 Ma)' 1994)

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ABSTRACT. Cropping patte rn at an)' place of humiJ tropics ba sically depends on soils a nd efficientmanagement of abundaot rainfall. Climate of Konkan region is warn) a nd humid. Rainfall is very hiah an dvaries usuall y from 200 10 lSO em. Rainfall probability ha s bee n computed 8 . different levels o f 16 sta tions o fth is n:-gio n by filt ine Gam ma d istribution mode l to \lo't'ckly rainfall tot al. The cxistina cropping pattern wasstud ied in relat ion with essured rainfall al different probabi lity levels. Suitable cropping patterns based onassured rainfall and soils of the rreion h ave been !Uest'!led 10 increase product ion.

Kt')' worm - Assured ra infall. Prob ability, Terrain. Textu re, Cu ltivation. Cropp in g pattern, Watermanegement, Kharland. Laterite soil.

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I. Introduction

Crop p rodu ction in high ra infall zone of thetropical countries is very closel y relat ed to soilcha racteristics. d istribu tion of rainfall and its effi­cient man agemen t, The prima ry constraint toagricultural develop ment in this region is the lack ofapplicat ion ofsuitable tech nolog y for soil a nd watermanagement, H igh ra infall intensity resul ts inincreased soil erosion an d run offcausing flood andloss of precious water, to the sea . During rainyseason storage ca paci ty o f root profile exceeds fre­quently and ground water recharge takes placewhere soil is deep . In sha llow or hilly region mos t ofwatcr goes as surface run-off. Information gene­rated from system atic rainfall ·analysis helps todevelop farm ing system which can increase andstabilize agricultural production through better useof natu ral and hu man resources.

Temperature of this region is relatively high andremains throughout the year in a range which iscongenial for agri cult ural production. Potentialevapotranspiration is much less than rainfall dur­ing rainy season. Hence crop production dependson the type and depth of the soil and management

(m )

of ab unda nt water available du ring the monsoonseason, (VcnugopaI1988) . Alt hough rainfall is high.bu t its distribut ion is erratic and va ries rapidly bothin time and space. Average rainfall does not give anidea of magnitude of year-t o-year vari ations. Forpla nni ng of crop seque nce, on e should kn ow fro mlon g reco rd. the chances of meeting the wat errequ irement und er di fferent ra infall system. Hen cecrop planning should be made on the ba sis of pro­babilistic rainfall . instead of average rainfall , whichtakes into accou nt the chances of success orfailure.

In th is paper. an attempt has been made to sug­gest cro pping pattern ofKonkan region. a high rain­fall zone. with the help of soil information andweekly probab ilistic rainfall computed by fittingGamma distribution model to weekly rainfalltotal.

2. Data

Although rainfall observations are recorded at anumber of stations in this region. to compute weeklyassured rainfall by fittint,Gamma distribution. themodel requires minimum 50 years data which are