Vergara - 1976 - Physiological and morphological adaptability of ri

CROP PLANNING AND ILAINFALL
5i
Climate and crop planning with
particular reference to rainfall
P. S. N. Sastry
SU MMARY
success or failure of crops both in rainfed and irrigated agriculture such as
The those of the ricc crop in South and Southeast Asia is closely linked with the
rainfall pattern. An understanding of the characteristics of rainfall distribution in
relation to the physiological phases of the crop variety and soil conditions is a prerequisite
for successful crop planning. In many areas. rainfall data are generally
available for an extensive network in comparison with other climatic elements.
For analyzing rainfall data in such cases_ use of criteria related to sequential
phenomena like dry and wet spells nith reference to the dilferent crop phases is recommended.
This would provide the specific information needed for agricultural
planning.
The climatic classifications based on simple climatic indices and soil-u-"ater balance
models are indicative of the agricultural potentialities of the different regions.
However. introduction of new varieties of crops into new areas requires consideration
of the individual varietal characteristics. climatic needs. and tolerances
derived from laboratory and field conditions.
INTRODUCTION
All facets of agricultural activity. whether it be the choice of crop rotations and
cultural practices. seedbed preparation. harvest and post-harvest operaticins,
introduction of new crops into new areas. or planning of plant-protection
measures. are greatly influenced by climate. Rainfall is the major climatic element
that affects crop growth and development. particularly vrhere rainfed
fanning is widely practiced. Also. in comparison with other climatic parameters.
data on rainfall are generally available for an extensive network. The discussion
that follows is therefore confined mainly to methods of analysis of rainfall
patterns as these relate to crop planning. Simple criteria related to sequential
phenomena like
needed for crop planning. Since the methods are applicable to all crops. rice is
not separately discussed. The necessity for effective use of specific crop and soil
characteristics in agroclimatic classification for regional crop planning is emphasized.
P. S. N. Sash)‘. Division of Agricultural Physics, Indian Agricultural Research Institute, New’ Delhi.
India