Ecology, Environment and Conservation Paper

CRITICAL LIMITS OF ZINC IN SOIL AND RICE PLANT IN HILL DISTRICT SOILS OF MANIPUR

Kondareddy, A.N., Indira Sarangthem, V. Venkatesh and D. Gopal

Abstract

Pot experiment for estimation of critical limit of zinc (Zn) in soil and rice plant in rice growing hill soils of Kangpokpi district of Manipur was conducted. Twenty four soil samples were collected from different paddy fields of Gamdeiphai, Sadukoireng, Utonglok, Saijang villages of Saikul block of Kangpokpi district of Manipur with Stratified Random Sampling. All the soil samples were acidic in reaction ranging from pH 4.5 to 6.06 with mean value of 5.20, electrical conductivity is ranging from 0.06 to 0.20 dSm-1 with mean value of 0.10 dSm-1, organic carbon content 0.30 to 1.59 % with mean value of 0.91%, cation exchange capacity of the soils 9.2 to 23.6 [cmol (p+) kg-1] with mean value of 15.60[cmol (p+) kg-1] and the clay content of soil varied from 33.50 to 54.40 % (mean 45.39%). The critical limit of Zn in these soils was established at 0.74 mg kg-1 and critical limit of rice plants at maximum panicle initiation stage was 20 mg kg-1, below which response to Zn fertilization may be expected. Soil containing Zn below this critical limit may be responded economically to Zn fertilization for rice growing.