Crop Responses to Added Fertilizers inCultivators' fields-A Technique for finding out Manurial Requirements of Bihar Soils

Abstract

The district of Shahabad occupies the extreme western portion of the State of Bihar adjoining Benaras, Gazipur and Balia districts of U.P. The northern and central portions of the district are fully cultivated agricultural lands and the extreme southern portion of the district consists of undulating plateau more or less unfit for cultivation. In the north between the Ganges and the railway line the soil onsists of new alluvium and the rest is old alluvium. The soils of the district on the whole consists of three main types, namely clay, loam and sandy-loam and its normal rainfall is 4+19 inches. Paddy being a major crop of the district is grown abundantly, and it covers an area Of nearly 1,134,130 acres. Since soils of the district differ widely and crop responses to fertilizers are often very variable, an investi- gation to find out the appropriate manurial requirements of paddy and other crops on different soil types of the district being con- sidered very necessary for advisory work was undertaken on behalf of the Field Ex- perimental Service started in 1948 ( pre- viously known as Manurial Tables Scheme ) of the State department of Agriculture, Bihar. The data presented here are the results of comprehensive fertilizer trials conducted in cultivators' fields for Shahabad district only. A brief outline of the working of the Manu- rial Tables Scheme along with salient features of the broad soil types of the State of Bihar was described by Mukherj Sinha3, a; a part of the experimental achievements of the Manurial Tables Scheme, has dealt with nitrogen response growth curves of paddy crop on three broad soil types of Patna dis- trict and has deduced, therefrom, anticipated yield increase of paddy due to various levels of nitrogen up to 60N which are very bene- ficial for cultivators of Patna district. The present paper is more or less a continuation of the similar work for Shahabad district.