Saviour et al.

onto mineral and humic particles and by forming

two different locations from Pudukkottai district, Tamil

insoluble precipitates (Goldberg and Glaubig, 1985;

Nadu during 2012-13.

Evans, 1987). The mobility, transport and partitioning

of B in soils are dependent on various soil chemical

Soil initial analysis

properties that include soil pH, the type and contents of

clay minerals, and the contents of Al and Fe oxides and

A composite sample was prepared from the randomly

(oxy) hydroxides, carbonates and organic matter (Keren

collected surface soil samples (0-15 cm) from two

and Bingham, 1985). To assess the agricultural impact

different locations before the commencement of the

of B, it is necessary to understand and quantify the

incubation study using stainless steel materials. The

different forms of B in soil intensively cultivable soils.

soil samples were processed and stored in polythene

Boron is found in soils in various forms. However, the

container to study various soil properties. The initial

contribution of various B fractions towards B availability

physico-chemical properties of the collected soil are

in soils has not been examined extensively (Datta et al.,

given in Table 1. The collected soils comes under the

2002; Chaudhary and Shukla, 2004). In almost every soil,

dominant soil series viz., Pattukkotai (Pkt) and Madukkur

readily soluble B represented only a small proportion of

(Mdk) series covering about 30,991 (48.7% area) and

the total B content, regardless of the extraction method

20,699 ha (32.5% area) respectively in Alangudi taluk

used. Most soil B existed in the residual or occluded

of Pudukkottai district. Except slight variation in its

form, which accounted for between 92 and 99%, with

colour, hardness and drainage, both the soil series are

an average of 97%, of the total soil B. The concentration

found to be similar in their properties. Both the soils

of organically bound B was higher than that of oxide

are sandy loam in texture and the soils of Pattukkotai

bound B and specifically adsorbed B, irrespective of the

(Pkt) series are light yellowish brown (10 YR 6/4 m)

readily soluble B extracting solution with the average

and well drained because of their hardness and friable

of 97%, of the total soil. The major portion of soil B

nature than Madukkur (Mdk) series which are brown

(92–99%) existed in the residual fraction. Since boron are

in colour (10 YR 5/3 m), poor drained and friable. The

significantly involved in reproduction process of maize

USDA taxonomical classification for the collected soils

crop (Li and Lang, 1997) and their deficiency may occur

under Pattukkotai (Pkt) and Madukkur (Mdk) series is

simultaneously in intensively cultivated soils (Agarwala

fine loamy hyperthermic Udic Haplustalfs and fine loamy

and Sharma, 1979) an incubation study was contemplated

hyperthermic Ultic Haplustalfs respectively. The bulk

to understand better on the B distribution among

density (1.39 and 1.42 Mg m -3 ), particle density (2.35

different fractions, the objectives of this research were

and 2.42 Mg m -3 ) and pore space (40.86 and 41.33%)

to determine the B fractions of soils treated with mineral

were determined in the soils of 2 locations.

fertilizer (borax), to evaluate the release pattern of B

fractions by adopting the standard sequential procedure.

Treatments structure

Thus. knowledge regarding distribution of B in different

A known weight of soil sample was taken (100 g) in a

fractions is essential to understand soil chemistry and

plastic container and imposed with different levels B.

B-nutrition for obtaining reliable information about the

The treatment structure comprised of graded levels of

need of zinc to plant at critical growth stages.

borax as 0, 0.5, 1.0, 1.5 and 2.0 kg ha -1 were replicated

thrice in a completely randomized design. The soils were

Materials and Methods

incubated at field capacity for a month (30 days) period

and destructive sampling was done at intervals viz., 0, 7,

A laboratory incubation study was conducted to study

15, 21 and 30 days after incubation. Various B fractions

the release pattern of boron fractions from micronutrient

viz., specifically adsorbed, oxide bound, organically

fertilizer Borax under maize growing sandy loam soils of

bound and residual B in soil were estimated by using the

sequential extraction as described by Raza et al., (2012)

was given below.

508